Author Topic: Never a straight line  (Read 41890 times)

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Offline BDA

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Re: Never a straight line
« Reply #120 on: Sunday,October 04, 2020, 06:41:52 AM »
Indeed!  :BEER3:

Offline SwiftDB4

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Re: Never a straight line
« Reply #121 on: Sunday,October 04, 2020, 09:02:58 AM »
Cosworth did make a sort of u shaped finger spring that fit between a pair of followers to hold all 16 in place for assembly and disassembly. 8 were required. I raced a Brabham BT38 with BDD may years ago. The BDA was advanced for its time, but the follower bores were short especially for big cams and were very susceptible  to wear and breakage.
 Years later I raced a SwiftDB4 with Toyota 4AGE. The Toyota was a lot more reliable and assembly was easier.
Hats off to you for working thru all the BDA issues.

Offline BDA

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Re: Never a straight line
« Reply #122 on: Sunday,October 04, 2020, 09:29:39 AM »
Thanks, Swift! If you still have that spring tool for followers, I'd love to see a picture of it and maybe where to get them. I hope never to need them but one never knows.

Through my process, I came to the realization that the follower bores was a weak point. Whether by intention or common practice at the time, the BD engines seem to be designed more for performance than longevity. I guess it really is a good thing that replacement standard size followers are actually oversized and that there is also a real oversized follower after that. Do you know if anybody tried lining the bores with steel?

I can well believe the 4AGE was a lot more reliable and simpler!

Offline jbcollier

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Re: Never a straight line
« Reply #123 on: Sunday,October 04, 2020, 03:45:10 PM »
Thanks to modern micro sensors, there is an easy way to measure degrees of rotation:

https://scooterlab.uk/product/the-buzzwangle/

There are other versions out there as well.  It has a magnetic base so it would hold to the TC crank nut/bolt.  Find true TDC using a piston stop and then simply turn until it reads the degrees of rotation you are after.  Really, really simple to use.

Offline BDA

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Re: Never a straight line
« Reply #124 on: Sunday,October 04, 2020, 04:02:13 PM »
That's really cool! I should have thought of that since I used the same electronic level to make a camber/caster gauge.

Offline BDA

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Re: Never a straight line
« Reply #125 on: Friday,September 10, 2021, 12:45:47 PM »
As you read this, keep in mind the title of this thread, "Never a Straight Line".

Elsewhere, I recently asked what your favorite shocks were. I had SPAX that I either bought when I first started building my car (middle '80s) or before I put her on the road in '90. I really didn't want to admit it to anyone but my car had never really felt like a Lotus should to me since I built it. It required a lot of attention on the highway and twisty roads were not nearly as fun as they should have been - in fact, they could be harrowing if I pushed it. Also elsewhere, I traced my experimentation with shock adjustment with minor improvement. I finally got a reasonably authoritative word from SPAX about what shocks I had and how many clicks of adjustment I had: they were probably 40 years old and could have either 8 or 16 clicks of adjustment (not very definitive!). It seemed likely that even though there was only about 20,000 miles on those shocks, they might be the cause of problems and at the very least, I felt I needed to know what I had.

After the feedback about shocks, I chose Protech. It wasn't an easy decision and I would guess that AVO would be as good. I ordered them from SJS. When I got them (after $60 of shipping by DHL), they were beautiful!

I started installing springs on them and I noticed that one of the rear shocks was much softer than the other. I emailed SJS and told Steve. He got back to me that I should adjust the softer shock to be like the stiffer one and then reset the knob so that it was now at the same position as the stiffer shock. That didn't really make sense to me because that seemed to imply that there were infinite or at least twice as many adjustment clicks as advertised (13). I tried to quantify the difference between the two shocks by chucking the shock in a vice, extending it, putting a 20 lb weight on the top and timing how long it took to compress. The time difference was very different. I stiffened the softer shock all the way and it was still softer in my test. At this point I decided to call Protech.

They knew about me from Steve. The tech there said to do the same test but for extension. I had similar results and in fact there was a difference with the front shocks too. After a few more tests and calls to Protech, they said to send them in. They would check them out and send me dyno sheets on them when they returned them. I packed them up and took them to a DHL shipper and the bill was almost $300! I don't understand why it was about $60 to send them to me but almost $300 to send them back!? I probably should have stopped there and called Protech about that but I just sent them. I emailed them the tracking number and a request for some help with part of the shipping costs understanding that that really wasn't part of the deal.

After four or five days, I emailed them for an update and again asked if they could help me out with some of the shipping costs. The tech wrote back and apologized saying they had gotten really busy and would be sending my shocks to me the next day. He didn't mention anything about being able to help me with the shipping. I got them a couple of days earlier than DHL estimated. The dyno sheets were interesting. If you research shock dyno sheet, you'll find there are several kinds (here's one description: http://edge.rit.edu/edge/P16221/public/Problem%20Definition%20Documents/Reference%20Documents/guide_to_dyno_graphs.pdf). The sheets they sent me were pretty basic (see attached). There is a sheet for the fronts and the rears and I think the main idea was that the fronts and the rears were very similar. In fact, they are all similar! That was a bit surprising to me. I called them and told them I got the shocks. I thanked them for their service - I have absolutely no complaints about their service - in fact, I thought it was excellent - and I asked a few questions about what was wrong. Apparently, some dirt or something got on the shims during assembly. They were happy with them so I was too. The work and shipping back to me was on them. I thanked them again and he said it was the least they could do. Well, I couldn't disagree with that but at the same time, I didn't feel I had any grounds to complain. After all, I got new shocks with their dyno sheets. How many people get that?

I put the stiffer springs on them (250/130). I thought I'd try them first since they did not require being taken off the old shocks. Then I put them on the car. The rears required a bit of fitting - the upper bushes were a little too wide for the mounting ears on my car so I had to file them about 1/8". The top eye on the shocks were a bit taller and were fouling the bolts that attaches the front of the body to the frame 'T' so I filed the bolts down. I didn't want to file on my beautiful shocks (they really probably too pretty to put under a car)! The rest actually went without a hitch. Normally I get a helper to push the upper pivot pins in but I was able to do that by myself without much effort. I finished checking and tightening everything, put her on the floor and was ready for a test drive tomorrow.

Tomorrow is today and I went for a test drive. WOW!! It was immediately more stable - even at slow speeds you could tell the difference. It was more like the car I remember back when it was new - only with more grip! I went on a twisty road that I had used to test shock settings. I got up to 60 mph through the turns but it was nail-biting. I carved through those turns at 60 with ease. The stability and grip was amazing! I had a new car!!

I realized that for whatever reason, since I had built the car, I had been driving on either shocks that were set too stiff or that were completely worn out. It wasn't that long ago that I learned anything about shock tuning. When I took the springs of my SPAX shocks, I could pretty easily compress and extend them in fairly quick succession. They were certainly done.

So far, I love these Protech shocks! They were REALLY expensive when you consider the shipping. If I had it to do over again, I might decide to buy shocks locally and then deal with the seller if they seemed off but they are all made in the UK and I might have ended up in the same place anyway. A retailer like DBE or r.d. might have exchanged them but they might also have referred me to the supplier.

So my story has a happy ending! I'm so happy, I can even easily look past the cost of shipping my shocks back to England! I think what happened to me could have happened to anybody regardless of who made the shocks. It just had to happen to me!  :(  I have no reason to expect that it would happen again if I bought another set of Protech shocks.

Offline BDA

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Rebuilding an NG3 (hopefully useful info for other trannies as well)
« Reply #126 on: Monday,July 17, 2023, 02:47:31 PM »
Well, this is an old thread that I've used in the past to chronicle some of my adventures in wrenching on my car. I probably could be more religious about using and updating it but...

I had planned to write this post after my latest adventure but things aren't going as smoothly or as quickly as I would have liked so I'll try to remember everything up to this point and then update as events warrant.

The latest adventure is rebuilding my tranny (NG3). I was having trouble getting into 1st gear all of a sudden. The linkage and clutch cable adjustment all seemed to check out. Also, I had no problem with other gears. I called Michel at Alpine-America (https://www.alpine-america.qc.ca/) and he immediately said the 1st gear synchro was the issue. I had been planning on rebuilding the tranny at some point and I had about two and a half months before the LOG in Knoxville which I had already signed up for so with the help of my next door neighbor's son, we pulled the tranny out.

It might be useful to note upfront that I am not taking out shift forks, except for the 5th gear which comes out with the end cover, nor am I opening up the diff.

After getting the tranny on a workbench, I opened it up and everything looked good. There was nothing alarming in the oil when I drained it and there were no chipped teeth (I didn't expect any but I was still glad to see that!). The Secondary shaft is the one that is the most work. I tried to take pictures of everything but I know the truth is that there will always be that view that I didn't take a picture of that I wish I had.

TIP #1: take pictures of everything (including several views of the same picture). Some parts are in groups (synchros, sliding gears, gears, springs, etc.). Try to take a picture of how each individual piece fits with the others. Be careful because some of the synchros have spring loaded rollers (in my case) and they can fly away or at the least get dislodged before you get a chance to take a picture of how they are supposed to go. It happened to me but luckily reading the (crappy) manual and thinking and staring at it for a while, I figured how how it goes back together.

As I took things apart, I grouped each "logical" part of the stack with a zip tie to keep them together and to keep them in their relative orientation. The next thing I did was get some cheap plastic tubs to put each group in after I cleaned them. Each tub had a label with what is in it.

WARNING: When you are cleaning things, you naturally flip them around and after a while, it might not be obvious what the original orientation was anymore (at least if you're a skatterbrained as I am). I don't really have an answer for this but one thing that might have worked is to clean the parts while they were still tie-wrapped together and then promise to clean and dry them one more time just before assembly. While most everything in the stack of stuff on the secondary shaft has only one orientation and most of them are obvious, it's still a worry that I have that I'll put something in upside down and won't find out till it won't shift or worse, won't take power or something (my mind conjures up the worst scenarios - especially for something I've never done before).

TIP #2: I've sort of mentioned this already but label everything. I punched a hole in a piece of paper and threaded a tie-wrap through it and onto the part or group of parts. I kept detent springs, balls, and plugs in a small zip lock bag with a label. (At this point, the irony of my suggesting any organizing techniques to anybody has finally struck me!)

The next step was getting replacement parts. I had already got a set of synchros from Michel at Alpine-America BUT, there are two different sets of synchros for the NG3 and how do you know which set you need? Well by the VIN of the car your tranny came out of!! Of course, there was no way I could know that so when I ordered my synchros a couple of years ago, I sent Michel the suffix number on the tag of my tranny. Now that I am about to really need to worry about them, I called Michel and he said he sent me the more common of the two sets. He also said that the 1 & 2 synchros were the same for all NG3 boxes but the 3, 4, & 5 synchros were the ones that were different. I test fitted my synchros with the hubs and they all seemed to fit well but the new synchros had a few thou smaller gap to the hub (stood a little higher in the hub) and the old synchro gripped a bit better than the new synchros. I tried to measure the height, OD at the top, and OD at the bottom of the synchros and as best I could tell, the new ones matched the dimensions of the old synchros. I asked Michel about this and he said I have the correct synchros and that the new ones will grip better after some use. Getting the right synchros may not be a problem for other boxes (336, 352, 365, etc.).

Next was bearings. The first thing I noted was that most of the bearings didn't have any identification stamped on them. For those you'll need some dimensions: ID of the inner race (i.e. shaft diameter), The OD of the outer race, the width of the bearing (this usually means the total width of the bearing at the widest part). You'll obviously need to know what kind of bearing it is (tapered roller, double tapered roller, ball bearing, double ball bearing, etc.). Then you'll notice that there are two bearings that are roller bearings that don't have inner races. The inner races are machined into the shafts. On my NG3, the outer race has a groove for a positioning ring to position the bearing in the case. The location of that ring can be different from one model to another. The diameter of the "inner race" on the shaft can also be different from one model to another. Hmm... This might be a problem.

Remembering when Certified Lotus rebuilt his tranny (https://www.lotuseuropa.org/LotusForum/index.php?topic=1704.msg21940#msg21940 and https://www.lotuseuropa.org/LotusForum/index.php?topic=1704.msg22243#msg22243) he got his bearings at 123Bearing (https://www.123bearing.com/). I went to their website, which is very good by the way, and found most of the bearings and seals I needed. I did not find any bearings without an inner race. Those are apparently Renault specific. One thing I was disappointed about was that they didn't have "sets" of bearings, for example all the bearings they have for an NG3, or a 352, etc., but that was minor matter. They have a "mail contact" link at the bottom of the home page at least and you should not be afraid to use it. They are very responsive. They also had all the seals I needed. Their shipping is pretty good in spite of the fact that they are in France.

123Bearing is not the only source you should look at. I was referred to Renault16Shop (https://www.renault16shop.com/). They are in Holland and probably more useful for the older boxes. For example, I just did a search for 336 and got lots of hits for those trannies. They also sell some general purpose bearings. For example, the NG3 uses two bearings that are the same except for their shaft diameter. I got the common one at 123Bearing but Renault16Shop had the less common one for a lot less. They even have those Renault specific bearings... but not for an NG3. Several (all?) Renault boxes have very similar general designs and so they used similar bearings without inner races. Unfortunately, Renault16Shop did not have mine but they are more likely to have them for some of the other boxes. They are also VERY responsive. I have emailed them many times about different things and have always gotten a quick substantive reply. If you are looking for NG3 parts, be careful as they do list some transaxle parts for a Fuego but they did not have any NG3 specific parts so they probably have the parts for an NG0, NG1.

While Renault16Shop caters to some of the older Renault cars, I was unable to find a similar company that catered to Fuegos (at least at the level of transaxle parts) in spite of the fact that they are more current and were well received when they were in production.

I've been talking to Michel at Alpine-America and he thinks he can get those bearings. So far I haven't heard if he can.

There is a spring connected to a cross shaft, which has the shift "finger" on it, in the end cover. The spring helps center the shift lever. Somehow, mine got mangled and I cut it up to get my cross shaft out so I need to replace mine. The spring is listed on Lotus Supplies's website. I have called them (always getting voice mail and never replying to my messages) and I've emailed requesting the availability of that spring as well as some other parts so I can order them but have gotten only occasional replies to my emails and none about parts availability. I am beyond disappointed in their response especially after I have bought so much from Richard over the years with no problems at all. I'm hopeful that Michel will be able to supply those parts.

While Michel is much more responsive than Lotus Supplies, he's not as good as he might be either. His French accent is so thick that it is difficult to understand all that he says. I just called him about my bearings and I'm pretty sure he said that it is rare to change the Renault specific bearings I'm interested in.

TIP #3: When emailing Michel at Alpine-America, unless you speak French, include both English and French translations of your note in your email.

So that's pretty much where I am at the moment. I can't start to assemble the box till I either get those Renault specific bearings or give up on getting them.

To be continued. Stay tuned!
« Last Edit: Monday,July 17, 2023, 04:38:47 PM by BDA »

Offline Bainford

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Re: Never a straight line
« Reply #127 on: Tuesday,July 18, 2023, 09:11:00 AM »
That's quite a saga. Transaxle issues is the one thing that really scares me about Europa ownership. Though my 365 is working well (as well as they do, anyway), I have been considering sending it off to Michel in the next year or two for an internal inspection, etc. Nip any potentially expensive problems in the bud.

Regarding your bearing, inspect it and the inner race (shaft journal) closely with magnification. If it exhibits no significant spalling or pitting, it should be good for service. Roller bearings elements have pretty decent contact area (compared to ball bearings), so if their lubrication has been kept clean, they will likely be in good shape. In the transmission, the loads are largely radial, which also bodes well for long bearing life when in the presence of clean lubrication. Nonetheless, I fully understand the desire to throw new bits at it while it is apart.

Good luck. Watching with interest.
The Twin Cam plays the symphony whilst my right foot conducts the orchestra. At 3800 rpm the Mad Pipe Organ joins in.

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Offline BDA

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Re: Never a straight line
« Reply #128 on: Tuesday,July 18, 2023, 10:40:14 AM »
I didn't talk about all the looking for those Renault bearings in my post! I even tried to get ahold of a Renault dealer in England but they wouldn't answer me, I searched for Fuego specialists online, I joined a Fuego forum that JB recommended hoping someone knowledgeable would reply to my post - nothing. The irony in all of this is that I replaced my 365 with an NG3 because I figured the support for it would be better. I'm starting to think that that was a mistake!

What I also didn't mention is that when I got a $150 price on a double tapered roller bearing that goes on the secondary shaft, I wondered did it really make sense to replace all the bearings on a car that was likely not to get a whole lot of miles on it. Would these bearings be good enough for another 100,000 miles or would I have to try to do this again in 50,000 miles? I asked a buddy who knows about trannies (and engines) about them, his comment was the general rule that if you are questioning it, you should go ahead and replace them. Well, I agreed with that, I also wanted a more informed opinion. With one of the bearings costing $150, I thought I was probably looking at $600 just in bearings! So I went to see him at work (he works for a really great restoration shop (https://roadscholars.com/). He was building a 4-cam type 547 Porsche engine with a roller crank which is a really complex task - he said because the cams are gear driven with no lash, it can take three days to get the cam timing right! He took a look at my bearing and said he would replace it and that it was probably making noise already but I couldn't hear it. That convinced me to change them all. It also turned out that the other bearings were a LOT less than that one so the $600 estimate was way heavy. Here's a 4 cam motor that was on BaT (https://bringatrailer.com/listing/1955-porsche-4-cam-carerra/)

The opposite side of this is that in my experience, manual transmissions generally last a LONG time as long as you don't abuse them and you keep oil in them. Of course, I don't know the history of my gearbox (and I'm tired of cleaning drip pans from the leaks!)

It's not financially feasible for me to replace the primary and secondary shafts (with the races for those Renault specific bearings) so the next best thing is to replace the bearings. The outer races of those bearings are pretty much like the races on all the other bearings. They have a "cloudy" appearance with small (the size of a pencil point) apparent pits scattered in the cloud. They are too small to feel but given what my buddy said about that double tapered roller bearing, I figure it would be worth the effort to replace those bearings too. However, if Michel can't get them, I'll just reuse them (see the opposite side referenced above and that Michel rarely changes them).

UPDATE: I got the bearing I ordered from Renault16Shop! Now I have all the bearings I need except those two Renault specific ones. The bad news is that I had also ordered a roll pin for the shift finger. I had to drill out the one I had to get the cross shaft out and Renault16Shop listed a roll pin for the shift finger on another box. I hope I already mentioned that the cross shaft arrangement is a mod that Richard does to the NG3s he sells. I figured that Renault probably used the same roll pin for all their shift fingers and Richard wouldn't change something like that. Wrong, the roll pin I got is too small. Another thing to look for!

Offline BDA

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Re: Never a straight line
« Reply #129 on: Thursday,July 20, 2023, 05:39:23 PM »
UPDATE: our own Swift-DB4 found the pinion gear at 123Bearing here: https://www.123bearing.com/bearing-housing/gearbox-bearing/rnu10552-s01-snr

I'm waiting to find out how he found it. 123Bearing has a dimensional search feature and I plugged in 72mm for the OD and 19mm for the width while in their Gearbox section. That brought up a slew of gearbox bearings with those dimensions but none of them were what Swift found so it appears that this bearing falls through some gap in their search engine.

Offline BDA

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Re: Never a straight line
« Reply #130 on: Monday,July 24, 2023, 05:23:40 PM »
MINOR UPDATE: I got the bearings pressed on the diff carrier and I installed the outer races of those bearing in the case halves. They came out without any drama and I worried that they wouldn't fit snuggly but they do. My method of getting the outer races into the case halves was pretty simple and very very slow. I lined up the race with the hole in the case as evenly as I could and then tapped the race with the back end of my largest punch occasionally measuring the depth (or actually how much of the race was still proud of the casting) at different points on the race. A few times, the race would get deeper on one side by 0.040 or so and then I tapped it on the other side to even it out again. I was very motivated not to get it the race cocked in the hole and thus possibly damaging the sides of the hole. As it went further in the hole, I didn't need to measure and I could tap a little harder but I never tapped very hard at all. At about 1/2 or 2/3 of the way, I screwed the finned nut in to the depth it was when I took it out. Then I continued tapping till the race bottomed on the finned nut.

I assembled the case with just the diff carrier in it. It would spin easily and there was no discernable side to side play. I was going to set the bearing pre-load but figured I'd just have to do it again so I didn't. I took everything apart and unscrewed the finned nuts 1/2 a turn each figuring that should be a good starting point for adjusting the back lash and bearing pre-load when I finally closed the case up.

Michel said he should have the bearings by the end of last week but I didn't hear from him. I'll call him tomorrow.

Offline BDA

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Re: Never a straight line
« Reply #131 on: Friday,October 06, 2023, 05:16:59 PM »
A lot has happened between the last post and this one including building the tranny with the old pinion and primary shaft roller bearings because Michel at Alpine-America did not come through for me. For a couple of reasons, I decided to get a new pinion bearing now that I knew that 123Bearing had them (thanks Swift!!) and I found a guy, Olivier, who said he could get the primary shaft roller bearing. (Swift also gave me a link for the primary shaft roller bearing but by the time I gave up on Michel, that link had died. Olivier came through for me so I took the tranny apart cleaned everything and then this time using all new bearings and seals, I rebuilt it. One thing that might be worth noting is that the primary shaft roller bearing had to be tapped on. Recall, that this bearing is a roller bearing that runs on a race that is machined into the primary shaft. I used a very small brass mallet (about 3/8" diameter face) and once installed, it rotated with a little force but loosened up a bit with turning. I only mention that because I didn't expect that and it is tighter than the bearing that came out. I have no reason to think it is the wrong bearing.

I set the diff carrier bearing preload with an empty box. The spec is between 2 1/4 lbs and 6 3/4 lbs. I got it to about 3 lbs or a little more. then I put the secondary and primary shafts in the case, used Permatex Gear Oil RTV (recommended by a Permatex guy) on the sealing surfaces and torqued everything up. This afternoon, I went to set the backlash on the ring and pinion. I got it between the recommended 0.005" and 0.010". However, with the box in neutral, I couldn't turn the ring gear by hand at all. I backed off finned nuts about six or seven net fins worth (which would have been about 0 preload without the shafts in the box) and I set the back lash again at about 0.007". With the box in gear, I can turn the input (primary) shaft to turn the ring gear. There is steady resistance but it's not hard to turn with my hand. With the box in neutral, the ring gear is still difficult to turn by hand and it must be done with two hands. There is no reason to test the bearing preload now because it would be way off the scale of my spring scale (> 8 lbs). With a dial indicator on the ring gear and prying gently on either side of the diff with a screwdriver, the dial indicator does not register movement.

So what is my next move? Should I back off the diff carrier bearings a bit more so I can turn the ring gear with one hand? Open the box and set the preload again and reassemble it again in hopes that backlash adjustments will make more sense? Or declare victory and put on the bell housing and put the car back together?

Offline jbcollier

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Re: Never a straight line
« Reply #132 on: Saturday,October 07, 2023, 06:37:30 AM »
Assuming you got the diff carrier bearing preload right the first time, put it back the way it was.  Any diff is hard to turn by the ring gear with new bearings and proper preload.

Offline BDA

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Re: Never a straight line
« Reply #133 on: Saturday,October 07, 2023, 08:37:52 AM »
I’ll put it back and try turning it with the input shaft and report back.

Offline BDA

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Re: Never a straight line
« Reply #134 on: Saturday,October 07, 2023, 12:00:28 PM »
Ok, I'm back. I put the finned nuts back where they were when I adjusted the preload (with no shafts in the box) and then I re-adjusted the backlash tightening and loosening the finned nuts to move the outer races of the diff carrier bearings together, each time rotating the input shaft while the box was in gear enough times to rotate the ring gear one or more revolutions. I got the backlash to 0.007" - where I wanted it. I rotated the input shaft to turn the ring gear a couple of more times and rechecked the backlash.

The input shaft can be turned with the box in gear (4th) with one hand with little effort. With the box in neutral, the ring gear can be budged (maybe one tooth) with two hands with great effort - enough to raise the box off the bench.

Does that seem reasonable and usable?