365 5th Gear Indent & Plunger

[SilverBeast]

I looked through my old messages. I got the reverse detent ball and spring from member Peter Boedker (pboedker). I also got his reverse lockout kit. At the time he said he had a few left. So you might contact him.

Thankyou Kendo - just to be clear I am looking for the 5th gear indent INSIDE the 5th gear housing and it consists of a plunger and spring. (The external Lotus indent system is the one with the ball and spring - I have that assembly.)     

If I recall the post correctly Peter Boedker was offering the Reverse Lockout kit AND the internal spring/ ball bearing for the 5th gear detent so the external reverse solution for both could be completely removed (cam, housing, spring and bearing).

[jbcollier]

Yup, S-Beast is correct:

http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg706#msg706

Specifically:

http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg5746#msg5746

[SilverBeast]

Here is the link for pboeker's solution/kits http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg8263#msg8263

Edit: Mr Collier beat me to it!

[Dilkris]

Thanks so much everyone!! - I now have sufficient leads to pursue this to a conclusion. (It is also now clear that Lotus remove the Renault 5th gear internal indent system on the 365 and replace this function with their own external indent set up- but it still remains a mystery as to why !!. ) 
jb - I was fascinated with your pictures of the reverse lock out system and was wondering why you went for this approach as opposed to  the Ferrari system of visible gates - was the decision made on visual reasons or is there a technical reason for not going "Ferrari" - or maybe you just don't like Ferrari's   

[jpane]

In the LOTUS EUROPA MASTER DOCUMENTATION MENU found at http://lotus-europa.com/manuals/

A series of 5 pictures and a drawing are available from Tom Rollins, the previous owner of my current Europa, of a 5 Speed Reverse Lockout.

Thought this should be added to this discussion.

[jbcollier]

Gates are great at protecting expensive trannies, not so great for shifting quickly.  You can find Ferraris with the gates removed, or, long ago, cut away (yikes).  An open shifter with proper delineated rail selection via internal spring loading and reverse lock outs is much nicer to use and quicker to shift.  I go from 3rd to 2nd with nary a second's thought.  As it sits naturally in the 3-4 slot, 5th to 4th is equally easy.

I think the Lotus shifter mech has a lot of inertia and this may mask the internal selector guide springs of the stock Renault transaxle.  Mine is a cable shifter so I can't fairly comment on that.  Mine shifts like butter.

[Dilkris]

It appears we have just reinvented the wheel - why I never search the Master Documentation Data is beyond me.  As jpane points out, within another post (by Aaron Hines) quotes - "The external 5th gear/reverse detent is a poorly designed factory addition to the 365-07 transaxle.  I installed Renault's internal 5th gear detent"

Within the Transmission & Final Drive section, information extends to include 5th gear lock out methods (Tom Rollins) as advised.

Once again, many thanks to all.

[pboedker]

Coming in a little late to the discussion for various reasons, I have a few comments to the Lotus detent system, as I see it. 

My theory is that Lotus needed to do something about a reverse gear lockout when switching from the 336 box to the 352 box (4 speed). So they added their own detent plate with one cam to the backside of the transmission. When the 365 (5 speed) was introduced the detent plate got another cam, and the internal Renault plunger was removed. And now all the trouble began, because the detent cover had to be adjusted very delicately to even have a small chance of getting it right.  "That is the theory that I have and which is mine and what it is, too." 

For my part I never succeeded in adjusting it properly which led me to removing mine and fabricating my own reverse liftup handle and a copy of the Renault-style internal plunger for 5th gear. Using those instead of the Lotus detent cam has given me now 15+ years of trouble free gear changes in my Europa. 

I still have a couple of the 'plunger+spring' available for sale and might look into having another batch produced if necessary. I also have some liftup handles which can be used on cars with either the 352 or 365 box.

[Dilkris]

Just to close the thread, I PM'd Peter Boedker, who replied as a PM, (Meanwhile he'd posted on the main Forum  ), All now in motion to close this query. Once again, big thanks to all.
Now onto the next problem...   

[barryinwhb]

If I understand your modification correctly you have completely removed the external reverse/5th gear cam and now rely on your gear lever device to prevent accidental selection of reverse. I seems you also have no problem selecting 5th gear without the external cam and relying on your own version of the internal Renault style spring plunger. If you still have your plunger/spring units available I would like one. Also a drawing or photo of your reverse protection device would be appreciated; unless of course you have a spare device!

[Exlimey]

My car  has Peters kit, slightly modified I believe, the car has no springs,plungers indents etc. A rubber 3/4” chair leg protector fits on the gearbox covering the shaft. This way there is no strains anywhere on the shift linkage which should last longer? The tab on the gearstick lifts to select reverse.
Tunnel as present off for winter dash refinishing,boot surround cut from an old road sign.

[FourLoti]

Hi: At the risk of revving up even more dialogue on a topic that's received plenty of coverage already, I thought I'd share this photo and info since it seems to apply to the original question and may be helpful in the future.

I've been working on my '74 TCS for 6 months after rescuing it from 25+ years of "storage." Have not been able drive it yet due to nagging brake system issues, but I finally decided to go through the shifting mechanism. Turns out I have TONS of play at the front shift rod clevis connection, so new bushings are in store. However, when giving things the once over, I found that the 5th gear tang on the external detent setup had apparently been ground off.

At first I thought it was another DAPO "fix," but reading this thread helped me realize (I think) what the deal is with my car. It definitely has strong 5th detent action, so the internal spring and ball are in place. Looking at some other articles, I believe what I may have is a factory expedient used in the very early 5 speeds. My car, 3826, is an early build '74, built in July, '73. Or perhaps they just kept using the 4 speed detent plate until they ran out?

But of course, this still doesn't answer the question of why/when Lotus stopped using the internal setup. As an aside, I found photos of the same setup on a Renault forum where posters were scratching their heads as to why a used "Renault" box had grown some sort of homemade looking mutation.  https://www.aussiefrogs.com/forum/index.php?threads/365-box-mod-from-a-lotus-europa.148492/

Ron

[BDA]

That did not come from the factory. My car is 3635 and it did not have one that looked like that. I believe the DPO modified (or made his own) "Cam Reverse Indent" (from the parts manual (http://lotus-europa.com/manuals/tcparts/f/tcfl.pdf), I always called it the R/5 detent cam). It used to have two ears. The one on the "R" side of the cam was obviously to keep you from going into R without meaning to. The one on the "5" side of the cam is apparently to keep you from going into 5 without meaning to. This makes going into 5 much more difficult than it should be and that's why the DPO either ground off the 5 ear of the cam or made his own - it looks like he made his own.

On 5-speed trannies, there is usually a spring and/or detent mechanism to "center" the gear shift (I don't remember a similar situation in the Hewland of my old race car - the only 4 speed transmission I've been in which is admittedly a poor example in this discussion). The R/5 detent cam apparently provides that function. When I had my 365, I considered shaving down the 5 ear to make it easier to get into 5 but I think cutting it off is a bit extreme. I don't know because I never tried it as I ended up replacing my 365 with an NG3.

I believe that r.d. enterprises has replacement cams (DBE probably also has them). My advice would be to get two replacement cams and "massage" one of them in hopes of getting a better change into 5 without detrimental uncertainness about where the gear shift is or is going and then use that one. The second one is in case your efforts with the first one fail.

[jbcollier]

I have no idea why Lotos felt the need to come up with such a Rube Goldberg solution.  I can only speculate that built in inertia and friction masked the original Renault set up.  FourLoti is indeed lucky to have found their car has a modified set-up.  Myself, I’d leave well enough alone and enjoy shifting with pleasure.

[FourLoti]

Thanks JB:  Yes; it seems I am lucky and I take back the aspersions I cast on the former owner. Hidden in the Lotus Ltd. Technical Manual, I found this very relevant write up by Glenn Davis from the October 1984 issue of Lotus ReMarque - see photo.

I do indeed have the internal spring and plunger. so apparently that Definitely Astute Prior Owner followed this plan, or one similar. Unfortunately, a quick search for those Renault parts comes up empty, but perhaps they are still out there somewhere. (BTW, I can't imagine who would want to try his first suggestion of finding and adding a larger ball!)

Back to the question as to why Lotus did this, don't rule out the possibility it was due to being cheap/frugal. If you're contracting for a thousand or so gearboxes at a time, you might be able to shave a few pence off of the unit cost by deleting those parts. Especially when you can (theoretically) accomplish the task with a virtually free mod to the existing cam. Or maybe it was just "adding lightness"? 

Ron