Author Topic: Still have gearchange problems  (Read 1508 times)

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Offline Sparkrite

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Still have gearchange problems
« on: Sunday,December 17, 2023, 10:42:05 AM »
With my tcs I am still having some difficulty going from 1st to 2nd,less so from 2nd to 3rd and 2nd to first. It is also initially very difficult to get out of first. It was not like this before. I have set the play at the clutch cable to about 2-3 mm, adjusted the pedal stop,and with the pedal depressed the cable moves about 20mm, the clutch separates from the friction disc with about 60 thou of clearance. With no engine running the gear lever goes through all the gear positions really well. I never changed any of the gear linkage settings, I have simply taken out a lot but not all of the slack in the linkage. The strangest one for me is 1st to neutral being difficult I just can't understand it.

Offline BDA

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Re: Still have gearchange problems
« Reply #1 on: Sunday,December 17, 2023, 11:36:00 AM »
Since the difference seems to be between when the engine is running and when it is not, and because you are having trouble getting out of a gear, I think that implicates the clutch. I might try adjusting in a bit more free play.

I would also try to get the last of the slack out of your linkage. This post might be useful (https://www.lotuseuropa.org/LotusForum/index.php?topic=3898.msg41416#msg41416). I’d also inspect the top hat bushings in the shift lever and the bushing that is associated with the center u-joint.

Can you help us out with more description of the symptoms? Does it grind?

Offline Sparkrite

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Re: Still have gearchange problems
« Reply #2 on: Sunday,December 17, 2023, 01:52:28 PM »
It can grind a bit into 2nd and 3rd unless I'm very careful. It can't be the syncros as they worked fine before I touched the linkage. The clutch "seems" to disengage as when I put it in gear, then held the pedal down, I could see the clutch disc rotate through the opening in the bell housing as I rocked the car forward and backward.

Offline BDA

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Re: Still have gearchange problems
« Reply #3 on: Sunday,December 17, 2023, 05:39:18 PM »
My linkage is different from yours but I had to teach myself to keep a little pressure toward the left when going from 1st to 2nd, otherwise it would grind going into 2nd. Apparently what felt like it was straight back was not quite and it caused a problem. It's possible that something you did to your linkage could cause your problem. If it is your synchros, I would expect the 2nd synchro to go first since that is probably the gear you go into and out when you're moving more than the others although, it my 1st synchro that went. When my 1st went out, it surprised me because it started grinding all of a sudden.

I guess I would make sure it wasn't linkage or clutch before I worried about synchros. Make sure the car doesn't move when it's in neutral and the engine is running and when it is in gear and rolling under power that pushing the clutch pedal disengages the drive and it starts to coast. I wouldn't trust what I could see looking through the timing window in the bell housing - not that it necessarily gives you bad information but that I've never tried it because I didn't think I could get a good enough view. Checking with the engine running is also more real-life.

It could also be a problem with your linkage and as I mentioned earlier, you should try to get all the slop out of it first of the shift lever-to-linkage joint and all the u-joints.. Also make sure the middle u-joint is adjusted properly (page 4 of http://lotus-europa.com/manuals/tcwork/f/tcf.pdf).

Offline Sparkrite

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Re: Still have gearchange problems
« Reply #4 on: Saturday,December 23, 2023, 04:20:37 AM »
I jacked up the rear wheels off the ground and started the engine with the car in neutral and the handbrake off, and one of the rear wheels was spinning. The more I revved the engine,the faster the wheel would spin. when I chocked it with a brick,the opposite wheel would spin. When I pressed and held the clutch pedal down and put it in gear,this made no difference to the spinning wheel.
So I am assuming my clutch and gear linkage is fine,but the problem is likely in the gearbox or oil choice. The oil I put in was Castrol Transmax manual EP 80w 90

https://www.opieoils.co.uk/p-77362-castrol-transmax-manual-ep-80w-90-mineral-transmission-fluid.aspx?variantid=116061&gad_source=1&gclid=CjwKCAiAp5qsBhAPEiwAP0qeJsB33wr-77mMywx-Qh1tZf8BPEXvJnxukYxui_RzBnX9G0MihwHoZhoC0tUQAvD_BwE

Offline Clifton

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Re: Still have gearchange problems
« Reply #5 on: Saturday,December 23, 2023, 03:34:17 PM »
Every time I've had these gear engagement issue's, it has been due to a lack of full release, the disk is dragging enough to keep the trans spinning. If it shifts ok at 3000 rpm but is harder at 6000 rpm, it needs more space between the disk, PP, and flywheel when disengaged. Increase the distance between the floor and when it starts to engage and try again. What works good at idle is not the same with higher revs.

Offline Sparkrite

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Re: Still have gearchange problems
« Reply #6 on: Sunday,December 24, 2023, 06:45:20 PM »
It definitely feels like the disc is dragging. The previous owner had adjusted about 50% more  pedal travel than normal and I think this has affected the pressure plate,so it no longer functions properly when used with standard settings.

Offline Sparkrite

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Re: Still have gearchange problems
« Reply #7 on: Sunday,December 24, 2023, 07:02:38 PM »
Just found an image of a new pressure plate which has different springs to my one.

Offline EuropaTC

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Re: Still have gearchange problems
« Reply #8 on: Sunday,December 24, 2023, 10:31:10 PM »
It may not be relevant to your problem but on my car the diaphragm springs weakened. Although I could disengage if I pushed hard I felt it was creeping as I held my foot down and engaging a gear was difficult. Fine on the move but from standstill it was just wrong. I ended up replacing the whole lot but I'm convinced it was only the finger-style springs that were the problem.  Mine looked like the second photo you posted.

Brian

Offline Lotuswins

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Re: Still have gearchange problems
« Reply #9 on: Thursday,January 04, 2024, 01:03:45 PM »
Have you had the trans out?  What has changed since it was working??

My thought is it may be the spigot bearing in the crank has siezed or is too tight?  When in neutral and jacked up, with one wheel blocked, can you turn the free wheel easily?

Jerry Rude
4005R

Offline Sparkrite

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Re: Still have gearchange problems
« Reply #10 on: Sunday,January 07, 2024, 02:10:56 AM »
I've had it jacked up and with one wheel blocked the other does turn freely. My latest thought are this
- with no engine running I can 'shift through the gears fine, so unlikely to be my linkage.
- with engine running and clutch pedal pressed I can select gears,so unlikely to be clutch or clutch drag.
- when car is rolling,the drive shafts and diff are rotating which is somehow affecting gear selection.
So it might be the syncro rings are worn or a combination of my oil and the temperature as it is winter now and most of my driving was done in summer. But if it was worn syncro rings would that make getting from first to neutral difficult.

Offline GavinT

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Re: Still have gearchange problems
« Reply #11 on: Sunday,January 07, 2024, 05:53:13 AM »

I never changed any of the gear linkage settings, I have simply taken out a lot but not all of the slack in the linkage.


Long shot:

I'm confused - slack in the linkage or slack in the clutch cable?

I'm wondering if the linkage is now hard up against a linkage adjustment limit and this is impacting the actual gearbox mechanism.
As in . . if we imagine the H pattern traced by the gear stick, the gears should be be selectable comfortably within the range of that H pattern. This seems to differ between the 'on blocks' and 'on road' scenarios.

What happens if you go back to square one?

Offline Sparkrite

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Re: Still have gearchange problems
« Reply #12 on: Sunday,January 07, 2024, 02:18:04 PM »
I took the slack out of the linkage. The bottom of the gear lever(bushes),the slack in the threaded rods as they enter the linkage tubes,the two universal joints and the slack in the pivot for the central helm joint.
I can select all the gears when stationery with engine on and also off.

Offline BDA

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Re: Still have gearchange problems
« Reply #13 on: Sunday,January 07, 2024, 02:52:37 PM »
Since your problem only seems to happen when the secondary shaft is turning, I'm betting it's your synchros. Also, the 1-2 and 3-2 changes are the most common gear changes while the car is moving so it makes sense that the 2 synchro would wear out first. After that, 2-3 and 4-3 are the next most common so it makes sense that the 3 synchro would wear next. 2-1 probably happens more often when the car is stopped than moving so it should give you less trouble (admittedly, that was not my experience and I can't explain that).

Rebuilding your tranny might make a good winter project.

Offline jbcollier

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Re: Still have gearchange problems
« Reply #14 on: Sunday,January 07, 2024, 03:54:12 PM »
Shifts fine when engine isn't running.  Stiff and baulky when the engine is running.  Your clutch is not fully releasing and is "dragging", preventing the synchros from working properly.  If something is warped, it may act like it is free when the engine isn't running but allow light contact (causing drag) when the engine is running.  The fact the previous owner had to adjust things so there was excess travel available, leads me to think this is the case.