Author Topic: cam/detent mechanism on 365 gearbox  (Read 1785 times)

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Offline Europa73

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cam/detent mechanism on 365 gearbox
« on: Wednesday,August 23, 2017, 03:14:32 PM »
has anyone ever adjusted the cam/detent mechanism.

if yes - how easy was it.

if this is a pain it will go back to the garage for adjustment.

Thanks,


also restoring 69 Elan +2 and driving a 1975 TR6

Offline BDA

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Re: cam/detent mechanism on 365 gearbox
« Reply #1 on: Wednesday,August 23, 2017, 03:30:37 PM »
The only "adjustment" I'm aware of is taking a file to one of the cam "ears." I had planned on experimenting with it if I had kept my 365 (as long as I had a spare), but I sold it and replaced it with an NG3.

Offline Grumblebuns

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Re: cam/detent mechanism on 365 gearbox
« Reply #2 on: Thursday,August 24, 2017, 01:15:59 PM »
I'm assuming you want to reduce the effort required to shift into reverse or 5th. Filing down the cam detent ears will certainly make selection of reverse or 5th gear easier. I'm wondering though  how the shorter distance the ball bearing moves with the shortened ears will affect  the reverse/5th gear lockout. It's been many years since I had a look behind the rear cover. I'm wondering if it's better to use a weaker spring behind the ball to reduce the effort required. Any changes to the cam detent is permanent. Changes to the spring are not. Pictures shows the cam detent in reverse and 5th gear.

Hopefully Peter Boedker will chime in on his thoughts.

Offline 4129R

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Re: cam/detent mechanism on 365 gearbox
« Reply #3 on: Thursday,August 24, 2017, 06:10:42 PM »
I installed a new ball-bearing and spring.

I cannot get R or 5 on 4688R.

I will see if a weaker spring helps, but now at least I know the source of the problem. Thanks for pointing me in the right direction.

Offline pboedker

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Re: cam/detent mechanism on 365 gearbox
« Reply #4 on: Friday,August 25, 2017, 12:16:04 AM »
Your description and photos describe the task very accurately, Joji.
I never succeeded in adjusting the ball housing properly. Even though I drilled the mounting holes to allow for greater adjustability of the housing I was always left with either reverse being properly adjusted and 5th gear needing an excessive force, or the opposite. I never understood why Lotus removed the internal 5th gear detent as designed from Renault. The Lotus detent cam design is only 'almost a solution' but maybe filing the detent ears could have made it work as intended.
In my case I simply gave up and removed the ball housing. I've been using the parts I describe in this link for many years now: http://www.lotuseuropa.org/LotusForum/index.php?topic=127.msg706#msg706
Peter Boedker
3904R Special
Denmark

Offline Steve_Lindford

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Re: cam/detent mechanism on 365 gearbox
« Reply #5 on: Friday,August 25, 2017, 12:35:44 AM »
Has anyone considered this method of solving SOME of the gear selection problems??


Offline jbcollier

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Re: cam/detent mechanism on 365 gearbox
« Reply #6 on: Friday,August 25, 2017, 06:45:45 AM »
I think you will find that the Europa gear change doesn't have enough side to side movement to fit a plate like that.  Myself, I would file off the reverse detent, fit a reverse lock out at the lever, and fit a lighter spring tension on the 5th gear detent.

Offline Europa73

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Re: cam/detent mechanism on 365 gearbox
« Reply #7 on: Friday,August 25, 2017, 06:54:56 AM »
question regarding the adjustment.

for my 5th gear my detent  is not close enough to the ball to push on the spring for any resistance.

is this a simple rotation adjustment that is required? or (apart from the locking nut) is there anything else that would stop the rotation adjustment.

Cheers
also restoring 69 Elan +2 and driving a 1975 TR6

Offline Grumblebuns

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Re: cam/detent mechanism on 365 gearbox
« Reply #8 on: Friday,August 25, 2017, 07:22:22 AM »
Having too light of a spring may have it's own issue. The PO of my TCS must have installed a much lighter spring for the ball. It made 5th gear selection much easier but it also made accidental hitting of reverse on the 3rd to 2nd downshift more likely unless you are extremely careful, it happened to me a couple of times.

I think Peter wrote that the detent spring is a non standard size. If so, there may be issues getting replacements of varying strengths.

Peter, I misplaced the bits you sent me and may end up buying another set from you. I'll send you a PM if I can't find the kit.

Offline buzzer

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Re: cam/detent mechanism on 365 gearbox
« Reply #9 on: Sunday,August 27, 2017, 05:34:38 AM »
Before you go too mad with springs and any filing first check that the ball is free and easy to move in its housing. My detent had a lip that when the ball was trying to ramp up the arm the ball was forced against the lip in the holder, which made it much harder to overcome.
Dave,

Other cars. Westfield SEiW. BMW E90 Alpina D3. BMW 325 E30 convertible and Range Rover CSK