Rob Edwards

Erkka-

[stupid question mode]
So for an 85-95, does that mean 2nd or 3rd gear? I leave mine in neutral with the parking brake on, makes it easier to roll it back and forth as needed in my tight garage. [/stupid question mode]

Vilhuer

Most of the spring will likely be in its normal position kept in place by small circlip at end of shaft to which flat springs lower end is mounted to. This locking mechanism was deleted from '87-95 gearboxes to make it easier to change that spring without tearing apart entire gearbox. We do have changed flat spring on relatives '85 box by removing only selector mechanism parts from above but this job is not easy. Puting back that circlip is real pain as there is only few mm's of space between it and closest gear.

For '85-86 it should mean between 4/5 as that flat spring in those boxes only works into one direction thightening further away selector goes from 4/5. In many cases spring is so weak that selector will remain in 2/3 area but according to all I have read and seen this is not the way factory intented it to be.

Same thing goes with '78-84 boxes too, 4/5 is where those coil springs and gravity wants to push selector. '78-81 used just gravity to take selector from 2/3 to 4/5, '82-84 have one extra coil spring to help on this. Some people have turned this springs action around and created 2/3 centering setup. This is only temperary solution as two springs are fighting against each other and one is going to loose this fight eventually. During this duel neutral position will start to move left or right from 2/3 depending on which spring is winning.

Flat spring and few other parts were changed in '87 MY specifically to get selector to remain in 2/3 area. Its possible to retrofit this setup to '85-86 quite easily. All it takes to do it right is about half dozen parts including transmission cover. Worst part is that this makes flat spring problem only marginally better. In '85-86 setup spring is pushed more due to only one direction away from stop action it has and this will probably kill it sooner than later '87-95 version dies. '82-84 is probably safest setup but even it is not immune to this stuff falls between gears and kills entire gearbox syndrome.

In reality it would be better to engineer entirely new setup to do both side to side action and reverse gear lock mechanism. This is most likely too much work for most of us. I'll rather spend that effort on 6 speed conversion.

Neutral is always best option as it will put least ammount of pressure any and all springs in the system. Either one of the closest to neutral position gear selected applies only if some gear is needed to keep car from rolling etc. This saves these similar type of springs in all manual transmissions.

fraggle

Is that spring an easy replacement for a PM? Transaxles scare me, though I've done my own t-belt job...

drnick

erkka, it seems as if replacing the now broken spring might be simply asking for more trouble later - and potentialy a total loss of the transmission. how bad will it be not to replace the spring?

Vilhuer

If you can take gearbox down on your own then its not too bad job after that. There is no need to take gears out. Just few selector mechanism pieces.

Have driven few were spring was in pieces like you have. Really hated it but its drivable without any real problems.

Maybach_Man

What other issues are there to check for ...obviously apart from checking syncros????

Geoff

Vilhuer

Condition of input shaft for example. On outside in front of gearbox its sort of pipe which is split into three pieces to allow clamp to press it tightly around torque tube center shaft. Sometimes one or two of these can have piece missing and clamp can't do its job properly anymore. This is usually result of either loose clamp bolt or wrong gearbox or torque tube installation someone did in past.

While gearbox is out its good time to change selector, input and drive shaft seals. If they are old its very likely at least one of them will leak soon anyway. There is very little point on buying these seals individually as total set should cost under $100. This is just 1/2 price of flat spring. IIRR reverse gear lock spring is NLA.

Maybach_Man

erkka
thanks for that... il check all you said this week

geoff

AO

This is really good info... I'm putting this into my keepers list.

drnick

the more i think about it the more i am reluctant to want to put a spring back in that i know will fail and potentialy destroy the gearbox. i cant see myself pulling the box and replacing the spring every five years as preventative maintenance... but i dont know if the shift will drive me crazy without it???