rene040269

I have a neglected '80 4-speed manual which i want to restore. For now i am trying to get her drivable but i have a lot of trouble getting her in gear.

Reverse is not a problem although i have to depress the clutch completely to the floor to shift from neutral in reverse without a grinding noise from the gearbox but it seem very hard to shift from neutral to any of the gears. Sometimes the shift lever will not engage the first or second gear at all, no matter how hard i push and that is something i don't want to do.

There is a lot (and i mean a LOT) of free play in the gear lever in neutral and the entire gear shift system is very sloppy, so i can figure out my gearbox or shift linkage is worn (probably both)

But what contributes the most? Can a worn out shift linkage cause this problem or do i have to open my gearbox? Is it easy to refurbish the linkage system and are there any culprits i have to watch out for?

Thank you guys for your advice!

wombvette

You should check the two bolts that mount the shifter to the bracket. If one, usually the lower one is out, the shifter will be very sloppy. Also you need to adjust the clutch so it will release earlier and completely.

cv67

x2

Also if the bushings are real bad replace before driving.Tend to get stuck in more than 1 gear sometimes that will ruin your day

blue427

I would get a shifter rebuilding kit from one of the vendors on the forum(car is over 30 yrs old so chances are the shifter is that old).After that adjust clutch.

mikep3

Its sounds like an old clutch that is no fully disengaged.

gkull

With the motor of does it shift through the whole pattern. With the motor running and the clutch to the floor if you can't put it in gear then just adjust the clutch throw on the Z bar

mac79vette

I had a problem one time where it was hard to get in to some of the gears and thought the shifter was way out of adjustment. It turned out the transmission mount broke and because the shifter is mounted to the frame and not the transmission it changed the shifters alignment.

dugsgms74

Could be a trans or a clutch problem. Im gonna assume that it goes into all the gears with the engine off. If so, put the car in first gear and push the clutch all the way in and try to start the car, if the car wants to lurch forward then you likely have a clutch problem.

rene040269

Great advice guys, i will try this today

rene040269

OK, so i tried to get the car into gear without the motor running. It takes a bit of fiddling around but i can shift all four gears no problem.

In any gear there is still a lot of free play in the shifter and it all feels very sloppy indeed.

I measured about one and a half to two inches of free play in my clutch pedal.

I have adjusted the rod between the pedal and the Z-bar, lengthened it about 4 mm. It feels if i have about half an inch less free play in my pedal.

I started the car and fully depressed the clutch pedal to the floor. No difference whatsoever: Reverse can be engaged but i have to press the pedal to the floor or the tranny will make a horrible grinding noise. With the engine running and the clutch disengaged i cannot select any of the four gears. As soon as i kill the engine i can select 1st to 4th gear no problem.

It does sound indeed like my clutch is not disengaging completely and the synchromesh of the forward gears is preventing the lever from shifting.

So what to do, adjust the clutch pedal even more? How do i know the clutch has enough travel to fully disengage?

If i have the car in reverse of 1st gear the clutch seems to work fine. I can pull away very slowly and calm and have the clutch engage in a very controlled motion without any vibrations or other signs of misfortune.

What can be wrong? worn clutch? warped clutch? Gearbox oil fouled preventing the synchromeshes to work properly?

larrywalk

The throwout bearing is likely mis-installed. If the clutch fork spring is not into the groove of the TO bearing, gear grinding and shifting problems will happen. Fortunately, one can inspect for this through the fork opening in the bellhousing.

gcusmano74

In your origional post you said the car was "neglected".
Sometimes, the rivets on the clutch disc will rust-weld themselves to either the flywheel or the pressure plate or both.
Could that be your probelem?

rene040269

Wel, maybe.

I have bought the car from someone who drove it regulary for 17 years but neglected it for quite a time. In order to find a solution which does not require the complete removal and overhaul of the gearbox and clutch i have to make some assumptions. (Yes i know: assumption is the mother of all f#ck-ups...)

For this moment i assume the clutch was in good working order and operated the way it was supposed to be. I cannot rule out the possibility that for example the clutch fork spring was positioned wrong as mentioned above but for now i am looking for a solution regarding wear or rust. If i have to pull the tranny so be it, but i would like to investigate the easy tasks first.

But it has definately something to do with ALL synchromeshes not working, with the engine running i cannot push of pull the stick into ANY gear besides reverse. The moment i stop the engine the stick can be pushed into any forward gear without much effort.

I have not tried to shift from 1st to second while driving because i am fixing the car which has a lot of issues and one of them is that all four brake calipers and the master cylinder are laying on my workbench, so driving is not a possibility right now.

So i am still looking for a clutch problem i think. As far as my synchromesh knowledge reaches: if the clutch somehow not completely disengages the input shaft will rotate/slip a bit causing the synchromesh rings to rotate against their springs and this will block the synchro rings to shift sideways, thus preventing the gears to engage. Right?

FireballXL5

Is there excessive side to side slop in the shift ****?

Sorry, I'm re-reading the whole thread... I may have something for you not sure if it applies...

FireballXL5

I was actually looking towards something else... But this little write-up explains it better..

http://www.corvettemagazine.com/tech...ifter-rebuild/

larrywalk

Quit wasting your time - check for proper throwout bearing installation! Your symptoms are clearly that the clutch is NOT disengaging cleanly thus it won't shift into any synchromesh gear. It will go into reverse, but with a lot of grinding - ouch!

Get a small flashlight and an inspection mirror, and pull the clutch fork seal back so you can look inside. I'll bet that's where the problem lies. You may have other problems too, but you'll be able to address a sloppy shifter when you have the trans out to fix the TO bearing installation. Sorry for the pessimism.

rene040269

No problem, I will definately take this advice, thanks! Only problem i have is that the car used to work OK before it was parked away for a long time and if the fork spring was positioned correctly before i fail to understand how it moved to an incorrect position on its own. Looking at your picture above: Could it be possible that the clutch fork spring is somehow worn or distorted (as is the whole car to be honest) and worked itself over the "ridge" of the throw out bearing? (Meaning: it was installed properly but is snapped out of the groove of the TO bearing?)

I understand from your post that it is visible through the clutch fork hole in the bellhousing, but if you are right can it be corrected without removing the transmission? Never worked on these cars before so i don't know if the clutch fork can be removed and properly re-installed from the outside?

Thanks for the advice

rene040269

I tried to check the TO bearing but with the car on the ground there is not enough room for a clear view. I will raise the car on jackstands this weekend and take a further peek.

A friend of mine had another probable cause which i would like some expert opinion on:

He claimed that it could be a sticky clutch plate. If the rear main seal leaks (not uncommon on an old 350 SB with a split rear seal, and my engine is quite dirty on the rear end) oil could be fouling the clutch plate and if i depress the clutch the spring/pressure unit moves away but the clutch plate sort of "sticks" to the flywheel. This means that even with a fully depressed clutch pedal the input shaft of the gearbox is still "connected" to the engine when i want to shift into gear, something the synchromeshes won't allow.

Could this be a possibility?

FireballXL5

I would imagine any 'oil' getting into/onto the clutch would just cause more slippage, and/or smell/smoke.. Throw out bearing, shift linkage, and trans mounts would appear to be the likely culprits from the info I've seen... But I'm no expert, and the car isn't in front of me... So it's really hard to accurately tell. Good luck, let us know whatcha find when you jack her up!

larrywalk

I think it is improbable that it slipped, but anything is possible. Unfortunately, to fix it requires removal of the trans.

BTW, a friend had the same symptoms; I recall inspecting this same thing - the TO bearing was improperly installed by a supposedly reputable shop which had rebuilt his engine! After the shop fixed their mistake everything was fine.