Hey guys- just bought a 94 coupe with 123k miles and a 6 speed manual last week. Everything looks and works great, but I have an intermittent problem shifting between 1st to 2nd gear and sometimes getting the car in reverse. The 1-2 shift issues happen during normal driving and the reverse problem seems to be when the car is driven for the first time of the day. When I test drove the car, I noticed the shifter had an extremely short "throw" and seemed really notchy and not smooth. It seemed like a completely different shifter than the other cars i test drove. Should I be leaning towards the master cylinder/slave cylinder, or a new transmission? Something aint right !!!

 

I'd probably first check to see if it's got an aftermarket shifter in it, which might benefit from adjustment. If it's a shifter with adjustable stops, then it may be preventing proper gear engagement.

I'd also consider the hydraulics as you mentioned. First check the fluid level. If it's low, it's possible that there's a leak (usually at the slave cylinder).

You can have your stock parts rebuilt by Powertorquesystems.com , or you can try your luck with aftermarket.

 

I didn't know you could adjust these shifters. I will check the fluid in the clutch MC this weekend. I haven't been able to mess with the car too much, cause the wife was really pissed when I drove up in it. I sold my bass boat last weekend and I told her I was gonna buy a honda accord with the money....
That didn't happen.

 

Check the hydraulics first,, for sure!

 

Does the 'bad' 1-2 shift coincide with a light in your dash that illuminates to read "1 to 4"? If so, you're problem is the CAGS unit.

Under certain conditions (low speeds/throttle angles/mph) it uses a solenoid to force the shifter from 1st into 4th. Mine was failing when I got my car and when I would try to shift to second, it would try to force me into fourth and crunching sounds would happen. On the 94 it is as easy to disable as unplugging the connector from the solenoid. This was designed to basically save gas by getting you into a higher gear sooner. I think manual transmission Corvettes still have this even today.

If you don't think thats your problem then there is:
Clutch hydraulics as others have suggested
Bad release bearing, fork, or pivot ball
Improper fluid
Worn syncrhonizers

If your having a lot of trouble getting into Reverse as well then it sounds like your clutch isn't releasing in full. Reverse is syncrhonized on the ZF6 and it should take much effort to engage. That said, mine definetly takes more effort to get into R then it does into a foward gear.

If I was you...
I'd change the fluid in the ZF first since its a good maintenance item to take care of. I've used GM Synchromesh with good results, I'm trying Amsoil Syncrhomesh this year. Others will say to use the BMW oil. While you're under there, do yourself a favor and unplug the CAGS. You'll see a large cylinder on the drivers side of the trans with wires coming out - thats it, just unplug the connector. While you're under there inspect the slave cylinder. They don't last forever and when they leak, they sometime leak INTO the bellhousing which holds the fluid from reaching the ground (so you never even knew you had a leak!). A failed slave cylinder (or master, or the hose) will cause shifting problems.

 

tell her you could've drowned in the boat, and nobody ever drowned in a vette. then tell her it matches her eyes and you think 'bout her every time you're in it. hope this helps

 

If the transmission fluid has not been replaced recently, I would begin there.

Search for transmission fluid choices in the forum.

Also an excellent source of information on your transmission:

http://zfdoc.com/

Everything you always wanted to know about ZF transmissions, but were afraid to ask!

 

let / teach her to drive it; once she takes some of her girlfriends for a spin, there won't be anymore talk about Honda Accords.

 

if its the cags, check with any corvette aftermarket supplier, some of the later cars require a "cags eliminator" to be plugged into the wiring harness; it fools the computer into thinking that the cags unit is still operational.

 

its possible the previous owner installed the bmw oil which has caused some owners issues.

I disagree w/ zfdocs recommendationt to use the castrol bmw crap.

Caused me all kinds of issues at wot. Missed shifts. Had to abort drag runs bc shifter wouldn't move into the next gear.

When I switched back to gm syncromesh, my problems went away.

I run the hurst short throw shifter and it works great. A small amount notchier than stock but not bad at all.

 

Guys- Thanks for all the great replies. I will be changing the Trannny fluid this weekend and see how that goes. Next- i will chnge the Clutch MC, Slave and hose. I will keep posting the results. The car is great- it has the usual issues, weatherstripping, minor window adjustments needed etc.. Oh yea- the factory Bose system is struggling too.

 

Hey guys here is a quick update- I unplugged the CAGS and changed the tranny gear oil out with AMSOIL Synchromesh. The 1st to 2nd issue went away and the car did shift smoother, however, I was still having the issue getting the car into reverse. This weekend I was trying to back out of garage and I couldn't get it in reverse at all. I tried shifting into 1st, as normal so I could get it to shift into reverse and this wasn't happening either. Something odd was going on- even though I could not get it in any gear, the car would surge forward when I tried placing it in 1st and it would surge backwards when I tried placing in reverse. This told me the clutch was not fully disengaging. I turned the motor off and it shifted into every gear with ease. Time for a master cylinder, slave cylinder and fluid change. Jacked the car up, pulled the slave cylinder (easy)and master cylinder (pita) and while doing so, stripped the threads on both ends of the hydraulic line. I can't imagine someone crossthreading both ends, maybe they were galded together after 18 years !! I had the slave and master bought, but I had to order the hose from Corvette Stainless Steel Brakes for $95.00, will be here tomorrow. The old fluid in the master looked like the oil I drain out of my Dodge diesel, during an oil change.
I will follow up tomorrow......