I busted my clutch hose last fall and have been trying to get it right ever since. The car was put away for winter so I have not driven it more then a few hundred miles. I replaced the hose and clutch master and slave, and I have tried all methods of bleeding known to man. (bleed with the front raised, the back raised, level, gravity bleed, 2 person bleed, reverse bleed) My quesitons for my fellow 6 speeder are:

(1) Does your car shift as smooth when the engine is running compared to when the engine is off?

(2) Is there any "notchyness" when you shift?

(3) Do you sometimes have to pause half a second and let it skip into gear when shifting?

(4) how easily does yours slip into reverse?

Basically mine does not shift as good as when the engine is off, I have some "notchyness" and I frequently have to pause a half second in shifts to let it slip into gear. I think I still have a problem with my hydrolics, but it's been so long that I don't remember how everything is supposed to feel. Any input is appreciated.

 

When the car is off the shifter feels smooth and fluid, when it runs it goes right in as well. If your having trouble I suspect a tranny flush may help depending on how many miles are on the car. It is a possiblity that your synchros may be on the way out, there should be no "waiting" to get the car into any gear. My notchyness comes from when I installed my hurst shifter.

Hope this helps

 

Thanks Kitt, it does help. I only have 29,000 miles on the car. From your description it sounds like I still have a problem :(

 

A 91 is 12 years old.......when was the last time you changed out the fluid? My girls car was a 99 camaro with a hurst and it had 1st to 2nd gear grinding, believe it or not a simple fluid change was all it took to correct it. I would suspect that this would be a simple approach, if it doesn't work, then something bigger may be at hand, but start off with the simple stuff and work your way up. Either way no harm will be done, moving parts always dig fresh fluids anyway....... :cheers:

Kitt

 

A fluid change is on my list, I had to order a 17mm hex socket which has not arrived yet. Last I checked it was in IL, on its way to Michigan. Before my clutch hose broke last fall, I had zero problems. Ever since, I have not had a smooth shift.

 

Easy solution - use a bolt with a 17mm head and two nuts locked together - turn the inner of the two nuts - the head turns the plug - cheap & simple.

 

My 6spd is a bit notchy, so I tried to take off the fill plug with my new $50 Snap On 17mm socket and it would not budge. I can only jack the car up about a foot so space and leverage is an issue. Any tips? Does it come off clockwise or anti-clockwise? :confused: :mad
:cheers:

 

It is removed counter-clockwise, like a normal screw. These plugs are frequently VERY tight. You just have to use leverage, which can be difficult if space is an issue. I think I was able to get a pipe in there and put it over the allen wrech. If all else fails, try the big hammer method. :smash: Hit the wrech with a hammer to loosen it.

 

The plugs are a PITA. The bottom plug came out okay but the side plug I chewed up getting it out and had to buy another plug. I used a 17mm allen wrench but you'll find it's a little loose... I put a socket with a 1/2" drive extension on the end of the allen wrench to get some extra leverage.

I thought they were normal thread....clockwise to tighten but I could be wrong....I can't remember much of anything anymore..

 

Here's what to do:
First: Bleed your clutch master by simply removing the cap and moisture barrier insert and slowly pushing the clutch pedal to the floor a couple of times. (Get someone else to do it so you can watch the bubbles rise up to the top.) Make sure that the fluid level is NOT OVER OR UNDERFILLED--very, very important!

Next:
Get 5 (yes five) quarts of factory fill. (Please...no Redline or Castrol/BMW debate) Drain the current fluid and refill with the 2.2 qts (or was it liters? Use the proper amount in any case!) Run the car for a ~200 miles. Not straight highway miles, normal shifting required. Drain it AGAIN. Re-fill with proper amount, and you're good to go. You WILL notice a positive difference.


[Modified by h rocks, 1:41 PM 4/24/2003]

 

I found bleeding my system to be VERY easy. I seem to be the only one. The first time I tried, no matter what I did my clutch pedal sucked and no air seemed to be coming out. I pulled the master cylinder back off the car and bench bled it with a fluid pump. I had some screw-in nipples from an old brake master bleeder kit. I screwed it into the brake fitting, and hooked it up to my bleeder pump. I pushed fluid up through that brake fitting until the reservoir was half full. I capped it, and reinstalled the master. Right away my pedal felt perfect. I bled the system a bunch more times and still didn't get any air. Although I still have grinding problems with downshifts into 2nd and 1st gear, all other gears are silky smooth, even reverse.

But, in general I don't think the ZF is a smooth transmission. None of the ZF cars I've driven were as smooth as the T5 and T56 cars I've driven. They are truck transmissions, and they shift like it. But, yours still sounds like it's got a LONG way to go.

 

Is it the same gear all of the time that you have trouble shifting into? Mine won't always go into third gear right away, and sometimes (but rarely) it will even pop out of third and into neutral. Since it is always the same gear that I have a problem with, it leads me to believe that I have a synchro going out.

 

FYI....I'm going through replacing the synchros now because of trouble getting into 1st and reverse gears.

I'm sending my tranny to:

standardtransmission.com

(approximate prices)
$690 for synchro kit
$400 for labor

GM dealer $650 to remove and re-install transmission

Shipping $????

I'll keep anyone posted if you want to know the progress.....

 

Standard Transmission's prices seem to be SUBSTANTIALLY lower than ZFDoc. He quoted me at a bare minimum of $1800 for a rebuild, and I would consider the minimum rebuild to include all new synchros. Standard seems to be just a little more than half the price. I'd be real interrested in getting feedback from you to see how satisfied you are with them.

What really intrigues me is the $400 for labor. That tells me that the rebuild isn't much more time consuming than any other manual trans. I can't get a straight answer from anybody as to why the ZF is like a voo doo trick that nobody can figure out.

 

Hey KC I'm very interested in your tranny results. Mine's okay for now, but you know how these things can surface. You always need a good tranny guy in the wings, especially with this ZF. Keep us informed. :cheers:

:flag :flag :flag

 

I found a local guy who did a ZF last week...he got one from a poor guy who took his Vette to AAMCO and they tried to fix it but couldn't get it back together. This guy spent two days getting the tranny put back together, which doesn't sound too bad. However, Standard Transmission told me two days to complete it...this guy spent two days just putting it back together. He asked what the problem was with mine and I said worn synchros and he said oh sh$$ and said he'd pass on working on it. I wasn't about to let a local guy work on it anyway but a buddy of mine knew him and called him for me.

I'd have to say the ZF must be so tight on tolerances and working space that they must be a real PITA to work on. I once read a note that someone had to cool and heat certain parts to get them back in. Don't know if that's true or not...

 

My ZF shifts smoothly, no waiting to get into gear. Your problem may not be a sychro or hydraulics, maybe you have a clutch disk or PP problem?

As for that pesky 17mm plug...Yes, I had a real fun time getting mine out also. My bottom one came right out, the side one was a different story. Make sure you use a good 17mm 1/2 drive allen socket. I got mine out by using a little heat on the plug (propare torch only). Don't use too much heat or you'll destroy the case. It takes quite a bit of torque to break it free. When I put it back in I used an anti-seize compound and torqued to 15-20 ft.lbs...someday I'm sure I'll want it out again. Also, it's just a standard right-hand thread.

 

Well, I put my old slave in just to see if it made a difference. Things got much worse. Could not get the clutch to release at all. So I pulled the slave again to make sure it was seated properly. When I got it back together and bleed, I attempted to start the car. Pressed in the clutch and "oh no" the clutch pressed hard and stuck to the floor. I pulled the slave again and found out I did not have the pin seated right in the fork. I had to really work to get the pin unstuck from being pressing between the fork and the housing. I put the new slave back in, bleed the system again. Just trying to start the car with the clutch in made the car move forward. I bleed the system and still had the same problem. I think the problem is with my new master (quite a bit of play now) and I am going to pull it this weekend and inspect it. I will also try bench bleed it before putting it back on.

My clutch start switch also stopped working, not sure if I bent the clutch pedal again pressing too hard or not. :bb So I used a paper clip to jump the connection and get the car started so I could get it parked for the night.

Hopefully my 17mm allen socket will arrive this weekend and I can do the trans oil change too.

sometimes I miss my automatic :(

 

If you didn't bench bleed the master, I highly reccomend you do. I installed it without bench bleeding it and I couldn't get ANY pedal.

When I did bench bleed it, I spent an hour trying to do it the half-assed way with the tube wrapped around back into the reservoir. All I did was suck all kinds of air. Like I said above (I think this is the same thread :lol: ), I used the vacuum pump to push the fluid up from the bottom and that made a world of difference.

 

For mine, I use a Big 17MM allen wrench ( Which I believe they carry at Sears - I got mine years ago for my '74 VW bug at an auto parts store). I use the allen key and also a 17MM open-end wrench on the allen key itself so that I can pull and push at the same time. Seems to be better when working under the car on stands and seems more stable as well (less likely to get cocked at and angle ans slip & strip).