ZF 6 Sp question

[G Winter]

Has anyone here had any experience with ZF problems?
Mine sounds like it goes part way in gear or not all the way out. Shifter feels just a little spongy is the easiest way to describe it. Are there any known problems with the shift linkage or the forks ?

Glenn

 

[Itshakes]

ZF-6 speed

I just changed the fluid in mine. It made a BIG difference in the shift quality. Use the GM fluid--expensive, but it works!!

 

[Hib Halverson]

Can you describe that sound a little better? Does the trans grind as you let the clutch out. After you move the gear shift?

As for the linkage, all C4 shifters have a rubber coupler which is beneath the shift boots. There will always be a slight "spongy" feel to the shifter.

Lastly, before you decide there is a problem with your six-speed, make sure you clutch and clutch hydralulics are working properly. Any air in that system, will cause shift probelms.

 

[G Winter]

I made a call to the ZF Doc. Bill Boudreau. Told him my problem and he is pretty sure I have reverse gear seizure.
Not very common but does happen on a certain percentage of 6 speeds.Seems the oil passages are not always as clear as they should be. Could have figured it would be me to have one.
Repair cost for parts, $450 to $800 depending on weather or not the shaft needs to be replaced. He will sell me a blueprinted refurbished for about $1600.
Anyone have a good use ZF to sell ?

Glenn

 

[92BlackVette]

ZF doc I heard is elite. If your hard up for cash check ebay, they have blue labels for around a G.

 

[G Winter]

About $1400 on ebay for new. This is going to bite anyway I
look at it.

Glenn

 

[G Winter]

Hib, the problem isn't going in, it is after clutch is released.
A nasty gear groan, which according to the ZF doc is the bearing in the reverse gear.

Glenn

 

[LT4man]

Glenn, what type of oil are you using in your trans? When did you last change it?

I change mine every 15-20,000 miles since it was new. I am using the BMW Castrol 10W60 oil in it now. Have used it for two (2) oil changes.

Shifts like butter. Never miss a shift. Well, almost never!

An oil change at this time might save your trans. Just my humble opinion.

AFTER CHANGING YOUR TRANS FLUID, BE SURE TO SAVE THE !

 

[ScottNoxid]

Glenn, what type of oil are you using in your trans? When did you last change it?

I change mine every 15-20,000 miles since it was new. I am using the BMW Castrol 10W60 oil in it now. Have used it for two (2) oil changes.

Shifts like butter. Never miss a shift. Well, almost never!

An oil change at this time might save your trans. Just my humble opinion.

AFTER CHANGING YOUR TRANS FLUID, BE SURE TO SAVE THE !

Greg, does that go for all 6 speeds, or just the C-4s. My C-5 shifts excellent, but could I use this oil in mine also? I am always looking for a little edge. Good to see you in business again you know when LT4man talks everone listens! JMOP.................
SC:WTT

While I am listening to LT4man I will

 

[gmjunkie]

Greg, does that go for all 6 speeds, or just the C-4s. My C-5 shifts excellent, but could I use this oil in mine also?

No,Yours uses ATF Dextron III or better!!
Mine shifts slick too,if it ain't broke I ain't fix'n it!

 

[ScottNoxid]

No,Yours uses ATF Dextron III or better!!
Mine shifts slick too,if it ain't broke I ain't fix'n it!

Thanks Junk, I agree with your if it ain't broke don't fix it. SC:WTT

 

[LT4man]

Greg, does that go for all 6 speeds, or just the C-4s. My C-5 shifts excellent, but could I use this oil in mine also? I am always looking for a little edge.SC:WTT

While I am listening to LT4man I will

My recommendation comes from Bill Boudreau, commonly referred to as "zf doc" and only pertains to ZF six-speed transmissions in C4s. Sorry, Scotty, but you would have to purchase another C4 to use this tip!

BTW, Bill's company is called ZR51 Performance and is located in Cave Creek, Arizona. He also works on the T-56 6 spd trans which is in your C5. Good man to use if you really put some hurt on your trans!

PLEASE DO NOT FORGET TO SAVE THE !

 

[G Winter]

Glenn, what type of oil are you using in your trans? When did you last change it?

I change mine every 15-20,000 miles since it was new. I am using the BMW Castrol 10W60 oil in it now. Have used it for two (2) oil changes.

Shifts like butter. Never miss a shift. Well, almost never!

An oil change at this time might save your trans. Just my humble opinion.

AFTER CHANGING YOUR TRANS FLUID, BE SURE TO SAVE THE !

I have Mobil 1 10-30 in mine due to availability at the time I put it in. I asked if that was a problem with bearings and shafts in the trans. Bill said it would have no ill effects on anything other than the syncros. He said they will glaze over because the Mobil 1 is to slippery. He said the oil is not the cause of my problem.
I have to take the rectangle cover off the drivers side and remove the reverse idler gear to check the reverse gear. Bill said rotating the gear with a finger you can feel if it is rough. Will get it up in the air and check it tonight or tomorrow afternoon. He sounded pretty confident that this is the problem. It can be repaired without transmission removal.
Is going to be a difficult decision on what route to go.:ugh

Glenn

 

[Hib Halverson]

Hib, the problem isn't going in, it is after clutch is released.
A nasty gear groan, which according to the ZF doc is the bearing in the reverse gear.

Glenn

Sorry.
I misunderstood your post as far as what the noise was. If it moans once you're in gear, I'd agree that a problem with reverse is probable.


Bill the the go-to-guy for ZFs. He does my ZF S6-40 work, when I need it.

 

[G Winter]

I talked to the ZF Doc again... I checked my reverse gear, not the problem. Turns out I caused my problem.
I put grease on the pilot bearing. Not good it drys out and causes wear on the pilot bushing. Looks like I will be replacing the pilot bushing.ad
At least it is a cheap fix.:cool

Glenn

 

[G Winter]

Update time. I had a few other things to take care of first like granddaughter's birthday.
I replaced the pilot bushing with a needle bearing style.I am not the fastest in the world took 6 1/2 hrs to get it back together. After about 40 miles all seems well.
There was even a buildup of brass on the transmission input shaft. A little emery paper took care of that.
Hope I don't have to pull the clutch again,really don't want to get to good at it.

A lesson learned, no grease on a bronze pilot bushing. Guess I am just a little to old school.

Glenn

 

[LT4man]

Hey, Glenn, buddy!

Don't be so hard on yourself. If you were doing these clutches all the time, that would be another story.

Clutch work is more complicated than a lot of folks realize. More than just removing and replacing parts.

Congratulations on getting this done!

Do you have any tips about the C-beam you would care to share? That is one item which gives a lot of trouble to some folks.

WHILE TEST DRIVING YOUR NEW GREASE-LESS PILOT BUSHING, DON'T FORGET TO SAVE THE !

 

[G Winter]

Hey, Glenn, buddy!

Don't be so hard on yourself. If you were doing these clutches all the time, that would be another story.

Clutch work is more complicated than a lot of folks realize. More than just removing and replacing parts.

Congratulations on getting this done!

Do you have any tips about the C-beam you would care to share? That is one item which gives a lot of trouble to some folks.

WHILE TEST DRIVING YOUR NEW GREASE-LESS PILOT BUSHING, DON'T FORGET TO SAVE THE !

The nuts on the C beam bolts are a real pain I used open end wrenches for that. I think someone offers some plates to assist this when you reassemble. I thought about making some but my knuckles were already damaged.The FSM calls for a sealant on the contact surfaces. If the OEM sealent was used it is hard and the beam does stick in place pretty tight. I use RTV the last time and had no issues with the cracking and popping that is talked about.
The first time I did this I completely removed the C beam.
This time I simply moved the back slightly to the drivers side, and the front a little to the passenger side.Then use a bar on an appropriate point on the transmission and the diff. You need to be selective here so you don't damage anything.I was able to move it back just far enough to clear the tail shaft.
I can't say I had any real issue getting the beam lined up and the bolts in.I think the FSM does say something about 1 3/8 in between beam and tunnel.Might be a good reference point for transmission position.
Be sure not to forget to install the drive shaft before moving the C beam into place
The first time I had the transmission tied tight on a transmission jack. This was a little to rigid and made sliding it back in a little difficult . This time I just used side guides to keep it a little steady.This way I was able to move it around freely. If you plan to use a floor jack to lift the transmission in place you should have two people and-or a bracket made for the jack to steady the trans.
After you have the transmission bolted in, loosen the fill plug. Much easier when it is still down and no exhaust in the way.
I am thinking of searching for a fill plug with a nut on it or weld a nut on the plug I have. Seems that no matter how recently the plug has been out , it comes out hard.
Hope this helps someone in the future. Any questions I can help with just contact me. I can say,,, been there done that.

Glenn

In this area everybody waves in corvettes they just wave a little harder.

PS headed out to a 500 t0 700 corvette gathering.
http://www.siouxfallsevents.com/eventDetails.CFM?EventID=171
http://www.blackhillscorvetteclassic.com/