Changing clutch – can I do this myself?

[ghlkal]

I’ve been reading through the FSM and posts here and on CF. Is it possible for a below-average shade-tree mechanic like me to do this job?

(The last time I replaced a clutch was 30 years ago on a 1973 Vega [remember those?]. I was younger then and had more free time)

I know I work slowly too (I read posts about changing L98 injectors in 30 minutes – it took me a lot longer to do that job.) I’ve read that Bill B (ZFdoc) can drop the tranny in 15 minutes. I’m worried that it will take me 2 hours just to drop the exhaust. I am really hoping to take the Z to Bloomington Gold. I’m working overtime in the summer so I could only devote a couple hours a day to this project.

What I really need is a helpful group like FBI or WAZOO nearby :-)

A local Corvette specialty shop quoted me $1250 for the job. Based upon past experience, I need to add 50% to that quote. I don’t want to drop $2K right now.

So, is this a job I should tackle, or will I screw it up and have to take it to a shop anyway?

Gary

[tccrab]

You can easily do this job at home, but I'd highly recommend that you have help.
The ZF is HEAVY!!
I did mine a couple of years ago with the help of my brother in law.
Removing the C-Beam is a bit tricky, I highly recommend Bill B.'s C-Beam plates for the re-install.

'Crabs

[USAFPILOT]

I helped Rhipser do it once...pretty straight forward, but the trans is heavy when laying on your back under a car on jackstands. People with a lift and transmission jack will have an easier time.

[Kevin]

the zf is just damned heavy! i can remember helping pete load one into someones truck at carlisle a few years ago. damn heavy thing

[LGAFF]

What part of WI are you in? I did mine on my own, the ZF weighs about 150-160lbs not so much heavy as the shape and surface make is hard to maneuver.

Might check with Pete to see if he has time to do it...I would think he would be cheaper than a dealer

[Paul Workman]

Dittos on the beam plates.

As for parts, the Veleo is no longer being made. However, the LT1/4 PP will work, if you even need one (recommended). Shorter PP bolt are needed is all.

Good time to flush the clutch, while you have the slave out.

If you can't find an OE clutch, call Pat at Ram Clutch. He has worked up a single or a dual disc clutch for the ZR-1; a conversion to a push type PP using a hyhydraulic TO bearing. Really nice stuff!

P.

[rhipsher]

Been there done that three times on my 90. Once by myself. And twice with the help of a friend. It's not a small job. But any shade tree mechanic can do it. There's some really good choices when it comes to clutches. Spec,Centerforce,Carolina,Mcleod,Ram ect.
http://i301.photobucket.com/albums/nn63/keeno1970/Clutchjob021.jpg
http://i301.photobucket.com/albums/nn63/keeno1970/Clutchjob028.jpg

[USAFPILOT]

that picture still cracks me up

[VetteMed]

I did it myself, the ZF is cumbersome, but nothing that a hydraulic floor jack can't help with. the key is getting the car high enough in the air to get the jack & trans under the car.

BTW, I have a NOS LT1 pressure plate, never used, if you need.

[rhipsher]

I did it myself, the ZF is cumbersome, but nothing that a hydraulic floor jack can't help with. the key is getting the car high enough in the air to get the jack & trans under the car.

BTW, I have a NOS LT1 pressure plate, never used, if you need. Yep! Get it as high as your jack stands will go. Once you get it out you'll still have to lay it on its side and drag it out from under the car.
http://i301.photobucket.com/albums/nn63/keeno1970/Clutchjob018.jpg

[Paul Workman]

Yep! Get it as high as your jack stands will go. Once you get it out you'll still have to lay it on its side and drag it out from under the car.
http://i301.photobucket.com/albums/nn63/keeno1970/Clutchjob018.jpg

Well, actually, working off jack stands, and ONLY working on the clutch, the ZF doesn't have to come out from under the car. I balance it on the cup of my plain ol floor jack, pull it out of the clutch, lower it, then let it down and roll it back and park it back out of the way in the tunnel area. Ya don't have to jack the car up quite so high, unless you just want to.

Good point about the Castrol TWS 10W-60 (synthetic that you get from the BMW dealer) and change the trans fluid too, while yer there. (Already mentioned changing the clutch fluid - easy when the slave is outta there too!)

P.

[ghlkal]

Wow, thanks for all the feedback, suggestions, and encouragement.

For my use, a stock spec clutch is fine. I found a Valeo kit on eBay - thoughts?

I've read good things about the C frame plates.

IIRC, it makes sense to try to open the tranny plugs while the tranny is still connected to drain and fill, right?

I don't see any oil throught the inspection plate, so I assume my rear main is holding OK.

Will the clutch housing drop down past the cats? I assume I just drop the exhaust past the cats.

It looks "interesting" to reach the T50 bolts on top of the tranny. Should I invest in a better quality torx bit for those?

What part of WI are you in?

I'm in Fredonia which is about 40 minutes north of Milwaukee (I'm between Milwaukee and Road America :))

a PM step by step for Transmission and clutch removal

Thanks Cliff

[VetteMed]

While the trans to bellhousing bolts do indeed have a torx pattern on them, a hex socket works fine on the outside of the bolts. I don't remember the size (15 or 16 mm perhaps), but I did not need to use a torx bit on them.

Definitely drain the oil before dropping the trans, otherwise it will all pour out the tailshaft as you lower it. Similarly, don't refill until it's back in position, bolted in.

Andrew

[LGAFF]

I bought a trans tailhousing plug from Autozone and it did not spill a drop...

[VetteMed]

I bought a trans tailhousing plug from Autozone and it did not spill a drop...

Also an option, especially if fresh fluid is in the trans. My luck, though, the plug would have fallen out while my face was under the tailhousing.

[rhipsher]

Pauls correct. You don't have to take the trans out from under the car. Just shove it to the back of the car. I pulled mine all the way out the first time because I wanted to clean it up.

[Bob Eyres]

IMHO, if you have less than 50K mi. on the car, you probably don't have to replace the pressure plate, only the disc.
But, if you do replace the whole assembly, make sure you get the correct year throw out bearing. They are incompatible.

[VetteMed]

IMHO, if you have less than 50K mi. on the car, you probably don't have to replace the pressure plate, only the disc.
But, if you do replace the whole assembly, make sure you get the correct year throw out bearing. They are incompatible.

Well, yes, the black tag (early) and blue tag (late) ZF used a different diameter input shaft sleeve, so the blue tag cars had a plastic sleeve pressed into the center of the release bearing. This plastic sleeve can be removed to make it usable in a black tag situation.

[Paul Workman]

OH!

Forgot to mention it before, but before you disconnect the drive shaft from the differential, mark the shaft and the yoke on the diff or you might reinstal it 180º from where it was, and likely cause vibration or "buzzing" at high(er) speed...Ain't dat right Lee?;) (And, for future, if you ever replace the U joints, same marking goes for the transmission end of the driveshaft too!)

Remove the MAP and fuel pressure regulator from the back of the plenum, or you might pinch them between the plenum and the firewall when tilting the motor to pull the trans. Good time to clean up the grounds too, since they're right there and easy to get to once the bell housing is off.

No time like the present to change to an aluminum FW too, but I digress...
And, another thing not mentioned yet: A bottle jack is needed along with the floor jack. You use it to support the engine when pulling the trans and reinstalling it too, and when aligning the C-beam after wards (before the bolts are tightened at either end) the tail of the trans (via the C-beam reference) needs to be approx 1" from the side of the beam to the tunnel, and approx 1-3/4" from the "roof", ± 1/4".

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/C-beamspacing.jpg

Hmmm.... Do I sense someone about to write up a checklist for the Registry newsletter??? HMMMMM????;)

P.

[ghlkal]

Keep these great tips coming! =D>

Now, will the clutch housing drop down past the cats? I assume I just drop the exhaust past the cats (I don't want to pull the exhaust manifolds too)

[rhipsher]

The cats won't be in the way. Just drop the exhaust. The C beam will be your biggest obstacle. Once you've unbolted it you'll need a rubber mallet to tap it back out of the way to free your transmission so it can drop.

[ghlkal]

last question (maybe ;))

Thoughts on this valeo clutch kit

http://www.ebay.com/itm/170622935008?_trksid=p5197.c0.m619#ht_2141wt_807

("fits" ZR-1 ... was this the original clutch?)

[VetteMed]

clutch disc may be correct, but pressure plate isn't quite correct, it's usable, with longer bolts. Not a bad option for the price.

[cvette98pacecar]

OH!

Forgot to mention it before, but before you disconnect the drive shaft from the differential, mark the shaft and the yoke on the diff or you might reinstal it 180º from where it was, and likely cause vibration or "buzzing" at high(er) speed...Ain't dat right Lee?;) (And, for future, if you ever replace the U joints, same marking goes for the transmission end of the driveshaft too!)

Remove the MAP and fuel pressure regulator from the back of the plenum, or you might pinch them between the plenum and the firewall when tilting the motor to pull the trans. Good time to clean up the grounds too, since they're right there and easy to get to once the bell housing is off.

No time like the present to change to an aluminum FW too, but I digress...
And, another thing not mentioned yet: A bottle jack is needed along with the floor jack. You use it to support the engine when pulling the trans and reinstalling it too, and when aligning the C-beam after wards (before the bolts are tightened at either end) the tail of the trans (via the C-beam reference) needs to be approx 1" from the side of the beam to the tunnel, and approx 1-3/4" from the "roof", ± 1/4".

http://i185.photobucket.com/albums/x220/6PPC_bucket/tech%20files/C-beamspacing.jpg

Hmmm.... Do I sense someone about to write up a checklist for the Registry newsletter??? HMMMMM????;)

P.

Paul, I ordered Bill B. Beam plates for the ruby are those dimension the same when installing Beam plates?

[VetteMed]

When you order the Beam Plates, Bill includes 2 pieces of steel that are used as gauges for approximating the correct distances as referenced in Paul's post.

[Paul Workman]

Paul, I ordered Bill B. Beam plates for the ruby are those dimension the same when installing Beam plates?

Yes. Be sure to mesure (using the two metal jigs) between the beam itself & the tunnel, not between the beam plate and the tunnel.

P.

[scottfab]

I would not put it up on jack stands as high as they'll go.
I've done this several times using both these ways.
If you can bench 160lb or so......
Get it just high enough that you can comfortably bench press the 149lb ZF6 up OR us a regular floor jack. Just balance the ZF6 on it as you jack it up. Use 6in bolts (two) with the heads cut off at the top of the bell housing to guide the ZF6 on and off. I put on at 10 o'clock an the onther at 2 oclock.

Beam plates? Yah I supose if you have time but if you're focusing on one thing at a time (clutch) you can skip it.
Pilot bearing and throw out bearing? Absolutely.
Drain ZF6? Yah if you haven't service the ZF6 recently and it's old oil.
I've just put a plastic bag over the end with good results.
I use the GM standard 10W30 oil in it.

Careful taking the rubber boot off the shifter. It can tear.
Get a spline alignment tool for the clutch plate. With practice you can slide the ZF6 on without it but as a first timer I'd get one.
The pilot bearing takes a special tool to get out or you can fabricate one as I did.
Let's see, I think that's about it. The usual inspection of the pressure plate and flywheel is necessary. Resurfacing the fly wheel is no big deal to have done but the pressure plate can be problematic as it has a slight concave surface form the factory.

In cast the above was not clear. Get yourself two long 6in bolts that match the thread of the bolts that hold the ZF6 to the bell housing. Cut the heads off and grind a slot where the heads were. This is for a flat blade screw driver should they get in too tight. With these sticking out of the bell housing you can keep the weight of the ZF6 off the shaft AND keep control over it as you slide it off (and on).

Be prepared for the bolts on the C beam. If they've not been off in a while they can be TIGHT.
As is common practice mark the drive shaft to get in on the same way both at the rear and front.
Inspect the slave cyl for leaks. Replace if necessary. Lots can be said about this but not now.

Once done you will have had one hell of a work out. :)
Good luck.

[rhipsher]

I strongly suggest installing the beam plates. And I think most here would agree. Unless you have small hands the size of a 6 year old you will save youself allot of time and trouble not only trying to menuver both the nuts up in there but menuvering an 18MM wrench up in that tight space and getting enough leverage on it to tighten them. Sorry Scott I totally disagree with skipping it.

[VetteMed]

I strongly suggest installing the beam plates. And I think most here would agree. Unless you have small hands the size of a 6 year old you will save youself allot of time and trouble not only trying to menuver both the nuts up in there but menuvering an 18MM wrench up in that tight space and getting enough leverage on it to tighten them. Sorry Scott I totally disagree with skipping it.

Agree 100%

[Paul Workman]

I strongly suggest installing the beam plates. And I think most here would agree. Unless you have small hands the size of a 6 year old you will save youself allot of time and trouble not only trying to menuver both the nuts up in there but menuvering an 18MM wrench up in that tight space and getting enough leverage on it to tighten them. Sorry Scott I totally disagree with skipping it.

Me 2!

ghlkal...

1) Just taking the bolts out of the beam for the first time will convince you "there must be a better way". Even with average size hands it is a bitch trying to get in there, especially to reinstal - keeping the washer from sliding to the side while trying to get the nut over the hole AND screwing the bolt in when you can't put your fingers on the nut cuz they're too big to fit... Worth every friggin penny if for no other reason than to ease removal and reistalling the beam, IMO. And, you don't use the washers with the plates as the plates now serve the purpose and then some. (I haven't tried it yet, but I don't see why one couldn't smear some (blue) Locktite under the plates so that they would remain in place next time the beam had to come off, for any reason. Hmmm.... Have to think about that some...;))

2) In fact the plates were designed to address the problem of slippage and squirming at the beam joints, resulting in the rear end wanting to kick out under WOT. The first time I pulled the beam off my Z I noticed the holes in the beam at the differential were oval - indicating the joint had been shuttling back and forth a bit. (I haven't experienced the rear kicking out with the plates in place, FWIW.)

P.

[scottfab]

I strongly suggest installing the beam plates. And I think most here would agree. Unless you have small hands the size of a 6 year old you will save youself allot of time and trouble not only trying to menuver both the nuts up in there but menuvering an 18MM wrench up in that tight space and getting enough leverage on it to tighten them. Sorry Scott I totally disagree with skipping it.

I guess I've just never had much problem with getting each nut back on. I takes very little coordination to slide the nut one at a time up there and hold it there between your index and middle finger then push the bolt up to engage it. As far as getting a 18mm wrench up there, what for? A crescent wrench is shorter and works fine. So I guess it comes down to how much $ you think holding 4 nuts in place is worth. As for the other reported benefits, I think if I spent that kind of $ on it I'd say they were wonderful too.
;)
On the other hand if you have the time to wait for the order to come in and you think you'll be tearing the C beam out a lot, go for it. You can list it as on of the performance improvements you made to the car.

[scottfab]

2) In fact the plates were designed to address the problem of slippage and squirming at the beam joints, resulting in the rear end wanting to kick out under WOT. The first time I pulled the beam off my Z I noticed the holes in the beam at the differential were oval - indicating the joint had been shuttling back and forth a bit. (I haven't experienced the rear kicking out with the plates in place, FWIW.)

P.

This is called "Torque steer" and it is a combination of frame movement and C beam twist. It can be aggravated by loose C beam fasteners. To my knowledge no one has measured this effect with or without these magic plates. But there is lots of anecdotal evidence they improve torque steer and improve mileage. There is still some slop in the C beam holes and the bolt even with the plates.
The best overall reason to buy beam plates is if you just can't hold the hardware on top of the C beam and you think your work may need to be redone soon.

[Paul Workman]

This is called "Torque steer" and it is a combination of frame movement and C beam twist. It can be aggravated by loose C beam fasteners. To my knowledge no one has measured this effect with or without these magic plates. But there is lots of anecdotal evidence they improve torque steer and improve mileage. There is still some slop in the C beam holes and the bolt even with the plates.
The best overall reason to buy beam plates is if you just can't hold the hardware on top of the C beam and you think your work may need to be redone soon.

Really???? I'm throwing down the guantlet here...;)

A few things you said here raises some flags:

"This is called "Torque steer"...To my knowledge no one has measured this effect with or without these magic plates...There is still some slop in the C beam holes and the bolt even with the plates." Those statements seem to be in conflict. No one has measured...still some slop...'magic plates'"?? If no one has measured, how do we know there's still some slop??:icon_scra

To the best of your knowledge no one has objective data on the effect of the beam plates as it relates to steering stability, YET there is objective data to show movement remains in spite of the plates??

And your referral to them as "magic plates" suggests (to me) either some subjectivity or perhaps some specific (untold) knowledge allowing you to scoff at the plates? If there is a objective source, please enlighten us!

In the mean time, I suppose the debate on their effectiveness is open. Pete said he doesn't use them, and we've seen him lauch as hard as anyone. But, after installing the plates the lateral "kick" I experienced on my Z was gone.

Was the improvement on my car due to the plates, or simply re-torquing the bolts??...I dunno. But, I will say this: In my experience with the C beam removal and reinstallation (especially) without the plates it was such a mo-fo PIA!! The first time I installed the "magic plates" (your words) they completely transformed the entire chore of removing and reinstalling the C beam to the point of not even having to give it a second thought! If you try them, especially if your hands are average to large, you might change your mind. "Magic plates"? You might be right about them - at least in some regard!

:cheers:

P.

[scottfab]

To the best of your knowledge no one has objective data on the effect of the beam plates as it relates to steering stability, YET there is objective data to show movement remains in spite of the plates??

Not sure I follow. Objective data to me means (as Hib would say) a quantifiable measurement. e.g. 1.5 deg of negative camber on the RF is reduced to 0.5 deg.

And your referral to them as "magic plates" suggests (to me) either some subjectivity or perhaps some specific (untold) knowledge allowing you to scoff at the plates? If there is a objective source, please enlighten us!

Not at all. I know of no one that has spent the $ that is willing to come forward and say there was no difference in torque steer. (believe me that is what it's called) . Just as with turn of the century elixirs that were sold to "fix what ails you" the proof goes the other way to wit. Proof that it does not work to cure all ills is impossible. Proof that it cures something specific should be possible. I await any such measurement.

In the mean time, I suppose the debate on their effectiveness is open. Pete said he doesn't use them, and we've seen him lauch as hard as anyone. But, after installing the plates the lateral "kick" I experienced on my Z was gone.

I do not doubt you feel some difference. I felt a difference too when I reinstalled my C beam and tightened the bolts good. and tight.

Was the improvement on my car due to the plates, or simply re-torquing the bolts??...I dunno. But, I will say this: In my experience with the C beam removal and reinstallation (especially) without the plates it was such a mo-fo PIA!! The first time I installed the "magic plates" (your words) they completely transformed the entire chore of removing and reinstalling the C beam to the point of not even having to give it a second thought! If you try them, especially if your hands are average to large, you might change your mind. "Magic plates"? You might be right about them - at least in some regard!

This I don't doubt either. I have no doubt at all that these plates make this task easier. How much easier is completely subjective. I worked out a sequence (after the third time) that works like a well choreographed dance. It's like removing and reinstalling the fuel pumps. Once you work out the dance it's no big deal. Then if you describe the dance to someone they can do it too.

P.

[rhipsher]

Aman to that Paul. Not only does the simple design eliminate the nuts but the added thickness of the SS plats give you more beef and strength to prevent the cbeam holes from wallering out. Aluminum is pretty soft stuff. Before installing the plates my car would kick out to the right. The drag strip christmas tree operator looked worried as my car would come right toward him until i straightened out. Not anymore. The car goes straight. Im able to powerslide the car around any corner an controle where it goes.
http://i301.photobucket.com/albums/nn63/keeno1970/Shreadthevreds.jpg

[rhipsher]

Always happy to display the added benefits of the beam plates.:)

[tf95ZR1]

Do NOT over-tighten the "C" beam bolts,
plates or not (I have them) especially by the transmission.
Ask me how I know...

[scottfab]

Gary
whether you put the magic plates in or not, do focus on those things
that really matter like your clutch plate and surfaces AND the
rear bolts on the bell housing. It was touched on in this thread
but needs more info shared .
Two of the rear bolts are grounding points for various things on the car.
You should clean the bell housing surface and the grounding lugs then apply dielectric grease to them before reinstalling the bolts.
This won't improve your gas mileage or times at the drag strip but will keep you from having to go back in and deal with it later.
When there are grounding problems there the symptoms are wildly unexpected and varied from car to car. No fun.

Later if you really want to improve things that mover around under WOT there is a really good thread going on stiffening the frame to avoid torque steer here.
http://zr1.net/forum/showthread.php?t=17491

[ghlkal]

Thanks to everyone for their helpful suggestions :cheers:

I've made a list to keep track of it all.

I contacted Pete and he's agreed to change the clutch at a great price and he'll even let me help :) We plan on doing this in a week or so.

I'm not sure why I'm hesitant about doing this myself - I guess it's because it's the first major job on my "new" Z and I don't want to screw up and take 3 weeks. I've really learned a lot between your posts and talking with Bill Boudreau and Jim Jandik.

[LGAFF]

It will be 100 times easier on a lft and 2 hands woulds really help, plus Pete is a pro and it will be a great experience