4+3 throw out bearing
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
4+3 throw out bearing
My 84 had the clutch replaced by the previous owner about 20K miles ago and now the total miles are 84K.
The throw out bearing needs replacement and I am trying to decide if I should replace the clutch and pressure plate again at the same time?
How long should it take to change the clutch doing it the first time?
The last clutch I did was about 8 years ago in an 84 Fiero which, after doing some research, I ended up pulling the transmision through the DS wheel well -after dropping one side of the cradle and pulling out the strut assembly etc.
Looking at my Corvette shop manual, it looks like you have to pull out quite a bit of stuff, exhaust system, the center bar thing and a bunch of other stuff -not like getting to the clutch in my 79 Z28!
Should I plan on one day or two?
I'll be doing this on jack stands in my garage -how high do I need to get the car off of the ground?
The throw out bearing needs replacement and I am trying to decide if I should replace the clutch and pressure plate again at the same time?
How long should it take to change the clutch doing it the first time?
The last clutch I did was about 8 years ago in an 84 Fiero which, after doing some research, I ended up pulling the transmision through the DS wheel well -after dropping one side of the cradle and pulling out the strut assembly etc.
Looking at my Corvette shop manual, it looks like you have to pull out quite a bit of stuff, exhaust system, the center bar thing and a bunch of other stuff -not like getting to the clutch in my 79 Z28!
Should I plan on one day or two?
I'll be doing this on jack stands in my garage -how high do I need to get the car off of the ground?
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
You can do the work on jack stands, but it would be a lot easier if the car was on a hoist. In any event, you should get the car up at least 24 inches off the ground and 30" would be better.
As you have seen, there is no tranny crossmember so you need a way to support the engine so it doesn't drop down too far once the C-beam (the center bar thing) and trans is removed. The distributor is pretty close to the firewall and you need to watch that clearance.
The trans assembly is going to be heavier than a typical 4-speed as the OD unit is part of the assembly. Don't try to remove the OD from the trans.
Once the trans is out, it won't take too long to remove the bellhousing; it's like any other SBC. You can easily remove the pressure plate and disc to inspect it and see if there is enough wear to warrant a replacement. You should also check the surface of the flywheel; if the prior owner didn't resurface the face, it might be time to do it now. If you don't know what the brand or quality of clutch and pressure plate was that got installed and you want something for performance use, then it would be a good time to oick up the assembly you would like to have.
As you have seen, there is no tranny crossmember so you need a way to support the engine so it doesn't drop down too far once the C-beam (the center bar thing) and trans is removed. The distributor is pretty close to the firewall and you need to watch that clearance.
The trans assembly is going to be heavier than a typical 4-speed as the OD unit is part of the assembly. Don't try to remove the OD from the trans.
Once the trans is out, it won't take too long to remove the bellhousing; it's like any other SBC. You can easily remove the pressure plate and disc to inspect it and see if there is enough wear to warrant a replacement. You should also check the surface of the flywheel; if the prior owner didn't resurface the face, it might be time to do it now. If you don't know what the brand or quality of clutch and pressure plate was that got installed and you want something for performance use, then it would be a good time to oick up the assembly you would like to have.
Team Owner
Joined: Jan 2003
Posts: 20,324
Likes: 250
From: Summerland B.C. Canada
I had mine up 18" to the frame rails, worked fine. You might want to make a jack adapter, to handle the trans. Here is a few pics of one I made, simple and effective.
http://members.shaw.ca/agent86/4+3%20Jack%20Adapter/
http://members.shaw.ca/agent86/4+3%20Jack%20Adapter/
Pro
Joined: Oct 1999
Posts: 515
Likes: 0
From: Nashua NH
it would be a huge remorseful headache if you just changed the TOB and 3000 miles later you need to do the clutch/pressure plate...I'd do the whole thing while I had the tranny out. I've done mine on jack stands...its no fun, but can be done. Take the dist. cap off so you don't break it when you pull the trans out... and dont forget the pilot bushing!
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
Thanks,
Glen
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
I had mine up 18" to the frame rails, worked fine. You might want to make a jack adapter, to handle the trans. Here is a few pics of one I made, simple and effective.
http://members.shaw.ca/agent86/4+3%20Jack%20Adapter/
http://members.shaw.ca/agent86/4+3%20Jack%20Adapter/
OP, the first time....it takes a while to do.
you need to familiarize yourself with the C-Beam and what all you want to do with it once it is out (shaving a bit off and C-Beam "plates") (search it out)
You need to jack it up as high as you can on jack stands...it makes it easier.
the $20 Kragen jacks work for "holding things" up....like cradling the back of the motor......letting down the exhaust.....etc.
Do yourself a favor and take the tranny loose from the bell housing....it is simple when you do it that way.
Drop the exhaust at the Manifolds, center support and then at the mufflers just by the rear bumper.....don't forget the air hose that runs down from the smog pump. Then let the whole thing down and slide it out and put it in the back yard for a while.
Last edited by jhammons01; Jan 25, 2010 at 06:46 PM.
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
I'm thinking that they just didn't change the TO bearing at that time?
Last edited by glava2876; Jan 26, 2010 at 11:39 AM.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
If the clutch replacement was done at a shop, the chances are pretty good that they would have included a throwout bearing as part of the job. The part is not that expensive and it has to come out anyway as part of the clutch R&R procedure. And a typical labor charge for a clutch job would include the labor for a bearing install.
Can you elaborate some on why you believe it needs replacing? Is there a noise? If so does it occur when pushing the pedal in? Is there a noise at idle with the trans in neutral? If that's the case, does the noise go away once you push the pedal in?
It's always possible there could be a problem with the clutch fork or the stud it sits on. Also, die the clutch fully disengage when the pedal is pressed to the floor? Another common problem for the C4 clutch hydraulics is a hose that is going soft or the slave cylinder is not working properly. Is the fluid level correct in the reservoir? Do you have to keep adding fluid?
Can you elaborate some on why you believe it needs replacing? Is there a noise? If so does it occur when pushing the pedal in? Is there a noise at idle with the trans in neutral? If that's the case, does the noise go away once you push the pedal in?
It's always possible there could be a problem with the clutch fork or the stud it sits on. Also, die the clutch fully disengage when the pedal is pressed to the floor? Another common problem for the C4 clutch hydraulics is a hose that is going soft or the slave cylinder is not working properly. Is the fluid level correct in the reservoir? Do you have to keep adding fluid?
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Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
If the clutch replacement was done at a shop, the chances are pretty good that they would have included a throwout bearing as part of the job. The part is not that expensive and it has to come out anyway as part of the clutch R&R procedure. And a typical labor charge for a clutch job would include the labor for a bearing install.
Can you elaborate some on why you believe it needs replacing? Is there a noise? If so does it occur when pushing the pedal in? Is there a noise at idle with the trans in neutral? If that's the case, does the noise go away once you push the pedal in?
It's always possible there could be a problem with the clutch fork or the stud it sits on. Also, die the clutch fully disengage when the pedal is pressed to the floor? Another common problem for the C4 clutch hydraulics is a hose that is going soft or the slave cylinder is not working properly. Is the fluid level correct in the reservoir? Do you have to keep adding fluid?
Can you elaborate some on why you believe it needs replacing? Is there a noise? If so does it occur when pushing the pedal in? Is there a noise at idle with the trans in neutral? If that's the case, does the noise go away once you push the pedal in?
It's always possible there could be a problem with the clutch fork or the stud it sits on. Also, die the clutch fully disengage when the pedal is pressed to the floor? Another common problem for the C4 clutch hydraulics is a hose that is going soft or the slave cylinder is not working properly. Is the fluid level correct in the reservoir? Do you have to keep adding fluid?
The previous owner did not provide a reciept, just his note in the owners manual that the clutch was changed for $ 875.00.
The clutch works great, no travel problems etc.
When I start out, no problem, but within a couple of miles it starts a soft squeaking, but close the windows or play the radio and you can't hear it at all.
Push in the clutch or even put light pressure on it and the sqeaking goes away.
Thanks again!
Team Owner
Joined: Jan 2003
Posts: 20,324
Likes: 250
From: Summerland B.C. Canada
Maybe the shop did not get the throw out bearing, positioned properly on clutch fork.
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
Is the clutch TO bearing etc real different in the Corvette Vs other chevy vehicles?
I have a 79 Z28, with 30K miles, that I have owned for just over 30 years and it has the Borg Warner T10 close ratio 4spd and I still have all the original clutch parts in it and have never had any problems with the TO bearing squeaking!!
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
^^Yes, but that C-Beam is it's own little animal.
I pulled the C-Beam...and then the 4 bolts to the Super T10 and that tranny was on the ground very easily. (linkage unhooked...ya' know the typical) But it was easy....I'm not sure and I didn't look for that...but can you get to the TO bearing with the Bell housing still in place?
If so, it would make that job a little easier
I pulled the C-Beam...and then the 4 bolts to the Super T10 and that tranny was on the ground very easily. (linkage unhooked...ya' know the typical) But it was easy....I'm not sure and I didn't look for that...but can you get to the TO bearing with the Bell housing still in place?
If so, it would make that job a little easier
Instructor
Joined: Nov 2008
Posts: 199
Likes: 1
From: Asheboro NC
remember that transmission is very heavy so be prepared to deal with the weight. once you have it out inspect the bearing on the input shaft. your noise could be coming from it. in a cold condition you can here it until things warm up. the bearing on the input shaft of my jeep went bad and it acted just like the TOB was going bad. I don't want you do to all the work and still have the noise and shift problems.
Instructor
Joined: Mar 2009
Posts: 230
Likes: 0
DId you figure out your sqeeking problem with TO bearing? I heard that was a 4+3 TO Bearing "bugs" . It made noise but was actually ok .Noise isnt as loud as when the TO bearing is ready to take a dump. My 85 does the same thing .Let me know , very interested
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
I will probably enjoy it a little and then the do the T/O bearing and probably the clutch as long as I have the tranny out.
Le Mans Master
Joined: May 2006
Posts: 9,226
Likes: 9
From: Irvine Ca
Now, I'm going to scold you.....(in a joking manner)
you list all these things that you addressed that made the car "appear" nicer while ignoring a potential issue with the bearing.
Once it goes bad and drops.....that sparkling new paint job is sitting on the side of the road. The TO bearing is trying to talk to you....you aren't wanting to hear it.....
you list all these things that you addressed that made the car "appear" nicer while ignoring a potential issue with the bearing.
Once it goes bad and drops.....that sparkling new paint job is sitting on the side of the road. The TO bearing is trying to talk to you....you aren't wanting to hear it.....
Thread Starter
Drifting
Joined: Jun 2009
Posts: 1,287
Likes: 448
From: Upstate NY
Now, I'm going to scold you.....(in a joking manner)
you list all these things that you addressed that made the car "appear" nicer while ignoring a potential issue with the bearing.
Once it goes bad and drops.....that sparkling new paint job is sitting on the side of the road. The TO bearing is trying to talk to you....you aren't wanting to hear it.....
you list all these things that you addressed that made the car "appear" nicer while ignoring a potential issue with the bearing.
Once it goes bad and drops.....that sparkling new paint job is sitting on the side of the road. The TO bearing is trying to talk to you....you aren't wanting to hear it.....