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I have been looking on this forum and my head is spinning from all the different clutches, pressure plates, TO Bearing people recommend.
I called Summit Racing to see what they might recommend...probably if I called back, I'd get a complete different recommendation.
This is what I was told...
Go with the diaphragm style instead of the 3 finger as it's easier on the foot was the first thing. I don't know what I have in the car now, but it takes about both of my feet to press that clutch in. In order of preference....Didn't even discuss Centerforce
Zoom – Close as factory as you can get
LUK - 04-084 Stock slightly better than Zoom – better quality in springs and material
Hays 91-1002 - Slightly better than LUK and Zoom with Steel TO Bearing
Justplain, you are on the right track. Any of those will do just fine, diaphragm is what you want. As I said before....check Rock Auto for those parts. When I did, the same clutch was half the price of Summit.
No, but when I was in college (pre-med), I worked at a chrome shop. I became very good friends with the owner. After college, and after buying the 56 in 73----------------which was pre-NCRS, I started fixing up the 56. The owner of the chrome shop would let me come in AFTER closing.and chrome my own parts. I went over board! I chromed everything that was practical (and some things that were not practical). I even completely disassembled the soft top frame and chromed each piece---------------and fortunately, got it back together.
Dowels about 4” long work fine but a little longer is fine if you have plenty of tunnel room for sliding the transmission back.
if your floor Jack is a full size unit with a removable saddle you can probably cobble something up to cradle the engine. I’ve used mine with home rigs to change out the 8-3/4 center differential section in my Plymouth (3 times) and to remove and cradle doors on it while rebuilding hinges. Just need to remember that once you get it down on the lift, it still has to come out from under the car so you need to get the car up in the air on jackstands pretty high so it will come out under the frame.and rocker panels.
I do a lot of measuring and checking things when doing a clutch/flywheel/trans change. I’ve bought a new flywheel that was warped and a new clutch that the pressure plate was bad and cocked in the and engaged unevenly. I would at least mount the flywheel and measure runout with a dial indicator at the quarter points to make sure it’s spinning flat. If you have a hydraulic press, I would probably test assemble the clutch/flywheel assembly and mount in it and verify it disengages fully in reasonable stroke distance and engages evenly around its circumference. Odds are everything will be fine but bad parts do crop up,
After you get your clutch kit, BE ABSOLUTELY SURE TO MEASURE THE THROWOUT BEARING to make sure it is the correct one. When I did the clutch in my '60, the kit was specified for Corvette but the kit had the wrong throwout bearing. Some vendors apparently make their kits for passenger cars and just say they will also fit Corvette.
Per JohnZ: Chevrolet has used only two sizes of throwout bearings for decades - 1-7/8" for passenger cars and trucks (flat-finger clutches), and 1-1/4" for Corvettes (bent-finger clutches).
So be sure you or your shop puts in the "short" throwout bearing (if you are going to use a bent finger diaphram pressure plate) or else you will be pulling the transmission again to just change the throwout bearing.
I'm not going to reiterate everything I know about clutch installation problems, but it may be worth your time to read these threads:
LUK diaphram pressure plate with standard clutch disc works just fine unless you are racing. Have one in both of my cars. Even have the "adjustable" throw out bearing in the 68RS and it has done just fine, although most cuss it.
Be sure to use the bent finger PP or the gorilla will give you fits (and not work).
With the bent finger diaphragm in my car I didn't like the feel of the over/under the gorilla spring. It was light at top and bottom and then heavier in the middle, as it is designed to do. So I removed it and used a much lighter spring. Now the pedal pressure is easy and even all the way up and down. That's just my preference.
I got the pilot bushing out (see my POST - poor mans pilot bushing removal tool) and it looks like it is bronze, but when I put a magnet up to it, there is some attraction.
The same with the pilot bearing that came with the Napa Part# NCF 1104084 which they claim is the same as the LUK - 04-084
Is there no magnetic attraction on the bronze bushing, or there is some? Perhaps there is some iron in the bronze??
The National HD bushing has been non-magnetic in the past. Has to be the “HD” one. Also AutoGear has them that can be ordered.
Are they completely non-magnetic? The one I pulled out of the car has the same magnetic attraction as the one from the Napa Clutch kit. I'll have to call them today and find out if its a steel or bronze pilot bearing.
OK, I'll be the one to say it . . . although I probably COULD do it myself (I'm 67), if I could relatively easily afford to have it done at a shop I trusted, that's the way I would go.
Me too. ( I'm 69 ) But the key word is "trusted" It is important to get a shop that knows how to work on old Corvettes.
My preference would be to DIY. Since you’ve done clutch replacement before, you know the moves or most of them. For a trans jack a small to medium size jack works well in the space underneath the car raised up on jack stands.
With the floor jack and trans ready to go the trans main case is rolled over onto the saddle. There’s a bit of a balancing act to get the main case centered up on the saddle. The trans is raised with one hand working the jack while the other hand works the tail shaft in at an angle to position it into place. Once inside the ‘hole’ the jack continues to raise the main case while working the trans in place backwards.
Finagilng the trans forward into the throwout bearing and clutch disc is always fun, of course.
The mentioned guide pins in the upper bell housing bolt holes helps the process.
John
My preference would be to DIY. Since you’ve done clutch replacement before, you know the moves or most of them. For a trans jack a small to medium size jack works well in the space underneath the car raised up on jack stands.
With the floor jack and trans ready to go the trans main case is rolled over onto the saddle. There’s a bit of a balancing act to get the main case centered up on the saddle. The trans is raised with one hand working the jack while the other hand works the tail shaft in at an angle to position it into place. Once inside the ‘hole’ the jack continues to raise the main case while working the trans in place backwards.
Finagilng the trans forward into the throwout bearing and clutch disc is always fun, of course.
The mentioned guide pins in the upper bell housing bolt holes helps the process.
John
I built this to help me take it out this time. Last time trying to do this myself was a pain. Worked great.
Are they completely non-magnetic? The one I pulled out of the car has the same magnetic attraction as the one from the Napa Clutch kit. I'll have to call them today and find out if its a steel or bronze pilot bearing.
the last National HD one I bought about 2 years ago for my Cobra was completely free of attraction to a magnet. Last one I put in my Corvette about 3 years ago was a custom machined bushing from AutoGear and it was non-magnetic.
the last National HD one I bought about 2 years ago for my Cobra was completely free of attraction to a magnet. Last one I put in my Corvette about 3 years ago was a custom machined bushing from AutoGear and it was non-magnetic.
I called NAPA and he said it is a brass impregnated graphite bushing. He said it was the correct one for my car. But it does have "some" magnetic attraction.
Last edited by jusplainwacky; 06-12-2021 at 03:13 PM.
The clutch is in...tranny in...all hooked back up. I adjusted the gorilla spring bracket with the 2 bolts...boy it doesn't take much movement to make a big difference. All this time I have had my gorilla spring/clutch rod not adjusted right. It use to take me 2 feet to push in the clutch, now it's so much easier.
One of the things I did notice...just like others; when I pushed the clutch to the floor, it sticks, so I again made some adjustments on the Z-Bar/gorilla spring "center point" and now it doesn't stay stuck on the floor. BUT, now when I push the clutch to the floor, there is very little pressure on my foot...it almost feels like it's going to stay stuck on the floor, but it doesn't. Should this be the way it should work, or should I adjust it so there is a little more pressure to keep the pedal to the floor.
I guess it's nice if your sitting at a stop light with the clutch in...but not sure if it's that great for fast shifting where you want the clutch pedal to spring back so you can push it in again for the next gear.
I haven't taken it for a ride yet, so not sure how this is going to feel on the road.
I was able to barrow an input shaft to line up the clutch, worked much better than the plastic one I was trying to use. As for the pedal travel, mine didn't work right
and I found there two different lengths for one of the rods, switched to the other one and all was well (I don't remember if i used the long or short )
Know your limitations.
It is a good thing, not a bad thing.
Good luck
There are many things in life where we think we cannot do something and put limits on ourselves....only to prove yourself wrong. And if you fail, try again...and never be afraid to ask for help.
06-08-2021, 04:57 PM
