Known, good part numbers for clutch rebuild kits for the 1500 series...

[fingle]

Greetings!

I am having the worst two weeks of my life trying to get someone to find the 11" clutch rebuild kit for my truck.

Does anyone have a known, good part number and manufacturer for the following rig?

1966 GMC 3/4T pickup
Two-wheel drive
1500 series VIN #
305 E V-6 enging
New Process SM-420 tranny

The LUK kit, and a kit from O'Reilly's Auto Parts in southern california, both feature a clutch disc that has major projections on both sides.

The former rebuild kit, as well the one before that, as well as the one before that, all feature a clutch disk that is nearly flat on one side, with very smail springs and a projecting splined hub on the opposite side.

I used to be able to order the correct kit. now everyone wants to sell me either a 12" disc and pressure plate, or a 10 and 15/16ths kit that comes with a clutch disk that I cannot bolt up, because BOTH sides impact the flywheel.

I'm losing my mind. Please, if you have any actual part numbers, let me know! All the parts houses I've been going to for the past thirty years or more have been unable to help!

Thanks!
- Patrick
fionn.mccueil @ verizon.net

[Jeannie]

Fingle,

The clutch kit is still readily available. See this thread for part numbers.

http://6066gmcclub.com/forum/showthread.php?t=47796


-Jeannie

6066 GMC Club (http://6066gmcclub.com)

[fingle]

Thank you, Jeannie, but those kits all seem to specify 12" disc plates, and only change to 11" if I select a different model of truck and engine than the one I actually own.

The correct clutch disc for my truck is nearly flat on the flywheel side, and I keep finding the kits that have the giant procecting springs on the flywheel side. It's very frustrating.

I am still hoping that there is someone out there with an actual part number for the right kit, rather than links to eBay and Amazon.

I have my old parts out of the truck again, so I'm going to haul both pieces down to my favorite shop and fling it on their counter and beg for help.

Although that didn't work yesterday, after my second favorite shop assured me that I would be getting the right part. OY!

Thanks for the help, though. I guess I can rent a car for a week and order something online on the off chance that it's right, if it comes to that, but that is an expensive fix!

- Patrick

[bigblockv6]

The only difference in the clutch for the V6 vs the inline 6 and V8 is the center splined hub, a local clutch remanufacture can reverse that hub. I've had this done before, basically they have to break off all the rivets holding the disc together, reverse the hub then re- rivet the whole assembly.

[snazzypig]

Don't rule out the 12" clutch. I believe it will work fine. Maybe someone else here can confirm that, or you can search the forum for more information.

[fingle]

The only difference in the clutch for the V6 vs the inline 6 and V8 is the center splined hub, a local clutch remanufacture can reverse that hub. I've had this done before, basically they have to break off all the rivets holding the disc together, reverse the hub then re- rivet the whole assembly.
Thanks! I've considered having the splined hub simply machined down on the new 11" disk, but maybe someone can do that for me. I just got a quote from someone who offered to do something like that for $245.00, but that seems a bit steep. I have to go retrieve my old parts from him so that perhaps I can at least get back to driving the truck with a soft clutch until I can solve this problem.

[fingle]

Don't rule out the 12" clutch. I believe it will work fine. Maybe someone else here can confirm that, or you can search the forum for more information.

I guess I'll measure the flywheel and see if it will accept a 12" disk on the mating surface. That could solve this problem. Thank you for the idea!

[bigblockv6]

Yes a 12 inch clutch will work on the stock flywheel. I first converted to a 12 inch clutch on my 68 KM-2500 30 years ago. Basically it was a Webber replacement clutch for newer trucks built in the 80's but also an upgrade for earlier model, the pressure plate bolted right up to the stock V6 flywheel. What needs to be done when resurfacing the flywheel is to make sure the entire circumference of the face is resurfaced for the larger clutch disc.:goodluck:

[aphaynes]

I believe GMCNUT rebuilt his clutch not long ago. I would search through his posts to see what he did to keep the 11"

[aphaynes]

Here ya go.
http://6066gmcclub.com/forum/showthread.php?t=48447

[Andice]

I simply took all of my old, worn out clutch parts to a brake and clutch shop and they rebuilt or replaced it all: disc, pressure plate, turned flywheel, new release and pilot bearings.

[Clarke]

I guess I'll measure the flywheel and see if it will accept a 12" disk on the mating surface. That could solve this problem. Thank you for the idea!

After my rebuilt 11" clutch disk failed me after 75 miles, I switched to the 12" kit and it's been working fine.

[fingle]

Well, the one shop in Orange County, California, that everyone assured me could rebuild an existing clutch disc, said "No, we cant do that." Might have to drop it off at the local speed shop and have them send it in for me, since the folks there assured me that this place did it for them "all the time".

I wish I could take the truck out of service for a while and solve this on a non-emergency basis, (the flywheel is going to need to be replaced due to excessive wear, and by excessive wear I mean I can't believe it works at all any longer) because this searching for any clutch plate that will work has become like trout fishing. You know the fish are there, but... maybe not...

[bigblockv6]

That's crazy because the only difference in the clutch plate on your V6 vs inline six & V8 is the center splined hub that just needs to be reversed.

[Clarke]

After my rebuilt 11" clutch disk failed me after 75 miles, I switched to the 12" kit and it's been working fine.

I'd like to clarify my earlier comment... The brake/clutch shop I have used for years, was able to get 11" disks to rebuild my existing one, but the new disks had predrilled rivet holes that did not align with the existing holes within the metal portion. Therefore, they "bonded" the new disks on. I questioned them twice and they reassured me it was fine; they do it on the big trucks all the time. Well, the bond only lasted about 75 miles, then spun off, and I wasn't hot rodding it either.

Anyway, there is a thread on here somewhere with all my drama. That's when I found out about the 12" clutch kit. The entire kit was a little over $200 and bolted right up onto the existing flywheel.

I was glad I did that, because my existing pressure plate was weaker than the new 12". Or, at least I was able to adjust more slack in the linkages per the manual.

Good luck,

Clarke

[bigblockv6]

I went from an 11 to 12 inch clutch on my 68 KM-2500. The particular setup was designed to be a replacement upgrade that fit all 1/2 to 1 ton GM truck applications and was compatible with later model 12 inch clutches used in newer light duty trucks. The only problem was the disc wouldn't fit to the V6 flywheel so the parts store sent it back to their distributor, it came back the next day with the center hub reversed. All I can figure is it was taken to a local clutch remanufacturer in San Francisco that did the modification.