The Stovebolt Site Forums The Parking Lot Big Bolts Clutch assembly on '48 gmc flatbed

Bear with me. This is my first post of what will probably be very many.

We're in the beginning stages of restoring my grandfather's 1948 GMC 1 1/2 ton stakebed that has been sitting for 30 years. It's got a 1951 248 engine sitting in it (we think. Anyone know where to find the block info?)

Our first two things to tackle, other than ordering shop manuals, is the tranny and the clutch assembly. We've got the muncie 420 transmission out, and we're most likely going to have to replace the clutch & pressure plate.

I've priced out several clutch assembly parts, but I want to make sure what are the right parts for the bigger trucks, and find out if anybody sells the entire assembly.

Thanks for your help. I'll be taking photos and sharing the process of restoring this truck. It's been in my family since it rolled off the showroom floor.

Best thing is to take the clutch and pressure plate in to your local auto parts store because usually they have someone who they use to refurbish and redisc the old clutch. I couldnt find the parts since mine was a goofy size plus it ended up being half the cost of buying a rebuilt when I finally did find one!

Dont forget to surface the flywheel when replacing the clutch. Also new pilot bearing and throwout bearing.

Theres a small machined surface behind the distributor tht has someserial numbers on it, it should start like 248hfgdka or 270sdkjahg, meaning the first 3 numbers are block size. While it could also have an a248 or b248 which has to do with oversized parts inside the engine.

Good luck, Jeff

If you have the 11" clutch with the pressure plate that is held on with 9 bolts then chances of finding a new or rebuilt one is not great. That's the size my truck has, and it was easiest and cheapest to send mine out through my local NAPA for a rebuild.

You may be able to get an even better price if you deal directly with the rebuilder, someone may know of one they have used?

Grigg

I had a hunch it was the bigger size. (hadn't measured it yet) I did find this website page that seems to sell it:

http://www.truckandcarshop.com/trucks47_59/t47_058.html

They have a 10-spline and a 26-spline in the 11" size. Hopefully that does it.

If that doesn't do it, I'll have to see about resurfacing it. They looks rather rusty, I'm not sure I want to use the same clutch parts.

I'm assuming the throw-out bearing on that same web page will work just fine?

turpentyne,

Have you started the engine and run it? The clutch seems like a strange place to start a rehab after sitting for 30 years. If there is evidence of a leaking rear main seal your new clutch could be ruined in short order.

Stuart

oh, we're starting there because the transmission and clutch plates are already pulled out of the vehicle. They were just sitting on the flatbed. This weekend when I head out to my grandparents place to work on things, I'm going to see if the engine will even turn by hand. Nothing on this vehicle is in condition to be started just yet.

Many many pieces were pulled out and left to rust, somewhere back in time. Thankfully somebody covered the carburator, so water might not have gotten into the engine.

I'll take a bunch of pictures this weekend and post them so everyone can see what we're starting with.

Turpenyne,
If you have that 9 bolt clutch it is a 10 3/4" and was used from 1938-53. I have some NOS pressure plate assembly's and replacement disc's. [email protected]

Turpenyne
I have used Unique automotive in Jonesburg Missouri several times. They only do clutch and brake resurfacing/remanufacturing.
About 4 years ago I dropped off a presure plate and clutch [ground the flywheel myself]from a 54 Pontiac.They ground and rebuilt the plate with new springs and rebuilt the clutch with new springs.
The whole deal was <$90.
All the shops around here send there work to them.

You pay shipping and I'm sure they'll treat you right.

Unique Automotive 636-488-5242 Give them a call

2-Ton