The Stovebolt Site Forums The Shop Area Driveline 1952 3100 1/2 ton pickup - needs some mechanical work!

Hello Stovebolters, I am new to the forum and a novice mechanic. I am looking forward to learning from you all. I just acquired a 52 1/2 ton Chevy pickup and though the body is in great shape she needs some mechanical attention. So far I was able to fix a leaky water pump (replaced it), replaced the 12 volt alternator, replaced a steering column mast bearing and replaced the ignition switch with an OEM one. Her biggest issue is she has a vibration when underway and I noticed she is missing her transmission crossmember and associated transmission mount. Also the fan belt pulley on her harmonic balancer is somewhat bent and I’m not sure if that too is contributing to the vibration. Praying to God there is no damage to the crankshaft though the engine, an 216, seems to have been rebuilt and appears ok. Otherwise as they say, “how did you like the play Mrs. Lincoln ?”. I am sure with some help from you all and some better mechanical friends that I have I will right size her in time.

No transmission mount. Engine is supported in the front under the crankshaft pulley. Bellhousing has a mount to the frame on either side. Tranny just hangs on for dear life.

What kind of vibration?

Does it vibrate while sitting still or only while driving?

Does it vibrate at all engine speeds?

Take the fan belt off and see if the vibration goes away. If it does, look at the bent pulley. Make sure the fan itself doesn't have any bent blades.

If it's only while driving, I'd look at those Coker (I assume) tires. They are notorious for being of inferior quality and difficult or impossible to balance correctly. You should look on the inboard sidewall to find the date code just for your own edification.

I assume you are joking Bill, yes?

No.

Welcome to the ‘bolt.

FYI. You might get more responses if you use the forums closely related to your questions.

I suppose I am mistaken as I was under the assumption that the tranny on all 1/2 tons 3100 series from 1947-54 were supported by transmission crossmembers and their associated transmission mounts, and not just hanging on for dear life.

The parts listing shows transmission supports for all 1/2 tons from 1946 thru 1953, and a rear support for 1954's with automatic transmssion.
Your frame should have four holes on the frame web on each side and a single hole thru the bottom flange to bolt in a transmission crossmember. The mount is a flexible rubber sandwich that bolts to the crossmember and has two holes to bolt to the u-joint socket at the rear of the transmission. Many of them likely got left off, as the crossmember has to be removed for good access to the u-joint for any repair.

Here's a pic of that area on my 1951 3100.

Thanks for that constructive reply. It is helpful.

Mike,
Did you find a cross member and tranny support bracket ?

I've had a few of these and only one had a crossmember for the transmission support. And honestly the mount had been removed so it did nothing. Currently I have a five speed transmission there with no support for it, either. Welcome aboard!