When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Add my welcome. Nice truck and hope you sort out your vibration. Has anybody else noticed that the truck still has its hyper rare spare tire brace? One of only a couple I’ve seen that are originals. One of the 53-56 guys copied mine a few years ago for his flatbed. Stu
Not sure how to check this without pulling the tranny? The H motor was introduced in1947, no? I wonder how to check numbers to see if it is the matching numbers motor?
Exactly what 38’ coupe said! See what it does sitting still. Then you can narrow it down to engine or driveline or even wheels. I know how much fun it can be to track something down…keep us posted!
Yes, but a bad coil or wires can rev fine at idle but go all to pieces under load. Still not definitive. I'm still not sure if we've determined electrical or mechanical?
That does look like it runs nice and smooth. Mechanical engine balance appears fine then (crank, pistons, flywheel, clutch, etc.). That leaves an engine misfire at speed or a transmission issue that becomes apparent at speed.
Have you coasted down an hill at high speed and verified no balance issue with the engine at idle?
The 47 flatbed has all new Tornell 10 ply 7.50 X 17 tires and it has been in storage awhile. Maybe these bias ply tires are flat-spotted and that is making the awful vibration??
The 47 flatbed has all new Tornell 10 ply 7.50 X 17 tires and it has been in storage awhile. Maybe these bias ply tires are flat-spotted and that is making the awful vibration??
I would think after 100 miles they would have worn in though. I can tell you from my experience with my F3, that’s on 7.50 x 17 tires, and has the stock 4.86 rear end and 4 speed…that at over 50MPH the thing is wound up pretty good, throw in a bad road and it may feel kinda rough, but I’ve learned it’s the nature of these old trucks. So I usually keep the truck at 45 50 and that’s the sweet spot, at least for me.
I should have been more clear, while coasting down a hill put the transmission in neutral and let the engine idle. If the vibration is gone it is engine or transmission input shaft related. If the vibration is still there it is transmission output shaft, u-joint, drive shaft, rear axle, or wheel balance. We can keep helping you narrow down what is the cause.
