Need Differential Advice
 

We let the tranny fluid get old and low on Grandpa’s 1954 3100 5-window. The transmission bearings let go. After rebuilding the tranny (3-speed manual), the mechanic inspected the differential and said it needs to be replaced. There are grooves in the gear teeth and the bearings are shot. He says that rebuilding the differential is difficult and it would be cheaper to replace it with a used unit. That would include the pumpkin and the attached drive-shaft.

This is a nice original truck with only 35,000 miles, but is there any alternative to using the diff from another ’54? Is a rebuild that difficult? (I understand that there are some leather pieces.)

Thanks,
Bill Yates
Austin, TX

I just looked at a sectional view of a rear and see no leather parts you refer to. I think the only difficulty in rebuilding will be to get the gears. The bearings will probably be the easiest to get. If you can get all the parts I'm sure it will be kind of pricey to rebuild. Maybe your best bet is to get a used unit with good gears. I had the rear on my '70 Ford p/u rebuilt about 10yrs ago and it cost $500 then. Get the numbers off the bearings and see if they are obtainable. Try NAPA, they might even have a ring and pinion. Obsolete Parts in Nashville, Georgia might have the parts also. Good luck

visit Chevy Duty pickup parts website
 

You can download their catalog. See page 7 Part#05-511 "rear axle overhaul manual" $5.99
Page 76 Part#93-5111 "axle gears" (3.55 ratio only) $399.95
Page 76 Part#93-512B "install kit" (Bearings, bushings, gaskets, shims) $274.95

Chevy Duty
 

I called Chevy Duty this morning. Their 3.55 gear set is described as "bolt-in". I spoke with the tech and he said it was an easy job, it just took a long time. Well at $75 an hour, I don't want my mechanic doing "easy but long" work.

We found a used diff in North Texas for about the same cost as the new gears ($400 plus shipping). Thanks all for the advice. Now I've got to get the speedometer working again. :(

Bill

Why did you not change the rear to a Camaro or Monte Carlo the Monte is the right width. Did your truck have a open drive shaft?

That's the first time I've heard of an alterative to the original diff. I wish you had seen my request earlier. The drive shaft runs through a tube.

Thanks,
Bill

PS The truck is now for sale.

Bill, I sent you a P M

'54 Chevy 3100
 

Here's a listing: http://tinyurl.com/2wlo4

I'm asking $12,900.
Thanks,
Bill