Differential Damage Question

D

Duckfarmer27

Junior Member
I posted last fall about noise in rear end. Finally got around to removing the rear end and tear down yesterday. This is off a 1930 pickup with various parts - just a driver that my grandson and I have fun with.

First problem was no snap ring in the front of the drive shaft and the thrust washer there pretty mangled. I don't think this thing has been apart in a long time but was at some point - no safety wire on banjo bolts, a couple on the left trumpet loose. When I removed the torque tube both nuts and lock washer for pinion nut were floating around loose. Result was what you see in pictures, pretty well hammered up carrier. Axles have no indication of end play at all. axles spin ok in carrier but seem a little stiff to me - but then I've never had one of these apart before.

I"m reading through old threads, Tom Endy's great articles, etc. So I'll digest all of that. But I'm guessing this carrier is probably toast. Figured I would get opinions from the experts on usability of that, what to check, drive shaft recovery if possible, etc.

Thanks for any advice.

Dale
 

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If we were on a tour somewhere broken down in a remote area, I would probably think about reusing that differential housing, but they are available for cheap money today so why even bother.

I think you have a handle on everything however I would also recommend you check the driveshaft for straightness. In instances such as yours, I have found they can become bent which will later be a source of a harmonic vibration due to the shaft spinning out of true alignment. Now is also a great opportunity to upgrade to a 3.54 or even a 3.27 ring & pinion ratio.
 
A year ago, I put a 3.27 ratio gears into our '31 model A cc pick up's rear end and it is now awesome on the road. I don't haul any weight in the pick up, so the '31 still climbs the Cascade Mt. hills wonderfully. At 60 mph, the model A engine is loafing along. Now I have a longer range of speed that I can now use more of second gear in. Since you now have rear axle torn down, now is the time to change out its gear ratio.
 
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Yes, the carrier is pretty beat-up, your R&P are well-used too. If you are just driving locally all the time, I would check the carrier for run-out (it's likely OK), check everything, as Brent suggests on the drive shaft, and put it back together, old bearings, gears, et al. You will be surprised how well it will do. If you tour with the truck, now is the time to change ratios and do everything "right". IMO
 
FWIW, I recently had a rear go bad too. Very bad! But not as bad as yours. My first inclination was to get a used rear somewhere and put it in. Upon reflection, I reasoned that I would get all new parts and rebuild the old one.I bought all my parts from Brattons, cost about $750 New bearings (4) $35.@, New cups/races, New 3.54 R&P $465, Gaskets about $16. Am I glad I did! The car drives much better now, There are improvements that I could have never foreseen. I swear it climbs hills better (??) Better gas mileage, Higher top end it seems smoother too. I am very happy with that job! However, I will not make it sound easier than it was. And it was rather hard! Parts are heavy and require special tools which I made and a lot of attention to detail but the results are worth it!
Terry
 
I've rebuilt rear ends for others and the most common cause of failure on what were supposed to be recently rebuilt ones is too much preload on the pinion bearing. Some books say 20 ft pounds to turn it. The correct figure is 20 INCH pounds. Don't over tighten the adjusting nuts or you will be doing it all again soon. If you have done all that reading, you are hopefully aware but better to say again than have you #$%^&* it up!
 
Brent -
Thanks for the comments, especially on the drive shaft straightness. Did not think of that but should be easy enough to do.

Steamer / Terry -
Good input, and Terry I have seen your thread on your work last year. Understand the comment on special tools - I end up spending time making them as well, but as a retired engineer that passes as amusement for me.

Synchro -
Yep, I've seen your comment before. As a teen age kid rebuilding my first car engine (50 Plymouth, or as I called it 'Hemi Under Rust) an old 6 cylinder flat head I broke a rod bolt by using the wrong torque value. Knew better, but it is funny how something like that can stick with you forever, making that task one that you always double check!

Jim -

Just might do as you suggest. This truck is a local driver, not a touring or show car. Although my grandson likes to take 'his truck' to a couple of the local car shows in our little town. I liked one of Tom Endy's comments that half the time of doing a rear is the cleaning, etc. That part I have to do and after pulling this one it is not much of a job overall. If I get everything cleaned up, painted and with proper fasteners removing it in a couple of years if we want to do more would not be that big a problem. Especially since I've built the spring spreader, hub puller, etc.

Thanks for all the good comments.

Dale
 
See my ad in the parts for sale section for various drive shaft and rear parts for sale from a low milage 1931 John Kohnast
 
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