Last night I reinstalled the rear axle shafts in my 1957 1/2 ton. Once I got the shafts in place, I checked the clearance between the axle spacer and one axle shaft per the manual, and I got approx .029”. The manual calls for .014” or less. Does anyone have a source for thicker spacers or any other ideas to fix this? I’m not sure how big of a deal the extra space is.
Did you put it in the same way it was taken out. They have a marring from where the end of the axles touch up against them. I think they could be given 1/4 of a turn to go against the sides that were not riding against the axles. That could possibly get you back to spec, maybe...
Thank you for your reply. The original spacer is only ground on two sides so it was easy to see how it had been installed. I found a NOS spacer that is ground on all four sides, and it can be installed with two different possible widths. That should get me closer to where it should be. I will post the results when I have time to install the new part.
I had just recently worked on my rear and the spacer is very crudely made. It is not a precision fit on the cross shaft and if you look inside of it you can see the score marks from the boring process when it was made. The width on the other had has to be correct tho. I have 2 different pumpkins from this type and both are the same. LOL
I agree. I have several differentials in my shop, and none of them fit the cross pin very tightly.
In the grand scheme of things, I doubt that an extra few thousandths of end play on the axle shafts would ever cause a problem. However, if the idea of running a little out of spec causes you to lose sleep, why not have a good machinist make a spacer block from oil hardening tool steel thick enough to get the clearance within specification, get it cherry red with a rosebud torch, and quench it in a bucket of motor oil. If it was my truck, I'd already have it reassembled and put a bunch of miles on it!
Thank you, Jerry. I respect your experience, and I know I tend to overthink things. In my neck of the woods, I am known as a problem solver if you have the time to let me do my thing. Sometimes it’s best to git er done.
I happen to have an extra 57 3100 spacer. Would be happy to mic the outside dimensions of it for you for comparison. The stock rear ends I've seen (only a few) seemed like they all measured about the same. PM me if you want to.
delky dave in Wyo
Thank you. I’m going to try the spacer that I mentioned in Post #3 above. When I do that, I’ll post my results and the dimensions of the new spacer compared to the old. I’d be interested how that compares to your spare.
Ditto to what hotrod lincoln said. Try the new spacer and see. But i wouldn't loose sleep over it. If you put the cross pin in and theres no chance of the axle coming in far enough ,or even close for that matter, to let the clip fall out, then whats the point? Your really not solving a problem if the problem dont really exists....JMO
This situation looks like a case of "tolerance stacking". If one or both axle shafts are a little on the short side, but still within the manufacturing tolerance, and the spacer block happens to be on the small side as well, it's possible the recommended clearance will be at, or beyond the specified limit. Add a little wear anywhere. such as on the ends of the axles, and suddenly the stackup is out of theoretical limits. At the very worst, I doubt if an extra side to side motion of the back end of the truck the thickness of a business card is going to cause any problems.
I checked my spacer at (axle wear marks sides) at 1.1567" and opposite side at 1.1587"
delky dave in wyo
Thank you all for your help. I’ve installed the new spacer. It’s wider than the original at 1.168” vs 1.157” so I got it tightened up a bit, but I admit this is more of a solution looking for a problem. Time to move on to the next stage.