TR2/3/3A TR3 axle end float

[TexasKnucklehead]

...so I used a home-made tool and had the axle halfs pressed apart, knocked out the race and seals, persuaded the bearing off the shaft and replaced all these parts. Anyone who hasn't done this doesn't know how much fun you missed. Anyway, I was careful to keep the shims and axles together with perspective sides of the car. I didn't check the end float before I started. I thought it was odd that the right side had 5 shims (.071") and the left had 3 shims (.030"). After getting it all back together, the end float on either side is exactly .016". The supplement in the book says it should be .004-.006, and that both shim packs should be "close" to the same amount to keep equal spacing on the differential cross pin.

I suppose I'll follow the books recommendations, but I wonder why it was set up so, and if I've changed anything while changing the bearings/races.

 

[TR3driver]

The pin in the middle (that the axles float against) has a fair amount of movement available. You have to have both sides assembled in order to check the end float. So, it's fairly common to assemble one side with a guess at the right number of shims, and then make the final adjustment at the other side. I think that explains the unequal shim packs.

Apparently, new bearings are not always exactly the same dimensions as the old ones; I had a similar experience with my Stag differential. After carefully selecting the shim packs using the old bearings (ground out so they would slip into place easily), the new front bearing turned out to be a good .030" thicker than the old bearing was. IMO that explains the change in overall clearance.

So, I don't think you've got anything "wrong", just go ahead and follow the book.

 

[mallard]

Darn it Randall, I hope I checked mine with the other side installed. It's been so long I don't remember. I'll have to make a note of that and check it again. It did seem to be a very time consuming job though going back and forth. I guess if I was going back and forth they must have both been in.

Problem solved I'll check it again.

 

[TR3driver]

As I recall, with one axle out, the other axle shows too much end float even with no shims at all. So I'm confident you were checking with the other axle installed.

The tedious "going back and forth" is exactly why it's not unusual to find unequal shim packs!

 

[TexasKnucklehead]

Randall's memory serves him correctly. With only one side installed, the end float is enough to make one aware that the other side needs installed before checking. I've gone back and forth several times and thought I had it smack on, but I only tightened two bolts per side. Then when all 6 are tightened to spec, the float is off again. Now I'm .002 too small.

Tedious is a good description, but I'll get it.

 

[TexasKnucklehead]

Sometimes I can miss the most obvious, and be such a knucklehead.

Generally I am capable of simple arithmetic, but after several attempts to get the end float within spec, I realized I must be missing something. Like the shims had spots of rust on them when I removed them. The rust effects thickness. Getting them reinstalled in the same order would have been a challenge, but in the same orientation... unlikely. Plus I painted the housing, and attempted to not paint the flange.

After cleaning the thick paint off the edge of the flange, and carefully sanding the rust off the shims and making sure it was all cleaned before assembly, I found the original shims installed provided end float exactly in the middle of the expected range.

The frame is now sitting on 4 wheels again (and there was much rejoycing).