rear axle bearings, shims

[Chuck]

I'm doing rear bearing and brake service on my '51 Champion and have two issues for which I could use some knowledgeable opinions. Both bearings have been removed, cleaned, repacked and re-installed (including the inner seal) on both sides.

1) The bearing race on the left (driver's) side did not go flush into the axle housing while the right side did. Could this be ok? I did notice that there was some what appeared to be baked-on grease residue on the inner face of the axle housing against which the race would be inserted. I cleaned it without removing it completely so I was wondering if this may be causing the problem. The race sticks out about 1/8 inch.

2) I'm not 100% sure about how the shims placed originally. I seem to recall that there some that were on the outside of the outer seal housing, perhaps left there just in case they were needed. Since a dial indicator will be needed to measure the horizontal movement distance of the shaft I tried to move them by hand just to see how loose they might be. Well, they don't appear to move. What's up with that? Are the freshly packed bearings making it all too tight? If so and I can't get a dial indicator to show movement, what should I do?

Thanks,

Chuck Savage
'51 Champion Regal 4dr.

[Roscomacaw]

Whatever shims are required to establish proper end play, get stacked between the brake backing plate and the flange on the axle housing.

An 1/8th of an inch sounds a bit much, but often that race DOES protrude a bit. Did you physically REMOVE the bearings from the shafts, or did you just clean them up and repack them without pressing them off the shafts???

Anyway, you stack whatever combination of shims it takes to achieve the end play, between the brake backing plate and the axle tube end flange.


Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

[Chuck]

The bearings were pressed off correctly. I didn't actually measure the height above flush for the race but I will tomorrow just in case and will let you know. I really appreciate your advice Mr. Biggs - this forum is invaluable.

Chuck Savage
'51 Champion Custom 4dr.

[sasjdw]

On a related topic, I'd like to replace the axle seals on the rear end of my '55 Speedster. I have the seals, retainers, etc. but I'm unsure if this is a task I should undertake on my own. Can the axle seals and front pinion seal be replaced w/out having to re-set end play or other critical settings/measurements?

Thanks,


James D. Wilkerson

[Chuck]

Mr. Biggs,
The bearing race is 3/16" above the axle housing. I pulled it again and measured the depth of the recess for the race and there is exactly enough room to the bearing and race to go in flush. So would it not seem that the bearing has gone onto the tapered axle as far as it can, preventing the race from going any further into the housing? Thughts?

Chuck Savage
'51 Champion Custom 4dr.

[Chuck]

I just got off the phone with Stephen Allen about my question, so for the benefit of the forum, here's what he said.

Both bearing races do not need to be flush and a dial indicator is not really necessary to set end play. Make the protruding side flush with shims, tighten the end plate and get ready to hammer the axles (with the nut threaded on and a piece of wood the protect the threads) inward. This will loosen the the bearings just enough to induce end play which you can then adjust by removing shims until there is just a perceptable amount of movement (the shop manual specs .005" end play)and you are good to go. Another thing is to lightly oil the felt washer/seal and trial fit it onto the hub to be sure it's not too tight or you could find the hub may grab and pull the felt out of alignment.

Hope this helps and doesn't contradict the advice of other "experts" here on the forum.


Chuck Savage
'51 Champion Custom 4dr.

[Roscomacaw]

No, if you read what I said, this is in accordance with what Stephen Allen's said.
The '51 shop manual talks about adding shims to both ends of the axle. (Actualy, it reminds you to reinstall any shims you found there when you took it apart) But since, as you noted, the seat for the race is just deep enough to fully swallow the race, you should be able to install the left backing plate without any shims Make damned sure the race is at least flush with the housing's end flange tho!). Then, shims are added to the right side as required to accomodate the race's protrusion with everything knocked in (via the hammer and wood you mentioned)+ whatever shimming necessary to achieve the required end play.

And, to answer James' question, you can replace the seals without worrying about axle end play so long as you're careful to reinstall everything just as it was. If you're gonna replace bearings and or races, you'll have to check end play again.
You can replace the pinion seal as well, without any readjustment needed. Just mark the yoke so that it goes back, situated on the pinion shaft splines, the way it was.
I wanna add here (just for the benefit of anyone that's reading only) that if you're dealing with a Twin Traction rear axle, you have to be SURE to have the little thrust block (between the axles' splined ends) in place when you reinstall the second axle![:I] If said block didn't come out when you extracted the axles, it likely fell down inside the axle housing and you can probably see it by looking in with a flashlight.

Miscreant at large.

1957 Transtar 1/2ton
1960 Larkvertible V8
1958 Provincial wagon
1953 Commander coupe
1957 President 2-dr
1955 President State
1951 Champion Biz cpe
1963 Daytona project FS

[DON]

Chuck
This answer is late but for anyone reading this artical there is one important bit of info. The two axcels butt whats called a thrust block which lies betwen the spider gears. By puting all the shims on one side pushes that trust block off center. Once I established the proper number of shims I would be more comfertable to then split the number of shims and place half of those on the other side thereby more or less centering the thrust block.

Don

[DEEPNHOCK]

Small point to add here.....

The shimming of the axle bearings (and the carrier bearings for that matter) is strictly for the bearing itself.
The bearing manufacturer sets the clearance required to put all the bearing components (inner race, roller, and outer race) in the proper position for maximum service life (based on load, side thrust, shaft speed, temperature, etc.
Since we are talking axles here, we'll stay with that...
If you have a TT (twin traction, ie: posi) carrier, the Dana people had a method to allow end play to be checked on the axle and not be changed by the movement (lateral) of the carrier. Hence the thrust block (which pushes against the side gear in the carrier)
The carrier will slightly preload the bearing cone against the outer race (via the clutch pack), but the axle bearing clearance spec is still required. This preload of the axle via the thrust block keeps the axle from moving laterally, causing spline wear, and increasing bearing wear.
You could set the axle bearing end play ahead of time without even having the carrier in the housing. Swapping shims side to side is defeating the adjustment process, and you could end up with a tight bearing (that could fail prematurely), or a loose bearing that is relying on the posi clutch pack to hold the axle bearing cone against the race. This will cause premature clutch pack wear.
In conclusion... Set your axle end play first. On each axle.
The Studebaker service manual is very specific about the procedure, and they had to be, as it was a vendor item supplied by Dana. If they wanted the differential to last out through the warranty period, they had to follow the manufacturers guidelines. And the component manufacturer has to follow the sub-component suppliers guidelines...In this case the bearing manufacturer.
By the way. The correct end play spec for an automotive style taper bearing is .001" to .005" (positive end play). You can't 'feel' this.. If you 'feel' the movement, you are probably in the .010"+ range. A dial indicator removes all the subjective nature of this adjustment. A dial indicator can be bought from Harbor Freight for $12.00 Is your Stude worth $12.00? You betcha it is...
Jeff (Fussy about safety things) Rice[8D]

DEEPNHOCK at Cox.net
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