Late Stepdown rear end question

[Deleted User]

I've finally gotten around to completely dismantling my late model, Dana 44 rearends. The goal is to check out and reassemble a low cost 3.07 Dana 44 for the '49. I wasn't happy with what I found in the driver's side axle, so I took two apart. The 4.55 rear end I took apart was exactly the same.



I noticed that the axle bearings on the passenger side, right side, were always in good shape with no, or very little end play from the axle. Also, there was always a shim pack present on this side.



Driver's side, left side, the axle bearing was always sloppy, so much end play I didn't dare measure it - but we'll say well in the .250"+ range, and no shims whatsoever.



I will say that the bearing race on the right side was proud of the housing, and needed shims in both cases. The driver's side, was not proud and may have been slightly recessed into the housing.



When I began to read in the mechanical proceedure book, the axle play is set by shims on the passenger side - but says nothing about the driver's side.



My question is Why? Why is the driver's side axle end play not addressed? How can I address it, as its obviously a problem given the slop in both rear ends I took apart. The lack of attention to this detail is obvious in how the bearings were beaten on the driver's side, and pristine on the passenger side.



Mark

mars55

I believe the answer is that there is suppose be a "Axle Shaft Spacer" installed in the differential. Thrust on one axle is suppose be transfer to the other axle through this spacer. In the club suppied "Hudson Shop Service Manual 1948-1952" it can be seen on Page 11-19 Figure 36 #42.

[Deleted User]

I'll give that a look, thanks.



I was thinking the spider pinion may prevent such transfer.



Just got in, so I'll be looking that info over.



Mark

Geoff

There are only shims on the right hand side in Step-downs with the Dana axle, and Jets. Don't ask me why. The Jet manual specifically mentions this. I had a similar condition with my Jet. Removed the required amount of shims, and the problem went away. It pays to replace the seals when you have this much play, as end play also increases up-and-down play, causing wear and strain on the seals. And remember, when checking this adjustment, you must have both wheels off the ground, otherwise the weight of the car may shift the end play over, and you get a false limit.

Geoff.

[Deleted User]

mars55 wrote:

I believe the answer is that there is suppose be a "Axle Shaft Spacer" installed in the differential. Thrust on one axle is suppose be transfer to the other axle through this spacer. In the club suppied "Hudson Shop Service Manual 1948-1952" it can be seen on Page 11-19 Figure 36 #42.

I did spot the spacer in the manual I have, exactly where you said it would be.



I do understand how this is supposed to work, as the spacer is drilled for the passage of the spider pinion through it with (from the drawing's dashed lines) enough lateral movement to transfer the position of the axles . It also spaces the axle spiders within the carrier, evidently.



Looks like a pretty important piece to me.



With as much axle play as I had in the left hand side of both rear ends, I'm kinda dreading how "hammered" this piece is going to look.



I'll try and get one out this morning and make a report.



Thanks for the input.



Mark

[Deleted User]

I had a good look at the spacer today. I didn't take it out as the spider gear pinion was trapped by the ring gear, and I didn't really want to take the ring gear off the carrier.



However, I could get a good look at what I wanted to.



The spacer serves as the centering point for the spider gears that the axles spline into. If this piece wasn't there, the axle spiders would fall out once the axle was removed. The hole which the differential spider pinion passes through, is elongated. I didn't measure it, so the total amount of movement I do not have. But, as you adjust the right side axle you should be pushing the left side over.



I suppose, when replacing axle bearings, you'd need to install the left side first without shims - making sure the race is flush and bottomed in the counterbore. Then install the right hand side and adjust the end play with the shims.



I'd also take the rear cover off and make sure this spacer is free enough to get an accurate measurement. There was alot of crud in the elongated voids not taken up by the axle's end play. Ideally, this spacer wouldn't bottom out its slot either to the right or the left, but be somewhere in the middle. If this spacer isn't free enough to move, you won't get the proper transfer of axle clearance, and get a false bearing adjustment.



Thanks for all the comments to help me get a better understanding of this situation. Maybe I can get this bugger back together and on the road again.



Mark

Uncle Josh

When setting up my 47 truck axle, I found that I could shift the spacer (and the opposite axle) by shiming either axle, so I shimmed each axle equally. That pretty much centered the spacer block. It's worked great for a year now.

[Deleted User]

Uncle Josh wrote:

When setting up my 47 truck axle, I found that I could shift the spacer (and the opposite axle) by shiming either axle, so I shimmed each axle equally. That pretty much centered the spacer block. It's worked great for a year now.

I'm thinking along that line as well.



I'll have a good opportunity to do that as I'll be going back together out of the vehicle and with the rear cover off.



One of my concerns is that the amount of play I had in both rear ends exceeds the amount of shims taken out of the right side.



It may be a case of working in some thrust buttons on the end of the axles to take up the excess slack. Or, at least on one axle. Its something I'm going to have to pay close attention to on re-assembly.



Mark