TT Ruckstell rear axle play

[Alex Dragone]

I was changing the rear axle seal on my TT rear axle and noticed quite a bit of axle play when pulling on the axle. I know TT axles are pretty well built and not like a car axle with Babbitt thrust washers. Any help is appreciated. Thanks!

[StevenS]

Do you mean axle play "in and out" ? Do you have a standard rear end or a two speed Ruckstell?

[Alex Dragone]

Yes axle play in and out and it’s a Ruckstell

[StevenS]

I just rebuilt my Ruckstell TT rear end and there were two things that would make it loose "in and out". First, there is a fiber thrust washer (about $7) that will wear down and cause play (you will need to sand the new one down to get the proper clearance). Second, worn parts in the rear end that need to be replaced ( a new "wider" fiber thrust washer can take up some of the extra slack, but not all of it, to avoid replacing parts). If you want to take your rear end apart, get the MTFCA yellow book on Ruckstell rear ends, it is spot on in getting the repairs right.

[richc]

As Steven pointed out, a new Ruckstell fiber thrust washer is inexpensive and can easily be sanded to the needed thickness where the differential neither wiggles side to side nor locks up when the casing bolts are drawn down. I secured my fiber washer on a workbench, as shown, making sure the screws were below the washer surface. Then hand sanded using a block backing. The important thing to remember is to frequently turn the washer a bit to make sure it gets evenly sanded. Making the turns in random amounts insures you are not introducing a pattern. It’s a trial and error process checking the fit as you decrease the thickness.

On the right side of your TT differential is a large ball bearing ring. More often than not they are worn to the point where there is axial play. Grab the outer bearing surface and see if is sloppy with respect to movement. If the TT did not have a Ruckstell installed there would be an identical ball bearing ring on the left side as well.

Rich C.