Ruckstell Pinion clearance

[oliverguy]

Hi, I'm having an issue with a Ruckstell axel rebuild. I'm using a 39 tooth ring gear and a 13 tooth pinion. On the drive shaft I'm using "modern" drive shaft spool with the tapered bearing. The driveshaft is new. I set the spool with those little shims as directed. I'm not using a gasket between the spool and the axel housings. I've rebuilt a standard axel before so the thrust bearing measurement etc seems ok. The problem I'm having is when I tighten the spool to the axel housings with the 6 bolts I can not turn the driveshaft. When I leave those bolts loose I can turn it but it feels choppy not smooth, like the pinion and ring gear are not meshed right.

I am able to shift the axel from low to high and back no problem. When on the axel stand with the ford half off and the driveshaft connected with the bolts, again if they are tight the shaft is hard to turn. Without the driveshaft connected, the ring gear and ruxstell turns fine. The pinion and ring gear look like they are meshed ok.

The inner workings of the Ruckstell seemed to go together fine, everything as per the Chaffin's book. The ball bearing on the Ruckstell side seemed a little loose but not excessive. My problem seems to happen when I get to the driveshaft attachment. I'm tempted to go back to the old cage drive shaft spool bearing set up and see if that elevates my issue.

Any thoughts of what I might be doing wrong? I may be in need of a hands on tutorial. If there is anyone within driving distance of Reading PA that would help me out for a club donation I'd be grateful.

Thanks

Bryan

[DanTreace]

Might not be part of your issue, but having installed several modern pinion bearings, had to check and re-check any interference of the locking collar.

On some driveshaft tubes, there are spuds of weld that can strike the locking collar set screw. At times had to grind smooth the inner tube at that depth spot, and at times had to trim the edge of the exposed set screw to be sure of no contact. Simple thing, but that collar set screw can catch and keep the drive shaft from turning.

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[speedytinc]

Have seen this primarily in shortened shafts that were not square. Could spool modification be off?
Could confirm bent or out of square by remounting D/S 180 degrees off.

[Chris Instness]

I have had the same problem Dan mentioned. If you are using a modern spool it is likely you may have to clearance the torque tube or grind the corner off the Allen screw on the shaft collar. Same symptoms you mentioned. Turned ok when not bolted to the axle, but would not turn after the pinion spool bolts were tight.

[Jerry VanOoteghem]

Put some prussian blue on your gears and rotate them to check the contact pattern of your gear mesh. It's the only way I know of to determine what's right or wrong with your alignment. Do not set gear mesh based solely on backlash!

[FordFool]

Ring gear bolts hitting the pinion gear??

[jab35]

Which shim(s) did you use for the pinion bearing? I found the "stock" shims gave correct mesh & clearance (with correct ring rear/axle thrust washers). fwiw, jb

[oliverguy]

Thanks for the advice everyone! It turned out to by the set screw on that collar contacting the inside of the driveshaft tube. It definitely looks like enough clearance, but I guess not!

[Jerry VanOoteghem]

Thanks for the advice everyone! It turned out to by the set screw on that collar contacting the inside of the driveshaft tube. It definitely looks like enough clearance, but I guess not!

Excellent! Thanks for the update!