While assembling my Ruckstell I ran into a little problem. All of the parts involved are new, bought from Snyder's. I assembled the differential then the sun gear P-144 and the planet gears P87. Problem is when I place the thrust plate P-145 on it is binding the sun gear, not allowing it to turn freely all the way around. It seems like the sun gear is a few thousandths too tall. The edge of the sun gear is slightly taller than the planet gears. Everything works fine till I tap the thrust plate down to seat it on the shoulders of the differential housing.
It looks like I could place some thin .001-.002 shims under the thrust plate where it mounts to the differential housing to get the space. I am on the large side of the clearance when I assemble to the bronze thrust plate P-139, about .005 and .006. Other than shimming about the only other thing would be to reduce the height of the sun gear, maybe sand paper on a flat plate. I think I just got a mix of parts that are all on the large side of the tolerances.
I do have the club book and the Milt Web book, nothing in either about this problem.
Any suggestions, am I missing something obvious? This is my first ruckstell.
Check w/Glen Chaffin in Calif
Do you have the P145 upside down? Are you checking clearances with the original axle gears assembled inside the P202? Is the spacer between the two axles too thick? Too thick of a spacer can bind things up.
Just a word of warning - the bronze thrust plate can be easily warped when pressing on the bearing. It happened to me and I had to press it back straight. Once that was done, it worked great.
I agree with John. Dave at Chaffin's stepped me through a lot of issues when I was rebuilding mine last year. 951-735-4791
Dig through your parts pile and find a worn steel washer. I assume you replaced the fiber washer in the back end of the bell with a steel washer instead of using the fiber. New ones tend to be a couple thou thick. That whole assembly just floats in the bell and reducing the thickness of the washer is the trick. You can also face off the end of the differential carrier a few thou if you have a lathe.
My spacers were good, and the axle gear was lower than the bottom housing. A friend who saw this on the forum suggested I cut a little from the center of the P-145 thrust plate, the raised ring where the sun gear rides. I cut off .0025" and everything went together and spins free now. Thanks for the replies
It's your deal, you can fix it any way you want but I would not have cut anything off the hardened thrust plate when there are at least three other areas to gain the clearance needed.
1. The thrust washer between the bell and the inner differential.
2. The end surface of the bell end of the inner differential.
3. The end surface of the thrust end of the inner differential. (Which is what I would have machined)
Stan maybe I am mis-understanding. It is the clearance between the sun gear P-144 and the thrust plate P-145, When I press the thrust plate on to the pins, to fully seat it, it binds with the center sun gear. The center sun gear can be felt to be higher than the planet gears.
The Milt Webb books talks about machining the axle gear if it is too high in the differential housing, that may cause binding.
This is my first ruckstell, so I am learning here. Last night I looked at your suggestions and could not visualize how that would effect the center sun gear to the thrust plate clearance. Please dont think I am arguing here, I have enjoyed and learned much from your postings about ruckstells.
The end of the inner differential carrier -- inside the three pins -- where the sun gear rides, is easy to machine to give a little more clearance for the sun gear. It is cast iron and easily machined.
I do not machine hardened surfaces as most of them are case hardened instead of through-hardened.