Jump to content

Unofficial Home of Old Simplicity & Allis-Chalmers Garden Tractors

sammiefish

312H differential washers ... again,,,

Recommended Posts

sammiefish
Im hoping someone can comment here.... I'm having difficulty deciding which way to go here. I have disassembled my differential to replace the washers on the axle tube side of the gear. What I removed was 3 washers... 2 machine bushings and 1 spacer washer... the bushings are .060" ea and the washer is .073" for a total thickness of .193" Ive read the differential article here on SimpleTractors and understand there was some discrepancies in the drawings for other applications. What I found in my parts manual is what I believe to be what I found in my differential #'s 11 & 12: 300 parts manual pic:


In the more recent 3/400 service manual it states to install 2 washers .0747" in the case. 3/400 service manual pic:


When cross referencing the 2 part #'s (11 & 12) they have been merged into a single part # and superceded to #2860190 WASHER 1 125 1 13IDX  so: total thickness of what I removed (old and maybe worn) = .193" the total thickness of what is recommended by the service manual is .1494" but is likely missing a washer in the description so if there were 3 it would be .2241 meaning I possibly have .0311" of wear to "replace" ??? Lastly, the grooved washer on the hub side of the differential has notches cut to accomadate the keys in the tube.... Were there originally notches? If not, the wear on the axle tube side washers would explain why someone would notch this washer. Any thoughts or recommendations... or does anyone know or know where I could find out the thickness of the new part #2860190 WASHER 1 125 1 13IDX ??? and for fun... here is a pic of the washers I removed... the bottom row are the old... the left one is the washer outside the hub and the 3 to the right are the axle tube washers... you see the damage caused when they were pulled over the keys...


Thanks

Share this post


Link to post
Share on other sites
HubbardRA
I will say this once again. Use only one washer behind the gear if you want to make sure the diff works properly. If you put three washers on before installing the gear, the diff will most likely be locked. To use two washers behind the gear is a "maybe it will work, and maybe not". Only one washer, and the diff will work as it is supposed to. All the other washers must be installed, but they need to go on after the gear is installed. The total stack height is necessary to position the right hub in the correct position. Remember that the location of these washers are doing nothing more than moving the gear inward or outward on the axle. The gear needs to be kept inward to avoid it meshing with both sets of spyder gears and locking the diff. As far as the notches go, if the washer has to fit over the keys then use the notched washer in that position. If it is on the smooth shaft then notches are not needed. Simple as that. This is not rocket science, just a simple mechanical assembly. Don't make it hard by overthinking the situation. Put it together, it will either work or be locked up. If it is locked, then move the washers around till it is unlocked. How hard is that to understand?

Share this post


Link to post
Share on other sites
sammiefish
thanks Rod, I agree, its really not that hard to understand... just a pain to split the diff more than once to move washers around.. new axle tube an all... ive been down for about 2 months with this monkey business... Ill get 'er though!!

Share this post


Link to post
Share on other sites
HubbardRA
Chris, When I assemble a diff, I have the bolts pointing toward the tranny with the nuts on behind the flange. With that setup, the right hub can be removed, then the diff can be unbolted and slid off in one piece. This makes moving the washers much easier. Sometimes, if the gear is not stuck on the keys, you can remove the right hub, then reach in with pliers and remove the outer washers, then the gear, without even removing the diff.

Share this post


Link to post
Share on other sites
sammiefish
hmmmmm... good setup idea... similar to the bolt weld trick i did on my 160039 tiller... where you can replace the 3 flange bearings without splitting the case.. of course mine was an early design .... : ) hmmm... thanks!!!

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


×