9" pinion yoke question

olddog · #1 (**permalink**) 06-05-2011, 07:21 PM

I'm re-assembling my 9". The pinion yoke splines had previously been drowned in Lock Tight. This was a major ***** to pull apart and clean up.

Should the yoke splines be coated with lock tight or would something like grease or never seize be more appropriate?

Rick Parker · #2 (**permalink**) 06-05-2011, 08:02 PM

They should NOT have Loktite on the splines. Oil would be fine as they slip together and are constantly bathed in oil during operation. The NEW NEW NEW pinion nut (do not reuse the original) is a mechanically locked torque retaining nut. It does NOT need Locktite. The mechanical thread interferance and the required torque for the nut keep it tight. If at all possible use a machined spacer in lieu of a collapsable one.

LuvDaBlues · #3 (**permalink**) 06-05-2011, 08:20 PM

Get a rebuild manual and find the required torque for the pinion nut. I agree with Rick, machined spacer....... no crush sleeve. Torquing the nut helps with the lash. And yes, set the lash or improper wear happens to the gear set. Hope you have the tools for that.

olddog · #4 (**permalink**) 06-05-2011, 08:29 PM

I am going with a solid spacer.

I have a new nut. I lathed off the tight threads on the old nut for setting up the solid spacer (easier to turn on and off).

I have a couple manuals and some other write ups.

Have a dial indicator for setting the backlash.

olddog · #5 (**permalink**) 06-05-2011, 08:35 PM

Quote:

Originally Posted by Rick Parker

They should NOT have Loktite on the splines. Oil would be fine as they slip together and are constantly bathed in oil during operation. The NEW NEW NEW pinion nut (do not reuse the original) is a mechanically locked torque retaining nut. It does NOT need Locktite. The mechanical thread interferance and the required torque for the nut keep it tight. If at all possible use a machined spacer in lieu of a collapsable one.

Rick does oil ever leak under the nut? I'm sure it will not make it through the threads, but if the surface on the pinion where the nut tightens up to was rough it might leak. I need to check that surface a little closer.

Wbulk · #6 (**permalink**) 06-05-2011, 08:44 PM

Some of those have a rubber seal under the nut. Some have a washer under the nut. If you have a washer you could just use silicone under the washer.

Wbulk · #7 (**permalink**) 06-05-2011, 09:32 PM

The crush sleeve or solid shim between the bearings is just to set the bearing pre-load of 10-15 inch lbs. for used bearings, or 20-25 inch lbs. for new bearings. It is measured without the ring gear engaged and with a lubed seal. Some people leave the seal out until they have the pre-load just right using an old nut. The inch lbs. is the force required to turn the yoke in the arch, not the force to get it moving, that will be higher. The 175 lbs. torque stated for the nut in manuals is supposed to be to crush the sleeve. It is a lot easier to get the crush started with a press and crush it down to within
.100 or so of the old sleeve.

Rick Parker · #8 (**permalink**) 06-05-2011, 10:56 PM

The guys that do this a lot (rear end shop) usually use a modified impact gun if they are using a solid spacer. Once they get the inch pound preload right with the correct length sleeve and any necessary shims the ultimate torque spec for the new pinion nut is not that critical (as long as it stays tight) .

Wbulk · #9 (**permalink**) 06-06-2011, 06:07 AM

Rick that is correct, and the 175 lb. torque for the crush sleeve is meaningless as many times it takes far more than that to crush the sleeve. I would say the crush sleeve method is little harder, since when you are getting close to what you want even a 1/16 th of a turn can change the inch lb. torque a lot.
Where some people get confused is they want to fix a leaky pinion/yoke seal and think they can just change the seal and torque the nut to 175 lbs. . That works for a solid shim but not for a crush sleeve and you may not know what you have.

olddog · #10 (**permalink**) 06-06-2011, 06:18 PM

Ok once again the parts supply industry has failed me.

Solid spacer set up on pinion. Help please.

Supplied bushing is 0.431" long
shims are 0.010", (two) 0.012, 0.016", and 0.020"

Put 0.020" + 0.431" = 0.451" total -- rotating torque 1 inch pound.
Put 0.016" + 0.431" = 0.447" total -- rotating torque 45+ inch pound.

No fricking shim combination between the two.

Any guess how much I need to put back?

Rick Parker · #11 (**permalink**) 06-06-2011, 10:46 PM

Start lapping the end of the bushing on some 600 Wet or Dry on a flat surface with a little light oil. Use your calipers to measure length, and remove .001 then refit, lap some more if necessary. Keep the end surfaces parallel. Baring that, find a local repair shop that can supply various thinner shims.