Cruiserdrew
On the way there
Looks like the pinion is just a bit to far into the differential. But it's a game of thousandths at this point.
Diff Rebuild Walk-through - '81 with 4.11s and New Rear ARB Locker (1 Viewer)
- Thread starter theamigo
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- Thread starter
- #22
Thanks. That's what I'm changing now.
Just a tip - when you want to check your pattern, rotate the pinion and drag the ring gear with your palm or something to put some load on it . Doing that will help define the pattern a lot better so it doesn't drag the paste across the teeth so far - it will give a much clearer imprint of the actual tooth contact pattern.
From the looks of the pattern, I'd say reduce the shim slightly. Some seem to respond faster than others - every gear set is always ground slightly different , it's just the way they are.
Sarge
From the looks of the pattern, I'd say reduce the shim slightly. Some seem to respond faster than others - every gear set is always ground slightly different , it's just the way they are.
Sarge
- Thread starter
- #24
Understood. I thought I was dragging it enough but I'll try harder next time.
- Thread starter
- #25
Update: I went from .35mm down to .10 in .005mm increments on my depth shim. I took pics each time. I seem to have a better pattern at the starting amount of .35mm. I then went up to .40 just to see what happened. Check out the earlier posts for .35mm pics.
The pics below are all at .008” backlash with carrier bearings adjusted properly.
Notice that with more shimming the inner part of the coast is actually closer to the middle of the tooth.
Here’s .10mm:
Here it’s moved up to .40mm of depth shim: Based on my limited experience I think this is an acceptable pattern for a used ring and pinion.
The pics below are all at .008” backlash with carrier bearings adjusted properly.
Notice that with more shimming the inner part of the coast is actually closer to the middle of the tooth.
Here’s .10mm:
Here it’s moved up to .40mm of depth shim: Based on my limited experience I think this is an acceptable pattern for a used ring and pinion.
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Cool, last pattern looks very close, good enough to run for sure.
After adding .010 to the pinion depth shim pack, you will need to remove .010 from the preload shim pack to get the same preload. At least that is the way Toyota does it in the early FSM where the thin preload shims correspond each to one step thicker in the pinion depth shim. So adding two steps to the depth means subtracting two shims from the preload stack. The preload is set by a set of 20 different thickness preload washers.
- Thread starter
- #29
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- #32
I'm now finished with the ARB setup, save the final installation into the axle.
It's setup much like a normal differential with the exception of a few additional steps required to plumb for the seal housing.
After removing the ring gear from the original diff I gently baked it in our oven at 190 for about 45 minutes. I checked it with an infrared thermometer every 10 minutes to ensure the temp was steadily rising, and I took it out around 175 degrees. It easily slid onto air locker with the holes lined up. I cleaned the threads again, and applied thread locker and torqued the ring gear bolts down to the manual's recommended 86 ft-lbs.
Carrier bearings went on next. Used the cones from the old ones to help drive on the new.
Also drilled and tapped the housing using a 7/16" drill with a 1/4" NPT thread tap I picked up from Ace Hardware.
I then unwrapped the seal housing to check it out prior to install. It comes in a Cosmoline impregnated paper. Looked a bit crusty? I spoke with Kurt @cruiseroutfit and he says the discoloring from the cosmoline was a bit more than usual but regardless they always clean them out, and are sure to blow compressed air through the tube. I did the same.
It's setup much like a normal differential with the exception of a few additional steps required to plumb for the seal housing.
After removing the ring gear from the original diff I gently baked it in our oven at 190 for about 45 minutes. I checked it with an infrared thermometer every 10 minutes to ensure the temp was steadily rising, and I took it out around 175 degrees. It easily slid onto air locker with the holes lined up. I cleaned the threads again, and applied thread locker and torqued the ring gear bolts down to the manual's recommended 86 ft-lbs.
Carrier bearings went on next. Used the cones from the old ones to help drive on the new.
Also drilled and tapped the housing using a 7/16" drill with a 1/4" NPT thread tap I picked up from Ace Hardware.
I then unwrapped the seal housing to check it out prior to install. It comes in a Cosmoline impregnated paper. Looked a bit crusty? I spoke with Kurt @cruiseroutfit and he says the discoloring from the cosmoline was a bit more than usual but regardless they always clean them out, and are sure to blow compressed air through the tube. I did the same.
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- Thread starter
- #33
I then proceeded to set up the diff as per usual, according to the factory manual. The slight variance here is that ARB supplies their own adjusting nut for the seal housing/ring gear side. I had to make a new DIY tool to adjust it since it doesn't fit the tool I made for the stock adjusting nuts.
After the usual progression through several iterations of depth shims and preload shims I came out with all specs in the right range, and good patterns:
Everything had thread locker applied and was torqued down as specified in the FSM.
I then finished by installing the seal housing and routing the tube through the hole in the bulkhead. I then installed the bulkhead parts as per the instructions, and pressure tested the locker.
Before I mount it in the axle I'll refine the bends a bit more to ensure proper clearance.
Seal housing installed, with spring clips.
One thing I saw was that the seal housing is made to rotate back and forth, slightly, when the pinion direction is changed. The instructions state this is expected, and necessary, so that the seals float on the bearing journal and self-align as it rotates. I also confirmed with Kurt. It's good. And no, the seal housing tube does not get to close to the bearing caps.
After the usual progression through several iterations of depth shims and preload shims I came out with all specs in the right range, and good patterns:
Everything had thread locker applied and was torqued down as specified in the FSM.
I then finished by installing the seal housing and routing the tube through the hole in the bulkhead. I then installed the bulkhead parts as per the instructions, and pressure tested the locker.
Before I mount it in the axle I'll refine the bends a bit more to ensure proper clearance.
Seal housing installed, with spring clips.
One thing I saw was that the seal housing is made to rotate back and forth, slightly, when the pinion direction is changed. The instructions state this is expected, and necessary, so that the seals float on the bearing journal and self-align as it rotates. I also confirmed with Kurt. It's good. And no, the seal housing tube does not get to close to the bearing caps.
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- Thread starter
- #35
So. That completes my front and rear diffs! My restoration is now on to installing the axles and moving ahead full speed to a rolling chassis. Please check out my build thread if you're interested!
Ready for mounting:
Ready for mounting:
Very nice! Looks pretty perfect
What plating did you have done? Is that zinc?
- Thread starter
- #38
Everyone calls it "cad plating" but nowadays it's a zinc base layer with a sacrificial gold chromate top coat.
Commercial Electroplating - Production Zinc, Nickel, and Tin Plating Services - Fresno, California treated me well. It seems they run this type of stuff through during lags in their main business. Took about 2/3 weeks to ship it off and get it back. Very happy with them. If you call, talk to Steve. While they do clean and dip the items before plating my suggestion is to also clean and brush larger particles and globs of stuff off before sending. The cleaner they are the cleaner they come back.
