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I think I oops my differential
Posted by: Kristi ()
Date: October 07, 2021 05:39AM

My differential was leaking FOR DECADES around my side bearing adjusting sleeves so while I was changing out my brake lines and everything associated with them, I decided to go down that worm hole and change out the o rings. I saw a YouTube video that suggested that 5 turns out would give you access and you could change out the o rings then turn it back in. I was very careful. After every turn I remarked my progress and turned slowly and methodically. Well, when I reached 5, the adjusting sleeve was loose. I could have just pulled it straight out. I didn't, but changed the o ring- old one was probably the original- and started to screw it back in. I had unscrewed it 5 complete rounds. I can only screw it back 3/4 of a round. What have I done? Is this recoverable with the differential still in the car? This is the passenger side adjusting sleeve on a 1964 Monza convertible with a powerglide tranny.

I need some advice, please. I don't want to have to drop everything to have a proper driving car.

Thank you.
Kristi
1964 Monza convertible 110/powerglide
owned since 12 years old!

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Re: I think I oops my differential
Posted by: Wagon Master ()
Date: October 07, 2021 05:51AM

Two possibilities I can think of.
1. The side adjusting sleeve was not started back in straight and has started to cross thread. Boy I hope not!
2. The carrier has dropped down slightly and needs to be raised back up to align the side bearing with it's outer race.

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Re: I think I oops my differential
Posted by: cnicol ()
Date: October 07, 2021 07:21AM

Most likely the carrier dropped because it was no longer supported by the bearing and well, gravity.

No big deal. With the adjusting sleeve ready and in position to begin screwing it back in, reach through the sleeve with your finger or a screwdriver and raise the carrier so its bearing can enter the sleeve.

Craig N. Coeur d'Alene ID.
66 Black Monza 4dr, 4.2L V8 49k
61 Seamist Jade Rampside 140 PG
65 Canadian Monza 4dr 110/PG 40k
66 Sprint Corsa convt - First car! Re-purchased 43 years later
2+2 gnatsuM 5691

+17 Tons of parts

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Re: I think I oops my differential
Posted by: TerribleTed ()
Date: October 07, 2021 08:10AM

The problem is that these sleeves are adjusted differing amounts. the procedure has nothing to do with 5 turns (they are fairly close to 5 turn but I have seen 4.5 to almost 6 turns). What you should have done is make the adjuster and the case before turning the adjuster. you then turn the adjuster out counting turns until it come out of the differential being careful to locate the exact spot where it become free and can be remove. After installing the new oring you start that adjuster at the exact same spot and then turn it back in the same number of turns it took to remove it. You current issue most likely has to due with the center of the differential not entering the inside of the adjuster freely. You often need to reach through and lift the chunk up a little to get alignment. In order to get you differential perfectly adjusted at this point you would need to access it through the top cover and do the adjusting steps with proper measuring tools as per the instructions in the manual and then check the gear mesh as shown in the manual as well. Since you now have no idea exactly where the adjusters were you can no longer reliably set it back to where it was (which may not have been 100% ideal anyway, but using the procedure I outlined is generally how this is done. We assume that the current adjustments are OK).

---------------------------------------------------------------------------------------------------------

Avid Corvair hobbiest since 1984.
I have personally performed ground up restoration on over 20 Corvairs.
I currently work full time at restoring and repairing Corvairs.
Located in the Atlanta Georgia area.
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Edited 1 time(s). Last edit at 10/07/2021 08:12AM by TerribleTed.

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Re: I think I oops my differential
Posted by: wittsend ()
Date: October 07, 2021 03:44PM

The poster did say, "I was very careful. After every turn I remarked my progress and turned slowly and methodically." They also stated, "This is the passenger side adjusting sleeve on a 1964 Monza convertible with a powerglide tranny."

So, I'd assume they did mark where they started, on only the one side and according to them it took exactly 5 turns before it came out of the threads. Thus, I assume they could get back to where they were to start (correct or not at the point of loosening). The important criteria would be the coming out at exactly 5 turns.

To the original poster; the setup is critical in two ways. The adjusters set both the play (backlash) between the ring and pinion gear AND the bearing preload. It is a matter of left/right positioning of the ring gear and also how much force exists on the bearing to hold everything in place when the torqueing of the parts occurs during driving. These settings are measured in thousandths of an inch (typically .005-.007 backlash) and inch pounds of force on the bearings.

While it is a "do at your own risk" I'd lift the differential as stated with a screwdriver or (sturdy) finger. Tighten the adjuster close to the 5 turns you counted. From there it is all "feel" and guessing as to how far to proceed. Too tight can be as detrimental as too loose. Hope it works out. BTW, the passengers side has the ring gear. So it will be rather heavy on that side.

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Re: I think I oops my differential
Posted by: vairmech ()
Date: October 07, 2021 04:20PM

Well before all the doomsday gets put down I can't tell you how many times I have done this in the car! There is a bit of science to it but not rocket science!

First off make sure the o-ring are is clean, even where it goes into the diff. Don't be afraid to take the adjuster out, makes cleaning easier. When you go back together you need lubrication for the o-ring! Make sure the adjuster starts correctly and you should be able to turn it by hand easily up to the o-ring, that way you know you have it started square. As has been said, you may have to lift the carrier bearing to clear the adjuster. Forget where you started as you will not stop there. You will tighten until you feel the bearing start to come up snug then back off by a tooth. Now go to the other side and do the same thing, the only difference will be when the adjuster comes up snug you will leave it there. ANY other method will leave the carrier bearings loose with NO preload and that is not good. I know there are those of you that mark and count and do other things and you say all was good, maybe it was but as most everyone here knows I go the extra step to make it better.

Ken Hand
Handy Car Care
248 613 8586

Vairmech@aol.com

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Re: I think I oops my differential
Posted by: Kristi ()
Date: October 08, 2021 05:32AM

Thank you all. This makes me feel a little better about my situation. I was very careful unscrewing the adjuster and stopped and marked after each turn as previously stated. When I removed the old o ring, I held it with one hand and removed with the other so as not to move the adjuster from the last point where I had stopped turning. The old o ring was so hard that it crumbled in pieces in my hand once removed! I cleaned the outside of the case and the adjuster very well before I started because i wanted a clean place to work and to mark. Once the o ring was removed, I cleaned the threads well and lubed the new o ring with 80W 90 gear oil. You can say I am OCD since I used to work in surgery at the hospital! I will try this weekend to do as suggested and lift up on the diff with a screwdriver. I want to eventually drop everything but I need space and for my hubby to share the garage!

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Re: I think I oops my differential
Posted by: wittsend ()
Date: October 08, 2021 12:37PM

Yes, it seems far from hopeless. There is ideal and there is tolerable. Regarding a differential that might be a few thousandths and a few inch pounds but it doesn't mean you can't get close enough.

Put it where it seems right to you. Rotate the wheel and check for binding. Gently drive the car and see if there are any noticeable sounds. The adjuster can be moved in smaller increments by flipping over the locking tab rather than moving to the next notch. Regarding any two adjacent notches there are four positions.

Nice to see a female enthusiast. My wife is tolerant..., but not a participant of my hobby. We had a number of females over on the Pinto site I frequent..., but the curmudgeons eventual drove them all away.

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