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How to replace ONLY ring gear and pinion without full rebuild?

lagunaMS

4 by drive
Joined
Nov 25, 2020
Member Number
3077
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Dixie
This is in a 97 Chevy K1500 with 6" lift on 35s, factory IFS front diff, GM 9.5" semi-float rear axle.

If I want to replace ONLY the ring and pinion in my rear axle, what is the absolute minimum I need to do in order to not burn anything up?

I already have a spare front IFS diff rebuilt with 4.88s and will install that after the rear axle is re-geared. I already have the gears for the rear axle. I don't want to replace bearings/seals or anything because they're all good and I'll be switching to a full floater later. Also leaving in the factory G80 carrier. It sucks but it will do for now.

I want to do this for the meantime for 2 reasons: the IFS diff is already rebuilt and re-geared, and I already have the rear gears. A SAS is on the horizon but this will get me 4.88s while I gather the SAS parts.

Can I just remove the carrier, unbolt the old ring gear and install the new one, install the new pinion, put the shims on the same sides as how they came off, check the pattern, and go if the pattern is good?

I'm willing to buy the dial indicator and whatever else because I plan on re-gearing the new SAS axles myself anyway. I plan to search the other threads where people have posted their patterns and review the feedback people gave. In a perfect world my pattern will be close enough but I want to be prepared in case it's not.

Trying to avoid wasting $500 on this axle getting a shop to do this if this is semi-doable myself.
 
9.5 are the ultimate half breed bastard.

Adjusting collar on one side, cast iron shim on the other. A shim kit will be 1 builder/super shim and pinion shim. Get 2 crush sleeves.

You want a dial indicator unless youve built a lot of diffs.
 
Thanks, I'll add that to the list. This will be the first diff I've ever done. Hopefully I'm not getting in over my head with it
 
I'll give this a semi-piggy back question. If I am moving gears from one D60 to another D60, which shims should I start with; donor gears or target housing?

I'm considering stabbing some 5.86 gears in my current 3.54 axle. All bearings look good.
 
Last time i did that ikept the shims with the housing and +.005 to the flange side of the carrier and it dropped right in perfect pattern. Not gona happen every time but it can
 
Last time i did that ikept the shims with the housing and +.005 to the flange side of the carrier and it dropped right in perfect pattern. Not gona happen every time but it can

So in your opinion, strip the 5.86 gears to bare then use shims/bearings that are in the target housing?
 
Update if y’all care, decided to start on the axle last night and today I got the diff reinstalled and pinion preload and backlash were all good. Went to check the pattern, had my dad hold some tension on the carrier while I turned the pinion, nice steady turn when all of a sudden there was a crunch and it got super loose.

went back behind the truck and rolled the carrier and noticed I forgot to put the goddamn center pin back in so the spiders got all wonky and busted up some of the small pieces of the factory “locker.” So this carrier is trash now. I was pissed and felt retarded, but oh well shit happens. Being mad about it ain’t gonna fix it so I’m trying to stay calm about it.

Luckily a K20 I just bought to make a truck bed trailer out of has an 8 lug semi floater in it. I’m planning to use the carrier out of that and just put the ring gear on that and then proceed to checking backlash and run another pattern this weekend.

Any reason why this wouldn’t work?
 
Did you just try to run the truck to turn the gear a d run the pattern?

No I was turning the pinion with a dial torque wrench while my dad was holding tension on the carrier.

It was turning fine at first but without the center pin in place the spiders gears fell out of place and caused it to bind up and crunch some of the tiny parts of the locker.

Is that what you were asking?
 
I just didnt understand how you could turn anything hard enought to smash metal parts hand turning a pattern.

This.

Also don’t worry about pinion trying to set pinion preload while still trying to set pinion depth and backlash. Good lord that would make things a nightmare.
 
I just didnt understand how you could turn anything hard enought to smash metal parts hand turning a pattern.

This.

Also don’t worry about pinion trying to set pinion preload while still trying to set pinion depth and backlash. Good lord that would make things a nightmare.

I wasn’t turning it super hard or anything. I was following what the GM service manual said to do- create enough resistance so that when I’m running a pattern it takes 40-50 ft-lbs of torque to turn the yoke. My dad couldn’t hold it right enough to make that resistance so I put the e-brake on some to add more drag.

I didn’t break spider gears, the pieces that snapped were some tiny little internal things inside the factory locker that got all cockeyed when the spiders fell out of place and I kept rotating. I didn’t notice it til it was too late because I was right in front of the axle turning the pinion.

As for setting the preload I was just following the order of what the service manual said. Install pinion, tighten nut to seat the smaller pinion bearing and take up the slack. Check rotational torque, tighten as needed and re check torque until the pre load is right. Then I put the carrier back in, checked the backlash which was good, then went to run the pattern and completely forgot the center pin. It was windy as hell today and a gust of wind blew sand into the shop so I had moved the center pin away from where I was working so could clean it, then totally spaced and forgot to put it back in.

I’ll upload a pic tomorrow to show what broke
 
Here’s what broke, I already took the spider gears out but they got sideways and broke this piece. It has a factory shitty locker so I assume it’s something to do with that

photo42336.jpg


photo42337.jpg
 
Also don’t worry about pinion trying to set pinion preload while still trying to set pinion depth and backlash. Good lord that would make things a nightmare.

Do you mind elaborating on what I should do different?
 
Okay I got some progress today. Had excessive backlash with the new carrier so added a shim to the driver side. Got .005-.006 backlash after the shim. Ran a pattern with a load on it and got these results. Am I correct in thinking I just need a thinner pinion shim? If I remember correctly the shim that was already on my pinion, which I reinstalled, was .024. Here’s the pattern I just got if anyone has any input

photo42719.jpg


photo42720.jpg
 
The more I look at this pattern and compare it to other people’s they have posted and gear pattern charts, I’m starting to think these patterns are acceptable to run like they are. This truck is a DD and sees a lot of street time. Good to go as-is? Or do I have more fiddling to do?
 
It’s a touch deep, if you really wanted to mess with it I’d say pull 0.003” out reset BL and recheck pattern again. Or run it cause it’s damn close.
 
It’s a touch deep, if you really wanted to mess with it I’d say pull 0.003” out reset BL and recheck pattern again. Or run it cause it’s damn close.

Thanks, if it’s safe to run it like this then I’ll probably do that
 
I drove a couple warm up laps around the backroads yesterday and then did a 20 mile commute to work today. No noises under acceleration, slight ringing on deceleration with the clutch out, and on deceleration with the clutch pushed in there is also a rattling sound. The carrier I used was from a squarebody semi floater axle so I'm sure it had some miles and abuse on it, but I didn't have a bearing puller to get the carrier bearings off and they seemed ok so I used them. There was a lot of play in the spider gears that I noticed when installing. If I get under the truck I can rotate the drive shaft about 1/2" in either direction and it makes the same noise as the rattling I'm hearing when I decelerate, so I think it's slack in the spiders gears that shows up when there's not a load on them causing them to mesh tightly. The yoke has no play whatsoever in any direction- up/down, side to side, or in/out. My rear u-joint has a very small amount of side to side slack.

I'm planning on replacing that u-joint and ordering a spider gear set and installing those after driving a few hundred miles of taking it easy. Does that sound like the proper course of action? Can I add an extra thrust washer behind the side gears in the carrier to make them mesh tighter?
 
Progress update. Drove 300 miles on the break in. Drained the fluid today and it was pretty clean. I put a Lock Right in it instead of new spiders. Rattling is gone so that confirms it was the worn to fuck spiders.

How does my wear pattern look to y’all?

12710212-4AD7-4BED-8400-D8573DD816B9.jpeg


831CC20F-374A-4571-801B-FB98489078E5.jpeg
 
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