Adjust front diff backlash 2013 Suburban

[George B]

Starting with a disclaimer. I know this would not be the ideal or even totally acceptable way of doing this. And I know the repercussions of getting it wrong. That said let me continue.

I have a gear whine when in four wheel drive that is speed dependent and changes during acceleration and deceleration but is present for both. I have noted that there seems to be excessive backlash between the ring and pinion gears. The history on this front end is that about 30,000 miles ago the side bearings in the front diff were replaced. I suspect the tech failed to properly set the backlash or one of the adjusters came loose.

What is the risk in trying to adjust the backlash to correct this? There are no shavings in the front diff and the unit is otherwise smooth and quiet.

What are the chances of my needing to replace the little tabs that are used to hold the adjusters? Can they be bent back and reused?

This is a part time unit that likely has very little running time on the front gears to begin with.

I know there are alot of what ifs here.

 

[swathdiver]

Starting with a disclaimer. I know this would not be the ideal or even totally acceptable way of doing this. And I know the repercussions of getting it wrong. That said let me continue.

I have a gear whine when in four wheel drive that is speed dependent and changes during acceleration and deceleration but is present for both. I have noted that there seems to be excessive backlash between the ring and pinion gears. The history on this front end is that about 30,000 miles ago the side bearings in the front diff were replaced. I suspect the tech failed to properly set the backlash or one of the adjusters came loose.

What is the risk in trying to adjust the backlash to correct this? There are no shavings in the front diff and the unit is otherwise smooth and quiet.

What are the chances of my needing to replace the little tabs that are used to hold the adjusters? Can they be bent back and reused?

This is a part time unit that likely has very little running time on the front gears to begin with.

I know there are alot of what ifs here.

View attachment 248002

Did you talk to Matt?

 

[George B]

Did you talk to Matt?

A little bit. Not sure if he opened his case or changed seals only.

 

[swathdiver]

A little bit. Not sure if he opened his case or changed seals only.

He rebuilt the whole thing and detailed it with pictures if I remember right.

 

[George B]

He rebuilt the whole thing and detailed it with pictures if I remember right.

I reached out to him more.

 

[George B]

After some more reading I have realized it will need to come out to be serviced. It looks like something I can handle. I am not sure if it will need a ring and pinion or if I can get away with a bearing inspection/replqce and lash reset. Probably would need to have a set of bearings on hand along with the seals and adjuster lock tabs. I don’t have the spanner or bearing pullers either.

 

[swathdiver]

After some more reading I have realized it will need to come out to be serviced. It looks like something I can handle. I am not sure if it will need a ring and pinion or if I can get away with a bearing inspection/replqce and lash reset. Probably would need to have a set of bearings on hand along with the seals and adjuster lock tabs. I don’t have the spanner or bearing pullers either.

I've been grabbing the special seal and bearing installers off ebay here and there. Still need the bearing pullers. I think your ring gear looks ok but would want to see the pinion. Mine has a noisy bearing that makes a racket between 35-45 mph.

 

[George B]

Bumping my old thread. I am wondering if I could get away with trying to adjust the lash on this. If I can bend the adjuster tabs back I should be able to turn the adjusters and move the ring gear closer to the pinion. If a tab breaks I will be committed to spitting the case tho. The question is, “Is it worth $800.00 to try it?”
I only run the front diff a hand full of times when I snows or in a boat launch. Ever at high speeds for long runs. Really, I have nothing but time, some RTV and a couple adjuster lock tabs to lose.

 

[swathdiver]

Bumping my old thread. I am wondering if I could get away with trying to adjust the lash on this. If I can bend the adjuster tabs back I should be able to turn the adjusters and move the ring gear closer to the pinion. If a tab breaks I will be committed to spitting the case tho. The question is, “Is it worth $800.00 to try it?”
I only run the front diff a hand full of times when I snows or in a boat launch. Ever at high speeds for long runs. Really, I have nothing but time, some RTV and a couple adjuster lock tabs to lose.

I don't know enough to offer any more advice on what you are asking. I do know that you can get one out of a scrap yard for half that price or less. Mine is noisy whether it is engaged or not. Noise doesn't change.

I'm just hemming and hawing on whether or not to do a gear ratio change and when to get my hands on a 9.5" 14-bolt for the back.

 

[ivin74]

Bumping my old thread. I am wondering if I could get away with trying to adjust the lash on this. If I can bend the adjuster tabs back I should be able to turn the adjusters and move the ring gear closer to the pinion. If a tab breaks I will be committed to spitting the case tho. The question is, “Is it worth $800.00 to try it?”
I only run the front diff a hand full of times when I snows or in a boat launch. Ever at high speeds for long runs. Really, I have nothing but time, some RTV and a couple adjuster lock tabs to lose.

If the adjuster tabs break, center punch the threads on the adjusters after you make the adjustments. The bad thing about this method is that the adjusters will not be usable and would have to be replace when the diff gets rebuilt.
Several years ago my diff was whining, I adjusted the adjusters, center punched the threads and it ran fine. I rebuilt the front diff since then and I also center punched the new adjuster threads.

 

[George B]

I haven’t dealt with this yet but I am thinking about it again. I am contemplating dropping the front diff out and adjusting the backlash to see if it quiets up. Bonus if it does. I would only be out $100 and my time.

But…
There is a part of me that says if the diff is out just install a reman and forget it. That’s $800.

Not sure.

 

[exp500]

Pic isn't the greatest for me, is the pinion depth correct? I would try that 1st.
We know it's in good hands with you.

 

[George B]

Pic isn't the greatest for me, is the pinion depth correct? I would try that 1st.
We know it's in good hands with you.

I don’t know. I have never had it open. I noted in the service history that it had bearings replaced at around 38k. I noted was noisy and low on lube when I used 4wd the first time.

 

[George B]

This came full circle this weekend. I noted I didn’t have functioning four wheel drive. I assumed the actuator in the front axle was bad until I saw a puddle of gear oil on the floor. The right side axle had come loose from the snap ring and walked out of the housing.

Upon closer inspection After disassembly I found that the snap ring had worn through the washer inside the extension housing.

I also saw that the adjuster retainer was broken in several places on the right side.

I rounded up a new washer, a pair of seals, two adjuster retainers and an extension housing gasket. Once I placed the new washer in the housing I noticed that I couldn’t tighten the extension housing without it binding the shaft by pinching the snap ring into the washer. I welded some tabs onto socket so I could turn the adjusters and reset the lash as best I could for a used axle. That moved the carrier over far enough to allow the extension housing assembly to be installed and allowed for a little end play for the right axle shaft. The rest went together without a hitch and it now runs smooth and quiet.

Whoever was in here before was incompetent!

 

[George B]

Pic of the retainers properly installed

 

[George B]

The backlash before I started.

 

[89Suburban]

Good job buddy!

 

[Geotrash]

Well done! That's a job I would've farmed out, so it's very cool to see you get it done. Any tips for those of us who might have to tackle it in the future?

 

[George B]

Well done! That's a job I would've farmed out, so it's very cool to see you get it done. Any tips for those of us who might have to tackle it in the future?

Thanks, I considered farming it out for a long time. The things that led me to go ahead and try it was the failure and the style of adjusters it has. I was not interested in working with the stupid little tabs they used to lock the adjusters in the older units but I would have. It only meant I would have to split the case. These made it easy. My hand was forced to attempt this repair when I was out a vehicle without much to lose.

I have alot of shade tree experience with stuff like this even though I may not come across that way. When I was younger I never shied away from something like this. I will spend copious amounts of time going over a job so I know what it will take.

For tips, I would say if someone lacks experience getting the tools you need like a dial indicator and a needle pointed inch pound torque wrench would be good. I have neither at the moment but could borrow/buy them if needed. I did this by “feel” and am confident in my work. Not having a tool to turn the adjusters would have been a deal breaker. I made one real quick but now I need to replace that socket. I would say not to overcomplicate the repair. Watch a bunch if videos and read a bunch of stuff. Then go get dirty.

 

[George B]

My home made tool for the adjuster nuts.