Loud wooing in front end... Help!

[HummDinger]

Update: I ended up doing a full rebuild to transfer case minus chain (sorry I didn't do a step by step... I was short on time when I did it) . All bearings were really bad. Apparently borg warner decided to use a bushing in the main drive gear instead of a bearing. The thing was all but gone and the main shaft was destroyed

Old and new bushing side by side.
Then I got to do it all over again when the new main shaft came in. [emoji12]

That took care of a lot of racket from the drive train but I'm still getting that same noise coming from the front diff. I have replaced every bearing in the front diff minus the wheel bearings. The only other thing I can figure is possibly a warped ring gear.
Has anyone else had issues with a warped or worn ring gear to the point it was making quite a bit of racket?

 

[Ghostbuster]

Man that sucks. Well it seems like it is time for new hubs and to re gear the front diff.

 

[Jeremy]

I'm just here to take notes. I'm sure this will happen to my truck soon.

 

[4speedfunk]

Warped ring gear?

 

[RamRod]

Wow that is quite the bushing!!

 

[HummDinger]

It does suck... I'll just keep plugging away at it and update as I find more problems. Thanks all

 

[4speedfunk]

Have you removed the front driveshaft and driven it? This will isolate the front axle from the drivetrain....see if the "wooing" disappears or changes pitch. Use 4HI-lock mode.

 

[HummDinger]

I have done that, and though it is quieter, the noise is still there and the same. I will be taking the front cover off and inspecting gears for any funny wear as well as re-checking the lash and backset of the pinion just in case something was screwy during the install. I did do some trail riding on Sat. (nothing crazy) and the noise got significantly louder. Hopefully it will be easier to pinpoint the issue now.

 

[4speedfunk]

My guess would be a pinion bearing pre-load issue. It should be 6-10 in/lbs. on a used bearing. You will need to pull the carrier and ring-gear out to properly check it. You will also need an inch-pound torque wrench (with a dial), to accurately measure it. Unfortunately, you must pull both half-shafts and remove the coupler and stub shaft from the drivers-side...just to get the carrier pulled out of the pumpkin. In other words...its so much work that its really best to yank the entire assembly out and get it on a workbench for a closer look. Before you do all that (or even pull the front cover)....

Just grab the yoke with your hand and see if you can feel any "shake" or "rattle" in it. You should be able to feel a slight rotational clunk (backlash) as you rotate it back & forth...but there should be no in-out movement or side-to-side movement at the yoke. Also, you should not be able to free-spin the yoke, (spin it like a top). If you have any of these issues, then you have no pinion bearing pre-load. Next...get a pan and pull the front diff drain plug. Its magnetic and it can tell you alot about whats goin on inside. If it looks like a metallic Chia-Pet...something has let go inside:

Slight dust=NORMAL
Shavings=BAD
Slivers=VERY BAD
Chunks=TOAST

Whatever the case, working on the AAM-7.6 is a piece-o-cake once you get it out from under the truck. If you have any of these tell-tale signs...just pull the whole axle out and do a tear-down. Its very difficult to fix anything with it installed in the truck. Its a tinker-toy of an axle, and one person can easily pull it and hump it over to a workbench. Let us know what you find out with the yoke jiggle.

 

[HummDinger]

Thanks 4speedfunk. My preload is good, but my ring gear... That's another story...

90% of the teeth on my ring gear are cracked [emoji36] At least I know what the problem is. Gonna get some prices on taking it to a driveline shop... What's a decent price to replace ring and pinion if I bring them the axle and new ring and pinion?

 

[4speedfunk]

If you bring a walk-in axle...I would say a fair price would be $300 in labor for a set-up and rebuild. You've already got new pinion bearings but you will need a new crush sleeve and R&P for sure. Also the entire set-up will need to be checked for the new R&P. You might consider replacing the carrier bearings, since that's the only used parts you'll have left. I normally replace the CV seals as well.

R&P's run around $150 - $350 depending on the brand. Backlash settings are quite different for 2-cut and 5-cut designs so make sure your builder is aware..

If all else fails...ship it over here and I can do it for you and send it back.

 

[Guerrero]

Ok, I know I'm new, and from Spain, but have you think about the tires?

I have a similar noise, that 4speedfunk tries to help me to pinpoint in another thread about the front driveshaft. My noise is very similar to yours but not only coasting, it's happen all the time, accelerate, coasting etc, but if I let the car run in Neutral the noise almost dissapear but can listen a bit. My noise suddenly appear at 30 mph, and beyond that is louder depending on the speed.

I put the car like you in four jack stand and run it until 30 mph and nothing of noise, but the tires were very bad, very bad wear pattern that can be seeing while the tires are turning. I still no change the tires because of money, its a set of four BF Goodrich All Terrain KO's 285 75 R16 from 2009 with 45000 miles. Try to put another tires if you know someone with an H3 near you to know that is not the tires...because probably they are the problem.

Hope that helps you out.
Best Regards, Guerrero

 

[HummDinger]

I got a price from a local off road shop today for 850 with a new G2 ring and pinion master rebuild. Still waiting for a price from another shop. I don't think I could be without a vehicle for that long but I really appreciate your offer. What state are you in?

 

[4speedfunk]

I'm in Indiana...46151.

 

[Schwarttzy]

I have yet to have a serious issue with my H3, but in the past I would just head over the wrecking yard and pull a used differential. Especially at that price. Bit of a risk, but I've never had issues.

 

[4speedfunk]

Great advice. At the very least...grab one for a spare and swap them out periodically. That way you always have a fresh one on the shelf and much shorter downtime if (when) something happens.

 

[HummDinger]

Thanks guys, I will be heading over to the local lkq to see what they have available since they won't tell me over the phone[emoji19] ... I've called around to other local yards and nobody seems to have them.
Thanks again everyone for all your time and efforts

 

[HummDinger]

Question... will a locking front diff from a newer model h3 work in my 2006? (http://www.gmpartsdirect.co/oe-gm/25800300) and what would it take as far as the install...would i just need a switch and relay or would i need the module box and all that for that specific locker? If that wont work do you have any recommendations on a locker or limited slip even, for the front of that thing? I would like to stay under $800 for the locker. the only one I can find that looks like it will fit is the ARB air locker and that's over $1000.

Thanks for your help

 

[4speedfunk]

Question... will a locking front diff from a newer model h3 work in my 2006?
Yes...a locker can be added to your stock 06 axle. You will need to drill a hole in the top of the pumpkin for the E-locker wiring. I would recommend you upgrade to the cast iron housing if you want to run a locker.

gm/25800300
That part number looks to be nothing more than the stock single track diff case (empty).

would i just need a switch and relay or would i need the module box and all that for that specific locker?
You can use a generic switch/relay rig...but it will be dependent on you (the driver) knowing whats going on, and when to use or not use it. Factory lockers are wired so they are automatically defeated in 4HI-Street and 4HI-Lock modes, and only operate in 4LO-Lock (Off-roading for Dummies). You will not have the auto-defeat if you wire it up using the typical aftermarket method. I recommend a lighted-switch so its obvious when its engaged.

If that wont work do you have any recommendations on a locker or limited slip even, for the front of that thing?
No.

I would like to stay under $800 for the locker.
Probably not gonna happen. In fact...I cannot find any info from Eaton regarding the E-locker for the AAM-7.6. It no longer appears in their catalog. I know some guys have bought them thru GM but, I cannot find any such part in all my searches. I sort of get the feeling that a locked AAM-7.6 was a bad idea, and everyone involved is acting like it never happened, (like asking Germans about the 1940s).

the only one I can find that looks like it will fit is the ARB air locker and that's over $1000.
Yup. Plus on-board air system. Its a lot of money considering lockers do nothing to "strengthen" the assembly. To put it bluntly...the AAM-7.6 is a turd. Adding a locker makes it an expensive turd, (but still no less of a turd). Go easy on the go-pedal, avoid wheel-spin, and always keep a spare assembly on the shelf. That's the best advice any of us have come up with.