Keeping it ten years plan, did not happen...

Post by **HenryJ** » Sat Jan 31, 2009 8:22 am

Lots of play in the drive shaft will be the first clue it is going again. That clunk you get during a change in direction for the rear axle. It doesn't happen all the time, but will get noticeable. You will be told that slack in the rear axle and the clunk is normal. That is hard to argue. Some is and there really is no way to measure it and show where the slack is said to be excessive.
It is not likely they will upgrade you to the G80. You can though. Start keeping your eyes open for a good G80 with the gear set you run, or just the carrier.
Pick it up and hold on to it if you find one at a reasonable price. The low mileage disc brake w/G80 complete axle assemblies have been going for $400-$750 around here. You can get a G80 carrier under $100 many times.

The first one I fought the open carrier. Replaced the improperly tempered side gears and damaged spiders. Then the canter pin hole elongated due to the soft carrier. That let everything slop around. Since then I have "cut the chase" and go with the G80.

Jim · Post by **Jim** » Sun Feb 01, 2009 8:32 am

Finally a pic

No mods installed yet except the front air dam.
The V8 is so sweet

I feel like I'm stealing something...I'm getting the same fuel mileage with the Tahoe as I was the Crew.

Jim · Post by **Jim** » Sun Feb 01, 2009 8:48 am

HenryJ wrote:Lots of play in the drive shaft will be the first clue it is going again. That clunk you get during a change in direction for the rear axle. It doesn't happen all the time, but will get noticeable. You will be told that slack in the rear axle and the clunk is normal. That is hard to argue. Some is and there really is no way to measure it and show where the slack is said to be excessive.
It is not likely they will upgrade you to the G80. You can though. Start keeping your eyes open for a good G80 with the gear set you run, or just the carrier.
Pick it up and hold on to it if you find one at a reasonable price. The low mileage disc brake w/G80 complete axle assemblies have been going for $400-$750 around here. You can get a G80 carrier under $100 many times.

The first one I fought the open carrier. Replaced the improperly tempered side gears and damaged spiders. Then the canter pin hole elongated due to the soft carrier. That let everything slop around. Since then I have "cut the chase" and go with the G80.

I can't find any slop in the rear,no clunk, the oil was clear too,

I still think it's the front diff.

Will the G80 work with Stabilitrak?

Jim · Post by **Jim** » Thu Feb 05, 2009 5:56 pm

update, they found the pinion bearings to be a bit loose in the rear, replaced, not it, found the side carier bearing visibly bad in the front diff, replaced that. They thought they had it, not. Now they are back looking into the rear diff as still having something bad.

Jim · Post by **Jim** » Thu Feb 12, 2009 6:19 pm

They think it's the wear pattern on the ring gear. The warrenty co sent a rep out to look at it, he said nothing has failed, won't pay for a new ring and pinion. I'm stuck with a bit of a whine (no more than my S-10 had) but I got the front diff taken care of and new pinion bearings out of the deal. I'll look for a G80 cheap locally.
Any better oil choices for the rear that may quiet the rear a bit?

Post by **HenryJ** » Thu Feb 12, 2009 6:54 pm

Being open it probably has synth? I really don't have any magic additives to suggest.
I did test Energy Release in a gear box and used to run it in the Jr. dragsters with pretty good luck.
That would probably be what I would try. Someone else may have a better idea though?

roadrunner · Post by **roadrunner** » Thu Feb 12, 2009 7:01 pm

If you indeed have a wear related whine in the ring and pinion I don't think there's much you can do to help it. A number of years ago the dealership I worked for even tried having a ring and pinion teflon coated to fix a whine problem. No luck. Sounded the same after it was put back together as it did in the first place. IMO if you can't bake a coating on and improve it I seriously doubt you can add anything to the lube to cure it either.

Jim · Post by **Jim** » Fri Feb 13, 2009 11:05 am

Dealer called me today, they want to keep it another day. It seems they have been through the same rear noise with a Suburban in the shop, they put the ring and pinion in it and the noise was still there. A former GM teacher of one of the techs suggested shimming the pinion out more (which allows more oil to flow behind) and then set up the back lash with the side carrier adjustment. This fixed the Suburban, they want to try it on mine before giving up.

killian96ss · Post by **killian96ss** » Fri Feb 13, 2009 11:29 am

Redline's Shock Proof Gear Oil works pretty good!

I used to run this stuff in a 12 bolt on an old 68 Impala drag car to protect the gears and I even used it in my Crew Cab for a while and despite what some people will tell you synthetics do not affect the operation of the Gov-Loc even though I know you don't have one "yet" in you Tahoe.

Moroso Climbing Gear Lube is also a good product that quiets down noisy differentials and provides great protection.

Lakewood BFL Gear Lube is another great gear oil that will cut down the noise while providing better protection.

Steve

04crewvt · Post by **04crewvt** » Fri Feb 13, 2009 7:14 pm

Come to think of it that's what the shop did to my 84 GMC Jimmy when we re geared with 4:11's ,when we set them up in the pumpkin they whined like a 6 year old in the candy isle who was just told no. They shimmed the pinion and no more noise. Good luck.

Post by **HenryJ** » Fri Feb 13, 2009 7:18 pm

Jim wrote:A former GM teacher of one of the techs suggested shimming the pinion out more (which allows more oil to flow behind) and then set up the back lash with the side carrier adjustment. This fixed the Suburban, they want to try it on mine before giving up.

I like the sound of that.

Jim · Post by **Jim** » Mon Feb 16, 2009 2:30 pm

Done, they said the noise is still there

Which of the Redline weight would you recommend?
SuperLight ShockProof, LightWeight ShockProof, Heavy ShockProof Gear?

http://synlubes.com/redline/gearoil.html
Keep in mind I'm in PA and it will sit outside, we get temps of 15-90 degrees generally.

As it warmed up on the trip to the dealer (24 miles) two weeks ago I was afraid they may not here it, it seemed to get quieter as it warmed up.

Jim · Post by **Jim** » Tue Feb 17, 2009 5:45 pm

Got it back it's worse than before, they know they are getting it back.

They plan on putting the pinion back the way it was. I don't think that's it the noise still sounds like it's from the front...they are fixing the wrong end.

It now has a coast whine or werr at low speeds 15-20 and a whine at real light throttle around 45 you can feel in the steering and a unbearable whine at 70. I'm sick

Jim · Post by **Jim** » Wed Feb 18, 2009 10:11 am

I talked to a local guru, he said if they moved the pinion out and have the pattern at a different place and now it’s noisy putting it back won't quiet it. He said they will have ruined the gear set if it was run for any distance. He said the mechanic would be a magician to get it back the way it was before and as quiet as it was when I took it in without a new gearset.

killian96ss · Post by **killian96ss** » Wed Feb 18, 2009 12:46 pm

Shimming the pinion in toward the axle centerline will not get rid of gear whine or lower the operating temperature.

I'm surprised anybody even suggested doing this.

Once a gear pattern has been established you can't try changing it later by moving the pinion because you will ruin the gears.

I'm not surprised at all that the noise is louder now.

If you really want to get rid of that whine in the rear, installing a new gear set is the best advice I can give you.

As far as which Redline gear oil to use, If you are keeping the same noisy gears and are staying with an open diff, go with the heavy shockproof gear oil, but if you plan on having a new set of gears installed or are going to put in a G80 Gov-Loc I would use either the light shockproof gear oil or their 75W/90NS gear oil.

Steve

04crewvt · Post by **04crewvt** » Thu Feb 19, 2009 5:10 am

If you have only put 48 miles on it since the shim I doubt the gears will have set to a new wear pattern yet. I know it didn't on 84, we just re shimmed and the noise went away. That being said at this point I think they should be putting in a new set on their dime. Then when the noise is still there (as you expect it will be) have them fix what you asked them to in the first place.
I know in my 98 HOE I have some noise issues that seem to be impossible to track down after numerous trips to both the dealership and my regular mechanics I decided just to use the volume knob on the radio to cover the sound until it gets bad enough for someone to actually find the problem without taking each and every piece of the driveline apart.

Jim · Post by **Jim** » Thu Feb 19, 2009 5:32 pm

It will be going in beginning of next week. I decided to call the salesman I bought it from to get some satisfaction. He was very receptive to my problem and request for a loaner car. I asked he drive it when i drop it off and drive it after the repair before I pick it up to be sure it's acceptable. Since they are in the next county that's valuable to me.