AWD diff questions

[Musicars]

I am dropping the oil pan on my '06 Denali. I thought I would replace the leaking right front seal since I have to lower the right side of the diff anyway. After looking it over I came up with some questions:

Videos I have seen use anaerobic sealant between the axle housing and the main housing. Mine clearly has been sealed with black RTV. It also has a coating of silver paint on everything. I assume that means it probably has been worked on before. Sound correct? What sealant is recommended?

I was thinking of using synthetic fluid but I have read that GM discovered synthetic fluid eats RTV is that true? Both the axle tube and housing have RTV sealant on them on mine. Am I stuck using conventional oil due to the RTV?

All the videos I have seen are for straight 4WD with the actuators. Anything different I should know about when taking out that seal on an AWD?

The right side leaks but I don't get any wiggle on the axle flange. The left side barely leaks but I get little wiggle on that flange. Is a little wiggle OK of am I looking at a bearing going bad? (I shot a short video but it was still 25MB in file size so don't know that I could put that video up until I figure a way to make it smaller)

Any input is appreciated.

 

[6speedblazer]

i have rebuilt a TON of front differentials. I have always used RTV ultra grey on both the case halves and pass side axle tube. I have yet to have one come back for a leak due to RTV.

i just re-geared a cast iron 7.2ifs unit last week for a lifted v8 swapped S10.

I have rebuilt and resealed a dozen or so from the GMT360 (mainly tbss) platform as the anaerobic sealer from GM tends to leak. Most of the time from above the pinion. i redid the front diff in my tbss about 3 years ago for this specific reason and it has been fine with ultra grey and royal purple.

 

[Musicars]

i have rebuilt a TON of front differentials. I have always used RTV ultra grey on both the case halves and pass side axle tube. I have yet to have one come back for a leak due to RTV.

i just re-geared a cast iron 7.2ifs unit last week for a lifted v8 swapped S10.

I have rebuilt and resealed a dozen or so from the GMT360 (mainly tbss) platform as the anaerobic sealer from GM tends to leak. Most of the time from above the pinion. i redid the front diff in my tbss about 3 years ago for this specific reason and it has been fine with ultra grey and royal purple.

Thanks for the info. It pays to ask questions. Based on the stuff I read from GM I would have thought the RTV was practically going to desolve when synthetic lube hit it.

 

[Musicars]

I removed the bolts that hold the right axle tube on but the tube will only move out about a quarter of an inch Is it normal for the axle to be stuck in an AWD unit? All the videos I have seen are of 4WD axles and they seem to easily come apart when you unbolt them. Do I need to beat on the flange to get this off? Obviously, I don't want to mess anything up.

 

[6speedblazer]

the axle have spring clips on them. Some times they fall apart. most of the time i just throw my hub puller on and slide hammer the bish out.

4wd stuff will just fall apart because the axle is 2 pieces. AWD is one solid axle on that side.

 

[Musicars]

the axle have spring clips on them. Some times they fall apart. most of the time i just throw my hub puller on and slide hammer the bish out.

4wd stuff will just fall apart because the axle is 2 pieces. AWD is one solid axle on that side.

Thanks, I kind of figured that it was a longer on piece and I was going to have overcome the force of a C- clip. I needed to make sure. Now I have to see if I can can get in there to pull it. I should have just dropped the whole diff while I was doing the oil pan. It would have been easier all around.

 

[Musicars]

When I pulled the drain plug I found a lot of gray metallic sludge and for the first 5 to 10 seconds the fluid came out a metallic gray then it went transparent. That seems to be common as the bearings wear out from what I see on this site.

Since this truck has 170,000 miles and this at least the second front diff, I thought I would track down a '06 diff and rebuild in my spare time and keep it as a backup.

I found a couple out of '06 Denali trucks. One claims to have 110,000 miles and the other "just under 100,000 miles". Both are asking $350 which is in the middle of the prices I have been finding.

1) Are the Denali trucks the same 3:73 gear?

2) One has a sticker with JM2 and the other WH3 but those apparently are not the axle codes. Is there any way to identify?

3) Anything I should check when looking at these?

Thanks for any input.