What did you do to your NBS GMT800 Tahoe/Yukon Today?

[wjburken]

Does anyone know if a JL4 equipped rearend is compatible with my non JL4 rear? I might have to replace the entire assembly, and a yard is telling me that it's compatible. Just want to make sure it'll swap on with no issues or modifications.

I would have thought it’d be compatible as I believe JL4 is for Active Break Control, but on RockAuto it does specify with or without JL4 on their rear assemblies.

 

[Tonyrodz]

I would have thought it’d be compatible as I believe JL4 is for Active Break Control, but on RockAuto it does specify with or without JL4 on their rear assemblies.

I know JL4 has that extra brake line/hose. I don't know if or how that would come into play bolting everything back together.

 

[wjburken]

I know JL4 has that extra brake line/hose. I don't know if or how that would come into play bolting everything back together.

Got me hangin’. No clue on that unless there are clips for the hoses welded to the axle housing.

 

[Rocket Man]

I know JL4 has that extra brake line/hose. I don't know if or how that would come into play bolting everything back together.

AFAIK all the mounting tabs for the brake lines are the same for all the rear diffs. Otherwise GM would have a ton of different housings which would make things overly complicated. Worst case scenario you add a universal brake line clamp at the new locations but I think you’ll be fine. GM tends to either have multiple mounting locations for all needed applications or make all the applications with mounting tabs in the same place. When I converted the rear brakes on my Silverado from drum to brake, there were just mounting tabs at the center near the pumpkin and the lines halfway across the axles were held on by large plastic clamps that went around the axle tubes that could be moved left or right.

 

[Tonyrodz]

AFAIK all the mounting tabs for the brake lines are the same for all the rear diffs. Otherwise GM would have a ton of different housings which would make things overly complicated. Worst case scenario you add a universal brake line clamp at the new locations but I think you’ll be fine. GM tends to either have multiple mounting locations for all needed applications or make all the applications with mounting tabs in the same place. When I converted the rear brakes on my Silverado from drum to brake, there were just mounting tabs at the center near the pumpkin and the lines halfway across the axles were held on by large plastic clamps that went around the axle tubes that could be moved left or right.

I'm still not sure if it's the T case or rear yet. I didn't mess with it today because it was raining all day. Got a price for $450 from an 03 Tahoe with 82k on it.

 

[Rocket Man]

I'm still not sure if it's the T case or rear yet. I didn't mess with it today because it was raining all day. Got a price for $450 from an 03 Tahoe with 82k on it.

Maybe pull the driveline and test the transfer case without the rear end connected. After it quits raining.

 

[Tonyrodz]

Maybe pull the driveline and test the transfer case without the rear end connected. After it quits raining.

My son said the same thing.
I heard the noise when the rear was jacked up and I was powerbraking it, while going from reverse to forward, then to reverse etc. Think the tc will still spin without either shaft in it? Front prop shaft has been out for years. I don't know anything about 4wd setups.

 

[Scottydoggs]

My son said the same thing.
I heard the noise when the rear was jacked up and I was powerbraking it, while going from reverse to forward, then to reverse etc. Think the tc will still spin without either shaft in it? Front prop shaft has been out for years. I don't know anything about 4wd setups.

no need to pull the d/s. you just need someone to power brake it and while you put a ear to it. kinda sounds like the rear is blown to me. if the d/s spins and the wheels dont move its the rear. also hand turn the d/s back and forth, if its got lots of play well you know.

 

[wjburken]

Personally, I would pull the rear cover and see what kind of goodies await you inside. At a minimum, it’s the cost of diff fluid and a cover gasket. If it’s not that, at least you’ll have fresh gear oil back there.

 

[Rocket Man]

Personally, I would pull the rear cover and see what kind of goodies await you inside. At a minimum, it’s the cost of diff fluid and a cover gasket. If it’s not that, at least you’ll have fresh gear oil back there.

Make sure you can get the fill plug out first. I know how that Jersey rust is.

 

[wjburken]

Make sure you can get the fill plug out first. I know how that Jersey rust is.

^^^^^Truth^^^^^

 

[Tonyrodz]

no need to pull the d/s. you just need someone to power brake it and while you put a ear to it. kinda sounds like the rear is blown to me. if the d/s spins and the wheels dont move its the rear. also hand turn the d/s back and forth, if its got lots of play well you know.

Driveshaft spins and the rear wheels spin. While it's off, turning 1 wheel, the other spins in the opposite direction. It's pretty much doing what it's supposed to, that's why I'm confused. There's really not any excessive play in the ds either, feels pretty good to me.

 

[Tonyrodz]

Make sure you can get the fill plug out first. I know how that Jersey rust is.

Is it up high on the ps? Never done one before.

 

[wjburken]

Is it up high on the ps? Never done one before.

 

[Scottydoggs]

Driveshaft spins and the rear wheels spin. While it's off, turning 1 wheel, the other spins in the opposite direction. It's pretty much doing what it's supposed to, that's why I'm confused. There's really not any excessive play in the ds either, feels pretty good to me.

what im trying to convey is i heard it making a spinning chipping sound, once you can get your head under there you should be able to hear if its the rear or trans case.

 

[Tonyrodz]

Thx guys.

 

[Rocket Man]

what im trying to convey is i heard it making a spinning chipping sound, once you can get your head under there you should be able to hear if its the rear or trans case.

Just make sure they don’t let off the brake while your head is under the truck!

 

[iamdub]

Does anyone know if a JL4 equipped rearend is compatible with my non JL4 rear? I might have to replace the entire assembly, and a yard is telling me that it's compatible. Just want to make sure it'll swap on with no issues or modifications.

I believe that's what we call "Stabilitrak". Instead of having one brake line that splits to feed both calipers evenly, each side is fed through its own hose so each can be controlled independently. I'm sure you could just swap your current brake line set over to the replacement axle. I don't see why the rear end itself wouldn't be a direct swap aside from the brake lines. Pay attention to the gear ratio of the replacement rear.

 

[Tonyrodz]

Just make sure they don’t let off the brake while your head is under the truck!

I plan on putting the rear in the air on jack stands while getting under it.

 

[mountie]

I plan on putting the rear in the air on jack stands while getting under it.

The 'picture' you just described could be something, other than 'automotive'..

Sorry... couldn't help myself......