What did you do to your NNBS GMT900 Tahoe/Yukon Today?

[Grady_Wilson]

Look for a high lift - most of the '20s cars seem pretty tall - similar in height to our Tahoe/Yukon/Esky trucks

My 1926 is taller than my 1929.
By 1929 cars started getting a little lower than the really old, tall passenger compartments and overall profile.
My 1929 Pierce Arrow is very heavy, coming in about 5,000lbs on a 143" wheelbase so it will be on the ground while my 1926 Rickenbacker is taller but much lighter being a smaller car.

 

[Charlie207]

any idea how long it's been since the fluid was changed? there's always some on the magnets if it's been a long time even when quiet.

Less than two years, only using Auto or 4Hi occasionally, even in the winter. Waaaay less than 20,000 miles.

 

[Charlie207]

this was my rear diff when I got it.. with 130 something on it. dead quiet still but it does seem like a lot.

View attachment 422269


this was my diff
View attachment 422268


I didn't take any of the front, but it was ugly too. so far thou no side effects from it. so it doesn't always mean it needs rebuilt, but if you got whining. yeah blah.

Your front looks like actual metal shavings, whereas mine looked like sparkling bearing flakes (ground up mica).

 

[j91z28d1]

Less than two years, only using Auto or 4Hi occasionally, even in the winter. Waaaay less than 20,000 miles.

ahh yeah 20k you probably got something eating itself.. if it was the first time it had been done with 100k plus on it. it would be expected.

probably time for full set of bearings and hope the gear looks ok?

 

[Charlie207]

ahh yeah 20k you probably got something eating itself.. if it was the first time it had been done with 100k plus on it. it would be expected.

probably time for full set of bearings and hope the gear looks ok?

Yay. I wonder if the previous owner left it in AUTO most of the time.

I wish the front hubs had the ability to stay together without the axles installed. That would give me time once the snow goes away to leave the front diff & axles out while I tear it apart, and have a shop install the parts. (or a buddy with the presses/pullers).

 

[gooffeyguy]

Yay. I wonder if the previous owner left it in AUTO most of the time.

I wish the front hubs had the ability to stay together without the axles installed. That would give me time once the snow goes away to leave the front diff & axles out while I tear it apart, and have a shop install the parts. (or a buddy with the presses/pullers).

How does a 2wd do it?

 

[Charlie207]

How does a 2wd do it?

RWD GMT900s use different front hub assemblies. The 4WD front hubs utilize the front axle /CV stub and nut to keep the bearings together. I suppose if I could find some worn out 4wd front C/Vs, and rip them apart to use just the stub to hold the front together while the diff is getting R&R'd it would keep my front wheels from detaching at highway speeds.

RWD front hub assembly:



4WD front hub assembly:

 

[89Suburban]

RWD GMT900s use different front hub assemblies. The 4WD front hubs utilize the front axle /CV stub and nut to keep the bearings together. I suppose if I could find some worn out 4wd front C/Vs, and rip them apart to use just the stub to hold the front together while the diff is getting R&R'd it would keep my front wheels from detaching at highway speeds.

RWD front hub assembly:
View attachment 422310
View attachment 422311

4WD front hub assembly:

View attachment 422312View attachment 422313

That is exactly what I did with the old CV's I removed/replaced. I disassembled them and saved those stub shafts/nuts just for this.

 

[gooffeyguy]

I thought I've seen something about people using 4wd hubs on 2wd vehicles.

I don't think the axle stub/nut holds the bearing together. The 2wd model just has cover plates to keep out dirt and shit.

EDIT: I guess it depends on the hub manufacturer and model. Some can, some can't. Some manufacturers use the same hub for both 2wd and 4wd applications

 

[Charlie207]

I thought I've seen something about people using 4wd hubs on 2wd vehicles.

I don't think the axle stub/nut holds the bearing together. The 2wd model just has cover plates to keep out dirt and shit.

EDIT: I guess it depends on the hub manufacturer and model. Some can, some can't. Some manufacturers use the same hub for both 2wd and 4wd applications

Not sure, but I'm not about to be "that guy". I suppose they manufacture two different designs for a reason.

And it would be weird that the axle nut torque spec. is like 188lb./ft., which seems like an awful lot to squeeze the outer C/V into the hub if it didn't do anything.

I've been doing some Googling, and seen both answers: does nothing and can run 4wd hubs without axles with no problems, or tempting fate by not having them installed. If I can find dead axles and chop the stubs off I might as well throw them in for that hypothetical situation.