Transfer Case Fluid Timebomb?

[henrys_dad]

I have a 2000 Silverado (4.8L) that's about to break 200K. I'm the original owner.

It has a manual 4WD shifter on the floor. I use 4WD maybe 4-6 times a year, mainly for pulling out of snow from a dead stop. I rarely drive any distance in 4WD.

The fluid in the transfer case has never been changed. Ever. I believe the OEM fluid is ATF.

The one time I tried to get at it, I stripped the drain plug bolt badly (unusually soft metal) and I've basically just ignored it since then.

Since I don't use 4WD much, is this a non-issue, or a time bomb of neglect?

Does transfer case fluid (ATF in my case) break down in any sort of passive way (not from overuse, but from just being old)?

Thanks.

 

[Chevys_n_Hawgs]

drill it out. re-tap the threads. change the fluid, then change it again after 500 miles.

 

[gathermewool]

The presence of oxygen, as well as moisture and heat will cause the ATF to degrade. Since you hardly use it, who knows how much longer before you start experiencing issues. The fact that you use it at all is probably what has kept the seals in good shape.

How much longer do you plan on using this bad boy? If forever is the answer, then I'd either do what Chevys_n_Hawgs says or shave down the head with a file until you can get a crescent or vice grips squarely on it. If not of this works, then maybe your local shop can tack something on that will give you a bit of leverage.

Regardless of how you do it, I'd get that plug off and change out the fluid. I'm going to say that doing so once and forgetting about it forever will probably be fine.

If you do decide to chase the threads, then make sure to have a quart of the cheapest ATF you can find (or the same stuff you'll be using to replace the old ATF, if the cheapest is what you want) to flush out any shavings.

 

[UNC197]

Have you tried using a bolt extractor?

 

[silverrat]

Suck it out the fill plug

 

[hypervish]

Originally Posted By: silverrat
Suck it out the fill plug


X2, you can pick up a fluid extractor pump from harbor freight for $5.

 

[deeter16317]

Even though you rarely use 4wd, the internals (including the chain) may still be turning. I don't know if Chevy still has the front axle disconnect or not??

 

[totegoat]

The ATF+4 in my 231 was brown when I changed it at 33,000 miles. Plug is (3/8" Allen).
Same oil in my 273 @ 33,000 is still pink. Plug is (10mm hex)
Both are New Process transfer cases. Good luck.

 

[ledslinger]

I think these housings are magnesium and require aluminum drain plugs. As suggested I'd suck it out the fill hole. Change it and use synthetic ATF. I have transynd in mine.

 

[demarpaint]

As others mentioned I'd suck it out the fill hole, re-fill, drive a 100 miles or so and repeat. You should be GTG.

 

[hisilver]

Had the same trouble on mine. The case you have is probably magnesium, as well as the drain/fill bolts. I would for sure change it out. The internals are moving even when in 2wd.

 

[atc250r]

If its an allen bolt, it probably requires a 10mm wrench. I'm guessing you used a 3/8 and that's why it stripped. Been there, done that! Now, get a magnet and check if the plug is magnetic. Mine was, and that made it easy. I took a 3/8 bolt which now cause the head was stripped, the threaded end fit right inside the head of the allen bolt. Then weld the bolt into the plug, being extremely careful not to touch the t-case in any way. Let the weld cool and then use a 9/16 wrench on the 3/8 bolt and the plug will come right out. No need to replace the plug, if the weld is good. The heat from welding will also loosen the bolt and make removal EASY! I did that years ago and everything is still good to go. Just be sure to put the ground clamp on the new 3/8 bolt so that current doesn't flow through anything else.