2000 Bravada. 130,000 miles. Typical problems, but I'm planning on making it to 200k.

I set out to replace a hub and change my oil this afternoon, but got a little ambitious and decided to change the transfer case oil, since I had some ATF on hand. However, I then got really ambitious, and took a look at the front differential, discovering it to be low on oil.

So, I topped it off with ATF. It took about half a quart. I finished up everything else, then drove home (about 40 miles at highway speeds). Everything sounded good.

Then I realize that the front differential isn't supposed to get ATF. Oops.

My preference it to drive back to the garage where I do my work (that 40 miles), then flush the front differential and refill with the correct oil.

Before you say that'* only going to make it worse, consider the following: I've owned this truck for about 8 years. In that time, I've never touched the front differential. So, it'* probably been low for a while. Yes, there'* a little bit of deceleration whine. Yes, I feel pretty dumb about it now.

I figure the addition of a half-quart of ATF is only an improvement over the half-empty differential I had before. I've been driving the thing without worry for years, why worry about the next 40 miles? So, I'm planning to drive it back up to the garage.

What do you think?

I have spent many days with the fluid issues on your front differential, and I wrongly placed the transaxle fluid in the front differential, caught it after a day. No issues. With the said, draining the front differential fluid on your Bravada is as easy as draining motor oil. Why not go to Wal-Mart, get a drain pan, gear oil and change the fluid. The hardest part is refilling the fluid, and it looks like you have the figured out.

Keeping the front differential fluid fresh and updating the transfer case fluid to the new GM spec are critical to preventing chatter when turning at low speeds and preventing premature drivetrain failure. The Bravada is expensive to repair, and keeping the front transaxle and transfer case fluid fresh are the best thing you can do to your Bravada next to oil changes and lubing the ball joints.

That'* basically where I am - transaxle oil in the front differential.

I did it in a garage where I had a lift. I have a feeling that filling the front differential in my driveway, without jackstands, would be quite a bit harder.

It sounds like you agree I can do the 40 miles back to the garage without causing any harm.

ATF is still a oil, and should not cause a problem. Diff oil is generally a thicker oil to stick to the gears. On a front wheel drive transmission the diff is built in to the transmission and is lubricated with ATF, the transfer case is also filled with ATF. So I wouldn't worry to much about it.

Yes, you should be OK, but you do have the option of going to Wal-mart, buying a pair of plastics ramps, driving up and draining the fluid. Very easy to do. The only hard part is getting the fluid into the case. That can be accomplished by some clear plastic tubing from any hardware store, sold by the foot. Get a larger diameter if you go that route, because that gear oil moves slow and no that case is sealed, so no easy route for air to escape.

How do I use clear plastic tubing to get the oil into the case?

Filling it at the garage, I used a very messy hand pump they had (similar in design to a grease gun).

I'd like to find a hand-operated transfer pump that will work for gear oil, ATF, other misc products, and transfer without spilling. I wonder if a hand-operated plunger-style fuel transfer pump would work.

Suggestions?

Go to most any hardware store. Purchase about 15 feet of clear plastic tubing, the larger diameter the better. Then go buy the biggest funnel that will slide onto one end of the tubing.

After draining the fluid, put the drain plug back in. Then remove the fill plug. Stick the clear plastic tubing into the fill opening. Then route the tubing up through the engine compartment. Then attach the funnel. You may want to secure the funnel in a manner so you don't have to hold it.

Add the gear oil until the funnel is full, then go drink some coffee. Come back in ten minutes,fill the funnel again. Go get some more coffee. In about 1/2 hour, the case will be full. You will know this when the excess gear oil starts to come out of the fill opening. Then remove the tubing, but the fill plug back in. and you are all set.

Not to nitpick this idea, but it seems pretty cumbersome and prone to losing a lot of oil. Since the fluids can be pricey, I suspect a good transfer pump would be cheaper.

What I need is one of these... I just can't find one...

I have a duel action pump, turned out to be very messy and hard to use.