Tranny Fluid

woyster_00z71 · February 22, 2005

Both my 2001 Tahoe and 2000 Silverado are getting up in miles and I have several things planned for them with my refund check this year. Both need the following done as they have never been done since I've owned them:

Transmission fluid and filter change

Transfer case fluid change

Tune Up

Shocks

Anyway, I have talked with a couple people and a couple different shops to get their take on changing the transmission fluid. The Tahoe has 93,000 miles and the Silverado has 87,000. I bought the Tahoe with roughly 43,000 and the Silverado with roughly 40,000. I don't know what was done to either of them prior to purchase. So, there seems to be a couple different trains of thought. One being to change the fluid as it is getting old. The other being to leave it be as tranny problems start after changing the fluid whereas if left alone the tranny would keep on going.

What are you opinions on this matter? I'm not having any current problems with either vehicle but I don't want to have any problems in the future either. What is the best course of action? How hard is it to change the fluids yourself in the driveway?

Thanks,

B.J.

DJinCO · February 22, 2005

I changed my transmission fluid at 30,000 miles and the transfer case fluid at 50,000 miles. The front and rear diff's are every 15,000 miles started at 3,000.

So I would say you are overdue for a fluid change. BTW, go synthetic when you change.

Everything but the transmission can be changed in your garage. The transmission really should be power flushed, filter CHANGED, and refilled. Not an in-home job, unless you live at a transmission shop.

asepgrad98 · February 22, 2005

due to the high milage i would change the filter and not do a full flush.

woyster_00z71 · February 23, 2005

How do you change the filter without draining the whole tranny? I know you have to drop the pan to get to the filter so wouldn't you lose most of the fluid anyway? Just wondering how to best go about doing this.

Thanks.

asepgrad98 · February 23, 2005

less than half of the fluid comes out when you take the pan off. i got 4 qts out last time, its a 11 qt system IIRC.

Bish · February 23, 2005

I changed my transmission fluid at 30,000 miles and the transfer case fluid at 50,000 miles. The front and rear diff's are every 15,000 miles started at 3,000.

So I would say you are overdue for a fluid change. BTW, go synthetic when you change.

<{POST_SNAPBACK}>

This used to be my schedule with a couple exceptions. Tranny every 25K, filter every other. TCase every 25K. Diffs front and rear every 25K. I followed that schedule up to about 75K. Now I do everything the same except the tranny. Now, I drain the tranny fluid (since it has a drain plug, yeh) and replace (about 4 qts for me) every oil change (5000 miles) and change the filter every 50. That way it keeps the fluid pretty fresh which I like since I tow. I'm now at 136K and so far so good.

Regarding the caution about flushing with that many miles, there's 2 camps. I have had vehicles flushed at high mileage and shortly thereafter had problems. If it is really gummed up, the flushing can dislodge some of that and clog or leak. In my case, I'm not sure it would have been any better to just drop the pan but I'll never know.

Regarding synthetic, I strongly agree using it in a built tranny but I have seen a friend get slippage in a 4L60E after changing to Mobil 1. Back to dino and all was fine. You're call on that one. Synthetic should run a tad cooler.

Oh yeah, getting the pan off is a minor PITA. On my Tahoe, I have to remove the shift cable bracket to get the pan off. The bolts thread down from above so I have to get my fat hands up there with a torx pointing down to get it off. Easier the second time

mcreyaufmiller · February 23, 2005

I agree witht he SYN change. Unless you are running a non-stock tranny, stay with the stock stuff. Of all places, Jiffy Lube for about $115 will do a power flush. They did mine and then analized the fluid for free. They lost on that deal, they had to flush with 36 quarts before the tranny flowed clean. Since then, I have added a shift kit and partial filled twice. All problems gone.