Early signs of tranny problems?

TX-TahoeLtd · May 5, 2004

Howdy!

I've got a 00 Limited Tahoe. I had the tranny flushed at 48k and I've got about 60k on it now. My wife was driving it and she said that she felt it doing some funky things, but I can't reproduce the probelm.

She said it felt like it wouldn't stay in gear. That's about all the info I could get out of her, so with what little info I have, it sounds like it was slipping. She drove it home and had to drive it again the next day and she said it went away.

I had my oil changed and when they were poking around, they said my tranny fluid looked a bit dark. Well, I just had it flushed, so this has got me worried a bit. It's a daily driver in normal Dallas traffic (if you can call it normal), no towing, no racing, no offroading or anything like that.

Should I have the fluid flushed again? Should I have it flushed and filter changed? Is there anything I can check?

On a side note, I have noticed on a few occasions that if I'm going ~40 mph and I stomp on it, it kind of bogs the engine down a tad and lags on downshifting. It does finally shift down and the RPM's go way up and then it shifts kind of hard into the next gear.

Related?

Aside from flushing the fluid and changing filters, is there anything else maintainence wise I should look into?

Thanks!

aero_ub · May 6, 2004

Well it's hard to say for sure I guess. But if it isn't doing it regularly and you can’t reproduce it, then I don't think that I would worry to much about it right now...just keep an eye on it I guess. If an auto is getting wore out then you should be able to tell, especially at WOT shifts. Instead of shifting hard into the next gear, it will just feel like it kind of slides into gear. Sometimes you can even watch the RPMs and tell that it isn't right, it will sometime take too long to actually engage or the RPM's might actually pop up a little while trying to shift.

The way you describe the down shift doesn't sound all that abnormal to me, and the fact that it drops into gear pretty hard w/o slipping shows that the clutch packs (at least for that gear shift) are not wore out. I have also seen some automatics that at just the right RPM and speed can act a little funny and kind of flutter between gears like it doesn't know which way it wants to go. Maybe this is what yours was doing while she was driving it?

I have not actually driven a truck like yours, just a general knowledge and experience with tranny's. If the tranny IS starting to go, then there isn't much you can do about it anyway but wait for it to get worse so that you can tell for sure. You just don't want to let it go for too long after it is obvious that it needs to be rebuilt because you can damage others parts in the tranny as well...making a rebuild more expensive.

I guess though, it wouldn't be a bad idea to have it put on a computer and see if it has put out any codes? Maybe someplace like AutoZone would do it for free? I know they do some tests for free, just not sure if they can do that. As far as changing the fluid and filter, I wouldn't bother if you just did it. I don't see where it would do any good. As a side note, when a tranny is in fact going, changing the fluid is about the worst thing that you can do and will put it out of commission in short order. This is because the clutch packs within the tranny have a build up of crap and carbon on them that actually helps them to engage at that point of wear. The new fluid put in has detergents in it and will clean that build up off of them and cause them to just slip. I had a tranny that felt like it was slipping a little one time and decided to change the fluid...two days later I couldn't get it out of the driveway lol.

Good luck

Ken

2001 HD · May 6, 2004

If you just did a flush, I would get the filter changed as well. The flush may have clogged up your filter. It is supposed to "Flush Out" debris and the old fluid.

TX-TahoeLtd · May 6, 2004

Thanks for the reply. I guess it's a wait and see game for now.

I may give it another 10 or 15k and then change the filter too, need to check the manual to see exactly how early this is. I know I flushed the fluids about 10k early.

Thanks again!

Quadrasteer · May 12, 2004

On my '00 Sub they flushed the trans and three weeks later the trans blew! My advice is not to let them use the two chemicals (B&G flush) one is a cleaner the other goes in with the new fluid and is a conditioner. When they dropped the pan after it blew the fluid was dark grey and smelled so bad they didn't think it was trans fluid. I would bring my own synthetic fluid and just let them flush the old out with the new.