Had my tranny flushed at 25k even though it really hadn't towed anything big at all. The fluid was BLACK and smelled burnt. We ran an extra 7qts through and still didn't get it back to red. Had it flushed again by a dealer 3k miles later, they couldn't get it to come clean either and also ran extra ATF through it. The second one was a freebie on GM after I complained to customer service. They want to "keep an eye on it" via the dealer.

What bums me is that they issued a TSB stating that black tranny fluid in the allison will not hurt it???? That is the biggest bunch of BS I have ever seen in print, what do you guys think? I put 700 miles on it yesterday, half towing 7k lbs, half empty. The fluid is already getting darker again. It also seems to be running warmer than before. It will run 160-190 empty if I am pulling a grade, it gets up close to 200, running flats it runs 150-160.

Doesn't sound like what most guys are experiencing. I want them to replace this tranny before the warranty expires but they claim it is working normally, which it seems to be other than burnt fluid.

As a side note, I paid $20 to the "other " site and haven't had a single response in three days on this subject, is there more help here?

BTW, truck has always been stock except for 285 tires.

I have seen a few of these trucks come in with similer situation. I have yet to see any of them come back, both of them took nearly 20 gallons of fluid being flushed through them to come out squeky clean. I also changed both filters on them. I dont know if they are getting black again, I advised both customers to let me know what happens and must be ok. I would ask the service dept for some type of extended coverage on the trans because of your concern over this. Or at the very least, ask them to drop the pan, and inspect it for debris, and replace both filters, perhaps even cutting open the spin on. I doubt they will find anything, but at least you'll know for sure. All in all, your only out 20 bucks and some time.http://www.dieselplace.com/forum/smileys/HiHi.gif

20 GALLONShttp://www.dieselplace.com/forum/smileys/Confused.gif Thats a ton of ATF!

I am pretty well convinced that this is not a normal situation. My '01 D/A went 97k miles as a work truck and never had dark fluid. I also know that trans fluid burns to black when there is a problem, not when everything is OK.

I think my next step will be to insist that they flush it clean, change both filters, then put it on a diet of TranSynd.

What bothers me is this, from the TSB they sent me home with"....trucks equipped with the Allison LCT1000 automatic transmission may experience a condition in which the transmission fluid has become dark/discolored (dark brown to black). There will not be any transmission performance issues with the transmission."

That is a pretty broad "out" for them. I honestly can not believe that they are trying to pass that off on people. Since when is burnt fluid the sign of a tranny without performance issues?

it says discolored, not burnt, thats the catch

Question is, can you have tranny fluid analyised like you can engine oil?? If so, draw up a sample, maybe the results might give some insight?? http://www.dieselplace.com/forum/smileys/Confused.gif

If fluid is prematurely burnt and cutting open the filters shows nothing, and nothing in the pan; I would suspect a burned converter clutch which can be checked pretty well with a scanner. (checking % of slip when the clutch applys. Or a problem with the dye that was mixed with the fluid at the manuf. I ran into the dye problem a few years ago using Citgo atf. Can.t tell you guys how many flushes we had to redo cause the fluid looked so bad. Analizing the defective fluid show nothing wrong and I was compensated for all the extra work.


mike

Question is, can you have tranny fluid analyised like you can engine oil??Ê If so, draw up a sample, maybe the results might give some insight??Ê http://www.dieselplace.com/forum/smileys/Confused.gif

Yes you can .....


Mac

I too believe if your fluid is darking ,assuming they did flush it not just drain and refill, both times,it's your converter slipping ....

If it were a clutch pack you would throw some DTC and or limp the tranny ....
Sounds like you have a bad one .... What turns fluid colors is heat ....
I would be conserned at this point with partical contamination through out the tranny ....
I would only except a complete tear down as a repair along with a New Convertor ...


Mac

Discolored might be the catch word, however, further into the TSB they identify the cause as viscosity breakdown due to heat. I still am baffled by the fact they claim viscosity breakdown due to heat turning the fluid black will not cause performance issueshttp://www.dieselplace.com/forum/smileys/Confused.gif It goes on to discuss using TranSynd "though not a requirement".

So there is obviously a problem. Fortunately it has been documented in the warranty period. Hopefully they will eventually give in and replace the trans and convertor along with a very thorough flush of the lines and cooler.

The flushes were not just pan dumps. The first one was done by my regular mechanic. He ran an additional 7 qts through trying to clean it up, and the spin on filter was changed. GM didn't trust it was done right and wanted a dealer flush. I did get them to pay for it since I had just had it done and had proof. The dealer did a flush but neglected to change the spin on citing that it had just been done (WEAK!).

Another 1000 miles or so should have noticably darkened the fluid again and I will be much more forceful in my quest for a replacement.