View Full Version : Brown Transmission Fluid? A problem?

01-08-2003, 10:52 AM
I have been reading that it is bad to change your tranny fluid if it is brown instead of the red color. What does this mean? On my 91 Regal with the 4T60 tranny, I bought the car about 5 years ago with 78,000 miles and I noticed that the tranny fluid was brown, so I flushed it. Within a couple months, it was brown again. The car now has over 171,000 miles and I flushed the tranny fluid again a little over a month ago. The fluid is already turning brown. Is this bad? I've been reading that if it is already brown, to leave it because the differing viscosities of the fluid will do bad things to the clutches. Is there a conditioner that will help this problem? I don't have any problems at all with slipping or skipping gears or anything with the tranny. And I've put almost 100,000 miles on the car with the tranny the way it is and I don't really forsee any problems arising (of couse, when do we ever?). What's your opinions?


01-08-2003, 11:12 AM

Transmission fluid is a hydrolic detergent that suspends metal shaving and other particles in the fluid to be collected in the tranny filter. After time, heat and other minor factors, it loses those properties and the shavings begin to fall and settle in the torque converter, tranny pan and anywhere else there is a low-flow of fluid.

Sounds like yours was never FULLY flushed. If you're not having any slipping problems after the time you just flushed it, I think you should be fine. You are correct though if tranny fluid is in for too long, and you flush it out, a slipping problem can occur... but the fluid has to roasted first to do so.

Bottom line: If you feel you're tranny can handle it (which sounds like it's been through worse) I'd do both a torque flush and a transmission pan drop. That changes out ALL the old tranny fluid and the old filter. Why both? If only the filter is changed, you only get 40% - 50% of the old fluid out. And if you only do a torque flush, you get all the fluid out, but the filter will not be changed. Cover both ends, and the fluid should last about 15K - 20K miles... a major misconception is that it doesn't last forever. That's what I've learned through working at Grease Monkey for 3 years. Hope this helps. Also...


- RedFox340

01-08-2003, 11:16 AM
Brown tranny fluid is an indication of overheating.
An auxilliary tranny fluid cooler may be beneficial in your case.
I believe these trannies naturally tend to run hot due to their small size in comparison to the size/weight of the car, which is why I NEVER recommend towing in a W-body on a regular basis.

If you've changed it before when it was brown, I don't think it'll hurt to change it again. My tranny fluid tended to get brown as well, so I stepped up the change frequency and the tranny has been fine.

01-08-2003, 11:53 AM
I thought the same thing about the overheating. I never understood why they put such a small engine and tranny in a car as big as it is. The Century was a smaller car and they put a 3300 in it, like that makes sense. But my car has been through the mill and it's still a solid car. I haven't fixed anything that's not general maintenance like alternator, struts, etc. The engine will outlast the body I think... :) But for as many miles as the car has, and for the engine being so small for the chassis size, it's surprisingly fast for what it is.

01-08-2003, 12:00 PM

Get it completely flushed and then flush it again after 3000 miles to get what was loosened up by the new fluid out. I would baby the tranny until the fluid goes red and stays red. You may have burnt clutch packs that need replacing, but flushing may take care of it... 8)

01-08-2003, 02:07 PM
Mine was brown last year and I took it to VIOC to get changed they charged me $88 :x And said we serviced your tranny but I dont think they did anything but change the fluid/filter.

01-08-2003, 03:50 PM

i would get a Filter kit from the GM Dealer. also i would recomend a tranny cooler. heat causes tranny filure. Brown fluid means its burnt and/or old. A tranny cooler would be a VERY wise investment for anyone.

To service the tranny only drain the fluid by removing the pan and then replace the filter and pan then refill the fluid. DO NOT do a full flush. my mechanic and every mechanic i have ever spoke to said it will cause you problems and usually results in tranny failure 5000miles later.

Also synthetics tranny fluid like "RedLine Performance" or "B&M TrickShift" are going to be allot better then the standard Dextron III fluid.

I have a OEM tranny cooler on my Lumina and a B&M Supercooler on my monte. Both should keep the tranny temps down and prolong the life of the tranny.


01-08-2003, 03:55 PM
Mine was brown last year and I took it to VIOC to get changed they charged me $88 :x And said we serviced your tranny but I dont think they did anything but change the fluid/filter.

That is all you want to do. never do a full flush.. ask any GM mechanic and they will advice you against a full flush..

Fluid and filter is the correct thing to do!


01-08-2003, 04:54 PM
I had mine changed a few months after I bought the car with 97,000 on it and I think it was the cars first change.

01-08-2003, 05:09 PM
when i bought my car at 111,000 miles in 4/00, i immediatly took it in to get the transmission flushed and filter changed. the fluid was brown shortly after, and i just let it stay that way until i did my 5-speed swap last summer. the trans had brown fluid for 2 years and had 170,000 miles on it. i never had any problems with it at all except that it would downshift realllly hard if i mashed the gas. otherwise the thing was fine when i pulled it out.

01-08-2003, 08:04 PM
Yeah, I haven't had any problems with it being the way it is. I'll probablly just leave it. It still runs great.

01-08-2003, 08:11 PM
Keep in mind the red color in trans fluid is just a dye so you can tell if it's leaking in the driveway. If it's not red, it's not necessarily bad. If it SMELLS burnt, then you have a problem.

01-10-2003, 11:46 AM
I definatly agree with Monte, only do a fluid/filter change. Also, I hope that you are certain that your transmission does not slip in the slightest. I changed out my fluid/filter when my transmission started to slip a little and 3 days later one of my ring gears wanted out of the tranny. And yes, it DEFINATELY got out. $1800 fix right there.

01-10-2003, 11:24 PM
Here's a new tanny question:

Last year my car started to have a low rumbling vibration when in drive at a stop light (stopped in drive). The fluid was a bit brown so I had the pan drain/filter change. The rumble never left so I took to popping it into neutral at lights (once it was stopped).

In the last month I've noticed a slight crackley sound when stopped in drive. It quits as soon as I pop it into neutral. The fluid is still red and doesn't smell burnt.

Should I consider some kind of conditioner?


01-11-2003, 04:22 AM
It won't hurt to try a conditioner. May not help either. How many miles you got?

01-11-2003, 06:34 PM
I'd have to guessamate about 150k since the odometer died at 86k almost 6 years ago.