Change Fluid.. Or Leave Alone?

[GMC-AT]

I have a 2000 Silverado with 250K. Just got the truck not long ago, so don't know any of the history. Anyway,  I was changing all the fluids and wondering if I should change the transmission fluid. The fluid is defiantly brownish red and needs to changed, but I have heard stories of folks messing with this and actually causing problems. Especially when doing a full "flush"  ...as for me I was thinking of just dropping the pan and changing that fluid with filter.  The trans works / shifts like butter now.. it's perfect.  The truck is just a farm truck now, only driven about 3K per year.. no towing or even much high speeds for that matter. 

 

[dcheeseman]

I'd do a pan drop, replace the filter, clean the pan out well as well as the magnet.  Use a high mileage dexron 3 transmission fluid (Example: Valvoline Maxlife).

 

Daniel 

[Pacfanweb]

15 minutes ago, dcheeseman said:

I'd do a pan drop, replace the filter, clean the pan out well as well as the magnet.  Use a high mileage dexron 3 transmission fluid (Example: Valvoline Maxlife).

 

Daniel 

This.  Change it. 

[Supreme Pizza]

I have looked into this matter very thoroughly on multiple occasions over the years. 

 

Benefits of changing the fluid: 

 

1) The transmission MIGHT last longer with new fluid. 

 

 

Disadvantages of changing the fluid: 

 

1) Transmission might fail immediately, or sometime over the next year. 

 

 

To me its just not worth the risk. If it ain't broke, don't fix it.  I have talked to many transmission shops about it, and they all said the same thing:

 

    If you know the service history on the trans fluid, and you know for sure that it was changed regularly - then keep changing it. If you don't know the history on the transmission, then LEAVE IT ALONE.

 

 Problem #1: As the fluid gets old, the detergent stops working. Crud builds up on the inside parts. When you introduce new fluid, it loosens that crud up and it clogs the valve body. 

 

 Problem #2: If there are seals inside the transmission that are not sealing very well, the leaks get clogged by crud. New detergent in the fluid washes the crud away and the seal fails. 

 

 Problem #3: The new fluid will be more slippery than the old fluid, so if you clutches are weak at all, then you just caused the transmission to fail by replacing the fluid. 

 

 Problem #4: It was working just fine..... until you messed with it.......

 

 

 

Many people will agree with this. Many will not agree with this. There is no correct answer. I highly advise that you just leave well enough alone and drive it. 

   

[Logan Lanfear]

Depends what you have into the truck.  Transmission sounds like it hasnt been maintained properly so it probably doesnt have much time left.  Leaving it alone will most likely give you the longest life possible.  And take it easy on it.  
Start saving for a new one.  Put the money from the fluid and filter into that.  If you change it you have the potential to lost 3 and 4th gear because of the lack of friction material in the old fluid.  Once its dirty in a worn transmission,it can be the only thing letting it shift.  

[Colossus]

It's likely already on its way out so if you have $$$ saved up to replace the tranny, go for it.  if not.. i'd leave it alone. 

[Supreme Pizza]

I own a 2002 and a 2003 Suburban. One has fluid that is brown, and clearly worn out. The other has fluid that is pink and looks pretty good. Both transmissions work perfectly. I have no intention of changing either fluid EVER. I have never had a transmission fail that had old fluid in it. I have had several fail with newer fluid in them. Change it, don't change it. - do what makes you happy. 

[Black02Silverado]

I would change it out.  No worries.  I changed out a 2000 Silverado's transmission fluid and filter at 150k miles and it was really brown.  No issues after the change.

[Guest]

I had a 1999 Chevy Lumina with a 3.5 or something v6. After a ton of miles and years, the overdrive started slipping in and out on the highway. The "experts" said, "nothing you can do, just wait for it to fail". I decided to change the fluid, and it started working perfectly again. Kept it for a couple more years and still sold it for $900. Great car and I'm into maintenance so I say change it. IMHO. 

[Supreme Pizza]

Although I would not change the fluid unless it has been done regularly since new, I agree that if your transmission is already failing, changing the fluid and filter would be worth trying before you replace the trans. Probably wont help, but its worth a shot. 

[Colossus]

14 hours ago, Zoomie said:

I had a 1999 Chevy Lumina with a 3.5 or something v6. After a ton of miles and years, the overdrive started slipping in and out on the highway. The "experts" said, "nothing you can do, just wait for it to fail". I decided to change the fluid, and it started working perfectly again. Kept it for a couple more years and still sold it for $900. Great car and I'm into maintenance so I say change it. IMHO. 

3.1L, or 3.8L for those years.  And those luminas were great cars.  Only thing you had to worry about was the head gasket. 

[michigan2500hd]

I've always really liked the 3.1liter. I had a 2.8 in a 1989 Z24 that broke a crank shaft ( my fault for always hot rodding it) so I dropped a 1994 3.1 in it. Mostly plug and play too.
What a torquey engine and for a v6 they had a great exhaust note.
I learned to tear that engine down in the driveway ( the top end of the engine) replace heads, etc and have it ready for cruising a few hours later. The good old days.

3.1L, or 3.8L for those years.  And those luminas were great cars.  Only thing you had to worry about was the head gasket. 

Sent from my SM-N950U using Tapatalk

[Guest]

Ya, that was a 3.1. I had the 2.8 in an earlier car. Great engines.