to make a long story short--my car has dramatic acceleration problems(still trying to figure out what it is), but since the car has about 126,000 miles on it, i figure a tranny fluid/filter change wouldn't do any harm(and will give me a better look on if the trans could be a problem).

my brother knows a guy that works at a transmission rebuilding shop and passed on that i was gonna change the fluid and stuff. the transmission guy said that can actually be a "bad" thing. according to him, the gears in the transmission get "used" to the fluid that's in it, and changing to new fluid can damage parts inside it. i've been working with cars for the past 5 years(even took a couple of automotive classes in high school), and i have never heard anything as stupid sounding as that. is there any possibility that by luck this "advice" is any true?

 

no but there is a better chance he's a dumbass

 

yeah i figured that. shocking isn't it? according to this town that guy is qualified to do transmission jobs at the GM place, yet i'm "not qualified" to even work at walmart doing half assed oil changes.

but thanks for the clarification, i know this is a stupid post, but damn, i didn't know *** made me so ****in' stupid, here's some more fun with the "qualified mechanics" that work in this town--

--i took my car to the "best muffler place" here and the guy working there told me that my stock exhaust were Flomasters(quietist flomasters i've ever heard)

--got the suspension/alignment work done to my car at GM(the front end got wrecked before i bought it). they failed to tell me that the frame and strut stuff on the passenger side had to be put on a frame machine and be pulled into place, along with the whole front end having to be put back together(the fender sticks out a little, hood/nose piece isn't sligned right--my brother works at an auto body place so he tends to notice these things). all they did was charge me out the *** for the work and told me to have a nice day.

it doesn't pay to trust someone to do a little bit of work to your car nowadays.

 

Hes probably using the old adage "if it aint broke, dont fix it" or in this case swap the word "fix" for "change".
You can never do any harm changing oil and filters, as long as your careful with sump plugs, filters, and checking levels afterwards.
I have some customers that insist on new oil\filter every 6months regardless of mileage, and i can honestly say, its never done any harm.

 

Read your owners manual. All fluids in the car should be changed on a regular basis. I think tranny oil is something like 3-5 years.

When was the last time you changed your coolant, brake fluid, diff oil? There are many cars out there still with original brake fluid in the lines.

Dropping the pan to changing tranny oil doesn't change all of it unless you can do a proper flush. Just dropping the pan only drains what's in the pan. There's still a lot of oil in the valve body and torque converter. Most of the time all anyone does is just drop the pan and change the filter. Although this will work, it's not a proper oil change.

 

i'll give my thoughts and experiences on this.
with an old tranny that never has been changed, most mechanics will agree, leave it alone.

why?
cause you never know what you will stir up inside the tranny on something old with miles on it.
besides all you are going to flush out is 4qts

personally i change tranny fluid and filters
but i do them one a year or every other year.

i have changed it on high mileage ones before, and they puked shortly after, and i had one that was fine.

again, even reputable tranny shops feel the same.

what i strongly recommend is if you do a change, install a drain plug.

what i do is since i have drain plugs in the pan, is drain the fluid, replace it, run it, drain it, repeat. this helps flush it out so to speak

you also go to a place that does flushes, but i have a feeling they would say the same thing, on high mileage, or trannys that werent changed regularly.

 

I know first hand what he's talking about and he's actually not a dumbass. It happens more with fords but can happen to others.
The clutch packs act like a centrifuge. The space behind the clutch piston will centrifuge sludge out behind the piston.
As the outer piston seal ring wears, this sludge acts like stopleak.
When the new fluid is put in it begins to wash the sludge out.
The worn clutch piston seal now will not hold pressure and the clutch fries. He probably knows many of the transmissions that come into his shop have the same story. "Worked flawless for 120K, I changed the oil and it quit the next day". This is what he's talking about.

 

oh wow now i feel like somewhat of an idiot, thanks for clearing that up(guess i'm just used to getting screwed over by the "top car people" in this crummy town).

so with my luck i'll just leave that alone right now(since i don't think that's contributing to the problem with my car), until i'm able to do it properly--draining ALL the fluid.

thanks for clearing that up though, if my brother explained it to me better i wouldn't have made this post, again, thanks.

 

I'll second that, as I've seen it happen all too often. My trans worked flawlessly for over 150,000 miles. Then I decided to install a trans cooler and flush it. 2 days later the 2-3 shift acted strange, and soon after I lost 2-3 altogether. And as much as I hate to admit it, I did pour a little sawdust into it I regained the 2-3 shift under all but WOT.

I installed a rebuilt trans, and installed a drainplug in the pan. I change what's in the pan at every oil change.

 

Personally, if your tranny failed after a fluid swap, it was probably in need of a rebuild already.

 

Smartest thing ever said here, this is why you don't ignore your damn services and wonder why the hell it failed.

While we're on it, when's the last time you checked your diff fluid? or does the idea scare you

 

or does the idea scare me? uh huh.

the problem here isn't the services, it's places that are supposed to help you out giving you bull****. but anyway i'm going through things one at a time rebuilding/fixing and servicing and whatnot(if the thought hadn't occured to ya--i'm not the original owner of the car so i couldn't tell you what was regularly serviced or not).

just posted this thread to see if there was at least a little bit of truth to what that guy said and to see how full of **** he is compared to the other so called "mechanics" in this town.

 

guess i should rebuild the tranny then, if anything to get the performance i'm supposed to get out of it. wish i had a damn shop, but thanks for the clarification everybody i've never heard anything remotely close to that, glad i decided to make a thread about it.

 

I think you all are talking about 2 diferent things here. I would NEVER recommend a tranny "flush" on an older tranny unless it's been done regularly throughout the vehicles life and I'm sure of that fact. It will tend to break up sludge and dirt trapped in your tranny and circulate it throughout and can and does cause many problems. But to just change the fluid and filter without any sort of flush is considered a good idea for any age tranny. This is the procedure we follow at the garage I work for. Ive never seen a simple fluid filter change cause problems but see many that say "I just had my tranny flushed at so and so and less than a week later it started slipping and now it's gotten worse".

 

I'll ***ume you are not familiar with how a transmission flush works. Its not a power or reverse flush like a coolant flush is. It simply removes old fluid from the system (usually from a cooler line) that the trans pumps while running, and replaces it with fresh fluid, again all powered by the transmission pump and not the flush machine. It cannot "break up sludge and dirt" like you state that the transmission normally wouldn't do.

 

Ya know, even if new/fresh fluid causes the tranny to croak in the driveway after a change, I'd rather it happen then and know what I have, than 300 miles into a 600 mile drive.