Trans fluid
10-05-2014, 10:30 PM
#11
Senior Member
10-07-2014, 01:37 AM
#13
Senior Member
It's not complete fiction. Each situation is different. But if I got a car or truck that wanted a trans flush the first thing I would do is check the fluid. If the fluid is extremely dirty, burned, and looks like it's never been serviced then I would always tell the customer that trans may not work after the flush. And have them sign a paper stating that they've been made aware and want Then when a full flush is done you clean out all that grit. With no grit in the fluid every gear becomes another neutral.
So, depending on the individual situation, it's sometimes better to just leave things as they are till the trans eventually goes out rather than help it along by changing the fluid.
So, depending on the individual situation, it's sometimes better to just leave things as they are till the trans eventually goes out rather than help it along by changing the fluid.
10-07-2014, 06:56 AM
#14
Senior Member
so it has to be extremely bad for it to be a problem? like I said I was just told this by a few different mechanics so im just trying to figure out the truth
10-07-2014, 08:24 AM
#15
Senior Member
Here's my take on things:
With regards to old transmission fluid, I have yet to purchase a vehicle with overly burnt fluid and swap it out, only to have the transmission die 15 minutes later. And I've owned plenty hunks of junk lol.
The main factor about transmissions and transmission fluid that most do not consider is whether or not the fluid they are using is compatible with their transmission.
What I mean by this is take the E4OD for instance. It says to use Mercon fluid. When I first bought my truck, it had burnt fluid in it and I drained it completely and filled it up with new fluid that was specified to work in Mercon applications. The truck ran fine for about 3,000 miles. Then it started shifting erratically.
Ok, so I drained that fluid out and put a different brand of fluid in that was specified to work in Mercon applications. Same behavior. After about 3,000 miles the transmission started shifting erratically.
Mind you, both of these fluids, per the manufacturer's label stated that they were Mercon compatible fluids.
So, I drained my transmission a 3rd time. This time, I actually spent some money on a decent name brand fluid. The truck not only did NOT have problems after 3,000 miles, it shifted so smoothly I initially thought it wasn't shifting.
From what I saw, the other fluids simply broke down after a certain period in my transmission. BUT, these same fluids worked for me in other applications just fine.
What I'm getting at is that the quality and brand of fluid you use has a lot to do with it. Most shops use a generic bulk "One size fits all" fluid that doesn't always work with all transmissions.
Some transmissions are very picky on what fluid you put in them. Most shops aren't going to go there with buying fluid specifically for your vehicle unless they specialize in one or two certain types of cars, which would mean they would already have a fluid that is proven to work with your application on hand.
Hope this helps.
With regards to old transmission fluid, I have yet to purchase a vehicle with overly burnt fluid and swap it out, only to have the transmission die 15 minutes later. And I've owned plenty hunks of junk lol.
The main factor about transmissions and transmission fluid that most do not consider is whether or not the fluid they are using is compatible with their transmission.
What I mean by this is take the E4OD for instance. It says to use Mercon fluid. When I first bought my truck, it had burnt fluid in it and I drained it completely and filled it up with new fluid that was specified to work in Mercon applications. The truck ran fine for about 3,000 miles. Then it started shifting erratically.
Ok, so I drained that fluid out and put a different brand of fluid in that was specified to work in Mercon applications. Same behavior. After about 3,000 miles the transmission started shifting erratically.
Mind you, both of these fluids, per the manufacturer's label stated that they were Mercon compatible fluids.
So, I drained my transmission a 3rd time. This time, I actually spent some money on a decent name brand fluid. The truck not only did NOT have problems after 3,000 miles, it shifted so smoothly I initially thought it wasn't shifting.
From what I saw, the other fluids simply broke down after a certain period in my transmission. BUT, these same fluids worked for me in other applications just fine.
What I'm getting at is that the quality and brand of fluid you use has a lot to do with it. Most shops use a generic bulk "One size fits all" fluid that doesn't always work with all transmissions.
Some transmissions are very picky on what fluid you put in them. Most shops aren't going to go there with buying fluid specifically for your vehicle unless they specialize in one or two certain types of cars, which would mean they would already have a fluid that is proven to work with your application on hand.
Hope this helps.
Last edited by qdeezie; 10-07-2014 at 08:49 AM.
10-07-2014, 05:09 PM
#17
I just ordered Motorcraft Merc V. Changing it out this weekend. The fluid looks terrible. Trans typically shifts good, 2nd is sometimes a hard shift but usually only if I'm gunning it. Which I typically don't do. I'm just hoping this will be good for whatever life is left in the tranny(which the longer the Better 
) truck has what I believe to be 176,000 miles on it.
) truck has what I believe to be 176,000 miles on it.
10-07-2014, 07:16 PM
#18
Senior Member
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10-11-2014, 05:08 PM
#20
Senior Member