Tranny fluid and filter

[Bifflefan]

I just read a post that got me thinking (yes thats dangerous).
What happened to the days when you changed the filter in the trans at a service. I took my old truck to the "whatever lube" about 5 years ago to get the oil and tranny fluid changed. For the trans part is was like 63.00 and they just sucked out what the could, ran it through a filtering system and put it back in.
Now the last i checked it was oil also and will breakdown because of other contaminants in it, just like motor oil. Then when i asked about the filter they said that was all they did was the filtering of the fluid.
This make no sence to me as the reason for doing it was to get the old filter out.
Needless to say I went back to doing the services my self after that.

 

[rentprop1]

Re: Tranny fluid and filter

I had a tech try and sell me on the $ 69 dollar special one time as well ( advertised as synthetic ) , he explained the process and I said for that price you can't be putting new fluid back in there, even if it was bulk fluid.....he was stunned that I knew what 12 qts of synthetic fluid would cost.....when I asked why they no longer drop the pan, he said its bad to let air get into the filter

I have a dodge 1500 and got some tips to get all the fluid out of the cooler up front as well, so in about a month I'm gonna try it in the drive way.......DIY with synthetic and the 2 filters on a dodge runs about $ 160.....the dealer wants $ 400....WTH ?

 

[NYBo]

Re: Tranny fluid and filter

Even replacing the fluid with one of those "transfusion" machines hooked to the cooler lines is half-baked at best. Dropping the pan not only allows you to replace the filter (if any; some vehicles no longer have replaceable filters), it also allows you to check for abnormal debris in the pan so you can get repairs before things get worse.

 

[rbh]

Re: Tranny fluid and filter

Yeah I would certanly go with a flush then fresh fluid and filter, as well I have installed the biggest tranny cooler I could find, cheap insurance for those long hard pulls.
rob

 

[bruceb58]

Re: Tranny fluid and filter

Drain the pan and determine how much fluid is in there. Then remove the pan and change the filter. Add new fluid with the same amount that you removed. Pull the hose from the transmission cooler which is the outlet. With another persons help, run the engine until exactly 2 qts have come out. replace the 2 qts and repeat until clean fluid comes out of the hose. You now have flushed the tranny and have all new fluid.

 

[TilliamWe]

Re: Tranny fluid and filter

As bruce is explaining, dropping the pan and changing the filter only removes about 4 quarts of old fluid. You still have 8 or more quarts of the dirty stuff in the trans. A flush is the only way to get ALL the fluid replaced. So the true way to flush and change a filter, is a two step process, and wastes about 4 qts of transmission fluid.
I have never heard of a service place filtering your oil and putting it back in?! That's asinine! The real service places flush out all your old fluid and replace it with new. But they don't change the filter. Not perfect, but better than "filtering and reinstalling your fluid"!

 

[NYBo]

Re: Tranny fluid and filter

Yep, reusing the old fluid is idiotic. The fluid is damaged by heat, and no filtering is going fix that. Burnt or severely contaminated fluid needs to be completely replaced.

However, unless the fluid is significantly contaminated or burned, dropping the pan and changing the filter roughly 4 quarts of fluid that comes out every 20K to 25K miles in a tow vehicle will be sufficient to protect the transmission.

 

[justchange]

Re: Tranny fluid and filter

I had the trans flushed on a '95 T-Bird. It had over 100k. the fluid in that trans looked more like 100,000 mile oil than trans fluid.


While they may just filter your old fluid, get it flushed and have them change the filter.

They work immensly better.

 

[Moody Blue]

Re: Tranny fluid and filter

Recently been reading about the pros and cons of flushing vs pulling the pan. Seems to be two schools of thought.

1) Flushing removes most (if not all) of the old fluid. With it, goes all of the friction materials that have become mixed into the old oil from various belts, bearings, clutches, gears etc. When you add the new fluid, you still have an old dirty filter and all that friction material is gone. There tends to be more slippage, resulting in higher temps and possible premature failure.

2) Dropping the pan and replacing the filter changes only about 1/2 of the actual fluid in the tranny. When you add new fluid, there is still 50% of the old fluid remaining with the friction materials. Sounds like a valid argument, and you get a new clean filter.

From what I have read, if you have not regularly changed the fluid, then don't flush the system. You are asking for trouble.

 

[mla2ofus]

Re: Tranny fluid and filter

To me the filter is every bit as important as the new oil. When a filter starts getting plugged it causes clutches and bands to slip when the trans is cold and the more they slip the more contaminants are released to plug the filter, so eventually it's off to the shop for repairs.
JMHO,
Mike

 

[NYBo]

Re: Tranny fluid and filter

1) Flushing removes most (if not all) of the old fluid. With it, goes all of the friction materials that have become mixed into the old oil from various belts, bearings, clutches, gears etc. When you add the new fluid, you still have an old dirty filter and all that friction material is gone. There tends to be more slippage, resulting in higher temps and possible premature failure.

I had never heard this lne of reasoning. However, it is completely false. The friction material (not the friction modifiers in the fluid itself when new) that prevents slippage isn't in the fluid, it's on the clutches.

From what I have read, if you have not regularly changed the fluid, then don't flush the system. You are asking for trouble.

The usual scenario that this questionable wisdom speaks to is this: The transmission is neglected, and starts to show signs of failure. The owner then tries a fluid change to see if it will cure the problem. However, the neglect has already taken its toll, and the transmission soon fails anyway. This failure is improperly blamed on the fluid change, but it was going to happen anyway. That being said, an improperly done flush, such as reversing the hookup to the cooler lines, can backwash the filter and send debris back into the small passages in the transmission. Very bad.

 

[rentprop1]

Re: Tranny fluid and filter

I'm currently at about 60 K on my truck and I noticed some slight tranny issues, I have never had a trans service ....what would you recommend a drop the pan or just flush the system.....

 

[bruceb58]

Re: Tranny fluid and filter

I'm currently at about 60 K on my truck and I noticed some slight tranny issues, I have never had a trans service ....what would you recommend a drop the pan or just flush the system.....

Both

 

[dan t.]

Re: Tranny fluid and filter

and if it is a Dodge set the bands while the pan is off, GM and Ford owners dont have to worry about this

 

[fishingman220]

Re: Tranny fluid and filter

i used to and my wife runs a carwash/lube shop, and the machine they use, it has a 20 qt tank on the side, and you hook up to the cooler lines. the tranny pumps the old fliud out and sucks the new in. true it is better to drop the pan and replace the filter, but it does replace the fluid insted of filtering the old