Tranny Service

[Trainmaster]

It seems to me that the days of transmission fluid changes causing problems are gone. Before synthetics, the old fluid turned to varnish and plugged up leaks. New fluid was highly detergent and opened those leaks.

With today's better oils, that doesn't seem to happen. I've changed fluid in plenty of 150,000 mile Fords with no problem. The stuff I drained actually looked pretty good too. But I just drop the pan and fluid and change the filter. And I always use OEM Motorcraft fluid recommended in the owner's manual. Just did my '08 with 125,000 miles.

 

[ManUpOrShutUp]

Glad this thread is open. My Expy is coming up on 150,000 miles. It has no shifting issues, but I'm preoccupied that service was never done on the transmission.

A local tech told me that a "straight" fluid replacement can sometimes be harmful (at this stage), considering the earlier maintenance was never done (particles coming loose and causing problems). He suggested draining the fluid, replacing the filter, adding an additive to the drained fluid (forgive the redundancy) and topping off with fresh fluid.

Do you all have any thoughts on this?

After having the seals blown out on my wife's Mazda (~230k mile) during a trans flush, we now just drain, change filter and fill.

 

[rowekmr]

Interesting he recommended reusing the old fluid with additive. I normally hear fresh fluid to replace what was drained is fine.



Glad this thread is open. My Expy is coming up on 150,000 miles. It has no shifting issues, but I'm preoccupied that service was never done on the transmission.

A local tech told me that a "straight" fluid replacement can sometimes be harmful (at this stage), considering the earlier maintenance was never done (particles coming loose and causing problems). He suggested draining the fluid, replacing the filter, adding an additive to the drained fluid (forgive the redundancy) and topping off with fresh fluid.

Do you all have any thoughts on this?

 

[Trainmaster]

I would drop the pan, drain the fluid, replace the filter and refill with the proper new Motorcraft fluid. I would NEVER think of putting in any "additive". I don't think 150,000 miles is any problem. I've done this on many Ford transmissions with higher mileage and never had any trouble. It always improved the operation slightly at least.

 

[BMW2FORD]

I totally agree with dropping the pan changing the filter and fluid with what's approved from Ford but no way add any additives on anything that hasn't been touched and over 100k or 10 years old. The most important thing to change right now at that age and mileage is the filter and only some fluid which is what a pan drop service will do. The main fear of changing trans fluid at this mileage is that some of the current clutch material is worn off in your current fluid so it helps the clutches to grab. Think of it as having sticky fluid sort of to say. When you change it, the new fluid has none of that material and is slippery so slippage can occur then glazing of the clutches and then its all over with. In my opinion, a flush is the worst at this mileage since you will change 100% of the fluid and if too much material was in the old fluid for sure it will slip. By doing the pan drop, filter and fluid change - all the fluid wont be changed but that's actually good and the filter is changed since if its semi clogged that will hurt flow and line pressure then result in slippage. In any electronic trans, its also a good idea to take it very easy on the accelerator for at least 100 miles after a fluid change and then a little harder on the accelerator up the gears progressively after that. This will let the trans adapt in case there is some slippage and give it its best chance to adjust itself for it. One key note is if you let it slip too much, transmission clutches glaze and then its too late. An additive can also cause glazing if it doesn't agree with the clutch material so I never add that unless OEM approved but usually factory correct fluids for the application have all the additives you need in the approved fluid. If there is no slippage and all works out, then i'd leave it like that for 50k and do it all again then.

 

[99WhiteC5Coupe]

Read your vehicle owner’s manual.

Ford does not recommend a transmission fluid additive, or a flush. It recommends a fluid and filter change.

 

[Shantheman73]

After having the seals blown out on my wife's Mazda (~230k mile) during a trans flush, we now just drain, change filter and fill.

I had TWO Mazda transmissions fail doing the same thing. Lesson learned.
HOWEVER, I flushed the fluid on my 07' Expy at 196k (no service had been done on it according to previous owner) and I had ZERO issues.
I will say though...Mazda isn't known for having robust transmissions. Our truck transmissions are solid.
I went ahead and had my Expy flushed again at 215K...and again...no issues.

 

[Trainmaster]

Every one's different, but I believe on that Ford transmission, you'll find a clean pan with no measurable wear. These things are bullet-proof. Eh, until they break.

 

[ManUpOrShutUp]

I had TWO Mazda transmissions fail doing the same thing. Lesson learned.
HOWEVER, I flushed the fluid on my 07' Expy at 196k (no service had been done on it according to previous owner) and I had ZERO issues.
I will say though...Mazda isn't known for having robust transmissions. Our truck transmissions are solid.
I went ahead and had my Expy flushed again at 215K...and again...no issues.

The old Mazdas were known for having junk transmissions. Their reputation has been pretty good since they started building their own. As much as I would have liked that vehicle to last forever, the only repair we had before the trans blew at ~230k was replacement of a leaky valve cover (purchased car new).

 

[Timo2824]

I think a lot of the crap in older transmissions came from the dip stick tube, that's why Ford removed it. My 05 E450 only has 35,000 miles on it. Went to check the fluid and the dip stick was covered in rust chunks. Ended up being the dipstick tube is rusting out, if it hadn't had one the fluid would be fine. Now it needs a full flush and a new tube...