Replacing our trans filter in preparation for a long trip

Debris isn't the only thing that can blog a fabric filter. Transmission fluid gets sludgy after getting hot for many miles. The effect was called (in the trade) "Morning Sickness" very slow response time ranging the selector DNR.

I am hoping the hideously expensive full synthetic MoPar fluid will help keep my Spirit's gizmo from premature Seppuku. That and a hellacious size trans cooler with a category 5 fan pushing air through it. @#$%^&! ONE ROW radiator. And no upgrades. Eliminating hot tranny oil will help.

This model car has a minimum of problems with the ECU and sensors. Yeah get a 2014 something...

"It bucks and stalls"
"Xsch lakma il pisto cray"
"Yes I know this is the highlands of Guatemala"
"Wakna poem manna xkra vistay nooem DHL"
"Delivery in 2weeks. A couple hundred dollars through DHL"
"¡Pishtay!"

So fortunate I am fluent in "Mam" idioma indigena since no one here speaks Spanish never mind English.

Blacklane wrote:
I've done this a few times. It can be an awful mess. I recommend a big piece of cardboard under the pan to absorb the drips, which are everywhere.

However, I've never really found any debris in the filter, certainly nowhere near enough to worry about flow rate.

I think the new fluid is the important part of this job. The next time I do this, I'm planning on just having the system back-flushed with fresh fluid, which will replace more fluid than a drain-and-fill, and it will clean the filter somewhat.

That would be my choice, too. I was a mechanic for 7 years and have done several of these back before they put drain plugs in the transmission pan. Very messy. I use to hate doing them because it made a mess and they frequently leaked after someone messed with them.

If the pan is a lightweight metal one and not a cast pan they're really easy to bend. Don't over-tighten the pan bolts because it will damage the gasket and cause a leak. If you tighten them unevenly it will warp the pan and cause a leak.

kellertx5er wrote:

aruba5er wrote:
I'd wait until I got back. What happens if you develop a leak in a few days while on the road.
If it ain't broke (you know the rest)

Using this logic, are you saying that one should never perform PREVENTIVE maintenance prior to a long trip?

Some stuff, like an oil change, would be OK right up until leaving.

However, more complex maintenance which involves gaskets, etc. I would give at least a week before a trip in case of problems.

On my old Suburban, I had the trans fluid and filter changed. Three days later, erratic shifting started. The fluid change had dislodged some dirt and it partially plugged a screen filter on one of the shift solenoids. Luckily I was at home and had it fixed quickly. On the road it might have been a much bigger deal.

Steve

I have done this 3 times in 107,000 miles. I make a mess every time so I use the cardboard. I like Rfishin's idea of installing a drain plug. I changed fluid every 30,000 miles and never noticed debris in the filter as others have said, but noticed a lot of stuff on the magnet on the bottom of the pan. After draining the pan and replacing the filter and cleaning the magnet. I reinstall the pan bolts and disconnect the trans line going to the cooler and keep adding fluid until the fluid comes out clean, then reconnect and top off fluid. If I was going to do this again I would add another magnet to the bottom of the pan because I think it collects more stuff than the filter. Also I would stay with the original OEM gasket, the rubber gasket I used from the filter kit leaked and after re torqueing several times I had to go back to the OEM gasket to stop the leak.

kellertx5er wrote:

aruba5er wrote:
I'd wait until I got back. What happens if you develop a leak in a few days while on the road.
If it ain't broke (you know the rest)

Using this logic, are you saying that one should never perform PREVENTIVE maintenance prior to a long trip?

I did it a week and a half before our trip just in case. If there's a leak I'll tighten a bolt and top off the ATF if needed.

aruba5er wrote:
I'd wait until I got back. What happens if you develop a leak in a few days while on the road.
If it ain't broke (you know the rest)

Using this logic, are you saying that one should never perform PREVENTIVE maintenance prior to a long trip?

I purchase a 1/4" tap and drill, plus recessed 1/4" plug 9the kind with the square dent in the top of the plug.

Drill out the bottom shell of the torque converter and let the fluid drain. It can take a couple of hours. 9-12 quarts total including what's in the pan.

Tap the hole, wrap the plug with teflon tape, then tighten but I don't play King Kong with strength of installation.

Job semi-finished. Torque converter and oil pan buttoned up.

I install SIX QUARTS of ATF into the oil pan, then start the engine. Range the selector drive-neutral-reverse. The pump will suck up all the oil in the pan. Start adding more fluid while carefully checking the full mark on the dipstick.

The burnt friction material, bronze bushing powder and steel filings (pump) hiding in the bottom (they gravitate down when draining) will depress you.

No worries about drilling into the converter. Any drill debris gets flushed out by the fluid.

And the quarter-inch pipe plug does not imbalance the torque converter enough to matter one whit.

I've enjoyed 300,000+ mile lifespans on THM 350 and THM 400 transmissions by using the full-drain maintenance. First drain at 50,000 miles, then every 100,000 miles following.

Ford & MoPar didn't get a severe case of The Stupids when they designed their systems - both have torque converter drain plugs.

Although messier than snot, this mechanical driveway service is w-a-y cheaper than pump forced flushing and there is no way in hell pump forced back flushing will touch debris hiding in the torque converter.

The older Ford C4 and C6 transmissions used to use bug screens for filters. Good for stopping cigarette butts and pop tops.

It doesn't have to be messy.
if there is no drain plug, just reach under and drill a 3/16 hole in the rear corner of the pan, and let'er drain overnite.
By next day there is very little drippage when removing the pan.
Clean up the pan, drill the hole out to 1/2", and weld a 1/2" fine thread jam nut inside over the hole, and use a 1/2 x 3/4 bolt w/ fiber washer for the plug. Or if no welder, buy a drain plug kit from Napa.

Blacklane wrote:


I think the new fluid is the important part of this job. The next time I do this, I'm planning on just having the system back-flushed with fresh fluid, which will replace more fluid than a drain-and-fill, and it will clean the filter somewhat.

This is the key to a happy transmission. Not all back flush are the same, Find a shop that provides 90% replacement of fluid. This will do more for you than just a filter replacement.

I'd wait until I got back. What happens if you develop a leak in a few days while on the road.
If it ain't broke (you know the rest)