Tranny Flush: Part Number Help

[RangerJoey]

Hi All,

I'm going to service my '99 4x4 5R55E tranny and just want to be sure I'm getting the correct stuff.

First, I wasn't going to do a full flush since there's 120k on the original fluid and I'd prefer to do this procedure annually, (bi-annually?), to introduce new detergents slowly. So with that, I saw the capacity for just a Fluid Drop and Fill is like 5 Qts or so. Is it still safe/recommended to use Mercon V or has something superseded that?

As for the gasket & filter, I think the filter for the 4x4 is MOTORCRAFT FT134. But I can't find the corresponding Motorcraft gasket. Is there a different part number for an all-in-one kit or something?

Thanks for any advice! Oh, and super random, but is Mercon V also used for power steering? I need to flush that too so....

 

[Dirtman]

Mercon V is still the correct fluid, and yes it is also a power steering fluid. You'll get more like 4 quarts out on a pan drop, total capacity is 10 quarts so most people will do the pan dop and fluid swap 3 times over a couple months to get most of the fluid changed if its never been done before. I highly recommend adding a drain plug so you can do the subsequent fluid changes faster.

After doing the 3 fluid changes in a row your good to just keep up with a normal pan drop and filter change every 15-20k. Some will argue thats overkill but I prefer to keep fluid fresh and not to rebuild my transmissions...

 

[Craig0320]

Yup. I change mine every 20-25k. 70 bux or 1500 plus on trans rebuild. I think you know which one to choose.

 

[RangerJoey]

Thank you guys! And I like the idea of doing this 3 times before winter hits. I was actually going to swap filters the first and 3rd time given the age of the transmission.
Am I correct thinking there's no official Motorcraft gasket?

 

[Dirtman]

Not sure on that, I always just use the fram or carquest kits from the parts store. Never bothered to look up motorcraft stuff.

 

[Craig0320]

If you want to clean the fluid up disconnect your top trans cooler line on your radiator and attach some clear hose to it and run to a bucket. Run the truck for 5-10 seconds at a time then shut it off and top off the trans fluid. Do this until you see bright red fluid running into the bucket. I have done this for years and gotten good results. You are going to need around 4 gallons or so

 

[kimcrwbr1]

There should be a drain plug in the torque converter plus you can blow out the cooler lines for a more complete oil change.

 

[Craig0320]

There should be a drain plug in the torque converter plus you can blow out the cooler lines for a more complete oil change.

There isn't a drain plug in the torque converter. There is no reason to blow out the cooler lines if you are pumping the fluid through the system and out of the top drain trans line. Blowing the lines out could just release debris and cause problems.