Trans flush and fluid upgrade after trans rebuild?

jimmyducati · June 05, 2017, 04:28:59 PM

I had my transmission rebuilt about 2000 miles ago and it seems to be doing fine (loaded the stock tune to be conservative for the first couple months). I have since added the AUX trans cooler and will be swapping to the cooler trans thermostat soon as well. My question is this: Should I have the newly rebuilt transmission flushed and filled with a high quality trans fluid (i really like amsoil products) or should I just start to do a "drain and fill" at regular intervals now that it is rebuilt? Ill be disappointed at best if this trans goes within the next 100,000 miles

TopherSho · June 05, 2017, 04:33:55 PM

That will depend on your philosophy .. and driving habits.

If you redline/race it a lot, i'd change it to a fluid with a better heat tolerance and shear handling. IE Amsoil\redline.
If you do not redline it all the time or run x-cross.. you might
1) leave the sealed unit alone. As long as the sealed unit was not contaminated on build, it should last 100k++
2) if you subscribe at all to the ''PTU's being kind of toss away parts'' in SHO's .. change it soonish, 20-40k mikles

jimmyducati · June 05, 2017, 05:05:23 PM

I do not drag race or drive like a maniac regularly, at most I like to get my speed up on the onramp at an accelerated pace

I haven't been on an auto-x course, but plan on it eventually. As for the PTU, I change it every other oil change with amsoil sever gear.

I think ill have it flushed by the shop that did the rebuild and filled with amsoil, then just a drain and fill every 20k.

SHOdded · June 05, 2017, 06:27:43 PM

A good idea to have that "breakin" fluid flushed out, then go about your normal daily business. Regardless of transmission or PTU.

pmezo33 · June 05, 2017, 09:38:57 PM

What kind of fluid was used from the shop that rebuilt the trans? Did they use mercon lv?

If it were me (and it was about a year or so ago), I'd get a BG flush done with mercon lv back in it. Then in a year, i'd do a 3x drain and fill or another flush. That's what i did.

jimmyducati · June 05, 2017, 09:59:55 PM

They said they filled with Mercon LV, but they also mentioned my PTU "only had about a half quart of ATF in it, so we filled it up"... I tried hard to keep my cool, found out they haven't driven it with the ATF filled to the brim in the PTU. Told them not to even start it, sent a quart of Amsoil Sever Gear to the shop and told them to completely empty the PTU and refill with the Amsoil. I tried to educate them on the type and capacity of fluid for the ford PTU but I think they remain hard headed.. "I ain't never seen a transfer case take gear oil"... I reminded them that If I needed a new PTU in the future, they will hear from my people.

pmezo33 · June 05, 2017, 10:39:07 PM

ATF in the PTU... that would not have ended well. Way too thin for what's required.

It is true that trans fluid is typically used in transfer cases, but even then, it's not always generic ATF. Every manufacturer has their own requirements. You'd think a shop would at least check. How hard is that to do? Just carelessness. Takes 2 minutes to check.

If that were me, i'd be flushing that PTU out with new 75w140 a few times in very short intervals.

SHOdded · June 06, 2017, 03:04:53 AM

I hope they replaced the trans-PTU seal if they found ATF in the PTU ... Be really sorry-a** if they didn't. Rare to see a trans shop that doesn't understand the variety in transfer cases & differentials. As long as they rebuilt the trans correctly tho, I suppose all is not lost!

jimmyducati · June 06, 2017, 09:04:54 AM

Quote from: SHOdded on June 06, 2017, 03:04:53 AM
I hope they replaced the trans-PTU seal if they found ATF in the PTU ... Be really sorry-a** if they didn't. Rare to see a trans shop that doesn't understand the variety in transfer cases & differentials. As long as they rebuilt the trans correctly tho, I suppose all is not lost!

They didn't find ATF in the PTU, they just assumed that the little bit of gear oil in the PTU was ATF that was very old and very bad. It was a case of 65 year old mechanic that "knows" everything and didn't bother to look up the proper fluid. He initially said that after the test drive they were going to put in a light gear oil, claiming that helps with stopping the leak that must have let all the ATF out in the first place. I told him that his light gear oil was still way to light, and corrected his false assumption that it only had 18 oz because it was leaking.