4EAT Phase I swap with Phase II

[99susx2]

Greetings!
I have a 99SUS with the 4EAT Phase II (spin-on external filter). Short story: the front differential developed a problem.
I have a (lower mileage) 98 GT 4EAT (Phase I). It'll bolt right in (with the matching rear Diff and all).

Problem(s): The wiring harnesses are different: the second speed sensor is in a different location and has it's own connectory on the Phase I.
On the Phase II, the second speed sensor is wrapped into the large connector.

Question: Is it as simple as building a patch "cord" between the 2 connectos?
(That is, take the Tranny end from my Phase II and the firewall end(s) from the doner car)?
Or, am I entering the realm of changing wiring harnesses and TCU's?

This is NOT my first time here, as my son and I changes a 4EAT (95) to
a 5MT (from a 97 GT) earlier this year. I'm hoping it isn't a major deal...

Thanks!

[99susx2]

Hmmm. No response? I've seen folks on the forum pull bigger rabbits out of the hat (and I appreciate it :smile: ).

So, let me back up a bit. There are 2 things wrong with my original (phase II) tranny. The first (as I mentioned) is a "loose" front Diff. That is fixable.

The second: IT tends to "burp" tranny fluid out the vent on the top. Did so soon after Kennedy Transmission rebuilt it 100K ago. Not alot, just enough to make it build up on the exhaust... and cook... and STINK... I'm worried about ignition of that oil and fire...

So, I think I have 2 choices. Replace it with an older (Phase I) with fewer miles (but a different wire harness) or solve the oil "burping".

Kennedy has "no idea" what it could be, but would be more than happy to take another $2500 to rebuild it, again.

Do I just get a rebuild kit and re-built it myself (never done it, but what the heck!)? Or, play with wiring harnesses and transmission control units...

Any thoughts, ideas, information or advise would be greatly appreciated.

[Airgne]

im sorry about no reply. i wish i knew more about autos for you. electric autos and me dont mix. i always swap for manual.

[Huffer]

I would try to stick with the same tranny and the same wire harness - if only for simplicities sake. The previous 4EATs came with different shift patterns, mechanically they *should* be the same but obviously the differences in the harness makes you wonder.

[99susx2]

Yeah. Think I am going to fix the Diff (I recently had the seals replacd and I do't think the lash was adjusted right.). Then I'm gonna try a tranny flush with Seafoam TransTune (recommended by a tranny shop), before I bite the bullet and re-build...

Any ideas on good documentation of how to re-build a tranny?

[Huffer]

I did a fluid drain with regular ATF and then added a bottle of LubeGard ATF on my old BD. It's still rocking along with no problems after 30k, and I had the dreaded torque bind too. Might be worth a shot.

[99susx2]

Thanks! I'll give that a try. Gotta be better than having it up on stands for another week...