94 A4LD Frankentranny help...

[cobraphx]

So I bought a 94 4 door Explorer 4X4 with a bad performance rebuilt A4LD. I did a lot of reading and decided to do a Frankentranny rebuild myself. Before the rebuild the tranny would not move the truck in forward or reverse.

So, I bought all the 5R55 internals, a bellhousing, and a rebuild kit with new frictions and bands. Replaced the rear race, and went thru the valve body. Everything went together nicely. Put it back in the truck, along with a new TC. And it was better. But far from right. It moved in forward and reverse. But it was hesitant to move, took about 2500 to 3000 rpm to get it to move. It shifted, but felt like a manual with a slipping clutch.

So, I figured maybe my rebuild of the modified valve body might be a problem. Ordered a rebuilt VB and replaced it along with upgrading the low reverse servo with the D shaped o-rings. Had to tap it in with a rubber mallet to compress the spring. Not sure if that is normal or not. Tested again... Sounds like forward engages better, but still takes a bout 2200+ rpm to get it to move. Now reverse is a problem. When shifting from park into reverse, no engagement. when shifting to reverse from neutral it seems like there is an extra detent right in the middle of reverse. If I shift it further to where reverse should be still feels like neutral.

So... Not sure where to go from here. I haven't adjusted the OD and intermediate bands since it was on the bench... but I don't think that would effect first and reverse. I didn't touch the vacuum modulator, just reinstalled it set the way it came off.

I have a feeling it will have to come back out. Trying to decide if I should just buy a rebuild, or try and find someone that could actually fix the Frankentranny. I think most shops will tel me they have to replace everything (since it isn't A4LD internals) and charge a small fortune.

Any advice would be welcome.

-Matt

 

[BrooklynBay]

You might have damaged the Viton D rings when you hammered the servo into place. Next time place the servo with the rings in the freezer for a little while to help contract the metal & rings prior to installation.

 

[cobraphx]

It would certainly be easy if that's the fix...

Thanks for the input BrooklynBay...

 

[XLTByAccident]

Do you have the ATSG manual? There are close to 20 pages dedicated to diagnostics.

From the manual...
Symptom: vehicle will move only when the engine is accelerated to a high RPM and transmission selector is placed in OD.

Several possible causes;
1) converter clutch shift value stuck,
2) converter clutch shuttle valve stuck in locked position,
3) lock-up piston in torque converter will not disengage.

Resolution:
1) check to see that converter clucth shift valve moves freely,
2) check converter clutch shuttle valve for ease of movement,
3) replace torque converter.

You didn't say anything about the torque converter in your rebuild. Did you have it rebuilt or are you using the old one?

Of course, it could be a lot of other things too.