Automatic transmission assembly trouble

[Wildthings]

I had some oil leaking between the two boxes of the automatic transaxle on my '91. The unit had about ten years of use on it since it was rebuilt, and on inspections the seals were obviously worn. Replaced all the seals in the final drive and reassembled the drive without issue. The only thing I did to the automatic section was to replace the seals on the #2 brakeband piston and cover which requires the removal of the valve body along with the #2 brakeband piston and cover. At this point I thought every thing was A-1 for putting the two boxes back together, but I can't get them to fully mate. Once the turbine shaft is splined up it becomes hard to turn the output flanges on the differential and once the boxes are within 1/8" of mating the flanges can no longer be turned by hand and the boxes can not be pushed any further together.

I notice that the piece that the Bentley on page 38.7 refers to as the "REVERSE PLANETARY RING GEAR/GOVERNOR DRIVE GEAR" seems to move around quite a bit.

I have tried leaving the turbine shaft out along with the shim set that goes between the two boxes and neither seems to make any difference. The unit was operating fine before I tore into it excepting the problem with the oils mixing.

I am guessing that one of the circlips that hold the friction plates in place has popped out of its groove but really don't know at this point in time. Looking for ideas.

[kourt]

My first thought is the snap rings on the ATF pump tower assembly. Those things can come off during assembly and sit on the bottom of the tower, making the whole reassembly sit proud by about 1/8".

kourt

[IdahoDoug]

Hmm. I am no help. I've done this twice successfully though it took some fiddling to line them up. The "locked flanges" thing may bear some explanation. If the trans is in Park wouldn't they be expected to be locked? Unsure but thought I'd mention it in case it helps.
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1987 2WD Wolfsburg Vanagon Weekender "Mango", two fully locked 80 Series LandCruisers. 2017 Subaru Outback boxer. 1990 Audi 90 Quattro 20V with rear locking differential, 1990 burgundy parts Vanagon. 1984 Porsche 944, 1988 Toyota Supra 5 speed targa, 2002 BMW 325iX, 1982 Toyota Sunrader

[Wildthings]

Making sure it wasn't in park was the first thing I did. There is a minor metallic screech from the automatic section when flanges are turned, which would be consistent with a snap ring having popped out of place.

I guess I will just tear into the unit a bit further and see what I can find.

[r.e.wing_fc3s]

i vote for shaft seal rings because the same thing happened to me. One didnt compress right and got caught sideways. luckily i had some extras. i like to use some atf assembly lube as well.
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Reference Automotive: NW Washingtons Vanagon Specialist. (360)366-6965. referenceautomotive.com

[Wildthings]

Well its together, I am not sure if I actually corrected what was wrong, but on disassembly I found that one of the washer parts of one of the trust washers had what looked like weld splatter on it which had caused some galling of the piece it sat on. I cleaned the pieces up with a file and stone and put everything back together and every thing slid right into place. I don't see how this would have caused the problem, but its together and so long as the tranny works correctly I am happy.

[VanandGone]

Just got my automatic back from being rebuilt, shipped away just the auto portion and am having the exact same problems with mating things back together as described above.

End play measurements were taken and were within specs to use the single shim that was there on disassembly. Turbine shaft test fit for proper engagement then new sealing rings installed.

The automatic section appears to mate fine with about 1/4 inch gap just covering the o ring, turbine shaft sits level with outer shaft at torque converter end and turns when axles rotated in the same direction.

The problem occurs when tightening the nuts slightly more than finger tight they feel tight immediately the gap does not change and the axle shafts feel bound and will not turn, backing off the nuts everything feel free and fine.

I have tried numerous times flat and level on bench, transaxle on top, transmission on top all ways it feels the exact same. Looking into the auto section nothing appears out of place to causes this, I've tried just about everything I can think of... I have done this job before and have had no problems what so ever.

If anyone has suggestions I would love to hear them!!

[kourt]

In my experience, mating the two works best when you use a rubber mallet on the exposed torque converter shaft, and tap/rotate it while mating the two. They eventually join whenever I do this.

kourt