2000 Eurovan - 01M valve body - Loss of reverse questions

[Michaelryanosier]

[Stripped66]

[Michaelryanosier]

I'll look into the pistons when I get home from work.

In looking ahead in the manual for reassembly...I see that you need a VW Tool 3459 to compress the B2 clutches to measure the depth for shims... Is there a work around to compress the clutches I can do or am I going to need this tool?

It looks like otherwise I'll need a depth gauge and a dial gauge. I see that the manual has a specific VW Jig for the dial gauge...but I've seen videos of different transmissions where mechanics just used a stand to hold the gauge in place...so really any dial gauge should do? or am I missing something with that.

[Stripped66]

I didn't have the tool to compress the B2 clutches when I rebuilt mine. I took depth measurements from the reference point while applying downward pressure on the clutches.

A couple of things to look out for: pressing the K1 hub off of the K3 drum. I used an old brake rotor, as described in this video: https://www.youtube.com/watch?v=sikS1-335c8 Even then, the K1 hub was on tight, and the K3 drum warped before the turbine shaft broke free from the K1 hub. I had to source a replacement K3 drum/turbine shaft assembly from GTA.
And, the frictions/steels for the K3 clutch provided in my rebuild kit were thicker than the factory clutch. I had to reuse the thinner, stock steels and surface the thrust plate to get adequate clearance. If you encounter the same problem, don't be tempted to remove a friction to get the clearance...
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[Michaelryanosier]

Here is the piston that I serts into the stator... It looks fine to me?

[Michaelryanosier]

I then tried to get to the piston behind the planetary gear....I removed the three 10mm bolts on the planetary gear and it exploded into a bunch of pins... So. Not sure how to recover from this. Can't find a diagram of the planetary gear anywhere. All time low.

[TheOneTrueQuux]

[Stripped66]

Quux is correct, you'll figure it out. If you have any question of whether the planets are oriented correctly, you can use the small and large sun gears to double-check the assembly. The thrust washers should also be divided accordingly. Maybe purchase a container of automatic transmission assembly grease and use it sparingly when reassembling the planetary (it's a bit tacky to help "stick" thrust bearings and other roller assemblies into place when assembling).

BTW, I'm confused why you disassembled the planetary gear set...there's no piston behind it. The B1 piston installs in the center support (that houses the sprag clutch). I can't tell from your pic, but perhaps you did not separate the planetary assembly from the center housing/sprag?...they just slide apart. And on that note, if the sprag is working properly, the planetary housing will only rotate in one direction within the center support. Rotate the planetary housing while pulling to slide it out from the center support. (and also watch for sprag rollers to come loose)

Likewise, you also claim the piston pictured above is from the stator housing, which is the B2 apply piston...it's not used for reverse (B1 is used for reverse).

Print out this diagram: https://at-manuals.com/wp-content/uploads/2016/03/Manual-VW_AG4_095_096_097_098.jpg There are no missing parts holding stuff together...it's all pictured. Things either slide apart or use circlips to hold it together (exception: press fit between K1 hub and K3 drum, mentioned earlier).
Reference this tech bulletin for the clutch assignments for each gear (as well as valve-body/solenoids): https://procarmanuals.com/pdf-online-volkswagen-01...ice-group/
This is a good video for reassembly (play it backwards for disassembly): https://www.youtube.com/watch?v=kD2qCH2Ic9A
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[Michaelryanosier]

Yeah, I erroneously disassembled the planetary gear...ooops. I'm trying to get to part #967 behind the center support. But did it incorrectly. I didn't realize that there is another c clip on the back side I'll have to look closer

That grease is going to be key and I had some ordered so hopefully it arrives soon. Otherwise the pins just keep falling out.

Thanks for the advice and info

[Michaelryanosier]

I can't believe those two pieces just slide apart ..mine was just pretty tight and I had to use a screwdriver to pry them apart..

When rebuilding the planetary gear a bearing in the bottom wasn't fully pressed in and the washer on it broke when the planetary gear put pressure on it...so that's a bummer. I can't find just that bearing but can find planetary gear assemblies.

So I got to the piston and it seemed to be sealed in it's slot pretty well it took a decent amount of plucking at with a pick and tiny flat head to get it out . No visual degredation... Would it be visually apparent if it was bad?

I'm apprehensive to order a whole rebuild kit plus now a planetary gear if I can't even determine the root cause of the failure...I'd hate to put $1000 into this and all the effort to get the trans back in just to not have the reverse resolved

I'm going to reach out to a buddy to inspect the clitch plates if they may be completely worn out or not...

[Stripped66]