TheSamba.com :: View topic - Automatic rebuild options for Subaru conversion

Thu Apr 29, 2010 11:11 am

I have two automatic transmissions. Both work. One is currently installed and the other is from an 89 parts van that I drove some before killing it. With an EJ22 installed what should I do or not do with the automatic?

Which torque converter should I use based on stall speed?
(Note: I have both a Z and H converter I could use.)

FYI: The old stouter Audi parts seem to be harder to find now. Or am I all messed up?

I need help here before I step up.

Fri Apr 30, 2010 2:17 pm

Sat May 01, 2010 2:57 am

Use whichever converter that has the lower stall speed and then send it in to get reconditioned and have them lower the stall speed some more.

With the suby you have more torque so it will stall higher that the stock motor did.

Yes the Audi parts are hard to locate, I do have an extra forward clutch from a 5000T that I am going to list when I'm done with my rebuild.

Jeff

Sat May 01, 2010 4:34 am

I just used the stock converter in mine. Was worried about the stall, but had no problems with it at all, takes off like a rocket. I think that both the "H" and "Z" have about the same stall anyway.

When my automatic section blew years ago, I had the final rebearinged by a well known rebuilder, and then about 40K later the pinion bearings failed. In my opinion I paid a lot of money to cause a tranny failure, I would just leave the bearings alone if I could do it again.

I did my Suby conversion at the same time that I replaced the tranny that second time. This time around I just got a used unit and resealed it myself. Several years and running well at this point. :)

Sat May 01, 2010 7:16 am

I wouldn't worry too much about the 'performance' parts for your tranny. This is what I would do if it were my personal project:

1 - All new seals, gaskets, steels, friction material, and bushings in the automatic section. I just purchased a few sets of bushings from RockAuto for $10 each and a new brake band for only 6.50
2 - Replace all the seals in the differential case. I would not replace the bearings unless there was a known problem, heat discoloration, or scoring. My experience has shown the original bearing sets are usually superior than replacements. Make sure you replace the 'mixer' seals, side cover seals, and governor seal.
3 - I am not an advocate of the governor modification. You can always drop down a gear manually when needed.
4 - Don't forget to piggy back 2 torque converter seals.

Just my 2¢

Gary

Sat May 01, 2010 7:56 am

I'm also trying a modified valve body from German Transaxle of America. I did know anyone was even doing that for a van till Ken told me. If he sells it I trust that it is an upgrade.

I hopefully will have it together next week to see how it performs.

Ya we probably don't need the modified and stronger parts, but it's our van and the van gets what the van wants.

I would not pull a good trans to throw the parts on but the first time mine had a funny shift between 2 and 3rd I started looking for the Audi parts.

Sun May 02, 2010 10:15 am

jrobewesty wrote: I'm also trying a modified valve body from German Transaxle of America.
What are they fixing with it?

Unlike the later computer controlled boxes which "seem" to benefit from such a part, I am not sure what failure mode they are treating with it????

Mon May 03, 2010 10:11 am

jrobewesty wrote: Use whichever converter that has the lower stall speed and then send it in to get reconditioned and have them lower the stall speed some more.
If I read it right, there are basically 3 or 4 converters. 1750 (Type 4,) unknown ( Early Vanagon to March 27 1981 - D code,) 2400 (Early Vanagon including 1.9 wbx - Z code ) and 2700 (Late Vanagon with 2.1 wbx - H code.)

The Type 4 1750 rpm stall converter was known to fry ATF and hence cook the automatic. Is this the D code?????

From what I understand, the lower the stall speed, the better the hook up but along with that is more heat. This better hook up seems to be better for economy. Heat kills and that is why there is an extra cooler on the van. In my case an added air cooler instead of the water cooler.

Above the stall speed things tend to be the same. So the question is, how long do we really drive below the stall speed with a Suby anyways????

So do I really want to mess with this if the converter is deemed not to need service by the rebuilder??????

Or what?

I am stupid and it does not seem to be clicking for me on this stall speed topic.

jrobewesty wrote: Yes the Audi parts are hard to locate, I do have an extra forward clutch from a 5000T that I am going to list when I'm done with my rebuild.
Is this all I need to upgrade? Or what elss what I need to find?

I read the earliest Vanagon automatics (up to Oct 1, 1981) had 5 inner and 5 outer plates. Is this same as what the Audi 5000T had?

Again, I have become all confused about this stuff.

I need to get a warm and fuzzy feel for all of this before I pull the trigger.

TIA, for all your patient help.

Mon May 03, 2010 2:40 pm

r39o wrote: jrobewesty wrote: Use whichever converter that has the lower stall speed and then send it in to get reconditioned and have them lower the stall speed some more.
If I read it right, there are basically 3 or 4 converters. 1750 (Type 4,) unknown ( Early Vanagon to March 27 1981 - D code,) 2400 (Early Vanagon including 1.9 wbx - Z code ) and 2700 (Late Vanagon with 2.1 wbx - H code.)

The Type 4 1750 rpm stall converter was known to fry ATF and hence cook the automatic. Is this the D code?????

I think there were actually a few more intermediate converters VW used over the years, each with a higher stall than the earlier one. VW was slow in getting this figured out. I wonder what the stall speed for a Suby converter is? That would probably be the minimum you should consider, then add in the weight of the bus and the difference in gearing and see where you want to be.

When you are running down the road at 3500 the converter is going to be all in no matter the stall speed, so one its not apt to hurt power or gas mileage all that much as compared to another. Torque muliplicaton would affect this as well, I have no ideas what the numbers are for that.

As I said above the stock "H" converter seems to work very well in my 91 Mulit with a 2.2 Suby.

Wed May 05, 2010 1:58 pm

r39o wrote: jrobewesty wrote: I'm also trying a modified valve body from German Transaxle of America.
What are they fixing with it?

Unlike the later computer controlled boxes which "seem" to benefit from such a part, I am not sure what failure mode they are treating with it????
The answer is?

Thu May 06, 2010 8:54 am

I'm waiting to here from Ken at GTA to get the facts straight on the modified Rabbit valvebody.

Again with the torque converters, the VW converter rated at 2700 stall will stall at a higher speed with the more torque from the Subaru motor.

My 1.9 converter stalled at 3100 rpm's which in town will cause less MPG and more heat in the trans.

Everything I've ever heard on stall(torque) converters is the higher the stall the more heat that is generated.

When you are cruzing at speeds higher than the stall speed of the converter they should all produce the same amount of heat if the converters are in the same shape.

And our converters do not lock solid (lock-up) so there is always some slipage that causes heat.

If any of this is wrong I'm sure someone will chime in to correct the info.

Jeff

Thu May 06, 2010 6:55 pm

jrobewesty wrote: Everything I've ever heard on stall(torque) converters is the higher the stall the more heat that is generated.

The 411/412's were known for burning up automatic trannies. The high gearing and low stall caused poor initial acceleration, which meant a higher throttle opening to get the rig moving and more heat being generated by the torque converter. Having a high stall, probably a greater conversion ratio, and a lower final drive ratio pretty much put an end to problem when the same tranny was later used in a heavier bus.

I got all kinds of dire warnings when I put a "Z" torque converter with a 2700 stall into my 411. All the doomsdayers were saying I would smoke it instantly. No problems to date and way better performance, I wouldn't go back.

Fri May 07, 2010 8:22 am

I can see where low torque and high vehicle weight it would cause major lugging to get the vehicle going and that too would cause heat.