In changing my transmission fluid in the old Barth is there a torque converter drain plug?

quote:

Originally posted by Kevin:
From reading earlier posts, it seems like Bill ny would know this.

Sorry, not off the top of my head. It's Friday night and I wouldn't be able to call someone on it til Monday.

But, if I had to guess, I would say it probably does.

Google brings this document up. No mention of a torque converter drain plug or draining the torque converter when doing a fluid change. HTH

Allison 600 series trans

Kevin, I have a shop manual for the Allison 640 - 643 - 650 - 653 transmission and I can not find any where a mention of draining the torque converter. Later I was looking at the number sequence on the list, my number was 0135 and yours is 0136. Your coach and mine were made at the same time. Best to you. Sky

When we changed the fluid in our allison 3060 last year we did not (unfortunately) find one--- would have been helpful.

Bud

When I changed to synthetic fluid in my Allison MD3060 6 speed, there was no converter drain and the instructions for the fluid conversion clearly stated that I had to change the fluid 3 times to get 90% of the old fluid out because of the fluid left over in the converter and cooler. I changed fluid and filters every year for 4 years and considered that was enough for awhile. Very pricey at $40.00/gal but is the way to go for sure with the Allison.

Look at and around the bottom of the bell housing and if there is no access to the converter then probably doesn't matter if there is a converter drain or not.

You can drill and tap for two 1/8 pipe plugs 180 deg apart. This makes balance perfect and provides an air vent for much quicker draining.

Or you can drill one hole and replace it with an aluminum pipe plug with an internal hole for an allen wrench. The aluminum plug's weight will be pretty close to that of the steel removed.

From my notes:

GM SB #82-7-111 - (Jun 16, 1983)

TRANSMISSION CONVERTER FLUSHING PROCEDURE

THE SERVICE FLUSHING PROCEDURE FOR ALL CONVERTERS HAS BEEN REVISED DUE TO THE ADDITION OF THE CONVERTER CLUTCH. IN THE REVISED PROCEDURE A PIPE PLUG IS USED TO INSURE THAT REBALANCING IS NOT REQUIRED.

THE PIPE PLUG CAN ALSO BE REPLACED IF A LEAK DEVELOPS. FOLLOW THE PROCEDURE BELOW:

1. DRILL A 11/32" HOLE IN THE CONVERTER BETWEEN THE TWO VANE EXTRUSIONS AND ADJACENT TO THE CONVERTER WELD SEAM EDGE. SEE FIGURE 1.

A. DRILL THE HOLE TO APPROXIMATE COMPLETION.

B. REMOVE THE DRILL BIT FROM THE STARTED HOLE AND COAT IT WITH GREASE TO HOLD ANY METAL CHIPS.

C. COMPLETE DRILLING THE HOLE AT LOW DRILL SPEED. NOTICE: TO PREVENT CONVERTER DAMAGE, DRILL AT RIGHT ANGLES TO THE SURFACE AND SLEEVE THE DRILL BIT SO IT CAN ENTER NO DEEPER THAN 1/4".

2. APPLY GREASE TO A 1/8 X 27 NPSF TAP AND THREAD THE HOLE.

3. DRAIN AND FLUSH THE CONVERTER AS CURRENTLY DETAILED IN THE SERVICE MANUAL.

4 . COAT A 1/8 X 27 NPTF PIPE PLUG WITH TEFLON PIPE SEALANT OR EQUIVALENT AND INSTALL. USE PIPE PLUG PART NUMBER 9427882 OR EQUIVALENT.

5. TORQUE TO 8 FT.-LBS.

6. PRESSURE CHECK FOR LEAKS AS DETAILED IN THE SERVICE MANUAL.

http://catalog.remyinc.com/Product/Details/9427882

Product Detail Part Number 9427882 Status Obsolete. Superseded By 10476561
Part Pipe Plug 1/8 - 27 Dryseal

Available from http://www.gciron.com/GM_10476561_p/gm-10476561.htm

Neither the 542 or the 2000 Allison torque converter had a drain.

So to drain the TC remove the transmission, carefully pull out the TC and then you can partially drain it. If you have a vacuum you can suck most of it out

Years ago they did put drain plugs in torque convertors, I guess the bean counters talked them out of it.

As for drilling a hole, it shouldn't be a problem. The chips will flush away when you break through, believe me. I have seen this/done this several times using self tapping screws with gasket washers. Check the hot rod/user sites for best place for the hole(s) (assuming there is a way to allow access to the TC plugs!)

Makes fluid changes way more efficient... you get all the fluid at once, no residual each time, no need for additional flushing. (less qts equals save money.)

I'm sure it was the bean counters at GM. But, it was the engineers at GM that came out with the Service Bulletin to put the plug in yourself.

Go figure.

quote:

Originally posted by Steve VW:
I have seen this/done this several times using self tapping screws with gasket washers.

I have also heard of pop rivets, but my preference has been the self-sealing pipe plugs per the GM SB. With rivets, be sure to use steel, as aluminum has a different temperature/expansion coefficient than steel. Being tapered, the the pipe plugs get tight and stay tight. The dry sealant on them helps, too.

All this procedure would involve removing the trans from the engine to expose the torque converter. Seems like a lot of work to avoid 3 oil changes.

I for one am a BIG FAN of synthetic trans oil. In the MD 3060 when Allison changed to synthetic (TranSynd) their warranty work went down by 70%. That speaks for itself. I changed to TranSynd oil right after I got this Breakaway at about 75K, 85K,95K miles, I now have 185K miles and it is going strong. I have a lazy shift from 3rd to 4th but have never had a breakout. When I changed the trans oil I discovered that it had the original oil in it and the filters had never been changed. I have been a bit concerned about this but so far so good.

Here is a link to the current TES 295 approved oil by Allison.

TES 295 approved oil

I would use either Castrol or Mobil Delvac syn.

quote:

Originally posted by MWrench:
All this procedure would involve removing the trans from the engine to expose the torque converter. Seems like a lot of work to avoid 3 oil changes.

The GM SB I referenced was for front engine rear drive gassers. A little less trouble.

I had our MCI bus changed over to transynd a few years ago. The Detroit Diesel shop did a complete flush and filter change so that i did not have to go thru the 3-4 oil changes. Benefits of transynd are cooler temps, easier shifts, and extended service intervals,...as much as 3-4 times longer, which more than pays for itself.