HELP stripped the threads from the transmission drain pan

[Steve Gutman]

My friend stripped the threads from the transmission drain pan on his 1993 BMW 525i. I actually think it’s a GM transmission. Nonetheless, what is the best easy repair? Can JB Weld for Aluminum be used? Can he just tap it to the next larger size? It only takes 9 ft/lbs of torque. I don’t think there is a lot of room to helicoil. Any suggestions would be most greatly appreciated.

[Mike Murrell]

If it were my vehicle, I'd pull the pan and take it to a good machine shop and let them make the repair. I would envision them simply over-sizing the hole and installing a new drain plug to fit the new hole.

It's my understanding that BMW used a GM 4L-30 unit in some of their cars. This may be what he has and they ain't cheap, not that any of them are.

If you go this route, be sure to thoroughly clean the inside of the pan to ensure any metallic debris stirred up from the surgery is removed.

My 2 cents.

[manny]

Mike

It sounds like the threads are stripped on the transmission body, not the drainplug.
If so, I would helicoil them.

[Mike Murrell]

Manny:

I thought he said transmission drain pan as in the drain plug? Maybe I misunderstood?

[Steve Gutman]

Sorry for the lack of description. THe bolt that holds the pan must have pulled out the threads, which I assume are in the transmission housing. On the Benz it is the housing, right? When I changed mine on my SL I recall that there was little room on the bosses. Please advise, if you can...

[Mike Murrell]

Steve:

I have a '95 Rodeo equipped with a GM 4L-30 transmission. Have had that pan off many times and if the threads in the body(not the drain plug) are the issue, Manny may have your answer.

The unit I'm speaking of is shown at the following URL. If his looks like this, be sure to drain BOTH pans - part 1 and part 73.

http://www.slhondaparts.com/browse.asp?Model=PASSPORT&Year=1995&TrimLevel=4DR+LX+4X2+V6&TransLevel=4ATKA&Section=C&Category=ATM04++%7CAT++++++TRANSMISSION+OIL+PAN%2D+OIL+CONTROL&Doors=4&Emissions=KA&PartCatalogId=50691+&ViewParts=true

[Steve Gutman]

My friend said he has the "other side" to do. I am loaning him my Inch/Pounds torque wrench.

[Mike Murrell]

Good idea about the torque wrench.

The torque consideration on those 10mm bolts is pretty much the same as the 722.3 MB transmissions.

If you over-do it. you'll cut small circular rings in the pan and create intermittent leaks.

[Steve Gutman]

He is going to use JB Weld. I'll post back the results. He called JB Weld and they said he could let it get semi-hard, coat the bolt with vasaline and thread it in. I think he is just going to use a little on the inside edges and tap it.

He told me there was 1/2" of metal sludge stuck to the magnet in the bottom of the pan.

[Mike Murrell]

That unit holds 9.1 qts. of Dexron-III

He'll drain 1 qt. from the front pan(smaller of the two). It's known as the Adapter Pan. The main pan in my case drains 6 qts. if I let it sit and drain awhile. You'll end up getting 7 of the 9.1 qts. No drain plug on converter. Filter change easy once pan is off. Three - 13mm bolts hold the filter on. Wix makes a good filter. The markings/numbers on the Wix are identical to the dealer filter which makes me wonder if Wix made it after all. The pan gaskets are a bundle at the dealerships.

You can get them much cheaper from WEB sellers such as this site or wherever you choose to go. I use no sealer, just new gaskets.

[Strife]

Originally Posted by Mike Murrell

Good idea about the torque wrench.

The torque consideration on those 10mm bolts is pretty much the same as the 722.3 MB transmissions.

If you over-do it. you'll cut small circular rings in the pan and create intermittent leaks.

After doing some major work on my car, I would say that fooling around with an engine/transmission containing aluminum components REQUIRES a torque wrench and actually using it. I know that good ones are expensive, but no one IMHO who owns one of these cars and touches a wrench to them can't afford the ones at Harbor Freight. Industrial quality? Probably not. Usable if not abused? Yes.

Mistakes can be very expensive. And my "torque wrench" in my wrist is seriously uncalibrated after years of not doing this work!

[Steve Gutman]

Yeah, I have four torque wrenches, from 30 inch/lbs to 250 Ft/lbs and I torque everything to spec, unless I cannot get a socket on it. I would love a "flank Drive" torque wrench but they are mighty expensive. I have only seen German ones. I did not check Harbor freight. I tend to under-torque...

I also have a '92 525iT (Station Wagon) with that trans. The service records show I can go another 10,000 miles before I need to change the trans fluid. I hope I fare better.