Transfer Case Crack Near Drain Plug, 2002 XLT

[sfbayjay]

2002 Explorer XLT with Borg Warner 4411 transfer case (4WD switches on dash, not AWD).

Inspecting the source of a small transmission fluid leak yesterday, I found a hairline crack in the case just below the drain plug. Crack is about 1" long and starts right at the bottom of the threaded drain plug port.

I've done a lot of reading here and found that others have had this problem, perhaps due to over-tightening drain plug after a fluid change. Nice. (Seriously, Ford? Torque spec for drain plug is only 11 ft-lbs? You can apply more than that with just your pinky... Can you say flimsy?)

Anyway, I see that some folks may have tried to clean out the crack and then patch it using JB Weld as a temporary fix. See discussion of this here.

Has anyone had success (even temporary) with this approach? If you drain the case to Dremel the crack, how would you get everything clean enough (free of trans fluid) for the JB Weld to bond?

If anyone has done this and has advice, experience, or pointers, I'm all ears!

Alternative I'm considering is replacing the whole case with a salvaged unit, but would like to delay that expense awhile if at all possible as I've just spent a load of $$$ on rear struts/springs, brakes, ball joints, etc...

 

[PopRichie77]

I haven't done this but grind it out and use Brake Cleaner to clean.

 

[sfbayjay]

How would you deal with the drain plug? JBWeld it in place and just rely on the fill plug (suction gun for future fluid changes) from now on? Or, thread it in with some kind of sealer (RTV, Teflon tape, ???), or maybe hit it with a dab of anti-seize on the plug threads?

Any ideas or thoughts welcome. I figure if I try this and it doesn't hold then I'm no worse off and will have to consider swapping out the case. Just trying to maximize my chances of success!

 

[rookieshooter]

I once sealed an aluminum housing on a Chry. tranny and worked great. Now it was not along the drain. Oh ya, JB was used.

 

[drdoom]

Different application, but I have had acceptable results with JB Weld on a cracked valve cover.
As for the Teflon tape & Anti Seize, I think I would use both, Anti Seize first, then a few wraps of tape on top.

 

[sfbayjay]

Finally getting around to thinking about this again after a couple of weeks spent tackling other projects on my Explorer (struts, springs, brakes, ball joints, and brake lines, to name a few). Thanks to all for your previous posts and advice.

I've posted a few pics of my cracked transfer case on the web. I'll try to attach a couple of them here:

If those don't work, here's a link to a small on-line photo album.

Does seeing these pics change your opinions/advice about trying JB Weld on this crack?

Thanks!

 

[sfbayjay]

Update - Solved (for now)!

OK - 6 months later and I'm posting an update on this project.

I managed to seal the stress crack at my transfer case drain plug, and after 6 months and most of a Northeast Ohio winter, things are holding tight. Here's what I did:

1. Drain the fluid from the transfer case (before draining, make sure you can get the fill plug loose, else you have real problems).

NOTE: When I removed the drain plug, the stress crack closed up quite a bit - the fill plug is tapered, so was opening up the crack.

2. Let every little bit of fluid drain out - I waited a few hours and then dabbed the remining bits from the threads with a clean(ish) shop towel.

3. Clean the whole area as well as you can. I used a wire brush on the outside along with some brake cleaner. Cleaned the crack, the case surrounding the crack, and the threads (inside) as well as possible.

4. Let everything dry really well - I had a floor fan in the shop and just pointed it at the case for awhile.

Here's what mine looked like:

5. Get yourself a tube of "Permatex Ultra Blue RTV Gasket-Maker/Sealant" at your local parts place. I know Permatex makes a whole bunch of different RTV sealants, but I can only vouch for the effectiveness of this one.

6. Smear a good bead of RTV along the crack with your finger. Jam as much into the crack as possible - I didn't do any grinding or anything - just smeared it as well as possible. Spread a little RTV to the sides, kind of painting the area along the crack maybe 1/2" wide on either side.

7. Time to replace the drain plug - here's what I did - Put a couple of wraps of teflon tape (plumbing tape) on the plug threads, then put a thin ring of blue RTV sealant along the back half of the plug, nearest the face of the plug that you'll see once it's back in the case.

8. Thread the plug back in carefully, with only a VERY LITTLE BIT of torque - i just used my fingers. STOP when you start to get the RTV squeezing back at you around the edges of the plug. Remember - for this crack, threading in the plug actually forces it to open up, so just get the plug to seat - the RTV sealant will do the job instead of torque.

Here's a photo of the sealed crack and drain plug:

Let the RTV cure for awhile before refilling case with fluid. I waited probably two hours while I changed out front brake pads - seemed to be plenty.

More pics here if you want 'em: Transfer Case Fix Pics

RTV will cure and turn to rubber (kind of). Soft and pliable, but definitely ON THERE. I did this repair in late September 2011. Checked status in late December and again in February and NO LEAKS. The blue RTV looks just like it did when it was first applied.

This approach was fast and easy, worked for me, and cost probably $20 total, including the Permatex RTV and replacement ATF fluid. Beats the heck out of hundreds for a salvaged transfer case!

I read about others using JB Weld and grinding out the crack, etc. I was worried about trying the JB Weld, as I'd read of others getting mixed results and I didn't want to permanently JB-Weld the drain plug in place. This way I can still remove the plug and if I have to repeat this in the future it's easy.

As always, your mileage may vary!

BTW: I used Royal Purple ATF for replacement all is well. (See related thread here: http://www.explorerforum.com/forums/showthread.php?t=329404)