Cracked Drain plug on gearbox..Advice?

[African]

Hi all well this is my fist post here, but I have been lurking and have picked up some great advice over the last year. Iv searched but have found no info on this, I apologize if its been covered.

I have 80seires I picked up last year. Iv have slowly been fixing it up as and when I can afford to.

Today I decided to do all the oil. Engine, Gearbox, Transfer case and Diffs together. All went smooth until I got to the Gearbox Drain plug (there is silicon around it) So I thought thats weird. pulled it off, cleaned it up, re installed. Filled up the gearbox... and in my final check see its seeping oil at the gear box drain plug. So I drained the oil (again) wiped the area clean and got the torch in there...and that when i just about threw up. Its Cracked! through the threads. I know its a tapered plug and previous owner or whoever did it last must have overtighned it and cracked it. (explains the Silicon)
So my question is what do I do now?
I dont have pics but the if you can envision it, the crack runs about 1/2" on the inside of the threads in the case and about 5/16ths" on the outside.
All i had on had was Thread tape and Gasket goo. So I taped the threads and applied gasket goo to the washer. It has not leaked since driving home. (50klms)

Anyone had this problem, what are the possible solutions?
Just leave as is and keep and eye on it?
is there a better recommended "FIX" ?
Its and alloy case, Can that be welded?

Any advise would be greatly appreciated.

Cheers Andy

just when you think your getting on top of things

 

[inkpot]

Have you tried replacing the gasket seal on the plug? If it gets tight enough, it should hols the gear oil in. John

 

[Romer]

Are you talking PS Gearbox?

If its working with the fix which is similar to what the PO did, I would leave it but keep an eye on it.

In a no hurry manner, keep your eye out for a used gear box, rebuild and then install along with new hoes and possible the Pump as well

If it make you uncomfortable and you don't have a cash problem, get a new one and change the PS hoses and pump while you are in there

 

[86tuning]

If its the trans or transfer they can be welded if you can get it clean enough. Cleaning is the hard part. The thread is m18x1.5 and is not a tapered thread. Oxygen sensors use the same thread so a tap isn't too hard to source.

On a passenger car, epoxy putty makes a semi permanent repair. On a 4x4 that will only work until it gets rubbed up against a rock. Welding is the proper permanent repair.

 

[Offroads4x4]

Clean the thread area real well and use Liquid Steel to fill the crack then run the plug in and out before it sets up all the way. Let it dry/cure fully then run the thread tap in the hole and clean up the threads. Put some RVT on the plug threads with a new washer and call it good. This should work well enough to hold the fluid inside.

You could wait and see how it holds while looking for a case or full gear box.

JM2C

 

[African]

Thanks Guys. Its the main Gearbox housing where the drain plug screws in. To my knowledge and by the looks its Cast Alloy?, if this is different to the Transfer case.. can cast alloy be welded?, and can that be done on the vehicle or does it require removing?

So far my temp fix is holding, dry as a bone, I may just be best going with an Epoxy steel fix and sealer and keep an eye on it to keep it going.

Will the crack expand when hot? or should it stay the same.

Offroads4x4 whats the best Liquid Steel? to go for. iv used JB weld for cracked fuel tank repairs.

 

[Offroads4x4]

That's the product name sold at places like Auto Zone, Home Depot and alike. It comes in a round tube with a silver label.

It's a 2 part epoxy dry clay base. Mix A and B like playing with clay then push it in the crack like puddly. Don't let it go inside the gear box is a no brainier but you get the idea. JB weld is more liquid as it try's to set and will run on you more before it sets.

 

[Funner]

Is there any reason you can't order a new one and swap out your rigged one when it arrives? Seems like jacking around with welding a drain plug is a bit much if it is currently installed and not leaking.

 

[Aggiesdm]

If its the trans or transfer they can be welded if you can get it clean enough. Cleaning is the hard part. The thread is m18x1.5 and is not a tapered thread. Oxygen sensors use the same thread so a tap isn't too hard to source.

On a passenger car, epoxy putty makes a semi permanent repair. On a 4x4 that will only work until it gets rubbed up against a rock. Welding is the proper permanent repair.

^^^ What he said! If its the tranny or transfer case, get it welded and tap that sucker.

 

[86tuning]

The fuel tank repair putty is epoxy putty and they are all functionally the same.

 

[African]

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[African]

 

[African]

Thanks Offroads.
This is a pic of it. Does not look to bad and Im feeling better that its not leaking at all. Not the best pic, It looked a lot worse from the inside as the crack runs longer. So long as nothing changes and it does not get worse, a temp fix should keep me on the road.
Im still curious if in the event this does get worse can it be welded?
Thanks

 

[Aggiesdm]

Thanks Offroads.
This is a pic of it. Does not look to bad and Im feeling better that its not leaking at all. Not the best pic, It looked a lot worse from the inside as the crack runs longer. So long as nothing changes and it does not get worse, a temp fix should keep me on the road.
Im still curious if in the event this does get worse can it be welded?
Thanks

I don't know why it can't be welded. If you find a good welder, he should be able to flux/fill it and then retap the hole. Good luck

 

[Howard705]

Leave it. Quit worrying.

 

[Sc0-]

Yes, it can be welded by a GOOD welder with lots of aluminum experience. Another option would be to use "timeserts" which replaces the aluminum threads that the crack runs through, with a steel threaded sleeve. Afterwards clean, sand, and degrease the surrounding area and use JBweld or similar 2part metallic epoxy for piece of mind.

Timesert kit, might be cheaper if you find a local garage that might have the kit already:
https://www.belmetric.com/timesert-...218_246.html?zenid=h32347ffnvs83p8q1lg1m4dhg5

 

[womble42]

Just thought I'd add this pic.
It can lot worse before it needs fixing. Time to find a new gearbox/ good welder!!

 

[Kernal]

Is this a manual 5 speed gear box drain plug (we only got automatics in the US)? Is the photo as posted oriented 90 degrees to the actual position?

 

[womble42]

Yes, that's the 5 speed manual ( on a 1hz ). I forgot that you never officially got either.
The plug is horizontal with the photo looking up.

 

[Kernal]

Does the gear oil drain out of the side of the gear box, not the bottom?