Weird Diff leak...

[viphoto]

Here is a weird one...can't say I have seen this before. Parked the car a month ago for pending brake booster rebuild...and a couple weeks later noticed a big puddle under diff. it has continued to leak since. Assumed I screwed up putting one of the seals in (only changed side seals and big oring..front wasn't leaking and I didn't want to mess with the crush sleeve.) So I finally decided to see which seal gave way and low and behold both were ok as was both drain plugs.. Wiped it down and watched it over a couple of days... seems there is a small weep hole in the side fairly low so it keeps dripping. Anybody seen this before? Diff was pretty greasy when I pulled it to do seals and paint. Maybe defect in cast iron..seems like a weird place for it to crack..I think maybe paint held it for a while ... I am sure welding is the best solution (and biggest challenge/hassle) May give the less approved "JB weld" or Epoxy solution a try..(I had good luck with hi temp JB weld on the block of an old MG race car a number of years ago).... any other options / solutions welcomed.

 

[JFENG]

They are supposed to only leak from the top vent and the fill plug. I’ll take a look again tonight just in case I missed something, but it appears your housing is cracked.

 

[JFENG]

Here is a pic of my spare different there are a cluster of deep pits in the casting but no crack and no leak (it’s full of oil).

 

[eriknetherlands]

There should not be a hole in the side, besides the fill plug.
Either there is a rust through pin hole, or it is coming from the vent above it. If you drive, the oil and air expends. If it is overfilled it may expel some oil, but it should stop once parked and rested for a day. If it continues to drip, my guess is you have a non OEM hole somewhere in the casing.

Isn't cast iron supposed to be welded with specific material, instead of the regular MIG wire for steel plate?

Ill trade you my normal diff, recently rebuild, never driven (nor proven, see my thread for info), for your cracked one ( I see it's an LSD ?) ....

 

[JFENG]

Vent is on the opposite side of where Mr. VIP shows his leak.
the hole could be fixed with a threaded plug.

 

[steve in reno]

If there is a hole or crack, that shows there is thin and rotting metal. Trying to add a plug to that scenario is foolish.
You changed side seals...and got new leak...either over filled or new seal leaking is my call.
I try to use logic first.
Not a mechanic (ask sfdon), Just my $.02

 

[aearch]

no brainer jb weld
done it a bunch of times

 

[mulberryworks]

I've had pinholes in aluminum water pumps. I imagine cast iron can have the same sort of casting issues. I doubt there's a thinness of the housing.
JB weld can work pretty well as can welding the housing, but in either case, cleanliness is important. Oil in the pores of the metal will interfere with the bond and make a good repair more difficult.

A solvent will get the metal clean before applying the JB Weld. Cast iron will usually require preheating before welding which will trash your new seals while also burning off the oil. Welding cast iron is not something I would attempt. I would find an experienced welder.

I like the idea of drilling out the leaking hole and tapping it and filling it with a plug but that should be done after disassembly of the diff. Failing that, it should get a full flush to get the swarf out. (Chips and bits from cutting)

I'd probably go with the JB Weld if it were mine.

 

[viphoto]

Thanks all for the input.... Gonna Start with the simple and work my way out.... JB Weld it is for now ....I don't really want to tear it apart if I don't have to ...
Cheers