Cracks at control plug

[blackstack]

I noticed a weeping of gear oil from the control plug of my rear axle drive . At first I thought it needed a new washer...when i inspected the hole closely after removing the plug and cleaning the area thoroughly I found there was a crack in the way of the threads and that is where the weep was occuring. Is there a fix short of gettinga replacement case?

The weep is slight but i fear a catastrophic failure.

[blackstack]

The link is to pictures of the problem.

http://www.flickr.com/photos/agingman/s ... 886723729/

What I think I will do is: clean and degrease the area, drill at the end of the crack, build a form to contain JB weld in place, build up with JB weld the area around the cracks to prevent a complete failure.

If that doesn't work I think a sleeve could be machined threaded to engage the undamaged threads and secured with loctite, the sleeve would be threaded on the id also to rcv a plug bolt

comments or suggestions appreciated

[undysworld]

Interesting problem you've got there. I like your suggested fixes. Man, having to replace that case would be a major pain in the rear!

A thought, in the direction of maintaining it as stock as possible, same tools and parts, etc.: IIRC, on the top of the transmission, the fill plug fits into a hex-shouldered connector (I think it's #8 here: http://www.pinzgauer.com/parts.php?cat= ... view=02-01 ). I believe that the o.d. threads on that connector may be identical to those on your plugs, and of course a plug fits into the i.d. threads on the connector. IF my memory is correct, you might be able to get another connector, repair your cracks as per your JB weld suggestion, then JB weld the connector into the case. That way, you'd still use a stock plug, but never again use the threads where the crack is.

I'll be interested to hear how this all works out, and how successful it is.

[blackstack]

I thought of just what you suggest as I lay sleepless in my bed early this AM and I think you are correct and that it would be a better repair....actually accomplish what my machine shop idea would with a lot less work

A problem would be that it would take a bit more gear oil to reach the overflow level...don't know if the overfill would be significant enough to be a problem

I think that in worst case the plug you are talking about can be replaced by a regular one....awkward to get at but doable...i will search my parts manual to see if I can buy one ...at any rate I will take pics and post them

thanks for the input!!!

[edzz]

I’d be very tempted to have that welded. A good heliarc welder should have no problem with what I see in your photos assuming the casting is a weldable alloy as I believe it is. It should be able to be welded without removal. Drain the oil out, replace drain plug, fill drive unit with argon or CO2 from torch to displace air to prevent any remaining oil from igniting. With care the threads way not be affected, would be good to have an appropriate tap on hand just in case however. May want to inspect all other plug locations for damage, looks like someone has been working without a torque wrench. Give Central Welding Supply in Anacortes 360-299-8625 a call they may be able to recommend someone on the island.
BTW really enjoyed your Alaska trip photos.

Ed