Wanted: chunks of the front diff

JPaul · **Posted:** Fri Nov 09, 2007 10:24 pm

I've got a bit a of a theory going as far as fixing the problem with the forn diff grenading, but need some help. If anyone has a chunk of their front diff (the aluminum housing part) I would like it, or a piece of the diff. That is unless someone knows the metallurgy of the aluminum.

I'm wondering if the diff is made of weldable aluminum. The theory goes that the diff housing is not designed properly to be able to withstand the forces involved with offroading (yeah, I know, that's a "duh" statement, but let me finish!)

I feel that it's because of the structural setup. The top of the case has a massive spine and tall ribs that wrap from the spine down to the sides. However, the bottom and pinion area are lacking in these features. I've seen some pictures from you guys and everything seems to either be a huge crack on the bottom of the case or a blown up pinion housing. If the aluminum is weldable, you could weld a spine and ribs to the bottom and around the pinion. Yes, you would lose an inch or so of clearance and would definitely need a skid plate under the diff to protect the new ribs, but the housing would be much more rigid and sturdy. In my opinion, it would be worth it.

Sure it could probably still break, but I think the chances of that happening will be reduced to the most extreme of situations. It won't match the strength of a cast iron housing, but it would be a heck of a lot cheaper.

I just need to find out if the aluminum can be welded or not. I spoke with JHCRASH abotu it and he thinks it could work if the metallurgy of the aluminum housing allows it to be welded properly. Some alloys of cast aluminum don't weld well, just like cast iron, so we need to find out if it can be, and the best way to do that is take a chunk of a housing and try to weld it up.

Thanks guys!

Jeger · **Posted:** Sat Nov 10, 2007 8:50 am

I have access to an alloy analyzer

I have never used it on aluminum though. It may not be calibrated for aluminum at the moment, I will try it out and see what I get. I may be able to tell you exactly what type it is and you could look it up and find out if it is officially "weldable" and the proper method to do it. Although I think Al, the former owner of JeepinbyAl welded his up. I think all aluminum is weldable, its just that some require heat treatment before, afterwards, or both to get the properties right. It will be sometime next week before I can try it out.

In the meantime check this stuff out

http://www.aluminumrepair.com/aluminum_repair.asp

ATXKJ · **Posted:** Sat Nov 10, 2007 9:24 am

As Jeger said any Aluminum can be welded -
however if it's forged - you'll never get the material properties back without reforging.

The diff case appears to be cast - so the main problem is the fact that there is a bearing surface on the other side so you have to be sure the heat from the welding doesn't warp the bearing area - or you'll kill the bearings.

chefdab · **Posted:** Sun Nov 11, 2007 8:04 pm

Yes Al did have reinforcements welded on to the diff when he had it regeared to 4.10.

Jeger · **Posted:** Fri Nov 16, 2007 11:05 am

Okay...I can shoot aluminum just fine..so if you all really want to know...someone can contact me and send me a piece of the diff in the mail. 1" square would be more than enough to test.

Wanted: chunks of the front diff

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