nother blown front diff

Diggerfreek · **Posted:** Tue Sep 22, 2009 8:31 pm

http://www.jeepkj.com/forum/showthread.php?t=40830

bugnout · **Posted:** Wed Sep 23, 2009 11:27 am

Anyone with a KK have any front diff issues?

Diggerfreek · **Posted:** Wed Sep 23, 2009 12:05 pm

Not that I know of so far.......

Boblemoche has the most highly modified KK with ARB locked 4.56's front and rear. To my knowledge, he hasn't had a problem, but hasn't really been off road since his lift.

I have a 4 inch lift and have wheeled the snot out of mine since the day I got it and have yet to have a problem or have a bad oil sample come back on the front diff......

rescu2000 · **Posted:** Wed Sep 23, 2009 7:38 pm

He broke it at Uwharrie I think. I'm going to drive down to Wilmington and check it out this weekend probably. If he has it pulled, I'll be bringing the case back with me and seeing what can be done to help this issue. I'd like to have someone quote fabbing up a steel one. (not cast). I know it has been looked at before, I just want to have it checked out. I can get pretty creative, so I just want to see what I come up with.

bugnout · **Posted:** Wed Sep 23, 2009 8:17 pm

I think fabbing up a steel version would be difficult. There are a lot of machined surfaces on the inside of the diff.

I've thought about this a bit, but don't see any solutions that hit me as fitting the bill perfectly.
-Adapting the KK's d30d doesn't really buy you a lot. You still have an aluminum diff. Better than the D30a but how much?
-Getting a nodular iron casting of the d30a and having it machined would give us a bullet proof diff, but the cost to prototype this would be very high.
-find a iron/steel IFS diff from another vehicle and adapt it. not many IFS center sections that are not aluminum. I think the first Liberator used a cast diff from a Grand if I recall. This might be doable, but no one has repeated the attempt.
-What about cutting the center section out of a Dana 30 solid axle from a wrangler or XJ and adapting it to IFS axles? Don't know how much work that would be. I think there would still be some significant machining needed for the axle adapters.
-Obvious bullet proof solution is SFA it, Not cheap, and you have to go up 6-8 inches.

The more I think about it, creating adapter plates for the D30D seems like the least amount of work and cost. Just don't think it gives you the bullet proof solution.

Diggerfreek · **Posted:** Wed Sep 23, 2009 9:12 pm

It's a d30m bugnout

bugnout · **Posted:** Wed Sep 23, 2009 9:32 pm

Diggerfreek wrote:

It's a d30m bugnout

mmmmmm

got it.

D made sense in my twisted engineers logic. I can imagine B and C being prototypes. Now I'll spend the rest of the night wonder what happened to E through L :roll:

Diggerfreek · **Posted:** Wed Sep 23, 2009 9:37 pm

I ask that every day at work.......... for example, a CAT 140 motor grader started as a G then H and now we moved to M

Front loaders went A, B, C, F, G, H......

or even better, dozers went H, N, R, T and now we have an E model

:roll:

rescu2000 · **Posted:** Thu Sep 24, 2009 12:00 am

What I'm thinking on the fab'd steel one is that you weld up plates to make the general housing and then get solid blocks and have them machined for the axle/pinion holes and weld them in place. That machining cost is obviously the big cost...

Pablo · **Joined:** Thu Feb 02, 2006 10:06 pm **Posts:** 1201

bugnout wrote:

I think fabbing up a steel version would be difficult. There are a lot of machined surfaces on the inside of the diff.

-find a iron/steel IFS diff from another vehicle and adapt it. not many IFS center sections that are not aluminum. I think the first Liberator used a cast diff from a Grand if I recall. This might be doable, but no one has repeated the attempt.

The main issue with this is that no lockers are available for that diff, so you are spending big money to be open in the front. Someone mentioned getting one out of a RAM 1500, but that never went anywhere either.

bugnout · **Posted:** Thu Sep 24, 2009 12:06 pm

Pablo wrote:

bugnout wrote:

I think fabbing up a steel version would be difficult. There are a lot of machined surfaces on the inside of the diff.

-find a iron/steel IFS diff from another vehicle and adapt it. not many IFS center sections that are not aluminum. I think the first Liberator used a cast diff from a Grand if I recall. This might be doable, but no one has repeated the attempt.

The main issue with this is that no lockers are available for that diff, so you are spending big money to be open in the front. Someone mentioned getting one out of a RAM 1500, but that never went anywhere either.

2002-2005 RAM 1500 doesn't look any better, no locker available. I did find that the 2009 H3 and H3T come stock with a cast iron AAM 7.6 front diff with 4:10's an Eaton E-Locker. Not many of those in the wrecking yard yet, but might be a solid candidate for a swap.

InCommando · **Posted:** Thu Sep 24, 2009 1:36 pm

The H3 is a GMT355, just like the Canyon/Colorado. Those are probably in the boneyards to some extent. They probably do not have the 4.10's, but what the heck is the cost of a gear swap if you are fabbing up adapters for the diff. swap anyway? Still, why go with such a tiny ring gear if you are swapping?

InCommando · **Posted:** Thu Sep 24, 2009 1:36 pm

tjkj2002 · **Posted:** Thu Sep 24, 2009 5:18 pm

InCommando wrote:

The H3 is a GMT355, just like the Canyon/Colorado. Those are probably in the boneyards to some extent. They probably do not have the 4.10's, but what the heck is the cost of a gear swap if you are fabbing up adapters for the diff. swap anyway? Still, why go with such a tiny ring gear if you are swapping?

You need the ones from the H3 Alpha version to get the cast iron version(due to the V-8),the others use the alloy version.

bugnout · **Posted:** Thu Sep 24, 2009 5:55 pm

InCommando wrote:

The H3 is a GMT355, just like the Canyon/Colorado. Those are probably in the boneyards to some extent. They probably do not have the 4.10's, but what the heck is the cost of a gear swap if you are fabbing up adapters for the diff. swap anyway? Still, why go with such a tiny ring gear if you are swapping?

the cast iron version of the 7.6 only became available this year and is std on H3's and H3T's. Not sure if the 2009 Colorado's get it as well, but I doubt it.

The only reason to consider this would be to eliminate the weak link, that is, the aluminum case of the D30 with a cast iron unit. IMHO, cracking the pumpkin is always a possibility everytime I take it offroad. Your right, the ring gear isn't any bigger than the D30, but breaking the ring and pinion is not the problem (yet). :wink:

Looks like 4.10 and 4.56 ratio's are available today. H3's come standard with 235/85 R16's around 32" so running 33" should not be an issue. if you want to run 35"s or greater requires going higher than 4 or 5 inches anyway so you might as well do an SFA

What would need to be done to adapt the AAM 7.6?
Need a way to mount it.
Need a new drive shaft
Need a way to adapt the axles. definitely custom setup, but maybe use GM inner, Jeep outer and custom between the CVs.

Cost
a couple thousand in labor to develop the mounts
custom DS and axles probably another grand
A brand new unit from GM, is probably around 2 grand.
another grand in misc stuff.
Lets say around $6000 for first product. - Not bad, but in the same neighborhood as low budget SFA

ridenby · **Posted:** Thu Sep 24, 2009 6:02 pm

Check this IFS out.

http://pirate4x4.com/forum/showthread.php?t=822407

tjkj2002 · **Posted:** Thu Sep 24, 2009 6:12 pm

ridenby wrote:

Check this IFS out.

http://pirate4x4.com/forum/showthread.php?t=822407

Yeah you will need deep,and I mean very deep pockets for that setup.

tommudd · **Posted:** Thu Sep 24, 2009 6:18 pm

People complain now about spending 600/700 on a good suspension lift so most would never go anymore than that for a replacement diff as they would think it was too much!!! :wink:

I find it all very amusing :lol:

nother blown front diff

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