I am currently using a reinforced gear welded aluminum front diff on 31"ag tires and it's holding up but I can't keep the upgraded 1/2" bolts in the passenger mount bracket.
I'm looking to move up to a set of 36" q series tsl tires and possibly be able to go up to a 39" sticky in the future. I'd also like to be able to run fluid in the tires. I wheel large rocks and the mud that is between them here in PA. I also would like to do the occasional crawl comp.
So the question is how large of a tire will a locked steel front diff handle?
I also considered custom fitting a tracker rear for a front ifs diff or do I just need to bite the bullet and upgrade to a custom 9" to replace the front diff?
What is the weak part of the steel diff? Inner axle or r&p?
I'm asking this irrespective of the obvious cv issues, which I have a solution for. And I don't want to go SAS, so don't mention it please.
I love the character and capability of these trackers and I want to retain as much of that as possible while going larger.

Shorthorn
I have been running and all steel diff and housing for several years on 32's in a 97 4 door Tracker with a 2.3 engine
I just recently switched to 35's and will be installing  ARB lockers front and rear.
I considered SAS but the cost to do it right was reaching 10K.
I will be doing the Rubicon again in a few weeks and Moab in October, so will know more then how well the steel front end with a locker will hold up.
I feel that sticky 39's is very questionable, of course it all has to do with your right foot and how bound up you get the front tires.

You said you have a solution for front IFS axles if you do not mind sharing what that solution is?
I tried the Toyota IFS kit out of Australia and those axles are not long enough for my 2-1/2" extended A-arms each side and the CV's bind up with the 10" travel my front suspension now has.
Thanks
Herman

Shorthorn
I have been running and all steel diff and housing for several years on 32's in a 97 4 door Tracker with a 2.3 engine
I just recently switched to 35's and will be installing  ARB lockers front and rear.
I considered SAS but the cost to do it right was reaching 10K.
I will be doing the Rubicon again in a few weeks and Moab in October, so will know more then how well the steel front end with a locker will hold up.
I feel that sticky 39's is very questionable, of course it all has to do with your right foot and how bound up you get the front tires.

You said you have a solution for front IFS axles if you do not mind sharing what that solution is?
I tried the Toyota IFS kit out of Australia and those axles are not long enough for my 2-1/2" extended A-arms each side and the CV's bind up with the 10" travel my front suspension now has.
Thanks
Herman

I am working on sourcing the parts, but a few years back I went to my local parts store and found the largest cv shaft that I could.  A 2010 3500 Chevy duramax shaft is the largest joint I could find. These fit multiple other Chevy trucks. The outer joint will fit right in a hub/knuckle from a 2000 Ford f150 which is the same bolt pattern as a tracker, but I will have to build a dual a arm setup. I am already running about 2" wider lower a arm. The Chevy shaft seems to be the same length as a late model Chevy tracker when measured from flange to the shoulder that contacts the back of the hub, but it will be a bit more limiting in articulation I think because the shaft between the joints is actually shorter due to the large joint size. If these will haskell 900lb/ft of torque towing 32 k they should stand up to a tracker on 39s.?