i don't know if this is truly hardcore tech but then i don't think too many stock FJ40 guys would want to do this either. if yall want to move it though it won't hurt my feelings any. I have no idea if what i did with this is right or even a good idea, i just kinda pulled it out of my azz as i went lol.
i've been wanting a 80 series width front axle for a long time but i wanted to be able to re-use as many of the parts that i've invested in my 40 front axle over the years- 6-shooter knuckes, longfields, detroit. I had heard of someone turning a rear axle into a front axle but never could find any thread about it, i know people have done it before though. i did some rough measurments and it looked like i could make an axle 8" wider than a stock 40 front if i cut the 40 rear axle right behind the brake plates. I had a set of axles laying around that i took out of my FJ55 so i stripped them down and got to work.
first thing i did was tear the rear axle all the way down and cleaned all the brackets off of it. then i cut the ends off flush with the brake plates with a chop saw.
i had to cut new notches for the ring gear so i cut the front diff cover off and then plasma'd the flange off the donor front axle to use it as a template, then i cut that ring up and used it to patch up the old ring gear slots on the new axle. i also decided to flip the axle so i wouldn't have to shave the drain plug and i can also use the old plug as a fill hole and also my vent. i took the plug and drilled and taped the middle of it for a bellows vent.
the ring off the front axle
i wanted to truss the axle before i welded knuckle balls to it so i made this jig to try and keep it from warping. i also put the 3rd back in it and filled it up with old oil to try and keep it cool. i also decided to flip it so i wouldn't have to shave the drain plug and i can use it now as a fill plug and my axle vent.
after i got finished trussing it i cut the brake plates off flush against up against them, again with a chop saw.
the truss-
After i got done with the truss it was time to work on the front axle some. Before i took the knuckle balls out i took a tape measure and got exact measurments from the inner axle seal surface to the side gear of my detroit on each side. i did this several times.
after that i cut the knuckle balls out and tried to put them in the rear axle....Oops, they didn't fit like i thought they would, too big. i tried to clearance the inside of axle tubes with a flap wheel but it didn't work. i wound up getting a buddy to machine the balls down a hair and press them in for me. i got my pinion angle where i wanted it and welded them on. i dont know if it was a good idea but i also drilled two holes top and bottom in the axle tube and made plug welds to the knuckle balls.
so then, i put my 3rd member in and got new measurements from the inner axle seal to the side gears of the detroit. i subtracted the original measurment from that one and i called up Bobby Long and ordered new inner axles for that amount longer then stock. i got him to make them about a 1/4 longer than my measurements and also to make the splines a little longer than normal just in case i had to adjust them. i also sent him my R&P for heat and cryo treating.
after that i reinforced the knuckleballs top and bottom put the knuckles, brakes etc on, welded up shock, link, and limiting strap brackets, added bump stop pads, built a mount for the ram and put a blue torch diff cover on it. i've been driving it for about a week now and plan to test it on the rocks this weekend at Morris Mt. in alabama. Wish me Luck!
i'll try and get a finished pic tonight.
This was a LONG project for me and could have gone horribly wrong at any point (and may still yet?) If this axle housing doesn't work out for some reason or another i WILL be buying a RuffStuff housing- i wouldn't do it again for anything!
i've been wanting a 80 series width front axle for a long time but i wanted to be able to re-use as many of the parts that i've invested in my 40 front axle over the years- 6-shooter knuckes, longfields, detroit. I had heard of someone turning a rear axle into a front axle but never could find any thread about it, i know people have done it before though. i did some rough measurments and it looked like i could make an axle 8" wider than a stock 40 front if i cut the 40 rear axle right behind the brake plates. I had a set of axles laying around that i took out of my FJ55 so i stripped them down and got to work.
first thing i did was tear the rear axle all the way down and cleaned all the brackets off of it. then i cut the ends off flush with the brake plates with a chop saw.
i had to cut new notches for the ring gear so i cut the front diff cover off and then plasma'd the flange off the donor front axle to use it as a template, then i cut that ring up and used it to patch up the old ring gear slots on the new axle. i also decided to flip the axle so i wouldn't have to shave the drain plug and i can also use the old plug as a fill hole and also my vent. i took the plug and drilled and taped the middle of it for a bellows vent.
the ring off the front axle
i wanted to truss the axle before i welded knuckle balls to it so i made this jig to try and keep it from warping. i also put the 3rd back in it and filled it up with old oil to try and keep it cool. i also decided to flip it so i wouldn't have to shave the drain plug and i can use it now as a fill plug and my axle vent.
after i got finished trussing it i cut the brake plates off flush against up against them, again with a chop saw.
the truss-
After i got done with the truss it was time to work on the front axle some. Before i took the knuckle balls out i took a tape measure and got exact measurments from the inner axle seal surface to the side gear of my detroit on each side. i did this several times.
after that i cut the knuckle balls out and tried to put them in the rear axle....Oops, they didn't fit like i thought they would, too big. i tried to clearance the inside of axle tubes with a flap wheel but it didn't work. i wound up getting a buddy to machine the balls down a hair and press them in for me. i got my pinion angle where i wanted it and welded them on. i dont know if it was a good idea but i also drilled two holes top and bottom in the axle tube and made plug welds to the knuckle balls.
so then, i put my 3rd member in and got new measurements from the inner axle seal to the side gears of the detroit. i subtracted the original measurment from that one and i called up Bobby Long and ordered new inner axles for that amount longer then stock. i got him to make them about a 1/4 longer than my measurements and also to make the splines a little longer than normal just in case i had to adjust them. i also sent him my R&P for heat and cryo treating.
after that i reinforced the knuckleballs top and bottom put the knuckles, brakes etc on, welded up shock, link, and limiting strap brackets, added bump stop pads, built a mount for the ram and put a blue torch diff cover on it. i've been driving it for about a week now and plan to test it on the rocks this weekend at Morris Mt. in alabama. Wish me Luck!
i'll try and get a finished pic tonight.
This was a LONG project for me and could have gone horribly wrong at any point (and may still yet?) If this axle housing doesn't work out for some reason or another i WILL be buying a RuffStuff housing- i wouldn't do it again for anything!
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) backed off the course on the outside of the curve. We bumped front tires, i bounced off and kept going, found out after the race that it tore his dana 60 knuckle completely off.
