I know the topic of the 8.8 diff conversion has been beat to death, but as yet I haven't seen it brought up from this angle, so here we go... There's a method we're familiar with, which Shelby used in production cars, of welding 8" axle tubes onto a 9" housing. Both rearends use 28 spline axles so as long as it comes together right you've got the 8" tube diameter and mounting points, the right width, and it all bolts in using stock hardware. My question is, can this also be done with an 8.8 housing? There are 28 spline 8.8 diffs out there, stock 8" Mav axles are 28 spline... Do they fit? I figure if I go with an 8.8 diff I've got to cut and weld a bunch no matter how I do it, so might as well go that extra step and eliminate the c-clips as a bonus, right?
yes that can be done. usually just the housing ends of the 8" or 9" that hold the axle bearing are welded on to the tubes of the 8.8. then you will also weld the spring perches on to the 8.8 tubes.
Dare I hope that the 8.8" axle tubes are just enough bigger than the 8" axle tubes to allow them to slip snugly together for strength and alignment?
Why bother with 28 spline axles ? Do it with 31's on an Explorer 8.8, better yet, just use the whole Explorer 8.8 and weld 9" bearing housings to the tubes and order new 31 spline axles to fit. This is basically what I did for my 89 V8 Ranger.
Because I'm a broke-ass junkyard engineer who refuses to accept that going fast costs money, and have been overly encouraged by past successes with that approach.
this is not a simple job. the ends need to welded on exactly center to the carrier bearings. the welds have to be really good. also when welding on the spring pads, the heat will warp the tubes. we will press them straight in a specially made fixture after all welding. the least costly way to get gears and a limited slip into your car is to buy one of the e-bay thirdmembers. i believe you can find them there for around 600. i cant sell the new gears bearings and limited slip for that much. sence you have mustang wheels, you most likely have need for a wider rear end. if you want to junkyard an 8.8, i suggest finding which year mustang rear is closest to what will work for your needed width. look at the 87-93vs94-98vs99-04. those get wider each generation. the newer ones even have some better ratios. one trick to fighting the warp is to weld all the way around the tube. ive see put a strap around the housing the meets the ends of the perch then they will do a 360 degree weld and not warp the tube. if you try this, make sure you drain the oil, take out the axles and carrier and clean the oil out of the tubes. i dont know how many times ive seen people weld on a diff full of oil and light the insides on fire.
Thanks for the advice! Yeah I'm probably either doing it this way if I can, or just welding new perches onto an Explorer 8.8. With my wheels I wouldn't even have to narrow it, just clearance the tunnel a bit for the offset diff, and make sure I get the pinion angle right... I just got inspired by reading a writeup where someone put an 8.8 in a GM F-body this way. By leaving 4" of the 8.8 axle tube in place and turning down their stock tubes a little bit, they were able to just stuff the GM tubes into the remains of the Ford tubes and everything was straight. I thought it looked like a cool idea, wondered if it might work for our stuff. But I guess if it were that simple for us, someone would have done it by now...
I have thrown a lot of money away because of "past successes" ...most...what is that old saying ..."reinventing the wheel"...
Yes you have and so have I. Then there have been other times when it resulted in something good we could contribute, like your rear disc brake conversion or my Econoline leaf springs.
