I recently blew my rear end - broke a few teeth of my spyder gear. Housing is good, just need a new rear end. What do you guys reccommend i do?? i have a posi 7.5 10 bolt rear end borg-wagner (spyder gear shattered) What do you think i should do??? rebuild rear end (but i heard 7.5" arent good to have to launch and race) or is there a swap for a 8.5 or 8.8?? SHould i just buy new posi unit and have put in. I found a 87 trans am posi rear disc brakes i might be picking up on saturday for 150 and might buy it, strip it, sell parts and keep rear end. But what other rear end you think i should go for. Heard a ford 9" rear would fit. Also, i am running 3.42 gears. I dont care about top end, i am more looking at acceleration. Is 3.73 to big??? Thanks 88 trans am 350 TPI

 

How much coin you got and how reliable do you want it to be?

I went through 4 of these rear ends with my small 350hp motor and installed a Ford 9" and it's the best mod I've ever done from a peice of mind standpoint. There are many different avenues you can go to get one set up, I've got $2500 in mine with 31 spline axles, full spool, Richmond gears, Strange center section, and disc brakes.

You can buy the bare housing to bolt into our cars for about $850-900 and then install your own parts to finihs it off.

Budget is the deciding factor, I went through 4 becasue budget was my issue back then and it was easier to spend $80-100 for a rear end, swap in my posi and go, but it got ridiculously monotenous after the 3rd one let go.

 

well budget is the factor here. I am going to pick up entire car for 150 with rear end in it. Is there any maintence i should do to it??? i bought rear diff cover w/bolts. is there anything else??? what fluid should i use??? also, what fabs have to be done to make a ford 9" rear end fit????

 

well budget is the factor here. I am going to pick up entire car for 150 with rear end in it. Is there any maintence i should do to it??? i bought rear diff cover w/bolts. is there anything else??? what fluid should i use??? also, what fabs have to be done to make a ford 9" rear end fit????

 

Just for your own sake, check the axle seals to make sure they're in good shape and not leaking, if so it'd be worth the time to replace them since they can leak onto your brakes. If you do decide to change the seals (if needed) I'd replace the outer wheel bearings as well since they are so cheap. You'll just have to get the slide hammer from the auto store if you dont have one so you can hammer the old ones out-they can be fun sometimes.

Change fluid throughout the entire car so YOU know everything is fresh as it's probably never been changed before. Normal dinosaur oil 75W90 works great and is tried and true, I've always used Valvoline with no problems, but then again I've never had rear ends go bad either until this car-but that's just because of design-go carts have bigger gear sets than we do

The cover with pre-loads is a good idea, you can also try welding the axle tubes. I did this on my 4th rear end and ironically enough that one lived the shortest life span

Unless you have mad skills and lots of time, trying to fab your own 9" is not for the average DIY'er. You'll have to have the axle tubes cut down or longer ones installed depending on what the donor car is for the 9", you'll have to cut the brackets off another 7.5" rear diff to install on the new 9" housing, get new axles to fit the new length axles tubes. Biggest thing is making a torque arm mount for the Ford 9". The Moser unit I have uses a big chuck of steel that bolts onto the diff housing and a few places I've talked to Moser will not sell those units separately, so your basically on your own. I'm not sure if Currie will sell just that torque arm mount or not.