Hey im kinda new but i got a question. I want to put a posi in my stock 3.8 96 thunderbird and it has a 7.5 rear. I just want to get a one that would be relatively easy to put in and replacing the least amount of the rearend. I need a little advice on what to get. Thanks
I agree. Even if you just upgrade the 7.5 you still have to pull the whole pumpkin. You might as well upgrade to 8.8 for a few more $$$ and the same amount of work... it is a direct swap.
You could always find an 8.8 that is already a trac-loc. Then its a direct swap (provided its the same ratio) Its still a direct swap even if you change ratios, you just have to change the speedo gear to. And as yours is a 96 I'd bet that you have a 3.27.
If this is your daily driver than a 7.5 will hold up. Find a super coupe in the parts yards. The super coupe should have a traction lok. Either axle's will work. The smart way is to purchase the whole rear K. Generally is would be cheaper because they have less work & you get all parts together. look for the L in the gear ratio tag.(like 3L55 8.8)
I run a 7.5 in my oval track car with 4.10 open(rule) gears. I have used both V6 & V8 axles. Remember I race from a rolling start. If you will be drag racing Even a little go with the 8.8 & V8 axles for sure. If you will be drag racing hard go with aftermarket axles.
yea this is just my daily driver with the v6 in it so which cars have the 7.5 posi in it with the gear ratio of 3.27 in it also the 8.8 posi. Thanks for the relies.
lets face facts s well, the chances of findign a used 7.5 trac lock is rare , i can count on one hand how many i have seen, 2 ! the 8.8 has much more availablity, ie cheaper !
Half-shafts are our "axles" coming out of the differential.
You can use the 8.8 pumpkin out of a non independent suspension (IRS) car but the rear end's side gears will have to be machined. There is an article about the machining instructions somewhere. . . . .I can't find it right this instant. . .sorry.
Half-shafts are our "axles" coming out of the differential.
You can use the 8.8 pumpkin out of a non independent suspension (IRS) car but the rear end's side gears will have to be machined. There is an article about the machining instructions somewhere. . . . .I can't find it right this instant. . .sorry.
I'd just go for the 8.8 over the 7.5 - have a better rear end for down the road - maybe you'll need it
jk89cat said:
lets face facts s well, the chances of findign a used 7.5 trac lock is rare , i can count on one hand how many i have seen, 2 ! the 8.8 has much more availablity, ie cheaper !
isnt the 8.8 rear a widder punkin so i would need shorter axles? also would the mark rear work in the rear without the half shafts without any machinging required?
Ahh, nope. Same set-up, same lengths. Ford kept it simple for budget reasons, the car fits around all of it.
As for the Halfshafts, I wouldn't cut corners, even thought the V6 halfs can fit, once you see the difference between the two, you will want to go with the V8 ones.
Just don't cut corners. If you are upgrading your rear end, do it all the way.
But if u can’t upgrade to an 8.8, the 7.5 is plenty strong for a daily driven v-6 car. That’s why Ford put it there.
I know of a few people with v-8 ford rangers with the stock 7.5 rear end and they are still together. But they haven’t put drag slicks or huge off-road tires on them yet so the tires spinning is sort of a shock buffer. There not as weak as people make them out to be and are perfectly fine behind a v-6, but it shouldn’t be behind a V-8.
7.5 traction lok pumpkins are avilable, but 8.8 traction lok are a lot easier to find. I can go out to the local wrecking yards any day of the week and find about a dozen MN12s with 8.8 traction loks, but I only see the 7.5s about 2-3 times a year. Whichever you were to choose would cost about the same as the other to purchase or rebuild. The 8.8 would bolt right in to your car and is a stronger piece.
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Related Threads
?
?
?
?
?
TCCoA Forums
1.5M posts
26.9K members
Since 2002
A forum community dedicated to Ford Thunderbird, Mercury Cougar and Lincoln Mark owners and enthusiasts. Come join the discussion about performance, modifications, troubleshooting, maintenance, and more!