Well guys I'm back and on to a new problem. Rebuilding the rear diff, come to find out this is a 7 1/4 ring gear open axle. I've tried searching around for a limited slip carrier or even a part time locker and coming up with no luck. I have seen that some of the jeeps in the 90's use a Dana 30 axle, ring gear measurement I've gotten, the 2 that I've seen, is ether a 7.125 and 7.2 Has anyone tried this or can confirm that this will work before I wast the money?
Rear diff upgrades
- Thread starter Gorm2297
- Start date
drop in 8.25” a member has for sale in, Ohio.
FOR SALE - 1989 Plymouth Fury Police Car Posi Rearend
FOR SALE - 1989 Plymouth Fury Police Car Posi Rearend
Wont find much in way of the 7.25 in the car now.
Depending on what you want to do and spend, the 8.8 out of a ford explore/mustang is a great route too. A little work to have it cut to fit but, get gear, posi, disk brakes, part availability.
Depending on what you want to do and spend, the 8.8 out of a ford explore/mustang is a great route too. A little work to have it cut to fit but, get gear, posi, disk brakes, part availability.
AMC Diplomat
Well-Known Member
Rebuilding a 7 1/4, unless it's a show car and you're going for maximum points on a restoration, is a waste of time. Hunt down the right 8 1/4 or weld spring perches on a ford 8.8
Or, if you've got unlimited funds, get an 8 3/4 cut to fit
Edit: or be cheap, slap it back together with whatever you can find used, and don't try any burnouts
Or, if you've got unlimited funds, get an 8 3/4 cut to fit
Edit: or be cheap, slap it back together with whatever you can find used, and don't try any burnouts
AMC Diplomat
Well-Known Member
This is the inside of my 7 1/4 after cleaning it. It's pretty burnt up and worn out, but it still works and I can still drive the car while I rebuild an 8 1/4 on my porch (kinda cold out) Sometimes keeping the car moving keeps the project moving
Well as for show restoration it's not going to be a show car for say but the car holds incredible sentimental value personally, do the closest to stock we can keep it, minus the few upgrades we want to do to make it more reliable and drivable now a days like limited slip and gear ratio, the better for our end goal no matter how difficult it may be
Mikes5thAve
Well-Known Member
Adding limited slip parts to a 7 1/4 is going to increase the chance of breaking it. If you really want to go that route change the axle to an 8 1/4 or something else.
8.25” would give you reliability, gear options, suregrip, bigger rear brakes and keeps you closest to factory. The 7.25” doesn’t even make for a good boat anchor at the end of the day and posi parts for them are pretty scarce these days. 8.8 would give you the most bang for the buck all around but sounds like more than you’re after at the moment.
Aspen500
Well-Known Member
Info only for what it's worth, but my Aspen had a 7.25" when I bought it in 1987, with a 90hp S6 and 4 speed OD and 72,000 miles. I never abused it (how can you with 90 hp, lol). In 1988 the spider gears broke one day, out of the blue. My point is, the 7.25 is fairly weak.
It got replaced with an 8.75 SG (along with a 440 and 727 auto) in 1989 btw.
It got replaced with an 8.75 SG (along with a 440 and 727 auto) in 1989 btw.
Steven Schupp
Well-Known Member
I have a good 8 1/4 posi out of a 1989 fury police car. 2.94 gears. Would a good upgrade.
What are you asking for it and what's your location?
Steven Schupp
Well-Known Member
New Philadelphia OH 44663 $300
ECCO Machine
New Member
The Dana 44HD out of a ZJ is very close on width and will take the OEM back plates & drums. Obviously have to lose brackets and weld on perches. I think I paid 150 for the used axle. My '78 SE was originally a 318/904 car with a 2.73 ratio 7.25 incher.
The ZJ 44HD were mostly 3.73 posi units, which is how mine came. When I swapped in the 511 stroker, I changed to 3.07 gears to get some top end back, since it will roast them through 1st and into 2nd anyway.
The 44HD pumpkin is what was used in the Viper, FYI.
This is with Cooper Cobra 295/50-15s on Cragar 61015 wheels
They do stick out a little, wish there was a 5.25" backspace option, but 4.25" was it for this style in 10" width
The ZJ 44HD were mostly 3.73 posi units, which is how mine came. When I swapped in the 511 stroker, I changed to 3.07 gears to get some top end back, since it will roast them through 1st and into 2nd anyway.
The 44HD pumpkin is what was used in the Viper, FYI.
This is with Cooper Cobra 295/50-15s on Cragar 61015 wheels
They do stick out a little, wish there was a 5.25" backspace option, but 4.25" was it for this style in 10" width
MoparDan
Well-Known Member
I went to have mine rebuilt afew years ago at a differential shop, and they found out there were no parts available for it....
Yeah, sadly i came to the same results. I just rebuilt my carrier and made it a limited slip by adding clutch discs to the clutch packs in it.
AMC Diplomat
Well-Known Member
You made it limited slip using the open carrier?
Bought a carrier rebuild kit, and an extra pack of clutches and put 2 extra clutches in on each side
AMC Diplomat
Well-Known Member
What about the springs?
As far as I've looked into it limited slip doesn't require the springs like posi, I'm hoping it works like it should honestly haha
