3.55 7.5 rear to 4.10 8.8 rear

[cbr600rx7]

I was looking for a few misc parts in the bone yard today and ran across a clean early 2500 Mazda pick up. I figured it would be worth checking the axle code and sure enough it's a 8.8 with 4.10 gears. I think it also has the larger 10 inch drums that would also be a nice little upgrade. The bone yard charges $125 for rears if you pull them your self.

To me this seems like a worth while upgrade since I could use a little more pulling power and typically don't drive over 60 mph with the truck (Mostly 55MPH zones around) my concern is that my truck is a 93 and the donor truck would be a early 2000s.

 

[tomw]

Get the U-bolts that hold the thing together, and that should be a bolt-in/on.
The brake fittings are likely the same size, but all you have to do is connect to the flex line on your vehicle.
The driveshaft u-joint yoke could be a problem if they are different sizes. Measure. Check what replacement u-joint is listed for your current and the 'donor'. If they are the same, that is not going to be a problem. The driveshaft length should not be a problem, except for possible differences in the axle centerline to the nose of the yoke, it should be very close.
Just taking measurements and comparing should answer your question. Checking the parts for the donor, for other rear end combinations, should pretty much answer whether the donor is a one-off or uses common parts.{essentially common to other years also}
tom

 

[turbo91xlt]

Double check its an 8.8... B2500s had the 2.5l 4 cyl and thus came stock with 7.5 rears.

 

[Captain Ledd]

I've seen a few 4 bangers with factory 8.8's, not common, but they're out there. Though that being said, I would check the actual axle tag/bolt pattern to believe it over the door code.

Just grab the pinion mating flange off the end of the driveshaft. You can get conversion u-joints, and then you're sure the flanges bolt up.

 

[84tony]

I swapped out an 7.5 with 4.10 open for a 8.8 with 4.10 limited slip on my 97 ranger 2.3l 5 spd with towing package. The donor 8.8 was on a 93 ranger 4.0. Both had 10" drums, but the brake shoes and hardware were different between the two years, so I just put the 10" drums of the 7.5 onto the 8.8, bolted right on. Everything was bolt in, no modifications were needed. If your 7.5 has 9" drums and you want to upgrade to the 10" I believe you need to get the emergency brake cable for the 10" drums, not 100% sure.

 

[cbr600rx7]

Thanks for the advice. One set in the bone yard is 3.73 and the other set is 4.10. Both are open diffs. I really would like to find a LSD rear but they seem to be hard to find for less then $500

 

[cbr600rx7]

Found another 8.8 with LSD out of a 2001 FX4 truck. It is rust free and $400 shipped to my door. NY state has major rust issues so most of the stuff in junk yards are rusted out. Since the 8.8 is out of a ranger and still uses rear drum brakes it should be a basic bolt in correct?

I know to get the 8.8 u bolts since it has longer axle shafts and probaly new parking brake cables. Also the speed sensor will not be used since the older trucks use the mechanical speedo off of the transmission.

 

[cbr600rx7]

I was able to get a good deal on a explorer 8.8 LSD with 3.73 gears and disk brakes for $150. The old owner had already flipped the spring mounts and was running it on his ranger. The factory 14 steal rims hit the caliper slightly however I have not checked the 14 inch alloys yet.

 

[cbr600rx7]

I took a little time and checked the alloy fit. It is much closer but will definitely require a little trimming on the very edge of the calipers. You could probaly run a 10mm spacer and not even need to trim.

 

[cbr600rx7]

The 8.8 is in and after a littleness trimming on the top of the calipers the 14s fit with out rubbing. The disk brakes are huge inside of the 14s however after trimming they fit with out the need for a spacer.

The explorer 8.8 is massive compared to the 7.5 with 9 inch drums. Can't wait to get it on the road and see how it does. I still need to fab up new brake lines and get new parking. Brake cables but the swap was very strait forward.

Note: any one who is doing this will need 8.8 upper u bolt brackets and the explorer u bolts. I had a set from the other 8.8 that I scraped but if you are pulling one from a junk yard make sure you keep your hardware. The 7.5 stuff is to small.