Rear End

[Jim Shepard]

While researching new rear ends for my “go faster” project, I settled on certain year rear end assemblies from Ford Rangers and Explorers. These have the 5X4.5 bolt pattern and desired 3.73 gear ratio. After spending all day looking at 10-12 of these I discovered they apparently all came with an offset pinion flange. While this isn’t necessarily a deal-killer (after all, it apparently worked for Ford), I’m wondering what folks think. The offset is about 2” to the passenger side.

[wayfarer]

The 8.8 has been used in a variety of swaps and the offset does not seem to be a issue or, if it was, it was routinely left out of the discussion.

As long as your drive shaft does not contact the floor then it should be good.

The offset is a guarantee of keeping the u-joint working.

[lostviking]

I used a Jeep Cherokee 8.25 rear. Cheap and easy to find, plus they come in the 3.73 ratio you want. If you get a 1997 and up rear, they have 29 spline rather than 27 spline axles. I've found them using an online search of wrecking yards for $250.

[Jim Shepard]

I’m looking for drum brakes and something similar in length to my B2B, about 58” backing plate to backing plate. Is the Jeep in the ballpark?

[Dave72dt]

Chrysler used to offset engines to the right to clear starters and steering gears.   You can also see greater differences from a straight line vertically from the trans to the diff as long as the pinion angle is correct.  As long as it clears all the crossmembers of driveshaft tunnel, that offset shouldn't be a problem.  Can you expand on the "go fast" project?

[Tooljunkie]

The offset as mentioned isnt an issue if there is clearance. 
no different than the drop from transmission to pinion.

[The Oil Soup]

I used a Cherokee 8.25 rear (3.55) with drum brakes and it is slightly narrower than the stock rear but no problems with clearance.

[JBNeal]

The engine and pinion offsets are more for packaging advantage than for performance gains.  The universal joints transmit torque within a certain cone of travel, anything beyond that begins to wear the joint out prematurely.  This is why ya see older ridiculously jacked up trucks on the side of the road with dropped driveshafts.  Since the shorter axle shaft generally transmits most of the engine torque to the road, the longer shaft complements this torque application under changing road conditions, like rounding a corner on sorta wet surface.

[Jim Shepard]

On 9/18/2021 at 9:09 PM, The Oil Soup said:

I used a Cherokee 8.25 rear (3.55) with drum brakes and it is slightly narrower than the stock rear but no problems with clearance.

What year did you use?

[Jim Shepard]

On 9/18/2021 at 7:26 PM, Dave72dt said:Can you expand on the "go fast" project?

I’ve driven the truck basically stock since 2004. My top speed with a fluid drive three speed and 4:10 rearend has always been about 45 mph. My “go fast” project is the addition of the T5 and new rearend so I can at last stay out of folks’ way on the interstate. I think if I can do 65 mph, which the 0.72 overdrive and 3.73 rearend will let me do at a reasonable rpm, I shouldn’t piss too many people off… Redline on these trucks is about 3200 rpm and the above combination should be under that.

[Los_Control]

The offset does not cause a issue, ujoints correct it.

Many will install a V8 engine 1" to the right to clear the steering box. Just saying the offset can be your friend, not a deal breaker for your truck.

 

Dual ujoints there is no issue.

 

[The Oil Soup]

The rear end was from a ‘93 Cherokee, and the original drive shaft bolted up to it.

[Ram Man 02]

On 9/18/2021 at 6:38 PM, lostviking said:

I used a Jeep Cherokee 8.25 rear. Cheap and easy to find, plus they come in the 3.73 ratio you want. If you get a 1997 and up rear, they have 29 spline rather than 27 spline axles. I've found them using an online search of wrecking yards for $250.

^^^ I agree

i have changed directions with my truck but i to was going to go this route years ago.  97-01 jeep cherokee is the best but honestly the flathead dont make more torque then the stock jeep does so any year 84-01 will be fine

[Jim Shepard]

Thanks.

[Jeff Balazs]

Hey Jim;

if your engine is up to snuff then you should be able to get the higher cruising speeds you want by putting a 3.73 or 3.55 in. I have a 3.55 cherokee axle in my 52 3/4 ton with a 4 speed FD trans and it will go well over 70 if needed. But as you already know these trucks are always going to be happier running at a slower pace. My truck is very solid feeling in the 50 to 60mph range. I are very glad I decided to go this route with the 3.55 swap. Made the old truck very usable.

Hth, Jeff

 

[Jim Shepard]

Thanks Jeff…

[Jeff Balazs]

Jim

There are probably several combinations that will get you where you want to be. I know there are members out there that run T5's with a 4.10 Rear axle and do quite well. It all depends on the internal ratios your trans has. In my opinion this requires a very careful trans selection.....as there are many variants of the T5 available.

What I can say for certain is that using a stock transmission a 3.73 or a 3.55 and 30" high tires work pretty well.

I hope this makes sense.

Jeff

[Jim Shepard]

Jeff,

My choice of 3.73 is based on my T5 gear set and 29” tires. I have the 4.10 now so I know what that’s like…

[tom'sB2B]

Something also to consider is the emergency brake set-up. I used a 3:55 from a 89 Cherokee. The e-brake was a ratchet style between the seats. I had hoped to use the original pull handle under the dash, but found that there was not enough travel in the handle to engage the brakes. So, I found a ratchet style brake handle and mounted it to the floor.

I also know someone who used the foot style e-brake near the driver's side door. Fabricated a bracket to mount it on. Works well too 

[lostviking]

On 9/22/2021 at 5:07 PM, Jim Shepard said:

Thanks.

Get one from a 97 or later Jeep. Those have 29 spline rather than 27 spline axles. Same width or course.

[lostviking]

On 9/27/2021 at 11:33 AM, tom'sB2B said:

Something also to consider is the emergency brake set-up. I used a 3:55 from a 89 Cherokee. The e-brake was a ratchet style between the seats. I had hoped to use the original pull handle under the dash, but found that there was not enough travel in the handle to engage the brakes. So, I found a ratchet style brake handle and mounted it to the floor.

I also know someone who used the foot style e-brake near the driver's side door. Fabricated a bracket to mount it on. Works well too 

I'm still figuring out how I'm going to do mine. I want to use the stock handle that comes up through the floor next to the shifter.  I seem to remember someone doing it that way along with a T5 swap I think. I'll need to search for that thread.