[Mad Man]

We put an 8.8 in my 55 Nomad and only had a minor modification of the floor plan as a result of the offset differential. We were thinking to get another short rear axle and replacing the longer side to better 'centre' the diff. I think you might be about 1 inch overall narrower than stock in that event. In any event, I love the 8.8 posi, disk brakes 3.73. (We redrilled the axle plates to accept Chevy wheels)

2drwagon, It would seem you must have your springs mounted inboard, (Pocket Kit?) to do that modification, as you will end up with a narrowed rear end. I rather like the idea one fellow had of cutting 7 inches off the long end, and four off of the short end, and then re-weld them on the opposite sides they came from and switch the axles as well. This made the axle almost centered, and only 1/2 inch narrower. This is how I plan to do my 8.8 swap.

 

[Mad Man]

starts with "for my swap"

about 3/4 of the way down.

Here's some additional information pertaining to the 8.8 swap that I learned while doing the swap into my '57.

Drum brakes come on the '91-'94 models. Disks are standard on '95-2000 models (Explorers went to IRS in 2001).

The "weak link" of the 8.8 is the connection between the cast center section and the axle tubes. Subjected to enough power, the tubes will spin in the housing. The fix is simple, though. Just weld the tubes to the center section.

The pinion offset (2.25" to the right) is just enough to cause issues in a tri-five if you try to install the 8.8 as is. It will hit the driveshaft tunnel on the passenger's side way before the suspension bottoms out. Of course, you could modify the tunnel in your car to make it wider and get around the clearance problem. According to the formulas published by the u-joint companies, the offset also puts the u-joint at its limits.

The popular "budget" way to shorten the 8.8 is to cut 3 inches out of the driver's side axle tube and weld it back together. This allows you to use a second passenger side axle which can be had cheaply enough from a salvage yard. I'm pretty sure that that's what Josh did in his car. You end up with a rear that's about 56.5" wide and a pinion offset of about 0.75" to the passenger's side. There is a catch to this in a tri-five, though. The 8.8 tubes neck down just before they go through the axle flange. And when you shorten the rear, the spring pads need to be right on top of the area where the tube necks down. This is not an issue with pocketed or inboard springs, though since the spring pads will need to be monted inboard of the area where the tube diameter changes.

For my swap, I cut the driver's side axle tube 7" inboard of the flange and cut the passenger's side tube 4" inboard of the flange (the exact locations of the cuts do not matter, but the end removed from the passenger's side must be cut 3" shorter than the end cut off the driver's side). Then I swapped sides with the cut ends, sleeved and welded them back together. Now, the axles can be "flipped" to the opposite side from where they started. What you end up with is a rear that is 59.5" wide and a pinion that is offset by 0.75" to the driver's side. With this method, there are no clearance issues, the spring pads can be welded on to fit stock location springs, and most any backspacing that can be used on a stock rear can still be used. You also don't have to buy a spare passenger side axle.

All 3 methods of fitment noted above will work in a tri-five. Each method just presents its own set of problems to overcome. Depending on the other components and modifications being planned, each has its own merits as well. The 8.8 is definitely a strong rear that will stand up to a lot of abuse and is truly a "budget" upgrade. I have in the neighborhood of $500 in my swap including the original purchase price and all new brake components.

 

[vintage55]

I know this post is old but I am wanting to do this swap in both of my Tri Fives. I was wondering is the donor Explorer a 4wd or 2wd? Or are the rear ends the same for both?

 

[sspracing]

I know this post is old but I am wanting to do this swap in both of my Tri Fives. I was wondering is the donor Explorer a 4wd or 2wd? Or are the rear ends the same for both?[/QUOTE

I’m pretty sure they are the same. I ended up going with a Ford 9 and using the disk set up for the 8.8 which worked perfect on my big bearing Ford 9”

 

[vintage55]

The rear end on the Explorer does not use the old style U-joints. I see there is an adapter that bolts on to the yoke converting to U-joint style. I also saw there is a Yoke available to replace the new style to the old style. How did you guys solve this?

 

[sspracing]

I used a big bearing Ford 9” rear end only using the 8.5 disk brake hardware

 

[Rustaddict]

The rear end on the Explorer does not use the old style U-joints. I see there is an adapter that bolts on to the yoke converting to U-joint style. I also saw there is a Yoke available to replace the new style to the old style. How did you guys solve this?

There are places that you can purchase the flange adapter for the driveshaft. Ford was nice enough to use an odd bolt to fasten the driveshaft to the rear axle so you'll need those if you go that route. You can rob those from a junk yard and it'll be a fun experience because they put them in with loc tite from the factory.

 

[bigblock261]

Not complicated really...

The rear end on the Explorer does not use the old style U-joints. I see there is an adapter that bolts on to the yoke converting to U-joint style. I also saw there is a Yoke available to replace the new style to the old style. How did you guys solve this?

The Explorer uses, starting from the rear, a companion flange to which bolts a 1330 series flange yoke. The flange yoke and the four bolts are factory Explorer and should be acquired with the rear axle. To this flange yoke, install a 1310/1330 hybrid u-joint (Precision 353 or the like), then the stock trifive 1310 driveshaft and you are good to go.

As long as the transmission is stock length, in the stock location, it fits. If not, the driveshaft length will have to be changed.

We avoided changing the whole driveshaft to 1330 for tunnel clearance considerations. Hope this helps.

 

[hutchenc]

The Explorer uses, starting from the rear, a companion flange to which bolts a 1330 series flange yoke. The flange yoke and the four bolts are factory Explorer and should be acquired with the rear axle. To this flange yoke, install a 1310/1330 hybrid u-joint (Precision 353 or the like), then the stock trifive 1310 driveshaft and you are good to go.

As long as the transmission is stock length, in the stock location, it fits. If not, the driveshaft length will have to be changed.

We avoided changing the whole driveshaft to 1330 for tunnel clearance considerations. Hope this helps.

Yep...not a huge deal. I used my stock driveshaft as well along with the Precision 353 u-joint. Works like a charm. If you don't get the companion flange, you can find them on ebay and elsewhere on the interwebs.

 

[real550A]

After reading this early thread, I went for it, and obtained a 31 spline, 4.10 posi., 8.8 out of a 2001 Sport Trac.
I did the 3" swap side for side, sleeved and fillet welded. Drilled the axles and drums for 4.75 wheels, and installed 3" long, 1/2" studs.
While at the yard, I found an aluminum cover from a Mercury Mountaineer, which I cut down, just to dress up the axle a bit. The whole thing worked out great, and total was under $600. with brand new TracLoc from Ford.

 

[Dragsix]

That’s a nice install!

 

[real550A]

Thanks, Dragsix!
Slowly coming together. Installed the AutoGear Super M22 last night, now working on a driveshaft setup. Getting close to firing up the 355 "mystery motor".

 

[Mr. Fink]

I have also been thinking of using an 8.8 rather than a 9”. With the axle swap what was the final width result? What wheel size and offset are you planning to use? Also, are you planning on using the ebrake? Pinion offset an issue with the narrowed 8.8?

Sorry for all the questions. These have been on my mind.

Thanks!

 

[real550A]

No problem, happy to answer any questions you have.
After swapping axle tube ends, I assembled the unit, spaced everything to insure axles were in proper position, clamped and welded the tubes. It ended up being 59-5/8" wide, with the drums on.
I went with 15x8 Americans, with 4" backspace for the street. Will be running 15x7 Monte Carlo steelies for vintage drag racing.
Installed '57 E-brake cable into Ford sleeves, simple swap, hooks up with stock hardware. Pinion offset is now 3/4", so negligible.

 

[Mr. Fink]

No problem, happy to answer any questions you have.
After swapping axle tube ends, I assembled the unit, spaced everything to insure axles were in proper position, clamped and welded the tubes. It ended up being 59-5/8" wide, with the drums on.
I went with 15x8 Americans, with 4" backspace for the street. Will be running 15x7 Monte Carlo steelies for vintage drag racing.
Installed '57 E-brake cable into Ford sleeves, simple swap, hooks up with stock hardware. Pinion offset is now 3/4", so negligible.

Thanks for the information—very helpful. I am going to run 10” with a 3.75 backspace. It seems that I am going to have narrow both the left and right sides.

 

[nad427]

After swapping axle tube ends, I assembled the unit, spaced everything to insure axles were in proper position, clamped and welded the tubes. It ended up being 59-5/8" wide, with the drums on.

Just out of curiosity, what steps did you take to ensure that weld blobs don't make their way into the gearset? Did you pull the guts out first, or find some other way to plug the tubes till welding and grinding was done? And also, did you pull the tubes clean out of the center and swap them, and if so how did you pull them?

 

[real550A]

Trying to retrieve my pics from crashed computer. I took a bunch during the process.
I sleeved the inside of the tubes where the welds were, nothing could get inside. Just thoroughly washed everything after the saw cutting was done. Only swapped the two ends, not entire tubes.
Also, I welded the tubes to the center section, as Ford just had a couple plug welds there.

 

[Old Buzzard]

For those that have this axle. Might someone know if the 8.8 is used only, if the explorer is a v8?
I see some specs that are 4.0 V6, in 2 HP ratings, and a v8. That spec shows the 8.8 in all of them.
Going junk yarding in the am.

 

[hutchenc]

Pretty sure all Exploders used the 8.8.

 

[49cadillac]

Trying to retrieve my pics from crashed computer. I took a bunch during the process.
I sleeved the inside of the tubes where the welds were, nothing could get inside. Just thoroughly washed everything after the saw cutting was done. Only swapped the two ends, not entire tubes.
Also, I welded the tubes to the center section, as Ford just had a couple plug welds there.

Are you using a wagon fuel tank?