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Discussion Starter #1 (Edited by Moderator)
I think most of us know the choices for a Ford rear end in an older small or mid size Ford. If you have a Fairlane they only came with an 8” or 9” rear. Mustangs and Falcons did come with the smaller 4 bolt 6 cylinder rear. An 8” looks good next to those and is a fairly strong rear end.

One weakness of these rears is actually the size of the axle. 8” and 9” axles both came with 28 spline axles. The axle can be the weak link in these rears along with the 8.8”. High performance and truck 9” rears came with 31 spline axles. Any one looking to upgrade has also seen how much it costs to go that route. The 8 and 9” do have the advantage of the removable center section and no “C” clips holding the axles. I had an 8” rear that was open and now had enough power that it was a problem getting the car down the strip.

A posi unit and good axles would hold up well at my power level. All of the sudden I was over $700 just to upgrade it a bit. I wanted to “explore” my options at that point because most of the parts are similar in price no matter which rear. I have seen many references to 8.8 Explorer swaps.

A lot of the 4x4 guys swap them into Jeeps and other vehicles because of the strength and low cost. So what is the deal? The information I have seen would say a 31 spline 8.8 would be stronger than pretty much any 28 spline 8” or 9” rear because the axles are no longer the weak link. When I measured the smallest diameter on both shafts it told why.


The area of a 28 spline was .83” versus 1.35” for the 31 spline measured at the narrowest spot. So is there a strong inexpensive solution? I think so. It is the Explorer 8.8 rear. All have 31 spline axles and most have posi. Pick early or late to get drum or disc brakes depending on what you want. 1995 on up should have disc brakes with a nice parking brake that is a simple drum inside the disc. As long as I was doing it I went for the discs as one more befit to the swap.

Follow along to see how I did it. First I went to my local U-Pull to score a rear end. With special thanks to my brother Jon who stuck with me until we got all the parts we needed. Do a search for axle codes before you go so you can look at the door tag and make sure you get what you want. I also checked the axle tag just to be sure and the ring gears are marked as well. Ratios I have seen listed range from 3.08 to 4.10. Most I saw were 3.73 gears with posi.

This next trick is what makes this work. Explorers have one axle tube that is about 3” longer than the other and they are about 3” wider than my stock rear. Most cars are centered. Be sure to get 2 short axles because you are going to end up putting a stock short axle in that long tube. A stock 1964 rear is about 57.5” and the narrowed 8.8 will end up being about 1” narrower than stock. Time to remove the original 8” rear end.


$86 for a 31 spline posi rear with good disc brakes. I consider that a deal. If you do it yourself make sure you get all the cables to the front of the truck for the parking brake. Living in Minnesota I actually got a fairly low mileage cash for clunkers rear axle. I hate the whole concept of CFC but that does not change the fact that things can get very rusty.


You may get a rear with a sensor installed in it. You can pull the wire and leave it or I found a ½” pipe tap will run down the hole so a pipe plug can be used.


The next step is disassembly and cleaning. If you do it yourself make sure you take pictures or document where the shims and caps fit. If your bearings and gears are good you can just put it back together as is when done.


It seems there is often a tar like substance in the tubes after a while.


Here are some tools I used to clean the tubes. The copper is two pieces soldered together used to scrape the tube first. The brushes are on ¼” threaded rod that was run down the tube with solvent.


This is how it looks when clean. This also shows the nice weld on the shortened tube. Do not use a torch to cut off brackets you will not use since it will warp the axle tubes. I already had a sway bar or I may have looked a little closer at the one from the Explorer. The Explorer rear spring mounts can be used again. I ground the welds down and used a cut off wheel.


I tried the electrolysis rust remover that I saw in an article here. I did the whole axle and all the parts. The rear I picked was actually in very good condition other than the rust. I started with a Barrel and did the axle half at a time.


I flipped the axle and kept going until it looked good. I went over it with with a wire wheel on an angle grinder before I primed it. Then it went out for powder coating………until I saw a $3.99 can of semi gloss black at Menards. Hey it is a budget build right?


This rust thing is working well. I used some perforated angle to drop in a smaller tank and cleaned up the bolts. I was able to reuse almost all the fasteners.


I did not measure the long axle as a reference and I would suggest you do if you are not bringing it home with you. It would be nice for who ever narrows it. Cutting and welding the axle is one of those areas that I thought I could do it but knew there were shops set up to do it that have the tools and expertise to check and do it right. I chose Tin Man Fabrication in Oak Grove MN. Tin Man Fabrication, Inc. - Full service street rod and specialty vehicle shop. Jim shortened the one tube based on the short axle, straightened both tubes, and welded my spring perches on for a price that I thought was a value. After seeing the work I am glad I did not do it. I also could not have checked it for straightness. Check it out he also makes some parts for things like mod motor mounts in older cars.


I test fit things before I painted them just to be sure. It fit right in. My 8” had 5/16” bolts through the springs. The Explorer had a larger bolt that I could not use. The bolt centers the spring so I found some thick washers that fit inside the spring pads and put them on my existing spring bolts. The lower brackets in this picture were tossed. I am glad I tested them before welding them in.


A 64 Fairlane rear has springs that are not parallel. If that is true in your car allow a little extra width to accommodate the angle. In my case that was about ¼” wider than the spring width.


The Explorer rear also has larger tubes. My mounting plates would not work as is. I used the Explorer U bolts and they needed to be moved inboard to eliminate the original rubber isolated spring mounts. Here is a copy of my paper template.


Time to transfer to metal.


This is the top of the plates tacked in place.


Here is the bottom. I had originally eliminated the rubber spring isolators. That did bend this a little since it used to be bolted to another part. I needed to reinforce it so I added this angle bracket. I figured with the three holes I can adapt to slapper bars or cal trac like bars if need be in the future.


Here they are with a $3.99 powder coat.


Next it is a matter of getting the parts you need to finish the job. I used new explorer hose assemblies and bent a new line to go between them. If your backing plates need cleaning up there are two rivets holding them together. Drill them out to clean and paint and then pop rivet them back together. My used brake pads were half there but it was in my budget to spend $20 for new pads.


The hose to the body did not quite line up. The original bracket also held the fuel line in place. I used a clamp on the fuel line and cut and remounted the bracket. A coupling and a short line will make it work.


Due to the larger rear axle tubes my old sway bar brackets did not work. This is what I came up with. Basically muffler clamps with a bolt welded in for the mount.


The disc brake rears have a notch that grabs the cable from the little drum brakes inside the rotors. I plan on using the Explorer cable. It runs to the drivers side with a single cable. I then hope to connect it to my cable from the original with some kind of clamp.


A note if you buy a ring and pinion install kit. I bought a Ford Racing one for a Mustang. The Explorer has larger axle bearings and seals so get one for an Explorer. I also found that the two Ford Racing dealers in my area would sell 10% over cost to clubs. It was cheaper at the dealer than anywhere. All parts were also made in the USA unlike the Auto store bearings I picked up.


Every thing here could be done well under $500 with new bearings and seals. Try that with a 31 spline 9”.


Since I purchased mine from a U Pull they punch a hole in the cover to drain it. I welded a ¼” coupling to it so it could be a drain plug in the future. I also welded a couple rod couplings to the cover so I could mount an aluminum “M” just for grins. Hey it is an M cooler.


I now have better gears for my application. I also gained posi and 31 spline axles. The little bit narrower also rear makes it a little easier to get my tires on and off. Now it is time for some bigger tires.


.
 

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Wow awesome article ..... great write up .... and awesome pics to show what you did i plan to go this rout with my 64 falcon as soon as i figure out how to shove the engine in it .....
 

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Nice job on the swap! What kind of transmission are you running and what did you use for a driveshaft? I started this exact mod last summer, but got caught up in University before I could finish... still lots of loose ends to tie up on the conversion.



As a sort of augmentation to your thread, here's a quick-link to my thread which might be of use to fill in any gaps (I'm pretty sure I listed a lot of key dimensions):

http://www.fordmuscle.com/forums/fairlane-pages/485623-64-read-end-swap-info-explorer-axle.html
 

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Great write up....

Just wondering.....do ya really think it is that easy the warp the tubes using a torch to cut off brackets?

I mean...if one was realy careful...used heatsinks....took extreme care...

...enough time between cuts...you get the idea....

Now I'm wonderin' if I need to get my nine checked...damn-it.....

Thanks..

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Discussion Starter #6
Nice job on the swap! What kind of transmission are you running and what did you use for a driveshaft? I started this exact mod last summer, but got caught up in University before I could finish... still lots of loose ends to tie up on the conversion.



As a sort of augmentation to your thread, here's a quick-link to my thread which might be of use to fill in any gaps (I'm pretty sure I listed a lot of key dimensions):

http://www.fordmuscle.com/forums/fairlane-pages/485623-64-read-end-swap-info-explorer-axle.html
Thanks and I looked at some of your info too. I will say I had the opposite experience as you at the shop. All I will say is mine was under $200 and no more than was estimated to do the job. I am in the process of putting in a 4R70w and need to head to the Upull for a drive shaft and larger yoke.
 

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Discussion Starter #7
Great write up....

Just wondering.....do ya really think it is that easy the warp the tubes using a torch to cut off brackets?

I mean...if one was realy careful...used heatsinks....took extreme care...

...enough time between cuts...you get the idea....

Now I'm wonderin' if I need to get my nine checked...damn-it.....

Thanks..

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I am no expert at this but have seen some warnings about using a torch. My axle was a little off and I did not use a torch. I have heard this before about stock axles. Mine may have been in spec but now I know it is straight. I don't know how much you can see in the picture but both tubes have some primer burned off. It is where the tubes were heated to straighten it. You could look on the bright side and hope you torched it in the right spot to make it straight. If yours is out of the car I would sure consider it.
 

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8.8's work suprisingly well in harsh enviroment. My 94 GT has one with 31 spline Strange axles, a Torsen T2 carrier from a 2003 Ranger offroad and 3.73's and Trckflow reinforced cover. I take it to the strip and hit it hard and have not broken a thing, they supposedly require less power to run vs. a 9 inch because of where the pinion is located, are lighter in most cases than a 9 inch, use 12 bolt GM bearings and are only .075" smaller in ring diameter than a 12 bolt GM. The bad news? offroaders are buying them up quickly from pick n pull.
 

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Great write up! If I remember correctly, the shorter axle is 2 15/16 shorter than the longer axle...I could be wrong, it's been about a year since mine has been done, but it is right around there.

One thing that needs to be mentioned is make sure the axle tubes get welded to the carrier!!! It doesn't have to be a continuous weld, stitch welding is perfectly fine...if not done, there is a strong possibility of twisting a tube out! (I had to swap one out for a guy in his Explorer for that very reason!). Just my .02
 

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Great article. I swapped an 8.8 into my Falcon back in 2005. Because of the width, I used one from a 1996 Mustang Cobra. Two upgrades I made were to fully weld the tubes to the center section and eliminating the C-clips by welding on 9" bearing retainers. I used a MAC girdle and a rebuilt Traction-Loc. Cost me less than a 9" build and parts are cheap and easy to find.
 

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I just transplanted a 94 Exployer rear end into my 65 Fairlane. Since mine is an extreme budget build, and I have to drive it daily, I did not narrow the rear end. The stock drive shaft had to be shortened 1", and because of the rubber bushing in the tail piece it still has a slight vibartion. Anyone know how to fix this at home? The only issue with the offset pinon was the passenger side e brake cable bracket under the cockpit had to be trimmed down and the cable pulled out board 1 inch. For less money than rebuild parts for the original 8" I have a newer model rearend that is stronger and easily upgraded in the future if need be. The bigger drum brakes also greatly improved my all manual drum brake system. The wider axle will allow for more backspace on my wheels in the future so I can stuff a wider tire under the wheel wells. There's no problem getting the wheels on and off as I jack the car up under the rear seat, even though I had to use two wheel spacers per side to get the factory wheels to go on, the center hole is too small for the 8.8. I'm extremly happy with the swap, and when I can park the car to start it's rebuild I can make everything look pretty.
 

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I'm using a 98 Explorer rear end under my 68 Fairlane, to try and compensate for the roughly 2-1/4" passenger side offset of the pinion, I swapped axle sides. Put the longer driver's side axle on the passenger's side and the shorter passenger's side axle on the drivers side. After doing the swap, the pinion is now offset to the driver's side roughly 15/16". Important note if someone tries to replicate swapping axle sides, the passenger's side axle ends at approximately dead center of the pinion.
 

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I Want More, great write up. I want to do a 1994 8.8 (drum brakes because of clearance) into my 1956 Customline. Do you think using two right side (shorter) axles will fit my 56 1/2" axle flange to axle flange requirement? The wheel well width really limit a lot of what I can do. Appreciate your thoughts.
 

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Discussion Starter #15
I Want More, great write up. I want to do a 1994 8.8 (drum brakes because of clearance) into my 1956 Customline. Do you think using two right side (shorter) axles will fit my 56 1/2" axle flange to axle flange requirement? The wheel well width really limit a lot of what I can do. Appreciate your thoughts.
Are you running small rims and worried about clearance from the calipers? I can remeasure mine. Are you looking for the total width from the outside of the axle flanges?
 

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Correct, flange to flange. I'm putting 7 or 8 inch Torque Thrust Ds on it for rims. The problem with disc brakes is the inside clearance with the leaf springs, thus drum brakes. The rims will fit nicely in the kinda' narrow wheel wells if I stay with the factory axel width, that is what I want to narrow the 8.8 down to. Axels are expensive so if I can use two right side (short) axels, I can save a bit of money. I just don't know how far I can narrow the rear end down to using two short axels. If I can't get down to 56 1/2 inches, I guess I need to get after market axels. Thanks for you help.
 

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Discussion Starter #17
Correct, flange to flange. I'm putting 7 or 8 inch Torque Thrust Ds on it for rims. The problem with disc brakes is the inside clearance with the leaf springs, thus drum brakes. The rims will fit nicely in the kinda' narrow wheel wells if I stay with the factory axel width, that is what I want to narrow the 8.8 down to. Axels are expensive so if I can use two right side (short) axels, I can save a bit of money. I just don't know how far I can narrow the rear end down to using two short axels. If I can't get down to 56 1/2 inches, I guess I need to get after market axels. Thanks for you help.
I hope this helps. First I don't think there is any differewnce between drum or disc in width but a 14" rim may not clear the caliper. I have a feeling flange to flange we are talking different things. the housing axle flanges are close to 51". The total width rim to rim is about 56 1/2". Don't get a disc rear if you do not have them up front. A master cylinder would be a problem.
 

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I agree with the disc issue, but I'm still dealing with the issue of narrowing the rear end. How far can I go with two right side axles? It would sure save a bunch of money if I can narrow it down to 56 1/2" (outside flange to outside flange) using stock axles. I just don't know, nor have I been able to find on the web, anyone that has used two right side axles to narrow an 8.8" Ford.
 

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Discussion Starter #19
I agree with the disc issue, but I'm still dealing with the issue of narrowing the rear end. How far can I go with two right side axles? It would sure save a bunch of money if I can narrow it down to 56 1/2" (outside flange to outside flange) using stock axles. I just don't know, nor have I been able to find on the web, anyone that has used two right side axles to narrow an 8.8" Ford.
Read the article again. That is exactly what I did. Two short axles and one tube shortened. About 56.5" when done.
 

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Did they pull the axle tube, cut and reinstall or remove th 3" at your spring perch and reweld?

I've read some post of people pulling the tube and cutting to size.

Jet
 
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