8.8 Ford Explorer Swap into 66 Coupe

[MikeStang 247]

Yeah I know its not a 69 But I also know a lot of you guys also have 64-68 Cars as well so thought I would drop this on here in case anyone was wondering about it, or wanted to do it...

I have a 9" housing I could use but would still need to get a center section plus axles etc...

So after some reading and research here is what I found and why I am going to perform this swap.

The 1995 and up Explorer's have an 8.8" rear which is supposed to be almost a direct bolt in for the 67-68 cars, but the center section is offset to the driver side by almost 3", even tho the over all length is about 1/4-1/2" difference... Several people have reported that all you need to do is move the leaf spring pads and bolt it in and swap your Pinion Flange and it will work...Stories Vary on clearance in the tunnel area with regards to the 3" offset...

 

My reasoning for wanting to go to the 8.8" over the 9" is two fold... First off Price, secondly the advantages of the 8.8 from the exploders which are quite a few.

The 8.8s from the 95 and up exploders come in several gear ratios, but the most common seem to be 3.73 with Limited Slip Diff, have 31 Spline Axles, and factory Disc Brakes with internal Drum brake parking assy.

 

I recently scored a low mileage complete rear for $200.00 for the local pick and pull and they already had it pulled, and when I say complete I mean from caliper to caliper, along with the sway bar, all the parking brake cables and brake lines.. Upon inspection inside the rear looked pristine which I think is due in part to the Factory synthetic oil that is recommended and the low mileage on this one.

 

I will be shortening the long side and using a second short side axle to complete the unit.

Have never shortened an axle housing but for the price If I screw it up I can get another one and try again, but after extensive reading on the subject and talking to a local shop that has done several of these it doesn't appear to be a problem.

The guy at the local shop that has done several suggested I make my cuts, bevel the ends then clamp it up in some C-Channel on top and bottom and weld it up... he said that this is the method he has used every time and the tubes area always straight when he is done and he has not had any issues out of any of the rears, but he did state that one should take their time when making the welds and move around to prevent warping.

 

Anyhow would like to hear from any of you guys who may have done this swap.

 

Also in addition I am getting the Alum driveshaft from the same explorer and going to take it and have it shortened and balanced so I will also have a nice alum Driveshaft to go with this thing to boot haha.

[det0326 179]

Hey Mike to begin with I have a short axle if you decide to go that route that will be free if you want it. Don't know the shipping charge form SC to to you tho that might be the deal breaker. I put a 2000 explorer 8.8 in my 69 and the width is about the same width as the stock 69 . I did mine a little differently than most, I cut 5 inches off the short side and 7 inches off the long side reversed the two pieces, found some dom tubing with OD  that was a press fit in the axle tubes, pressed them together and welded up. I also cut a slot on the dom tubing OD and made sure it was placed on the bottom just for oil passage to the wheel bearings. Worked out great and pinion is centered. The pinion center as it comes from the explorer is offset to the passenger side 2 inches not 3.  If you want the axle just let me know .  The down side of the way I did it is I had to have custom axles made.

 

Dave

[MikeStang 247]

Yeah from what I have read they say you need to cut 2-7/8" off the long side and it should be same length as the other side, but I will check and see what it measures out to be.

May take ya up on the short side axle before its over with. I will have to go pull one as most places locally want to sale the whole rear end not just an axle, but I can hopefully find a You pull it and get just 1 axle but that means spending time in the heat in a junk yard to remove all the brackets etc just to get an axle LOL.

Shipping may be the easiest and most cost effective in terms of time savings LOL

[MikeStang 247]

My notes show removal of 2.875 from driver side tube should get me where I need to be, but ill check that and verify before cutting.

I plan on documenting this with pics to go into the How To section

[MikeStang 247]

PM Sent Det.

 

Oh I am also planning on installing a 4 link set up on this axle so that will also be in the write up...Stay Tuned

[det0326 179]

My notes show removal of 2.875 from driver side tube should get me where I need to be, but ill check that and verify before cutting.

I plan on documenting this with pics to go into the How To section

yes u r correct, you have to cut 2-7/8 off the long side to make the short axle work. As the rear end sits in the explorer tho the pinion center in relations with the end of the axles is 2 inches offset. where the 7/8 inch comes into play is the carrier pin between the axles is 7/8.  When you use the short axle and cut 2-7/8 off to make it fit the pinion will actually be offset 7/8 to 1.0" toward the drivers side so you still won't be in the center but people run them this way without problems I am told.

 

Dave

[MikeStang 247]

Yeah I haven't heard any horror stories of them blowing up or anything running a little offset.

Don't our cars have offset Pinions as well? one axle is always longer than the other If I recall?

So in theory am I not making the same thing I have now?

I have no doubt it will work just fine, just trying to understand the mechanics of it all

[det0326 179]

Yeah I haven't heard any horror stories of them blowing up or anything running a little offset.

Don't our cars have offset Pinions as well? one axle is always longer than the other If I recall?

So in theory am I not making the same thing I have now?

I have no doubt it will work just fine, just trying to understand the mechanics of it all

Yes Mike a lot of people run the shorten explorer rear ends with the 1 in. offset with no problems. 

I think the 8" and 9" rears are centered tho if you measure from the wheel mounting flange to center of pinion it is same to both sides + or - their tolerance of course. On the other hand the explorer doing the same measurements you'll find that an un shortened rear end will be offset 2" to the passenger side and Ford even offset the engine mounts as well. I guess they did this because some of the explorers came 4 wheel drive so they decided to offset the 2 wheel drives also to make things easier.

 

Dave 

[ashleesmach1 28]

Neat!

[MikeStang 247]

Completed the shortening last night...Pics to come

[Vicfreg 773]

Mike, I have an 8.8 installed in my 1968, which is about 2" wider than the 1966.  I used a Ford Explorer rear end as well.  Some lessons learned:  

• The explorer rear sits under the springs, so the spring perches need to be ground off and new ones installed underneath the axle housing 
• The explorer rear has a lot of attachment points/brackets for the rear sway bar, etc that will just be in the way, so grind those off too
• The explorer rear has a modern rear universal joint attachment, that uses metric 12 point bolts to attach the rear of the driveshaft.   Your new driveshaft will have to mate up to this, so keep that in mind.
• The emergency brakes on the explorer rear are a problem for early year mustangs to deal with.  For the rear disc brake version that I got, they have those small drum brake shoes inside the rear disc that are used for the parking brake.   The 1965-1968 "pull handle" parking brakes do not have enough travel, or physical leverage to set the modern parking brake.  I retrofitted a Lokar set up that took me a long time to get to work and it still does not work right.  Consider using later model Mustang style rear discs on that rear, that have the integral parking brake feature
• The offset center did not pose a problem for me, there was plenty of room in the rear transmission tunnel
• You will need new U-bolts and shock mounting plates, as the 8.8 axle tubes are much bigger than the 8" or 9" rears.  I used off-road Ford Ranger u-bolts, and I believe my shock plates came from Scott Morris.
• Drain the rear and inspect it.  If all is ok, then don't forget to add the Ford Friction Modifier.  This will prevent the gear housing "chatter" that you can get with the modern clutch based traction lock differentials.

Good Luck, please post some pics...

[MikeStang 247]

Thanks for the info Vic.

I have the Alum driveahaft that came off the rear end so i will have it shortened and rebalanced and install the 4R70W Yolk on the frontso shaft wont be a problem.

I have already removed all brackets except one sway bar bracket, and I plan on running a 4 link so no need of those pesky leaf spring plates or bolts hehe.

Ill probably grab a mustang hand brake and adapt it, or perhaps adapt a 69-70 parking brake set up.

I do happen to have a Lokar park brake set up for a 69 i didnt uae on my 69 maybe i can get that to work somehow?

Also the tag on my rear end said 75w-140 synthetic onlyfor the oil...i got some mobile 1 that says Friction modifier included and its 75w140 wt synthetic....wonder if this will be ok?

[Vicfreg 773]

Hey MikeStang.  Sounds like a plan.  The four link will be a great addition.  Tell the supplier you are using the late model rear, there may be some clamps or something that may need to be modified to fit the bigger tubes.

 

69 - 70 brake is a good idea, never thought of that.   If you want to use a handbrake, check out LatoRacing (Mike). He has the Grabber Green project posted in the fourm.  He is installing a late model handbrake in his '70 and has details.

 

The Mobil 1 sounds ok, I just used the Ford stock synthetic, and used their little bottle of friction modifier.   

 

The one thing I did not do was swap the differential cover out.  I should have used one with the drain plug and "girdle".    I have attached a pic of the Ford Racing one. 

 

 

 

 

[MikeStang 247]

Yeah I gotta find one of those Diff Covers Cheap Somewhere.

Right now the rear is complete and sitting on jack stands while I finish my Rotisserie haha