Vintage Mustang Forums banner

1 - 20 of 38 Posts

·
Dimples
Joined
·
3,757 Posts
Discussion Starter #1 (Edited)
You hear about the Explorer 8.8 swap being the most affordable path to having a super-strong rear end with disc brakes and steep gears (3.73) while driving both wheels. For context, I was coming from the stock 8 inch, 2.80 gear open diff axle with drum brakes.

This swap is often described as "grab an axle for less than $200, shorten it if you have to and you're on the road!". I'm paraphrasing of course. What I encountered was more involved, partly because the bearings and brakes were shot on the rear end I picked up, but in the final analysis, I would never run junkyard bearings/seals or brakes anyway. While it's apart, that stuff had to be replaced. Here's the rundown of cost:

PARTS/SERVICES-------COST-------SOURCE
Housing Shortening--------$110.00----Scottrod's (local shop)
Driveshaft Shortening------$120.00----FW Gear & Axle
Assembly + Short Axle-----$125.00----Pick N Pull
Pinion Flange----------------Free--------Friend ($20ish value)
Shock Plates - Currie-------$50.00-----Craigslist
Gear Oil - Mobile 1----------$60.00-----Autozone
Rear Brake Hoses-----------$40.38-----Autozone
Rear Brake Rotors----------$31.99------Autozone
Rear Brake Pads------------$23.99------Autozone
Rear Brake Calipers--------$79.98-------Autozone
Parking Brake Shoes-------$19.99-------Autozone
Brake Fluid------------------$6.00--------Autozone
U-Bolts - Pro Comp---------$35.99------Summit
U-Joint - 1313/1330--------$17.97------Summit
Spring Perches--------------$23.97------Summit
Bearings and Seals----------$75.97-----Summit
Metal Plate for
Brake Line Mount------------$6.97-------Lowes
Line Clamps -
parking brake cable---------$5.00--------Lowes
RTV---------------------------$6.89-------Autozone

Rear End Total $840.09

Notables:
- There's a chance I could have saved money by shopping something like Rock Auto instead of Autozone, but I'm glad I did it this way. There was enough experimentation involved with scoring the right parts that I needed a local place to deal with and they treated me right.
- 67+ doesn't have to shorten the axle housing or need the extra short side axle, so that could save you a lot of time and expense.
- Had to fab brake line mount plates because I cut off the stock mount. I can post pics later.
- Had to fab a new parking brake cable connection at the axle. I can post pics later.
- Shock mount plates were a hassle. First I tried to make the stock plates work, but they don't really have enough meat to work with the larger U-bolts. Tried to fabricobble the Exploder mounts to work, but the angle at the shock was wrong and fixing it would have been a real PITA. I eventually found some used Currie shock mount plates on Craigslist and highly recommend going that route. I don't have a part number, but as long as they work with the 3.25 inch U-bolts, you'll be glad you went this route.
- There are more costs here that will depend on your shop supplies. For instance, I went through a box and a half of blue nitrile gloves, had to buy a sledge hammer to remove the pinion and bought a new oil drain pan for fresh gear oil extraction when I had to re-do the diff shims (that's a whole other story).

So, with all of this new experience, would I do it again? Hell yes. It's more involved than I was led to believe, but the final result is outstanding. For another $??? I could have built the 8 inch or found a 9 inch with similar specs, but this setup performs great, and I'll be able to get parts for it forever.

Edit: updated to include Parking Brake Shoes and Pinion Flange

Mustang Explorer Rear1 by Blake, on Flickr

Mustang-Explorer Rear Wheel by Blake, on Flickr
 

·
Registered
Joined
·
5,726 Posts
In the process of doing mine as well, but fortunately for me I can take off most of your 1st 3 prices; I parted out the truck and actually made money, so a free rear axle, I shortened it myself, and paid $25 for a short axleshaft- otherwise almost identical to yours. The other thing I did was found the lower leaf plates from Speedway Motors that fit the axle, had the right U-Bolt width, and shock mount tabs. Mine's done too, just waiting for the car to come back from paint so I can shoehorn it in! Yours turned out really nice!


BTW- since you weren't technically asking any questions and I responded, I hope I don't get schooled about it by a lurking bystander.......
 

·
Dimples
Joined
·
3,757 Posts
Discussion Starter #3
LMAO, we?re good. All questions/commentary welcome.

I did the same thing you did with my driveline. Bought a wrecked fox body Mustang, sold off the parts and kept the engine and T5. So the 5.0 and transmission was basically free.
 

·
Registered
Joined
·
127 Posts
I had to buy a pinion to u-joint flange too. Didn't see that on your list.

I've done two 8.8 conversions: one shortened by myself for my 66 and one not shortened for a street rod. New bearings, seals, hoses, lines, frame to axle hose, ... it adds up. I think I even got new parking brake shoes and bits. I like the shock plates in the pic. I reused mine (welded up holes and re-drilled). Yours look much nicer.
 

·
Registered
Joined
·
5,726 Posts
Nice! I love it when a plan comes together!!


BTW- are my eyes playing tricks on me, or did you run 2 separate hoses from the brakes to the body?
 

·
Dimples
Joined
·
3,757 Posts
Discussion Starter #6
Good call on the flange. A buddy had one from an aerostar van so that was a freebie. Thanks for mentioning that.

Also worth noting that the driveshaft required a new weld-on yoke at the back to accommodate the outside snap ring style of the Moog swap joint. This added $20 to the shortening, but that price is reflected above.

As for the brake hoses, it?s all stock explorer stuff. The extra hose is for the vent tube.
 

·
Registered
Joined
·
5,726 Posts
It looks like the hose from the left caliper goes up to the body.... duh- just figured it out. Your right side ties into the left side at the hose itself, then it goes up to the body (1 hose from housing to body). It's far to the left rather than almost centered on the housing like your stock 8 would have been. I should have known that having just put one in my '67 F100 as well as having the next one on the floor waiting for install... lol
 

·
Registered
Joined
·
4,836 Posts
Just wondering what vantage the Exploder rear has over say a SN95 or S197 rear end? If you don't shorten one side for the 67 and later cars isn't the pumpkin off center? Does this cause issues with exhaust driveshaft, vibration?
 

·
Dimples
Joined
·
3,757 Posts
Discussion Starter #9 (Edited)
Just wondering what vantage the Exploder rear has over say a SN95 or S197 rear end? If you don't shorten one side for the 67 and later cars isn't the pumpkin off center? Does this cause issues with exhaust driveshaft, vibration?
I don?t recall exact specifics, but if I recall correctly, the explorer rear is the perfect width for a 67+ and the perfect width for a 65-66 if one side is shortened to be equal, where a late model Mustang 8.8 is neither.

Nothing wrong with an off-center pinion as far as vibration and such. This has been hotly debated and confirmed in the past.

Edit: also 31 spline axles vs most Mustangs having 28 spline. Not that that is a huge deal, but a nice bonus.
 

·
Premium Member
Joined
·
10,063 Posts
You would also need to weld spring perches on since late model mustangs don't use leaf springs
The leaf spring perches on the Explorer rear end are not the correct spacing (43") for a Mustang so you have to cut the originals off and weld replacements on.
There has been numerous discussions on this forum that nobody sells a perch with the correct radius for the 3.25" diameter Explorer axle tubes. You have to buy 3" perches and grind them out to a larger radius.
 

·
Premium Member
Joined
·
10,063 Posts
Rear Brake Rotors----------$31.99------Autozone
Rear Brake Pads------------$23.99------Autozone
Rear Brake Calipers--------$79.98-------Autozone
https://flic.kr/p/Yke8MA
At the P-N-Ps around here they usually have several Explorers in stock. If the one that has the gear ratio you want has worn out brakes find another one with an undesirable gear ratio but good brakes and swap them out before you head up to the office to pay. Save a chunk of change by not having to buy new calipers, rotors and pads.
 

·
Dimples
Joined
·
3,757 Posts
Discussion Starter #13
The leaf spring perches on the Explorer rear end are not the correct spacing (43") for a Mustang so you have to cut the originals off and weld replacements on.
There has been numerous discussions on this forum that nobody sells a perch with the correct radius for the 3.25" diameter Explorer axle tubes. You have to buy 3" perches and grind them out to a larger radius.
You are correct that any later model 8.8 is going to need new spring perches welded on. As for the spring perch availability, not so. I found 3.25 diameter perches on Summit.
https://www.summitracing.com/parts/cur-ce7000b

At the P-N-Ps around here they usually have several Explorers in stock. If the one that has the gear ratio you want has worn out brakes find another one with an undesirable gear ratio but good brakes and swap them out before you head up to the office to pay. Save a chunk of change by not having to buy new calipers, rotors and pads.
I think this is a perfectly legit way to save some money here. I wasn't really focused on the brakes when I bought mine, I just cracked it to make sure the gear teeth looked good. That said, I really don't trust junk yard brake parts. Especially calipers. Everything on mine was hosed so it didn't matter anyway.
 

·
Registered
Joined
·
2 Posts
You are correct that any later model 8.8 is going to need new spring perches welded on. As for the spring perch availability, not so. I found 3.25 diameter perches on Summit.
https://www.summitracing.com/parts/cur-ce7000b
Those are the perches I used for my '69 Cougar. I found a junkyard Ranger driveshaft that was the correct length and already had the 8.8 flange on one end. I pressed the FMX yoke on the other end and it all bolted right up.







The car came with a 9 inch, 2.70 open. The stock brakes were hosed so instead of dropping any money on the rear drums, I went this direction. I ended up trading the 9" for a 393 stroker crank, worth maybe $250?



I used the stock Explorer lower leaf plate and welded a small square onto the top of the shock mount so that it will accept stock shocks.

 

·
Dimples
Joined
·
3,757 Posts
Discussion Starter #15
I used the stock Explorer lower leaf plate and welded a small square onto the top of the shock mount so that it will accept stock shocks.
I tried the same thing and once installed, the shock mount angle was WAY out of whack. Maybe it's better for a Cougar or something later than a 66?
 

·
Registered
Joined
·
1,766 Posts
I did my 8.8 swap into my 68 a couple years ago. I left the pumpkin offset. Since then I have broken 2 driveshafts (which destroyed my transmission each time).

I've been babying it for the past year, but being in fear of going over 70mph is no way to live. After much speculation on here and at the driveshaft shop, they think I was exceeding the critical speed of the DS. They don't think the pumpkin being offset had much to do with it (I'm not 100% convinced).

Anyway, I'm considering yanking it out and centering it this winter, if only for the piece of mind.

My plan is to take the car out soon and really hammer on it. If it breaks again, upgrade everything over the winter. If not, I'll leave it be and try to stop worrying about it.
 

·
Registered
Joined
·
812 Posts
I did my 8.8 swap into my 68 a couple years ago. I left the pumpkin offset. Since then I have broken 2 driveshafts (which destroyed my transmission each time).

I've been babying it for the past year, but being in fear of going over 70mph is no way to live. After much speculation on here and at the driveshaft shop, they think I was exceeding the critical speed of the DS. They don't think the pumpkin being offset had much to do with it (I'm not 100% convinced).

Anyway, I'm considering yanking it out and centering it this winter, if only for the piece of mind.

My plan is to take the car out soon and really hammer on it. If it breaks again, upgrade everything over the winter. If not, I'll leave it be and try to stop worrying about it.
Interesting.

I also did the 8.8 swap a couple of years ago in my 68 and left it offset. I am using an 88 Tbird driveshaft(49" C-C) with a T5. I replaced the u-joints myself and used the Exploders flange yoke. I have zero vibrations and take it to 75+mph all the time.

What is your driveline (pinion) angle? Possibly that is your issue?

Hopefully others will chime in here. The debate over the offset pumpkin has been brought up numerous times and I think the masses agree it shouldn't cause any issues. There are tons of people running the offset in all types of vehicles these days.
 

·
Registered
Joined
·
1,766 Posts
Interesting.

I also did the 8.8 swap a couple of years ago in my 68 and left it offset. I am using an 88 Tbird driveshaft(49" C-C) with a T5. I replaced the u-joints myself and used the Exploders flange yoke. I have zero vibrations and take it to 75+mph all the time.

What is your driveline (pinion) angle? Possibly that is your issue?

Hopefully others will chime in here. The debate over the offset pumpkin has been brought up numerous times and I think the masses agree it shouldn't cause any issues. There are tons of people running the offset in all types of vehicles these days.
I've checked and re-checked angles a bunch of times. While my driveshaft is custom with the slip built in, it's nothing exotic. Looks just like this replacement piece for a modern Mustang with the slip yoke built into the shaft:



If I can find my gopro I'll strap it under the car so I can really see what the rear end / driveshaft is doing.

The driveshaft shop ran their calculations (tire size, gear ratios etc) and said I'm getting close to the critical speed for the length of shaft I have. They recommend going to a 2 piece shaft, but if I do that I'll still center the rear so the angle on the now shorter shaft isn't as severe.
 

·
Registered
Joined
·
812 Posts
Sorry for hi-jacking your thread BlakeTX

Here is a :beer: to smooth things over.

Beau M - Is there a reason for going with the slip style? I know you are running a modified drive train (understatement), just curious is all.
 

·
Registered
Joined
·
1,766 Posts
Sorry for hi-jacking your thread BlakeTX

Here is a :beer: to smooth things over.

Beau M - Is there a reason for going with the slip style? I know you are running a modified drive train (understatement), just curious is all.
Yeah, the toyota tranny is a solid flange, just like the rear end. Slip has to go somewhere :) Here's a pic from the first time it exploded, you can see the aluminum adapter and what was left of the driveshaft:







Sorry for thread jack OP. You are correct the Explorer isn't quite as easy as it may seem, but I still feel it's a great choice. Oh, and I run the slapper bars because even with bashin in the passenger footwell my rear end pinion would still hit the floor under load. (another offset pumpkin issue)
 
1 - 20 of 38 Posts
Top