8.8 swap

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When I get the 4 wheel disc done, I am going to pick up a Jeep Grand Cherokee master cylinder or something similar with an adapter. I think DoctorDiff has a master cylinder also.
 
Does anyone know how much the 8.8 pinion offset within the pig is? In other words what's the offset after equalizing the axles?

I've seen a measurement of 3 7/8" difference from pinion center to the axle flanges. This would work out to about 2" offset from the diff center. That is the number given for pinion offset in this reference:

http://www.therangerstation.com/tech_library/Explorer8_8.html

If my math is right taking off 3" from the long driver side will give a new pinion offset of 1/2" to the passenger side, indicating this is the offset of the 8.8 within the pig. Does that make any sense? :scratch:

The math:
59 1/2 (8.8 disc to disc) divide by 2 = 29 3/4 to center.
29 3/4 less offset = 27 3/4 short side disc to pinion center.
59 1/2 less 3 = 56 1/2 shortened diff disc to disc.
divide by 2 = 28 1/4 to diff center
this is 1/2" longer than the short side disc to pinion center.

My reading says the 8 3/4 is either 1 3/4" or 1 3/8" offset to the passenger side. If my math is right the shortened and centered 8.8 has its pinion centered about an inch to the driver side of the 8 3/4.

Edit: The 8 3/4 pinion offset is about 1 1/2" to pass side. The shortened 8.8 offset is 1/2" to pass side. This places its pinion about 1" closer to the driver side.

My purpose is to see if it works to cut an 8.8 down to 50 1/2" disc to disc for my Demon. Dutchman says they need to cut a minimum of 3.5" when shortening 8.8 axles. If the above is right the short side can be cut down 4" and the long side by 2" plus 3" (total 5") and wind up right where an 8 3/4 has its center.

It's late... I could be way off :drunken:
 
I will be playing with my rear end on Thursday :eek:ops:
I will measure mine then and see for you. Just FYI, you may get some weird answers on this because the confusion of the way it is written. Meaning you described the offset off from center and then finalized the measurement by comparison to the 8 3/4.
I cut 2 15/16" out of my diff, and left a very tiny gap when welded back together. Thus making it shortened 2 7/8", making both axle tubes the exact same length.
 
You're right its confusing. It was past my bedtime. Hopefully the edit makes it as clear as mud.
 
id still really like to see a stock width 8.8 explorer swap into an a-body. it would be a lot easier in my case, and im sick of fighting with my 8.75. over a grand in it, and its still noisy when it heats up. and no rear discs.

anyone have any pics they can share? expecially of where the pinion winds up? i like to stock width, as im runniong mustang wheels already.

michael
 
My Duster, inner fender lip to inner fender lip measures 68".
The 8.8 is 59.5 disc to disc ( 2 3/8 wider than the 8 3/4 drum to drum).
That gives 4 1/4" from disc to inner fender lip on each side if your car measures the same.
If you want the tires to tuck under I think the rim should be about 2 inches inside the lip. (This is my guess, can anyone verify?)
So the rim should be no more than about 2 1/4" outside the disc.

http://www.americanmuscle.com/black-bullitt-17x8-9498.html

This 17x8 bullitt rim has 5.7" backspace so 2.3" outside the disc.
Could be OK but I don't know if 4" of offset compared to the normal 1 1/2" would cause vibration or cause the d-shaft to hit the tunnel.
 
There are a couple guys running a stock width Explorer 8.8. I think only on the Duster though. If I remember correctly, I think 360Duster is running a full width 8.8 over in Germany.
 
jrlegacy23 said:
There are a couple guys running a stock width Explorer 8.8. I think only on the Duster though. If I remember correctly, I think 360Duster is running a full width 8.8 over in Germany.
Click to expand...

Do the full width guys have issues with the drive shafts coming very close or hitting the side of the tunnel? Just wondering as mine is narrowed to be equal length on each side.
 
I don't know if they do. I have not heard of any, but that does not mean it does not. The 8 3/4 is factory set at 1 3/8" over the same direction, So I would imagine that 1 inch off the factory location would not. But it is one of those, don't know til you try it.
 
I picked up a used 8.8 from a wrecker today out of an explorer with 4:40 gears and posi.

The pinion is indeed 2" to the passenger side. Three inches off the driver side moves the pinion center 1 1/2" toward the driver side so the offset built into the pig is 1/2".

Here's a calculation on what it would cost to use an open Dana 60 that I already have in a truck:

housing, open carrier, 4:10 - free
axles - $305
limited slip $470
rear disc kit $350
shipping cost ??

Already at $1125 without shipping...

Advantage 8.8!
Also less weight.
 
drewmac said:
Does anyone have pictures of a finished swap?
Click to expand...

There are a few in my build thread in my signature, here is one of my pics:
attachment.php
 
I just finished this swap in my 72 Swinger ....well almost finished. The old worn out shocks that were on it are too short to reach the ford mounting plates by about 2". The BIGGER problem is that the angle on the ford mounting plate is off. Has anybody come up with a solution other than to throw caution to the wind and just jam the shock in? I'll post pics to better explain when I can...right now I've got trick or greater duty.
 
I was considering 3 different options:
1. Shorter shocks and just welding new shock mounts to the axle housing.
2. With some heat, twisting the ford shock mounts to the correct angles.
3. Buying a set of dana 60 or 8 3/4 plates and ovalling the holes a bit to fit.
 
Jlcaptain24 - howdy, neighbor!

Holy smokes, are those shock mounts pointing down AND out? I guess maybe you could find some sort of shock with a Heim-style end on it (dirt trackers use them all the time), but I couldn't say if it would already be in a binding situation when you installed it. If proper shock plates are easy enough to come by, I'd use them. Units from an 8.25 ought to have the right size, too.

Clair
 
jrlegacy23 said:
I was considering 3 different options:
1. Shorter shocks and just welding new shock mounts to the axle housing.
2. With some heat, twisting the ford shock mounts to the correct angles.
3. Buying a set of dana 60 or 8 3/4 plates and ovalling the holes a bit to fit.
Click to expand...

#3 sounds like the logical choice since their readily available and they'd put the shock mount right were it'd need to be but why would you need to "oval the holes" to make them work? Aren't the 8.8 axle tubes the same diameter as 8.25/8.75" rears?
 
fishy68 said:
#3 sounds like the logical choice since their readily available and they'd put the shock mount right were it'd need to be but why would you need to "oval the holes" to make them work? Aren't the 8.8 axle tubes the same diameter as 8.25/8.75" rears?
Click to expand...

They are 3 1/8" tubes. If you just clearance the holes a 1/16th on each side, you should be all set.
 
clair.davis said:
Jlcaptain24 - howdy, neighbor!



Clair
Click to expand...

Clair.Davis...hey man! Looks like you're right down the road from me! And yes, those mounts are pointed in a rather funky direction. You'd think the other end of the shock on the exploder was attached to the rocker panel! I'm liking the ideas everyone threw out.

My initial thought was just heat it and bend it....guess that's the caveman in me. I don't have a torch that will do the job though....so the caveman will have to sit tight. I'll look into the different shock plates. I pulled out a 7 1/4, so there was no way those plates would work...the axle tubes were as big as a broom handle. I'll let you know how it goes, and if I ever figure out how to post pictures I'll get some up. Thanks all.
 
dusterbd13 said:
id still really like to see a stock width 8.8 explorer swap into an a-body. it would be a lot easier in my case, and im sick of fighting with my 8.75. over a grand in it, and its still noisy when it heats up. and no rear discs.

anyone have any pics they can share? expecially of where the pinion winds up? i like to stock width, as im runniong mustang wheels already.

michael
Click to expand...
just cut the spring perches off move them out 3 in weld them back on,,mark your spring perches all the out to end and relocate for pion angle the axle gives 1.1 in wider on each side ...lets you to install wider tires with the right backspacing.....
 
bonehead said:
just cut the spring perches off move them out 3 in weld them back on,,mark your spring perches all the out to end and relocate for pion angle the axle gives 1.1 in wider on each side ...lets you to install wider tires with the right backspacing.....
Click to expand...
exactly my thoughts. but the pinion is heavily offset in these rear ends, and i already hit my mufflers with the 8.75 pinion yoke under hard lateral acceleration. thats why im concerned about the pinion location in the car.
 
I'm putting an 8.8 in my 65 right now. I'm at the same point of deciding what to do with the shocks. I was thinking of redoing the shocks to point straight up and down and adding a track bar. Perhaps to the same mount that the dampner was mounted to on the 8.8, although I think they should be as long as possible. I've heard the shocks work better in the 90 degree orientation anyway.
What do you think?
 
FWIW, I used the Mopar shock plates... I used regular 3" u bolts and "persuaded" them to fit the axle. It is kind of hard to source the correct length u bolts. Here you can see the shock mounts.
 

Attachments

  • duster shock mounts.jpg
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What are yall doing for brakes as far as proportioning valves etc or just run stock setup?
 
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