Ford 8.8 diff conversion
09-10-2010, 02:26 PM
#1
Banned
Thread Starter
Ford 8.8 diff conversion
A few weeks ago I busted my diff... I knew it was coming, just a matter of time.
So instead of forking over 500 bux for a used stock diff that i was just going to break again, I decided to fit something else in there.
Options that are easy to get are a Puddy diff or the IP nissan conversion. Both really good products, but WAYyyy out of budget.
So after doing some research as to whats available and what looked like it could work I settled on a Ford 8.8. This comes in IRS form in the 89-94ish T-birds and cougars, also in the Lincoln MK VII and 99+ cobra's. The Lincoln and cobra's use a nice aluminum case, the t-bird is heavy steal. They came with various ratios and some with LSD some with out. To get it sorted out I picked up a T-bird Diff for $50 from a local yard, This particular one came with a 3.08? gear and no LSD.
A week later I got it about 80% mounted in the car.
IGNORE MY FAB SKILLS AS THEY SUCK... I AM A TERRIBLE FABRICATOR, IT WILL ALL BE REDONE BY A REAL FABRICATOR ONCE IT WORKS.
No pics of it in the car yet, but here are my mounts.
This is the front mount. Which will be redone to also include brackets to bolt to the stock front diff mount locations.
This is the rear mount. Asside from some bracing and final welding this is it.
To make the drive shaft bolt up, I cut the flange off the stock s2000 pinion flange, Its in the process of having the center opened up a little. There is a lip on the stock ford flange thats exactly 2 inch in diameter. That will press together then be welded up. It lines up perfectly with the stock driveshaft.
Now that its mounted, time to get some good stuff for the guts.
Richmond 4.3:1 gearset.
Picked this up from a memeber of corral.net for $80 bux shipped.
This is a OE trac-loc LSD, clutch type and super easy to rebuild. You can do it with the diff still in the pumpkin its so easy.
$95 shipped from ebay
Now for the expensive part... The axles.
I called up the guys at DSS, they are going to do up a set of custom stage 2.9 axles for me, should have those in a couple weeks.
The ONLY issue with fitment is above the diff. I had to add some clearance. If I kept the diff low enough to not hit the gas tank the axles would hit the sub-frame. Pretty simple solution though..
Now there is enough room..
Also, the new axles are with-in 1/2 inch of being equal length, the stock axles are nearly 2 inches different.
Update is on page 2
So instead of forking over 500 bux for a used stock diff that i was just going to break again, I decided to fit something else in there.
Options that are easy to get are a Puddy diff or the IP nissan conversion. Both really good products, but WAYyyy out of budget.
So after doing some research as to whats available and what looked like it could work I settled on a Ford 8.8. This comes in IRS form in the 89-94ish T-birds and cougars, also in the Lincoln MK VII and 99+ cobra's. The Lincoln and cobra's use a nice aluminum case, the t-bird is heavy steal. They came with various ratios and some with LSD some with out. To get it sorted out I picked up a T-bird Diff for $50 from a local yard, This particular one came with a 3.08? gear and no LSD.
A week later I got it about 80% mounted in the car.
IGNORE MY FAB SKILLS AS THEY SUCK... I AM A TERRIBLE FABRICATOR, IT WILL ALL BE REDONE BY A REAL FABRICATOR ONCE IT WORKS.
No pics of it in the car yet, but here are my mounts.
This is the front mount. Which will be redone to also include brackets to bolt to the stock front diff mount locations.
This is the rear mount. Asside from some bracing and final welding this is it.
To make the drive shaft bolt up, I cut the flange off the stock s2000 pinion flange, Its in the process of having the center opened up a little. There is a lip on the stock ford flange thats exactly 2 inch in diameter. That will press together then be welded up. It lines up perfectly with the stock driveshaft.
Now that its mounted, time to get some good stuff for the guts.
Richmond 4.3:1 gearset.
Picked this up from a memeber of corral.net for $80 bux shipped.
This is a OE trac-loc LSD, clutch type and super easy to rebuild. You can do it with the diff still in the pumpkin its so easy.
$95 shipped from ebay
Now for the expensive part... The axles.
I called up the guys at DSS, they are going to do up a set of custom stage 2.9 axles for me, should have those in a couple weeks.
The ONLY issue with fitment is above the diff. I had to add some clearance. If I kept the diff low enough to not hit the gas tank the axles would hit the sub-frame. Pretty simple solution though..
Now there is enough room..
Also, the new axles are with-in 1/2 inch of being equal length, the stock axles are nearly 2 inches different.
Update is on page 2
09-10-2010, 02:50 PM
#3
Banned
Thread Starter
This is the same diff that comes in supercharged mustang cobra's. its NOT going to break in an S2000.
the ford guys dont have problems with these till they run big radials over 600hp.
Even then the fix costs about $200 in the form of a re-enforced cover that braces the bearing caps.
the ford guys dont have problems with these till they run big radials over 600hp.
Even then the fix costs about $200 in the form of a re-enforced cover that braces the bearing caps.
09-10-2010, 03:52 PM
#5
Join Date: Aug 2010
Posts: 151
Likes: 0
Received 0 Likes
on
0 Posts
intrigued.id love to see how this works out.ford parts are cheap and strong and on my foxbody i put about 780ft/lbs through an 8:8 (solid though not irs) the only problem would be strong enough axles. I think this is a very viable option if axles can be made strong for inexpensive :-D 
Trending Topics
09-10-2010, 06:38 PM
#8
Banned
Thread Starter
The axles will be the same price as normal stage 2.9, they have all the parts already, only the shaft has to be a custom length which is easy. The weak link on the axles will be the spines in the hub. The part that goes into the diff is a good 1/4 inch bigger than the stock honda stuff... and i have the small 28 spine LSD, I could go for the bigger and much stronger 31 spine from the 04 cobra if i wanted, but then i'd have to upgrade to the big dss stage 5 hubs..
As for weight... my mounts are overly heavy, but like i said, I'm no fabricator.. I'll have it done up nice later on once i know it works, etc.
Also, the pumpkin itself seems about the same weight as the stock diff, so if i was really worried about it i could get the aluminum housing from a Lincoln or cobra, those are ~20lbs lighter than the steel t-bird housing and just as strong.
I'll see if i can find a suitable scale to weigh it all once its done.
As for weight... my mounts are overly heavy, but like i said, I'm no fabricator.. I'll have it done up nice later on once i know it works, etc.
Also, the pumpkin itself seems about the same weight as the stock diff, so if i was really worried about it i could get the aluminum housing from a Lincoln or cobra, those are ~20lbs lighter than the steel t-bird housing and just as strong.
I'll see if i can find a suitable scale to weigh it all once its done.
good luck bud, good thread
