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spitsnaugle

Ford 8.8 IRS swap v2.0

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Well with wfritts911 gone MIA, I've been left to develop my own Ford 8.8 Swap kit. This thread is the progress of the design and production. 

 

Design is based on a 2002 Ford Explorer's 31 spline 8.8 inch independent rear diff. 

 

I'm using drive shaft shop stub axles, they're not currently listed on their site, however you can call and order them.

*Note* though the ford cobra rear is almost the same, the axle seal diameters are different, and are not interchangeable. 

 

At the moment I am prototyping the parts. I have yet to source materials or get quotes from machinists. 

 

In the end these should be 6061 Aluminum.

 

Rear mounts. 

Using Energy Suspensions Urethane bushings for the 240z. 

 

p2115615994-3.jpgp2011077387-4.jpgp1996526659-4.jpg

 

3D printed the prototype to check fitment. There a great bar here in dayton called Proto BuildBar, they have a wall of 3D printers, a 3d scanner, soldering stations and all sorts of electrical supplies, its a geek's heaven. 

 

Designed up the mustache bar specifically to the ford explorer's cover. (not the cobra sorry) Then had it cut out on my friend's router table. 

 

p2116714347-5.jpgp2022638766-4.jpg

 

The front mount is a modified ron tyler mount. I dont have images or photos of it yet.

 

 

 

Thats about the progress I have made so far, will keep you all posted!

Edited by spitsnaugle
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I think you mean Ford 8.8 Diff swap. Anyway, I'll be following this one. I didn't care for the amount of things you have to change out to use Fritt's conversion. My plan was the following:

 

8.8 Diff, mounts, etc.

DSS stub axles

930 CVs

Custom length axle shaft

And an adapter to go between the 930 CV and the factory stub axle, like you'd use to convert to Z31 CVs.

 

Chequered Flag Joe actually makes that adapter, but only in 39 spline, I believe, and he sells it as part of a kit. I'm interested to see what you come up with. Something a little less spendy would be nice.

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I think you mean Ford 8.8 Diff swap. Anyway, I'll be following this one. I didn't care for the amount of things you have to change out to use Fritt's conversion. My plan was the following:

 

 I'm interested to see what you come up with. Something a little less spendy would be nice.

 

 

Diff was implied. (there's two more threads by other users on the swap and neither uses diff in the title :P )

 

I am only making a front and rear diff mount for it. Everything else can be bought elsewhere if anyone really needs. 

 

Zcardepot has a 27 and 39 spline companion flange. I thought Joe was the source. They also have a much cheaper billet aluminum adapter if you're risky. 

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THANK GLOB, any ETA?

 

 

No ETA yet, designing the dogleg/drop mounts right now, the originals are in the way of the diff. If the explorer rear cover's mounts were as narrow as the Z car it wouldnt be a problem, but at roughly 14" apart they line right up with the drop mounts for the control arms. I think the cobra's cover would clear without issues, but I've seen enough broken cobra covers to want to avoid that route. 

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How would this compare with the 8.8 from 1993 Lincoln Mark VIII, I know 89-97 will work, but I mean is the differential housing the only thing you're using from the host vehicle?

 

And just for background, I wanted to do this in a 77 280z that I'm in the process of LS/T56 swapping.

 

I was planning on having a drive shaft made at a local axle/shaft shop to mate to my T56.

 

Interested to see where this is going to go.

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I'm sure you already thought of this, but:

If you are gonna take the cover off to install or remove the diff, be sure that you have good access to the fill plug and drain plug. It sucks to install a dry diff only to realize that you have no way to fill it. I would never do such a thing.....

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FYI, 

 

ZCar Depot 8.8   has put together a mount that is a perimeter cover mount, similar to what you mentioned making, I believe. 

 

 

Flat 1/4" plate, sandwiched between differential case and rear cover.  Should allow any ford 8.8 rear to be used regardless of rear cover design.

 

 

Still not 100% sold on their front mount though....

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Sorry all, I'm extremely slow with remodeling my home at the same time. 

 

I'm not sold on their front mount at all. And I dont like that it requires buying a new rear cover.

I was working with technoversions to revise their front mount for my use. I currently have my rear mount all designed up, but havent had a chance to make a test fit, check driveline angles to then figure out the proper height for the front.  

 

I could use a couple measurements for a double check if anyone is interested. 

I have a 71 240z, so I'd like to know if any later years vary- I want to know the distance from center line of the mustache bushing mount bolt to the center line of the axel. Accuracy is key. 

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And I dont like that it requires buying a new rear cover.

 

Yeah, but you should be able to run basically any 8.8 cover; steel, cast Al, whatever.  I guess with a steel cover, you'd have to run some 5mm spacers between the mount and the cover, to account for the steel cover being thin, which would throw the front diff to body mounting holes out of alignment.

 

The issue with doing a 'sandwiched' plate as you mentioned earlier is you have additional sealing surfaces to maintain. (So the whole plate will have to be very flat (±0.005"??) Are you thinking gaskets, or RTV here or what?

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