Soon to swap to Mark VIII rear IRS, what do I need to know?

I know alittle bit about the swap. Actually the only parts that I am going to use from the Mark VIII are the lower controling arms and diff as I have been told that the rest is the same.

I know that the Marks had open diffs so an Arburn Gear will be going in along with 3.27s.

I think I will replace all the bushings at once. Its probably the best way to do it. Are there any special tools needed to do this?

How hard is it to do the swap?

Now about the SC springs being to small to fit the perches. I know there was a group buy over at the tccoa but dont know if I can still get in on it. Is there any other solution to this besides running air bags in the back?

So I think I have covered all the bases. Is there any thing that I am missing here or should look out for?

Thanks!
Shane

I don't know if the spring perch, spring seat would need to set at an angle .

I would think you could get some aluminum plate, .500 ,cut round.Then weld a peice of aluminum pipe with the outside diameter matching the inside diameter of the spring.

Wasent there a drawing of the replacement spring perch in the TCCoA
post.

Good luck Randy

Unless it's from a Mark VIII LSC, that rear diff is open. You'll want to swap your cuts into that diff housing if you want to retain the trac-loc.

Search the TCCoA forums for someone selling a block machined to fit the stock springs in the Mark VIII air bag mounts. It's not terribly cheap though.

Thanks guys for the replys.

Anyone else have any other ideas? How hard is it to get the diff. out and replace the lower arms? Is rebuilding the diff. something I should do or have a shop do it?

Shane

How hard it is depends on how big your wrench is. You need to:

#1 - remove bolts for the rear spindle connections to the upper and lower control arms.
#2 - remove the rear bolts for the lower control arm.
#3 - Remove the bolts for the sway bar link.
#4 - Remove the rear spindle assembly with the axle shaft attached, pulling them out of the diff. (Easier than pressing the shaft out of the hub)
#5 - Unbolt the diff from the subframe
#6 - Unbolt the driveshaft.
#7 - Remove the diff.
#8 - Re install it all in reverse.

You'll need a qualified driveline shop to setup the gears in the new housing. Might as well have them do the swap and rebuild diff while there at it. Unless it is low miles.

I looked at one of the threads over on the tccoa and it said something about needing the bolt that goes threw the knuckle because it is longer and more supportive for the aluminum. Is there anything else that is Mark VIII specific that I need to perform the swap.

Shane