My M5R2 is coming out in favor of a ZF-S542, which is apparently shorter and will need an F250 drive shaft. What are the critical angles / tolerances that I have to watch going back to the 8.8", as it seems that may change slightly also? (I.E., will I require a wedge to avoid vibration issues? The truck is not otherwise lifted.)

 

nope, you shouldn't have any issues with drive line unless you have alot of lift.

Is it currently one piece shaft or 2-piece? The reg cab long beds where right on the dividing line. If its a 2-piece then i think you only need the front half of it. I know the reg cab long bed f250's are a 2 piece. But im not sure about your f150. If it is a 2 piece and you were closer to me, i know right where one is for cheap too.

 

Mine is a single piece shaft. Going with new universals while everything's apart.

 

You'll probably need to find a two piece out of an F250 with the ZF5. i'd hit the junk yards, but they wont be easy to find. And having them made will cost a pretty penny.

Is the truck 4x4? The whole time iv been assuming its 2wd, but if its 4x4 that changes everything.

 

No, it's 4x2.

So you can't get the length you need without going with two-piece? And fabricating a longer shaft at a driveline shop is not an option?

 

2-piece is what came on a stock f250 like yours with the zf5.

If you want to keep the one piece, measure from the yoke on the transmission to the yoke on the rear axle. If its over 60in then you have to use a 2-piece as most shops wont make a shaft over 60in long. And having a drive shaft made will cost a couple hundred.

I think the stock 2-piece would be the best solution.

 

Pardon my confusion, but are you saying that the single piece drive shaft from an F250 will come up short on my F150 when the ZF is installed? And this would be true even if the drive shaft came from a 1996 F250 Std Cab Long Box 4x2 w/4.9L I6?

 

With a 2WD ZF, you must use a 2-piece driveshaft, as the output yoke on the transmission is fixed. An F250 driveshaft, even for the same wheelbase truck, will be about 3" short on the back half, due to the size difference between the 8.8" and 10.25" rear ends. I had an F250 2-piece driveshaft lengthened (re-tubed) for about $125.

I chose to lengthen the driveshaft I had so that I could keep the stock driveshaft together in case I ever decided to put the original transmission back in the truck. You could put an F150 rear half on an F250 front half and get it balanced if you want stock parts. The front half has to be from a ZF; the back half can be from any F150 with your matching wheel base for sure, possibly others depending on where the carrier bearing is located in the different length trucks.

 

correct. The 1-piece from your truck will be will not only be short, but it wont have the necessary slip joint. There should be a slip yoke on your M5OD. But the ZF5 has a fixed yoke. So you'll either need to have a 1-piece that has a built in slip joint made. Or get the 2 piece that came off of a F250 with the ZF5.

If you go with the 2-piece you will need a front piece from the reg cab long bed F250 with the ZF. And the rear piece from any f150(i think all the rears are the same). This is because the yoke on the axles are different lengths and your f150 will require the longer rear shaft that goes with an 8.8

This could be a trial and error thing. Its hard to say exactly what will work. You'd have to measure, look around, measure. See what you can find.

I hope this is all making sense.