There's one on Ebay right now set up for an f250 with a ZF5. I'd buy it if I didn't need to do the heads on my 6.9.
http://cgi.ebay.com/ebaymotors/F-250...spagenameZWDVW

 

It looks like its made for 4wd applications...(just guessing) I did look at that a few days ago when it was $500, haha its 3 times that now

 

That would work on any application, the trouble with using it on a 4wd is that it requires a drive shaft bewteen the transmission and the overdrive unit. If you have a carrier on your 4wd, then it would work just great, but it works well on 2wd's. It would install easier if they supplied the side brakets though... it looks like there may be something there to mount with, but not what Gear Vendors generally puts out. I put a very similar unit in my F350, and it worked out pretty good for mounting and position. I simply took the carrier bearing off, and put the GV unit in it's place.The rear driveshaft was able to stay the same length, and as luck would have it, the front driveshaft from the Dodge I parted out for the powertrain was the right length...

 

Would I have to shorten my driveshaft? (2wd with a ZF5 trans)

 

I would stick with a kit that is offered by GV that bolts to the TC (or ZF Tranny for a 2WD) rather than add another driveshaft between the TC and the GV unit. It would be one heck of a job to make sure everything is perfectly aligned ( and stays aligned) to avoid vibration problems. Also with the frame of the truck twisting (especially off-road) I don't think this particular GV unit offered on E-Bay is a very good design which is probably why it is being sold off.

Given all the trouble you could get into vibration wise, I don't think it is worth saving $1,500 over a standard GV that bolts directly to the ZF5 or the Borg Warner Transfer Case for 4WDs.

Trying to splice this unit between the Tranny and TC on a 4WD in not advisable I would say. The front driveshaft would get too long and this will cause all sorts of problems.

 

I don't see how having the GV inplace of a carrier bearing would complicate things in terms of vibration and frame flex any more than having it hanging of the end of the TC/Tranny. Either way your probably going to have to do custom drive shafts. I personally like the idea of it mounted inplace of the carrier better than hung on the end of the TC, that way you don't put any extra stress on the Trans mount or trans/TC casings. I know it works, but that just looks like a lot of weight to hang on the very end of the TC/trans (I've seen them installed in person, looks odd, but seems to work just fine).

Just my 2c (and I wish I had the $$ for one)

 

The newer units sold by GV work because they don't alter the triangular drive train support; two points at the engine and one at the tranny.

I had similar concerns about hanging all that extra weight off the transfer case at first but then relized that if you were to make a 5 point drive train support (or 4 point if you support the GV with a crossmember like the tranny) it would be impossible to keep the drive train in alignment all the time since the trucks frame twists all the time.

One of the key alignments for a driveshaft to work (vibration free) is to keep the input and output shafts parallel. (they don't need to be in the same plane but have to be parallel) For this reason a good installer of a newer GV unit will adjust the rear axle angle with wedges to match the angle of the output shaft of the GV to the angle of the input shaft of the rear axle.

A five or four point support would put the tranny and GV out of alignment every time the frame twist causing vibration or at the very least wear out your U-joints in a very short time. This makes the unit offered on E-bay a less attractive unit as it relies on support from the trucks frame.

GV has put a lot of thought into their designs. Adapting to all the different transfer cases is a lot of extra design work and manufacturing cost, but that is what makes their newer units work as good as they do.




Unless you had a perfectly rigid frame work, there is too much possibility of mis-alignment due to frame movement which leads to vibration problems resulting from mis-alignment of the drive shafts.

 

I really don't understand how a GV in place of a drive shaft carrier would make any difference in terms of how constant alignment stays with frame flex?????

 

On a 4wd, you do not mount the GV unit before the transfer case, only US gear does that. If you think about it, you never need overdrive when you are 4 wheeling... The reason I don't think this particular unit would be a good choice is the fact the drive shaft is shorter on the 4wd's. I installed a very similar unit on my 92 F350 crew cab, and it really wasn't that bad getting the angles set. There was no need for messing with the rear axle, just the drive shafts, the angle came out the same as it was before I started. A standard wheelbase truck may be a shade different on that aspect, as I have more distance to level it out with. Driveline angle doesn't change because the unit is inline, and in all reality, it isn't much different than having the carrier bearing there.As far as frame flex goes, it again isn't much different than dealing with a carrier bearing. Gear Vendors does make a bolt in crossmember that goes across the frame, I just used the frame crosses that were installed by Ford and mounted to them. In doing all the mounting, I follwed the instructions supplied by Gear Vendors, and consulted their tech assistance people, who were great to deal with. With a carrier bearing, you have 2 drive shafts, so why would it be any different than with the GV unit?
On the aspect of frame flex causing vibration while wheeling, just how fast are you going to be going? If the frame is getting much flex, I doubt there will be much vibration due to the fact you aren't going that fast, unless spinning out. Also, not everyone is going to be working their vehicle that way, I use my trucks for hauling and general service that way, rock crawling and messing around like that aren't high on my list of priorities... I do get some frame flex from time to time, but am going slow enough that it is no issue.

Some trannies don't have an option for mounting to the back of the transmission, requiring a freestanding unit like that. The only units GV mounts to the transmission/transfer case are the ones with a removeable tailshaft housing, everything else is a unit like what was shown. The overdrive unit is also designed to keep the angle of the driveline going, so driveline alignment isn't as big a problem as it would seem. The brackets I referred to earlier help considerably in setting the driveline angle. I didn't see them offered, and so I commented on that fact. I'm sure they could be gotten from Gear Vendors quite easily.