My Gear Vendor Overdrive Drives Me Nuts
 

When it is working, it performs magnificently - increasing MPG by at least 1.5 MPG by itself and enabling aero improvements to the truck to bear fruit,.

But it is not very reliable. It has more bugs than coastal Guatemala and now it is leaking fluid.

Maybe I would have been smarter to have had an adapter made and installed a Tremec 6060 instead. I would have lost only 30 ft-lb torque rating (my old 444 doesn't make that much torque anyway - it dynos out at 560 ft-lb peak) and I would have gotten a better overall overdrive ratio(0.5:1 instead of 0.562:1) with only a single overdrive gear and the reliability of a manual shift transmission.

You'd think that with the cost of those things they'd be all sorted out.

Yeah, that's why I haven't bought one.

I mathed out putting a GV on the camper; it would take one hella lotta miles accrued and/or much more expensive gas to make it pay.

"You'd think that with the cost of those things they'd be all sorted out."

I agree.

Further, these things are not new. They've been around for decades. Obviously somebody likes them.

it is unusual that a product as expensive as it is, having as many problems as it does. i know the gear oil is exclusive also.
i paid only $250.00 for mine. did some trading and sold the extra parts i had left over. picked it up off of craigs, 1 good unit and a parts unit. i cut the drive shaft and welded it myself. i haven't had any problems with mine but i don't drive the truck as much as i could. the main reason i got it was to keep the 4:10 gear and still be able to drive it on the highway. if everything works out, i will be swapping engines, trans, and driving it more.