Idk, but maybe Gear Vendors have something.

 

Yes, gear vendors should have one. I think it would be the kind that hangs off the end of the tcase though, not sure.

 

Gear Vendors makes a OD for both 4x4 and 4x2.

I'm putting one in now. I should have results by midsummer.

 

:rockwoot:
can't wait to hear how it does

 

So, with a double overdrive and a 3.73 gear is see about 1575rpm at 70.
With the 3.08 and double overdrive, I see about 1200 rpm at 70.
Right or wrong!!!!!!!!!!

JonFord

 

What would be involved to hook this up to a 4x4?

 

Bolt it in and wire it up. Pretty simple had a hand in one. Guy took a six speed with a brown lite out.

 

I'm looking for 1225 RPM @ 70 MPH.

The 4x4 version is more common and less expensive. The 4x4 version has a switch that disengages the overdrive when you engage the 4x4.

Should be operational next week.

 

What do you mean by "Guy took a six speed with a brown lite out"? Do these things work all the time or can they be disengaged to to run the stock gearing? Sorry, I obviously know squat about these, but like the concept. Will they hold up to towing? I remember years ago, on TDS, there was a guy that towed quite heavy and he felt these were not up to the task.

 

The gear venders can be turned off or on . Go here an read sir .http://www.gearvendors.com/

 

Dave, was it you that said they trash an auto? I can't remember, I know i wanted one but i forgot about it since i have an auto.

 

It won't trash your auto.

 

I previously had one on a GMC with a 6.2 diesel. After installing the GV, the truck spectacularly destroyed two TH400s and was working on a third. Consult your favorite automatic builder.

You can tow your brains out with a GV. They were originally designed for use with a British Bedford deuce-and-half. Think you tow heavier than a deuce-and-a-half?

If so, get a CDL and trade your pickup for a 4700 tractor.

 

I know it's been discussed before about turning too low of rpms and therefore not pumping enough fluid to keep an auto cool because not enough fluid passes through the cooler. Would a 6.0 tranny cooler fix that or is it related to volume?

 

What is the optimal (I.E. safe) rpm to run a GV on 6.0/5sp AT?

 

my thinking is that it would be more related to clutch pressure. a little extra cooling couldn't hurt though.

 

If that's the case then it should be an easy fix. If it's not enough fluid to keep the tranny lubed then I guess you could upgrade the pump as well. I wonder if a new valve body and bigger cooler would be enough?

Can't wait to hear from Dave and how this works with 3.08 gears.

 

Durn drive shafts taking forever.

 

Dave what did you end up with MPG?
Which rear end gear did you run?
Thank You

 

In my optimum setup I get a 3-tanks average of 26.5 MPH.

Lately, not so much the wind got under my tonneau and wrecked it. Now I get a steady 24 MPG.

I run a 3.08:1 gear that (to my knowledge) is no longer available.

I use my GV overdrive mostly like a seventh gear.

 

Later-model automatics seem to have fixed the cooling problem. Undoubtedly by stealing design features from the Allison.

With my gearing and OEM-sized tires and the GV engaged I turn 1325 (engine) RPM at 70 MPH. I'm pretty sure that will kill a pre-2010 automatic.

ATF flow to the cooler is proportional to engine RPM. An Allison (and later Ford and Dodge automatics) have a secondary oil pump to keep flow up at diesel RPMs.