Gear splitter options

[nswsparky]

I have been looking around for gear splitting/double overdrive options for my 7.3 and 6 speed. The only option I have been able to find are the gearvendor ones for like $3100 which is a little spendy for me. Anyone ever see any more options out there? I noticed on the 6 speed there is a large jump between the higher gears and the trucks rpm's are a little high at 75. I think a double overdrive could bring my r's down a bit and raise the economy a little, I think the engine has the power to do it. And it would make towing in the hills a little easier.
The gear vendor one is fully automatic but I wouldn't mind a manual one with another stick on the floor.

Gear vendor unit for my truck
Gear Vendors under/overdrive transmissions the most awarded auxiliary transmissions.

 

[BIG JOE]

I had a Gearvendor (overdrive) in my 91 IDI 5 speed (purdy sick, even turbo'd).. served me well. Made a big dif.. cuz I could pull in 4th over, to keep the RPMs where they needed to be at highway speeds, and had options, for pulling hills.

I know that was 20 years ago, but I only payed $1800 for mine.. self-installed.. or is that $3100.. installed ? Or.. just a "sign of the times" ?

Joe

 

[nswsparky]

yea that is just the kit. install would be $800 because they have to modify the driveshaft.

 

[BIG JOE]

WOW.

I hadta shorten the D-shaft too, but I don't think I had 2K in the whole deal.

Sign'a the times I guess.

As far as product quality went.. I halfta say it was a Real good unit. Put prolly 90K on it, lotsa highway towing, not one problem.

Hope you find something.

Joe

 

[JLDickmon]

I have been looking around for gear splitting/double overdrive options for my 7.3 and 6 speed. The only option I have been able to find are the gearvendor ones for like $3100 which is a little spendy for me. Anyone ever see any more options out there? I noticed on the 6 speed there is a large jump between the higher gears and the trucks rpm's are a little high at 75. I think a double overdrive could bring my r's down a bit and raise the economy a little, I think the engine has the power to do it. And it would make towing in the hills a little easier.
The gear vendor one is fully automatic but I wouldn't mind a manual one with another stick on the floor.

Gear vendor unit for my truck
Gear Vendors under/overdrive transmissions the most awarded auxiliary transmissions.

for that kind of money, you could play around with tire sizes a little..
like maybe a set of 285's

 

[wpfd571]

Its gonna take a whole lot of driving to pay for the GV. I agree with JL play with tires. And remember its a truck not a prius.......

 

[nswsparky]

yea that is what I was thinking. Go with a bigger tire to lower the r's at higher speeds. That would also bring my speedo back to right on.

 

[dpantazis]

search for Brown Lipe auxiliary transmissions.

problem is going to be driveline length. if you are 2wd, you have the room, if you are 4x, its gonna suck.

you might look into a Ranger
Complete Units | Advance Adapters
but AA says only for the 4 speeds,

i think these guys put them on to ZF5's-
High Impact Transmission and Gear

you could try a truck salvage place. look for older grain trucks or the like.

at the end of the day, the $$$$ buys a lot of fuel

 

[nswsparky]

I have the Crew cab with the long box so I have miles of drivshaft length.

Yea I don't think the ranger will work for the ZF the ranger goes between the bellhousing and the transmission. Since the ZF has an integrated housing so it can't be used.

I could get like a Eaton 10 speed or something but that would take alot of work and I just spent $1500 on this trans so not for now anyway.

 

[BJS]

gears. gears & tires.

the GV will burn up if used in OD with the engine compression braking. You have to change the fluid in there basically every oil change also especially if you're towing.

It is essentially a small automatic transmission that only uses the case for a cooler and modified PSD will exceed the torque rating.

US gear is what I would put in if I ever found one cheap enough. they have discontinued making them however. They were a constant mesh gear driven unit with an electric shift solenoid. and mounted @ the back of the trans or between the trans & t-case for 4wd trucks. In the even the electric solenoid died to shift gears you are not stuck on the side of the road and you can shift them by hand if needed.

alas I'm pushing 4:10 gears down the highway with 285/75/16 tires and mileage dips over 60 and falls off a cliff above 70. I've done a bit of math and decided that while I would eventually pay for the unit IF I got better mileage but it would be a very long term investment.

For this example we'll assume $4/gal of diesel no prices aren't there but higher prices actually make the pay off quicker for fuel mileage increasing items. I've attached a spreadsheet that might help with the economy vs fuel costs comparisons.

we'll say for sake of arguement that you're averaging 15mpg now

at 15mpg you're spending 26.7¢/mile in fuel
at 16mpg 25¢ a 6% improvement in mileage
at 17mpg 23.5¢ a 13% improvement
at 18mpg 22.2¢ a 20% improvement
at 19mpg 21.1¢ a 26% improvement
at 20mpg 20.0¢ a 33% improvement

so we'll jump on the delusional wagon and say that you'll get a 20% improvement since the engine is spinning 22% slower

so figure an installed price of 3300 and a savings of 4.5¢/mile 3300/.0045=73333.33 miles oh and I forgot to factor in the maintenance costs.

Oh and I've seen posting many places that GV is advocating synthetic lubricants in the unit so add 2 qts of synthetic ATF to the mix every 5 k miles

and the final nail for me was talking with people who have a GV behind a PSD indicate that the mileage is not notably different usually 0.5mpg or less, rarely even a full mpg. A comment that sticks in my head the most is that it's better at quieting the ride (due to less engine noise) than helping fuel economy.