I do a lot of highway driving and would like another gear. I know there used to be a company, I think Saturn that made Overdrives that bolt to the back of a T-case. I have not been able to find one for a Toy T-case. Has anyone else been down this road? I don't want to loose my 1st gear crawing so changing axel gearing is not what I want to do.

 

I've never heard of anyone making a bolt-on overdrive for our trucks but a few make bolt-on underdrives (dual t-cases). http://www.marlincrawler.com/htm/tra...ansfercase.htm

The thing to do would be install dual t-cases for the granny gears and gear the axles higher or better yet just put on bigger tires. I kind of doubt the 22re would have the power to pull a much higher gear except downhill or with a strong tailwind. What speed and rpm's are you running at now in 5th gear.

 

Gear Vendors Overdrive?

http://www.gearvendors.com/

maybe something to look into

EDIT: they only list domestic BIG 3

 

Well I am constanly running 3100-3200 rpm for 40min at 70mph or so. I would like to drop that down to around 2800 with another gear. I could put bigger tires on but then you have more weight to move around and it is a 22RE. I think it could handle another gear. Yes, I would have to downshift a bit more but it would be worth the savings in fuel and wear on the engine.

 

i dont think at that rpm the engine would have enough power to maintain speed...

 

These engines "like" that RPM range. The overdrive on the auto tranny's will give you those kind of RPM's - search around a bit and just about every complaint about power that you'll see is from people with the auto tranny.

The downshifting and having to floor it to hold your speed will have a more dramatic effect on your fuel economy than the lower RPM.

 

22re's are made for higher RPM's, these trucks used to be just 4 speeds anyhow. BTW, my 5th gear went out on my 86 nd I just drove it in 4th for a whole summer at 70 and 4000 rpm, the 22re took it no problem. Eventually the tranny wouldn't go into gear though....

 

The R-series are a torque motor.. Good for low RPM. Above about 4000-4500, the torque really falls off fast.
2800 is a little low.. If you really want to gear it like that, I'd adjust my 3rds (or tire size) and use a crawler unit for the off road stuff. The 22R is going to struggle to pull 70mph at that RPM however, just due to the force of the air...