Well not having an unlimited budget I was trying to find a solution to having performance gearing but also lower RPM on the highway. I just did a full performance rebuild on the C6 so that ruled out an OD transmission. A Gear Vendors is just to expensive new and I haven't had luck finding a rebuilt one at a reasonable price. Then I found this:




It's a Mitchell Gear Splitter, a 3500D Underdrive (22.8%). Now I was hoping for an Overdrive but I can make this work. I'll be swapping the 4.11s to 3.25s, this gives me the highway RPMs I need when shifted in High and when in Low I'll get back to what I'm running now for gearing. It's way overbuilt for what I need but I shouldn't be able to break it .

 

That's an interesting find. Never thought to check older 1 ton + trucks for under/overdrives.

 

How did the OD work? im curious about doing something similar if it works well

 

I've driven a lot of 5 speed with splitter 5 tons for years. The one thing they had in common was a clutch. I've shifted down with my throttle pedal but not up, I've always used the clutch for that. I don't recall an automatic with a splitter, actually I didn't think it was possible or that it wasn't idiot proof enough to put behind an auto. Wouldn't you need to go to neutral to shift or is there that much slippage in that style of trans. just curious, would take a lot of power to run 325s.

 

I was allways able to shift my 79 bronco , with a c/6 ,in and out of 4 wheel on the go , it was easier that way than stopping to do it. But i don't know about doing a splitter that way with out a clutch . It probably depends on how the gears are cut , sounds interesting though. I have driven farm trucks years ago with splitter box's and they were not easy to shift.

 

I know its a splitter but it *sounds* to me like his intention would be to just run the unit in high on the road; no splitting gears and when he goes offroad, he would just shift the unit into low hence his re gearing of the rear end.

 

his last post was 3-20-2013 so hopefully he will come in a reply

 

That's an interesting idea and a damn good find. I'm no where near needing one of those but it'd be nice to have on a long haul to pick up other trucks or cars in the future. Awsome project that deserves pleanty of pics and details. Keep us informed.

 

This post was made in 2011. I didn't realize it was this old. Who knows maybe we will still hear about it.

 

Ha ha , same with me , I see something on here interesting and i jump right on it. It would be interesting to see how it turned out and if it did what he wanted .

 

I put a note on his message board yesterday so hopefully he will come back to this thread and let us know what happened. I want to upgrade my ratio for fuel economy while towing and I'm open to workable ideas outside of the usual 4.10 to 3.54 gear change. I'm real used to shifting gears, really good at destroying autos. lol

 

Im open to anything to cut the revs out of the daily driven big block. Especially when I achieve the money to put the built motor in

 

Did my own books for years. At $4. + a gal with an intention of doing 50,K over 3 years. 10 mpg isn't going to please me. Thats my entry fee for Bristol, Martinsville, Rockingham and the like.

 

Hi Folks,

I'm sorry for the late reply but my hours have been horrible lately. The Mitchell gear splitter is still sitting on the floor. I spent the entire winter fabbing up the cradle and picking up a gearset and preparing for a new driveshaft and then stopped. I decided to spend more energy going fast then further. I don't get to drive it often during the season so going faster was more important. The splitter would have been shifted when stopped, when on the highway low rpm's and then when at a track or mud then go for the low gears. The Mitchell unit is very robust and was well made, part of me really wanted to finish the build but going fast is an addiction and I need to feed it .

 

Where are you located at? Ill come remove it off your floor haha