Have any of you ever built a homemade Chain drive transfer case? If so how well did it hold up and how did you do it? I would like to see some pictures of a set up like this. What type of ratios did you have?

It would take the right case to do it. Our rules specify an OEM case, no drop boxes, so we are limited on options. The newer model alumnum cases have a planetary front section and I'm not sure about the older iron cases. It is an interesting idea as you could pretty much get any final you want! The idea has been kicked around, but I haven't had the time to tear into a case and explore the posibilities. I'd be interested in talking to someone that has done it as well.

Alan

what would be the point of a chaindrive transfer case in a pulling truck?

I know the mudboggers do it because it is light weight, and you can overdrive the front axle in relation to the rear axle which is a necessity to be able to stay straight through the mud

How would you change the ratio on a pulling truck without two chains?

The only way this would work in a pullin truck is to have one chain drive from the trans to the chain setup for the two axles. It is the chain from the trans to the other that would have to be adjustable
How would you fit this into a stock case and service it or change the ratio?

And then what about longevity - chain drives barely withstand mud for very long in a 2000 lb package, never mind 5-6000 lbs pulling another 20 or so tons

I suspect it would be easier to have two or three sets of tires of various heights and more productive?

.03

http://powerproracingproducts.com/categories/63.html
Used them in mudracing for years, Would never hold up to truck pulling. Bob

I was just looking through some very old pulling power Mags. 80's and some of the trucks were using a chain drive set-up. Our class says no profabs but nothing about home made units. Just getting around the rules were you can. Also, some of the country modified users run them just have not heard anything from the pullers out there that I emailed.

I wouldn't worry about changing the gear ratio on it once set for my combination. I would think that it would allow for a more precise final. As for longevity, look at the 1345, 1356's etc. They last for well over 100,000 miles depending on usage, and they will handle more torque than the venerable 205!

Alan

I have a friend who tortured his NP208 for 2-3 years while I was repairing my NP 205 every 3-5 hooks. Just because the aluminum case deals look wimpy doesn't mean they are not pretty darn stout.

The 205 is less than impressive to me unless you install the ProFab gears in it.

Bret

Well if you really want info, I have the chain drive unit from Bob Plummers El Camino blower truck he used to run in the 70's and 80's. So does anybody else remember back that far?? It is extremely heavy and has interchangeable gears.

Ken,

As for why you would use a chain drive versus a gear drive, the gear drive pushes the gears apart but the chain pulls them together. It is easier on the case. And a triple row 60 chain will handle more torque than any blown alky motor can throw at it.

Travis

I would appreciate it. Any specs or info that you could give me on it would be great. I would like to see a few pics if you could send them.
richard.alexander@cityschools.net