Pulling Forum - 200 overdrive box

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200 overdrive box

Printed From: Unofficial Allis
Category: Other Topics
Forum Name: Pulling Forum
Forum Description: Forum dedicated to Tractor and Garden Pulling
URL: https://www.allischalmers.com/forum/forum_posts.asp?TID=211770
Printed Date: 16 Sep 2026 at 1:04pm
Software Version: Web Wiz Forums 11.10 - http://www.webwizforums.com

Topic: 200 overdrive box

Posted By: Skylar cook
Subject: 200 overdrive box
Date Posted: 22 Jul 2026 at 9:34pm

Replies:

Posted By: DrAllis
Date Posted: 23 Jul 2026 at 9:34am

To get faster than road gear (direct drive) a cheap way to gain 10% is to find a 190XT four-pinion ring gear and bolt it to the 200 differential carrier and do lots of shimming to make the clearances correct. I know it's been done, because I engineered it in my head (1981) and passed the info on to a local puller (deceased) from Elkader, Iowa. He ran that tractor several years and sold it to someone else. As far as getting custom gears made for your tranny, good luck, as it seems no one is interested in doing that. There are issues with the design as your input shaft gear has to be larger diameter than the input bearing hole, which means install the countershaft first, then install the input shaft from the rear, then install the mainshaft last. It's been done but not handy. My brother and I built an overdrive box for a friend's 180 (twin turbo) and placed it inside where the Power Director clutch goes. We used Pro-Fab gears and made everything else. We upped the gear ratio once over the years and I think we are currently at 20% over direct. The tractor is parked and he should sell it. Call if interested after 4PM. 319-360-4788

Posted By: Skylar cook
Date Posted: 23 Jul 2026 at 9:53am