ECR:



The crawler box was designed to give the owners of Rovers with LT230 transfer cases a very low range option for off road use, but keep your highway gears in place... basically, the best of both worlds for dual duty Rovers, and a great asset for off road hard core Rovers!





The stock crawl ratio in a Defender is roughly 40:1. On the trail the 40:1 ratio means a pretty fast crawl ratio and that for some of today"s trails can cause problems. Problems such as stalling, slipping the clutch, hard start offs on steep hills and the inability to tackle some obstacles. The underdrive will drop your crawl ratio to 116:1 (with 3.54 gears, lower with lower ring and pinion gears). The higher the first number the slower the truck will crawl, 40:1 is average stock crawl ratio, 116:1 is a very slow crawl rate) and that means more control on the trail, and better off road ability for your Rover. If you simply changed your ring and pinion you would cut your highway speed and raise your engine rpms on the highway and you wouldn"t get anywhere near a crawl ratio of 116:1. The crawler is the best of both worlds of unbelievable crawl rations combined with unchanged highway performance.



Gear Ratios Stock LT230 Low Range 3.321:1

Low Range with Underdrive 8.933:1

사진3 Fitting the Underdrive to your Rover is quite simple. Care must be taken with the pre-load for the transfer case, but the unit assembles quickly and versions are available to fit almost any LT230 application.
The image above shows an Underdrive ins

사진5 This images shows a recent Underdrive install on a 1995 Defender 90 Station Wagon. The Underdrive lever comes out near the hand brake lever and has a small range of motion up and down and has full detents for positive shifting. We can even wire in a

사진6 This image shows our standard linkage set up in a 1994 Defender 90 Soft Top. Notice that this D90 has a Tuffy center cubby box, and that our linkage system works with it and operates smoothly and easily. Keep in mind that the Underdrive is available

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