I was looking at the rebuilt transmissions at marlincrawler.com and I notice that they offer a transmission (r150f) with a gear ration of 4:31:1 first gear for 650.00 more dollars. What would that do exactly? Sorry if this is a bit of a stupid question.

 

they only change the ratio of the first gear. The others stay the same. The factory 1st gear in those trannys is 3.83. So changeing it to a 4.31 means that your able to drive slower in first gear, and your able to get closer to your powerband without going so fast.

When your rock crawling/driving a technical trail you want to go as slow as possible in order to stay in control, and if your in control you can go many more places. This is the same reason they have double, and even triple transfer case set ups.

This is the exact reason why the r151f is more desirable than the r150f. The r151f has a 4.31 1st gear from factory. But they're getting very rare. So many people wanted them, and so few trucks came with them. Only the turbo models in 86 and 87 had them. Plus some were available overseas.

 

Oh okay, thank you!