I recently installed a 9 inch in place of my 8.8 It worked beautifully after we cut and welded and said a few choice words. Now the only hang up is the Speed Sensor. As it runs now without the speedometer and the odometer workin. Me and mudinford are tryin to custom fab a speen sensor on the driveshaft near the cv joint. We are planning on cutting teeth off the old speed gear off the 8.8 ring gear and mounting it there near the cv-joint on the transfercase. To make this work we are going to cut every 3 teeth, leaving 1 every 4 teeth. Has anyone ver done such a thing? Also is there any plug on the BG-1356 where i might be able to plug up a VSS? Or does anyone know of a t-case what would work? I know any New Process would do fine, still looking for any suggestions. Thanks for the help.
Gary

 

The VSS you are referring to is the speed sensor for the rear anti-lock brakes. If you modify the number of teeth or it's rotational speed, be ready for your ABS to never work again. The number of teeth CAN NOT be changed from the original configuration. Even if you keep the ring unchanged from the original size, putting it on the driveshaft will spin it at the incorrect speed than if it were on the ring gear. The speed sensor for the speedometer is driven off the rear of the transmission. Looks like the only option you may have now is to remove the ABS altogether if you want to keep the 9" in the truck. Hope this helps you out.

 

The speed sensor gear that was located on the 8.8 ring gear has 108 teeth on it. If i mount it so to the driveshaft flange than i would need to cut the teeth since the speed of the shaft is much faster rotationg than the ring gear or axles for that matter. So by cuttin every 3teeth and leaving every 4th due to the gears. Cutting the 3 teeth off will come out to be perfect with little play. I have 4.56 gears so cutting the correct nuber of teeth is hard to say since you cant take off .56 of a tooth. We might be able to trick the computer into thinking the vehicle speed gear is actually going slower than it is. If this works we are going to place the magnet(actual sensor part) on the t-case its self to read the speed gear. I dont have ABS int he rear. The sensor is called the VSS for Vehicle Speed Sensor, the only tie it has to the ABS is the wheel speed, and without the ABS system knowing how fast the wheels are turning it cant activate the ABS. If none of this works as planned, the idea is to tap in to the front ABS Sensor and splice the wires together tot he wire harness from the rear VSS. This however should work out better since the ABS ring on the front wheels is going the speed I need and should be made of the same hardware. There, hope this helps to explain in more detail. Thanks for showing intrest in helping me, i appreciarte it. :~Þ
Gary