Join Date: Oct 2003
Location: Temple tx
Bronco Info: '96 XLT 351W/E4OD/1356 No lift 33" tires, Custom engine, exhuast, and electrical mods.
Well, some of the math was a little wrong on the vss usage he used. But I corrected that with what i needed. What I'm doing about it though is this. Since I'm going to install a diff cage on my 9 inch. I'm actually making it to allow for several various configurations for VSS. The size of the ring is irrelavant as was posted in the artical. But the issue was that the formula never took into account tire squat only the tire circumfrence based on the tire size. Ie I have 33x12.50.15 Super Swamper Thornbirds. With the tread actually work out to sit 35.7 inches tall once mounted to my AR 15x10. Or 38.3 inches tall when mounted on stock ford rims of 15x8, ( I know the 15.8 is really a 15x7.8, but that is how they are sold as 15x8) But the point is your never going to be perfect due to tread wear and rim mounting options as well as load or tire squat. You just base it on tire size of 33 inches. Using that the number of teeth works out mor acurratly. Also the tooth size as far as height and width of the point itself are factors. If you measure the tooth gap between current 8.8 and the point width then you can resize to any diameter you want. This will also maintain accuracy. The reaso you cannot just do like you can opn a pc image and just shrink everything in proportion is that the sensor itself still is maintaining a constant size and pulse rating.
Now for how it will be mounted. As was listed in the post on the site many large trucks use the same setup of mounting ring on drive axle or other appropriate location. Just have to compensate for the rotational speed difference in your calculations. I haven't completed the assembly design yet but I'm considering several different options. Either remove ring of one of my old carriers which i keep as a constant reminder. Or make my own and then attach right in between the u joint yoke and the yoke assembly for my pinion. Then make a casing that has sealed bearings to fit one on drive shaft and one on the pinion yoke. The casing can keep the ring protected and seal as if still in the diff. and keep sensor clean. The caing will be able to attach to diff cage or maybe to axle hosing and allow for travel. This way no relacation of sensor wiring needed keep everything nice tight an sealed and accurate. Will get some pics together once axle pulled fromunder old pickup bed. And give you shots of the underside setup of my 96 xlt bronco.
Wanted to add this to it also. You DO NOT have to use an origianl ring or make a new one. As long as you can access a drive line part that will spin in sync with the axle system. Ie, drive shaft, couplers between trans and xfer case or where ever. You can actually add little points to the drive shaft itself you will have to adjust point size and point width between teeth. By width i do not mean the ring width but the flat surface or semi flat surface on top. Measure across the tip along the circumfrance of the ring. I can't remember the terms right now but I'm sure you know what I mean. Once i calculate everything I will post a grid and various options for how to set it up. So if you can't reproram the speedo cluster then can use one set or if you can then use a default set.