||09-05-2013 11:58 PM
Ring and pinion masters enter here.
Hopefully there is some good R&P masters here on this forum. I am reading up on my homework for my rebuild of my rear and have a question about some math related in the process.
I have been using the 30 page BillVista gear setup and I find it to be really helpful and he breaks everything down and even gives you a background on what each term means and what it does which it very helpful. But I am having some trouble grasping the Starting Shim stack calculations. I am able to understand it a little bit but it is the only thing that is bringing down my confidence on doing the rebuild. http://www.wranglerforum.com/images/...ing%20hair.gif
I would like a little more explaining about it. Here is the text I am at. If someone who has done this or knows any source to look up that info would be great!!
Starting shim stack calculations
If you are just changing the gears or if you are replacing the carrier and re-using the old gears, the quickest method is to simply start with new shims equal to the old shim stacks. You should measure each shim individually when calculating the old and assembling the new shim stacks, as measuring a stack of shims together can lead to inaccuracies. Note that any slingers or baffles (i.e. part numbers 2 and 6 in Figure 9) form part of the inner pinion shim stack. This means that if you are re-using gears that had a slinger or baffle (or both), but you aren't re-using the slinger and/or baffle, you must add the thickness of the deleted slinger/baffle to the starting inner pinion shim stack. The same is true in reverse. If you are using a slinger and/or baffle with a set of gears that didn't use them originally, you must delete the thickness of the newly added slinger/baffle from the starting inner pinion shim stack.
If both the old and new pinions have checking distance markings (aka depth codes), the starting point for the new inner pinion shim stack can be further refined as follows:
Alternatively, you can use the following chart to calculate a new inner pinion shim stack
- calculate the size of the old shim stack.
- calculate the adjustment by subtracting the new pinion marking from the old, being careful to observe the signs. For example, if the old pinion marking is (+4) and the new pinion marking is (-2) the result will be (4)-(-2) = (4)+(2)=(6). If the old number was (0) and the new number (+2), the result would be (0)-(2)=(-2).
- If the adjustment figure is negative, subtract that many thousandths of an inch from the shim stack and if the adjustment number is positive, add that that many thousandths of an inch to the shim stack.
- Example: old shim stack = 0.035” (35 thou), old pinion marking is (-2), new pinion marking is (+1). Adjustment =(-2)-(1)=(-3). New shim stack will be (35)-(3)=32 thou.
Thanks for the help!!!
Here is the chart that goes with the text.