Dana 80 pinion markings

[RyanG]

Building a dana 80 and I am confused about the pinion gear markings for shim selection. Workshop manual says should have a plus or minus a number off the centerline and then add or subtract to get correct shim, ok no problem. The pinion gear does not have a plus or minus on the gear head, only markings are what looks like two zeros 00 and then the number 12 180 degrees on the opposite side. Any ideas?

[Brad Clayton]

Very few gear sets have a plus or minus offset number, which is a good thing (less arithmetic needed). So your set is good to go with whatever your pinion shim selection was with the special tool setup or as long as the old gear set has a "0" marking or no +- markings.

[Keith Browning]

I ran into the same markings on the last rear I did. I assumed ZERO and installed the same amount of shim that came off of the original pinion.

 

The proof will show when you check your contact pattern.  Mine was good, hope yours was too.

[lmorris]

Found this in WSM.

[lmorris]

On a side note, I am currently rebuilding one of these. Does anyone have a rule of thumb for changing pinion bearing preload shims to change preload? I followed the WSM and reused the original shims, I am at 10 inch/pounds. Spec is 20-40.

[Keith Browning]

My rule of thumb when changing bearings but keeping the gear set is to reuse the shims and see what I have. Typically I end up in the ballpark so I cant tell you how much shim you need to remove to pull you up into spec.  Basically I do the same with differential bearings but there I always need new shims because the preload and the backlash are never right.  Set up tools? Haven't seen them around here in 20 years. Sometimes I hae no choice to work like a meatball.

[forddieseldoctor]

2 hours ago, lmorris said:

On a side note, I am currently rebuilding one of these. Does anyone have a rule of thumb for changing pinion bearing preload shims to change preload? I followed the WSM and reused the original shims, I am at 10 inch/pounds. Spec is 20-40.

I just built one a week or two ago. If you reduce the shim under the outer bearing by .001” you should come out right. 

 

When I do them I lay out all the shims on a piece of paper and measure each one individually and add them up. It makes it way faster when I have to adjust one. 

[lmorris]

Reduced by .002" and brought it up to 33 inch/pounds.

[forddieseldoctor]

Good. I tried .002 on the one I did and it moved it up to 50. It’s really just trial and error. And if you use a little bit of record keeping it helps keep the error at a minimum. 

[RyanG]

When trying to increase or decrease pinion bearing preload, I start off with what I have and then add or subtract in the thinnest increments of shim thickness. Usually get it in 2 or 3 attempts. I've done enough of these now that I have become pretty comfortable. Like Keith said when it comes to a simple bearing replacement on Dana axles, I reuse all of the old shims and have yet to have one come out wrong. Sometimes you might be at the loose end or tight end but within spec. The best pinion marking to have is 00, you simply select your depth shim and assemble. If you have a plus or minus number, my understanding is to select your depth shim and then add or subtract from the thickness of the selected shim based off of the pinion offset markings. I started this topic at the time because I had up until that point never set up a Dana from scratch( new housing, differential, ring and pinion, bearings and shims). I find doing the diff. backlash and preload setup to be challenging due to trying to get consistent measurements for diff. case endplay. Dana is good about including complete shim kits with there ring and pinions but it also helps to have a few extra outboard spacers on hand to get everything right.

[RyanG]

and always check your pattern at the end.

[8WA Sman]

Something that Spicer tech support told me makes the most sense...Hold the pinion so the markings are at 12 o'clock & 6 o'clock if there is nothing at 2 o'clock it's a zero.