hi my name is paul i have a 83 z28 5.0 4bbl yesterday i put a eaton posi unit in with richmond 3.73 gears and i am having a problem getting a correct wipe pattern for the pinion and ring gear i have heavy toe on the drive side and heavy heal on the reverse side my backlash is in spec between 8 and 12 thousands of a inch and i have 43 thousands of a inch shim on the pinion i drove the car home only 2 miles and got a grown noise at 30mps so i slowed down and the noise went away what do i do from here is the pinion in to deep? or not enough? please help thanks

 

http://www2.dana.com/pdf/5717.pdf

 

Use some periods! This isn't texting!

You should never drive a car with a bad contact pattern. It's possible that you have already ruined the gears, but lets hope not. You need to remove the cover and do another pattern check. Take pictures and post them here so we can see them. Don't worry about heel and toe contact. What you need to look at is root to face contact. That will tell you if the pinion is too deep or not deep enough. DO NOT DRIVE THE CAR AGAIN. Get this fixed before you ruin everything.

Read this if you haven't already. https://www.thirdgen.org/forums/tran...axle-gear.html

 

in this picture i am the middle picture the contact pattern is on the dotted line so you are saying my pinion is ok its my backlash that is off? my backlash is in spec and i thought backlash does not change the pattern unless it is drastic backlash like 50 thousands of a inch and i have to take the car back to work with my lift and tools are what are u saying can happen to my gears if i drive it slow back to work when i pop the cover off they will be in pieces?

 

http://trucks125ton.tpub.com/TM-9-23...289-34_669.htm

 

Please use some periods! I'm too old to try to figure out what you are trying to say.

If you drive it with the pattern messed up you are going to wear the gears in a way that you can not fix them. If you can not fix the car where it is then take it back, but do not drive it again until you get it right.

The pinion depth is off. The heel to toe pattern is not important. It's the root to face pattern that counts. This is controled by pinion depth, not backlash.

If you want more help I have to see some pictures of your pattern. And use periods. Some capital letter at the beginning of the sentence would help too. When I went to school we learned this in the second grade.

 

I am surprised that BGH didn't address your comment about 0.050", but my relatively limited experience is that a difference of just 0.003" makes a huge difference. No, the gears won't just explode, but you've already risked a permanent whine that'll never go away even with a perfect adjustment. I feel it worthwhile to always buy a spare new head bearing, then hone it out, for making it easier to determine pinion shims. It's maybe $25 extra, but it can save you more than that in labor the first time. Just don't forget to swap it out for a non-honed bearing before final assembly. Likewise on a solid spacer instead of fighting several crush sleeves.