Have any of you guys that have successfully set up your gears used a pinion depth checker? I always hear you are "supposed" to but aren't you checking the pinion depth when you look at the pattern it makes on the ring gear with the marking paint? I bought a depth checker for $100 but I can think of better things to spend $100 on if I don't really need the thing.


Would appreciate any feedback based on your EXPERIENCES (not assumptions please)...
Thanks

The actual project is as follows:
Installing a new Series 3 Eaton POSI w/ 3.23 gears to replace an old POS 2.73 open rear end - I hate one tire burnouts!!!

 

no you don't really need to set the pinion depth if you don't care about the parts lasting more than a few minutes. you're checking contact pattern with the marking compound not pinion depth. it sounds like you don't have a very good grasp of what's involved in setting up a gear set. you'll also need in/lb dial type torque wrench to check preload, i prefer a depth mike and something to use as a datum surface across the bearing cap surface ,indicator and mag base, press and bearing seperator.

 

ede-
Have you gotten readings that vary by a few thousandths when checking pinion depth due to the rough machined surface on the pinion? I came across this twice. I went ahead and took several readings and averaged them to set my pinion depth.
How close do you actually get yours to the stated pinion depth?

 

no, the back of the pinion isn't that rough, never checked to see how good of a finish it was with a meter. i use a 2-3 depth mike with a tapered depth rod, only about 1/16" or less contact area. i have a piece of aluminum bar stock i machined to fit across the bearing cap parting surface and bolt up using the bearing cap bolt holes, i use this as a datum to measure from and have to add .500 to the stated pinion depth to allow for the thickness of the aluminum.

 

You could use a magnetic base to hold your dial indicator.

 

well i bought the pinion depth setter sold at summit. The reason it's $100 is cuz the thing comes with a dial indicator. So if you already have one and you order this, you just bough yourself a brand new dial indicator - kind of deceptive if yo uask me. anyway i got it to work.
thanks guys