I couldn't rent or aquire the expensive pinion depth tools so I made a primitive one of my own using cardboard a steel rod some thread and a magnet. This gave me a ballpark depth number. I added a .020 shim to the original .042 one and came out with this pattern. Now Im having trouble reducing the backlash with no shims on the right side and a hard time driving shims into the left side. Does anyone have a solution to driving in hard time shims ? Thanks.
Pinion depth measuring
- Thread starter pocojo
- Start date
This primitive replicate of a pinion depth tool will give you the axle centerline and the vertical string slid over to the pinion gear center will give a vertical line from which to measure the distance from that line (axle centerline) to the pinion gear face. These measurements are necessary to determine the amount of shims needed to set proper pinion to ring gear depth. These measurements are crude but will give you a baseline and starting point to work from. There is nothing ignorant in asking questions.
Pocojo
What is the tolerance of the cardboard? ±/- 0.375"?
I think you made this entirely more difficult than it had to be. Unless you bought a brand new axle with no gears in it, then maybe you'd need a depth tool. But event then, if you made some setup races and bearings, this can be done much easier.
You're pattern is too deep. That shark fin mark is indicative of too much pinion spacers so go back to the original of .042 and just trial and error from there. If you have no shims on the right and are adding to the left, then you are decreasing your back lash. You need to create distance by adding them on the right, which moves the ring gear away from the pinion.
I suggest you watch the gear video from @hosejockey61 and read the billavista writeup on gears if you havent already. Those saved me a ton of time!
You're pattern is too deep. That shark fin mark is indicative of too much pinion spacers so go back to the original of .042 and just trial and error from there. If you have no shims on the right and are adding to the left, then you are decreasing your back lash. You need to create distance by adding them on the right, which moves the ring gear away from the pinion.
I suggest you watch the gear video from @hosejockey61 and read the billavista writeup on gears if you havent already. Those saved me a ton of time!
And I thought I was a cheap SOB on tools! In all seriousness (unless this thread is intended to be a joke), the tolerances needed come down to one thousandth of an inch. As jjvw eluded to, your cardboard creation isn't going to do it for you. You do get a 7 out of 10 for creativity though. But I have to take away 7 for the improper use of a shower curtain to hide everything behind it. You must completely open it up for full coverage.
Start with the pinion depth shim that was in there and go from there. Your pics show your gears as too deep, probably by about the 20 thou you added to the original stack. Just start with the original .042 that was in there. I don't even use a pinion depth tool on a housing with nothing in it. I'll just throw around 40-50 thou in shims in and take a look. No need to make it harder than it already is.
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With the original .042 the pinion wasn't making deep enough contact with the ring. These are new gears by the way and I already honed out the dummy bearings to set this up. You are right about making this more difficult than necessary as this is the first (and last ) time I will ever attempt this. I ll follow your recommendations and watch the video. Thanks for your input as rookies need all they can get.
Your advice and others seem to be the consensus and Ill follow them. for a 75 yr. old first timer I understand how easy it is to get in over your head with projects like this and I really appreciate all the input I am getting. Thanks.
And don't give up. Mike helped me quite a few times and in the end, not only did I learn alot but I'll have no issues in the event I want to tackle this again. It's all part of it, rookie or not. Stay with it and be patient. My rear went super smooth and the front fought me the whole time. I even ran a pattern, thought it was pretty good but could be better, changed it and ran another pattern, didn't like it and then went back to the one I liked. It's just part of the game.... Always start with whatever the shims were originally.
there was no pattern at all (or maybe some marks on every 10th gear) which led me to believe the pinion was not deep enough into the ring. And when I rotated the pinion yoke the ring only rotated some times with gaps in the rotation, again which led me to believe insufficient pinion depth.
That's harsh. If you look again it's in a shower. Give him the 7 back. OTOH pocojo could pitch his tool to FabRats, that's about how they determine tolerances in trannys and diffs.
Respect to pocojo for diving into diffs. Voodoo stuff.
KennethS
TJ Expert
I am a novice so keep that in mind. In the past I have removed the carrier, placed the shims, then shoved the carrier back in. Had to put the thicker shims on the outside and the thin shims sammiched between them to keep from bending them.
I read the 22 page billavista article and don't think there could be a more informative one out there. It opened my eyes to a lot of things I was doing wrong and will make things much easier going forward. An invaluable help, thanks much.
much less the string diameter divided by two to find the centerline. This is a well done troll job at best!
I thought the word "sammiched" or "sammich" only came from dwellers of Brooklyn NYC. I now stand corrected. Thanks for your reply, and yes I did sammitch them to prevent "foldover".
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