Setting up a Pontiac Olds 9.3. This is the best pattern I've gotten, however, I have .058" of a shim pack. Is that too much? Does the pattern look right? Backlash is at .010". Thanks in advance for the help. Do you really care what I used to post this message?
Thanks for the help guys. This is my first rodeo with gear setup. I decreased the shims to .03" and tightened the backlash to .006". This is the pattern I got, the problem is that I cannot get the coast side to move off the toe no matter what I do. Am I missing something else? Do you really care what I used to post this message?
I would give it more back lash .006 is too tight. On some gear sets you may not be able to change where the pattern is located on the ring gear. Make sure you put a bunch of load on the ring gear when you turn your pinion to check your pattern and run it a bunch of laps on the gears to check your pattern if that makes any since. When I make changes I will use a different color making die to help see what changes I have made. I would like to see a better picture of your last pattern.
Hey guys, sorry for the late reply, but here is where I'm at as of last night. I went back and started over. The pattern below shows a .023" shim with .011" backlash. Looks like it still wants more shim. Any suggestions? Damn coast side still won't move off the toe, I think I'm going to have to live with it down there. Do you really care what I used to post this message?
Thanks Vicky, I've been using those illustrations, as the ones in my book are a little limited. Any ideas for moving the coast side off the toe or am I stuck with that? Do you really care what I used to post this message?
Looking at your pics, its text book congruent and needing to increase the pinion shim thickness. Having a reamed set up bearing makes this a whole bunch easier,
I do have a setup bearing otherwise I would have already thrown the damn thing through a window already! I'm going to try going up to a .025" shim. If I can happy up the drive side, I'll live with the coast where it is. You can see in the first pics, where the shim pack is too thick that the coast won't move. Do you really care what I used to post this message?
Have you seen this Video? Watch it a couple times in order to catch His reference of in and out. Be sure to Read his comments too. You really need to get the drive side pattern to move down. In order for that to happen the pinion needs to be "deeper into the ring gear" and that's done by adding shims. In your first set of pics, I see the back lash off, and the pinion being in the right zip code. This is a dance, and just like any other dance it's a series or repeated steps.
Neat video. At the end, he says there are some gears that don't behave as they should, and he doesn't know why that is. This looks like one of those gear sets. If it's not a race car, it's something you're going to drive, you might want to find some other gears, or at least be prepared to listen to some noise. It might be ok, it might not. Do you know the history of the gears?
Gears are brand new from Fabcraft. And since I can't afford different gears, I'll have to live with it. Do you really care what I used to post this message?
Concentrate on getting the contact in the correct position on the drive side, with the correct backlash. At that point, you have to live with the coast side position as it is - that's the way the gear set was made. The contact position should be centered on the tooth, slightly towards the toe end of the tooth and have no hard concentration marks either towards the top or flank of the tooth. Also, make sure the serial numbers on both pinion & gear are matching, just in case parts were mishandled in shipping or something. When the gear set is produced, there is an amazing amount of work to do to get the contact in the test machine in the correct position - cutters have to be shimmed, cutting machine settings have to be adjusted, consideration for spiral angle change after heat treatment have to be considered. It's a time and labor intensive operation and some manufacturers do a better job than others. My expertise? I spent 40-years working for the machine tool manufacturer that produces the majority of gear manufacturing machinery and spent time working in the development shop, heat treat, customer training and visiting customers as a Field Service Engineer to assist with gear manufacturers gear development problems all over the world. I've assemble hundreds, if not thousands of ring & pinions in my life. Take it for what it's worth - just trying to help. -Bob
I will talk to Fabcraft, but I want to play with it a little more first as I'm sure inexperience is playing a role here as well. There is no oil slinger on this rear, so no problems there. I really appreciate the advice guys, I really want to learn to do this on my own. Do you really care what I used to post this message?
Going through some Packard gear research and the slinger thing came to mind as well. And also, from what I see there, more shim required then set the lash. Aside from that is there a depth dimension etched or stamped on the pinion? That number is measured from the axle (ring gear) centerline. While the mack daddy set up tools are awesome in this regard you can measure that pinion hgt from the parting line of the carrier bearing caps to get within a few thou of the number. Less trial and error. Also, very sage advice about good resistance when rolling it for pattern marking.
Ok, then forget trying to actually set it up just for now. Learning has a cost, you can spend $ and be taught, someone can spend $ to train you, or you can spend time teaching yourself. Throw big shims at it and see if you can get the pattern to swap. Play with it and note what happens with your changes. Keep shimming until it gets worse the opposite way then start coming back. Work your way into smaller shims for perfection. Don't get pissed when moving the pinion changes the backlash
31Vicky- Thanks for the video, it was a great explanation. I already have learned a great deal, and will probably learn more as I keep pulling it apart and putting it back together one f#$%#$% shim at a time. TagMan- The serial numbers do match, and thanks for the insight into how these gears are made. Highlander- I'll try the using the checking distance next time (at least estimate it without the proper tools). As far as the using resistance when making the pattern, I wasn't doing that at first, which is why I went back and started all over again using a .019" shim and trying every backlash on each shim. I'll keep on this and keep you guys updated with my progress. Hopefully it will help someone else out too. And again thanks for all your patience and advice. If your ever in Jersey, I'll buy you all a beer or 12.
Never trust the carrier bearing parting line/surface as the center of the bearing, check to make sure...I was changing a gear set in a Dana 60 in a brand new [74'] Dodge van and although I had a pinion depth setter that worked off the bearing cups just out of curiosity I checked the parting line; one was .050 off , the other at .047.!!. Don't remember in which direction but may have been done on purpose to aid in installing shims..
If the side bearings for the carrier are threaded then the parting surface should be close. Dana 60s are a different breed that requires preload to shim the carrier bearings. 9" Ford, Mopar 8 3/4, 8" Ford, even 10 and 12 bolt Chevy/GM are all very near center. I'm guessing your oldie there has threaded adjusters? And to emphasize a bit, it's a reference point. Knowing this in advance you can check the difference of where the old pinion is vs the hgt number and create a baseline. If it's etched (just a number pulled outta my ass) 4.870 and you measure 4.900 then your baseline is -.030, and again, THIS JUST TO GET YOU CLOSE, not the end-all number. Conversely, if you measure 4.865 you can probably consider the centerline dead on.
There can be no such thing as "too many shims" or "too thick a shim pack". It is either shimmed properly, or it is not.
Good info all around, thanks guys. Gimpy- thank you, I was getting nervous as the shims started to pile up. I talked to Dave at Fabcraft, he told me it is rare for a P/O 9.3 case to need more than .014"-.019" of shim, so I'm definitely not out of the woods with this gear set yet, but I'll keep at it and see what happens.
You coast pattern indicates you need to add more shims. The pattern did move closer to the center after you added a shim, you just need to add more. I have setup hundreds of gear sets but one comes to mind....I was given a chevy ring gear and an oldsmobile pinion gear (same ratio) and was able to set them up, they lasted the 25 lap feature. (note: they are cut at a slightly different angle)
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