I am setting up a completely new 9" rear with Strange aluminum center section, spool and 4.11 Richmond street gears, 69 series. Is this the correct wear pattern? .021" pinion shim and drive side wear pattern.
.018" pinion shim, coast side and .008" backlash. Which one is better for the drag strip and if it is off which way should I go? Thanks
optical dillusion? These are the correct pictures. But upon review they can look weird. It looks like I could go a little deeper with the pinion by about .003" more.
For now it will be strip only. It is a street gear not a pro "soft" gear. Once I finish the car it will have lights, etc. and be street driven very little. No more than one or two nights in BG or the BPG nats. Say 100 miles a year.
I build mine really loose . The third pattern down looks fine but its tough to see from the picture. just try to get a good imprint in the middle and about 20 INCH lbs on the pinion to turn it. I have not set up a street 9 inch R and P in so long. Just go by what Richmonds recomendations are on backlash. My pro gears are about done at 22 runs . We check the backlash and it has grown from 008 to 016 or 17 by then. I am hitting it with a stickshift though. MAKE SURE you are warming up that rear before the first run of the day. I have a heating pad on the rear,trans and dry sump tank and then I fire the car and run it through the gears to warm the rear ,trans and motor. I ALWAYS run synthetic in all three. Just realize that you are slowly peening the gears over. In my opinion used gears are junk. you can never get the pattern the same and thier properties have changed from the heat cycles. Just take it slow . Good luck George
I might go with .015 shims next and recheck the pattern again. Then when I add the sealer on these shims they will not move my pattern to far out. I am running new pinion bearings and I set them up at 10 - 12 inlbs rotating torque with a dail type torque wrench. I had them at 25 and it seemed way to tight. I am setting the backlash at the .008" like it says on the ring gear. I have no way of checking the pinion depth so I am going with the pattern apperance only. Thanks for the help. Got any more advice? Anybody? The last rearend work I did was over 5 years ago on some Rockwell stuff in 18 wheelers. This stuff seems so small. :laugh: I'll take some more pics later.
Im using the big bearing and big pinion -- maybe thats why the difference in Inch/lbs. Sound like you have got it down. I have been doing rears for 20 + years and have always just used the pattern. Good luck george
9 inch pattern Hey Jimmy , It is definetly not .021 shim you are going about it the right way though. .018 looks good. Concentrate on the drive side mostly this side -> (. this is where the car is going to hit hard. Looks good, maybe just a little deeper in the root. Looks like your going with the .015 0r .016 shim and if it is just drag race you could tighten the backlash a bit more too. I run my 8.5 GM rear drag race only at .004 that is .001 under GM specs. The ring gear never really gets a chance to heat up and expand like a freeway driving car would. It is entirely up to you though. Keep racing.... :3gears: and good luck with it. Jim GM JIM DIFFERENTIALS ANYTHING GM mitschke454@earthlink.net
Here is the wear pattern with the .015" pinion shim and .007 to .008 back lash. The back lash is just a little tighter by about .001 to .002" than the other pictures. It doesn't look as good to me as the .018" pinion shim did. What do y'all think?
shims I think .018 is your winner too. could be 17 but I think that will do just fine . Just make sure you check in 3 equal distances around that ring, if they all look the same button that thing up and hit it. Jim
I reinstalled the .018" pinion shim and then worked on getting the back lash right. I checked in 3 places, two are .003" and one is .007". I retightened the ring gear bolts and it is the same. Should I remove the ring gear from the spool and check for high spots with a flat file?
oh boy... Yes I would . Make sure it is real clean. See that is why they say check in three spot around the gear... Good cacth. If it does not come out right and they are new gears see what the manufaturer says or the place you bought them from. if they are used it is entirely up to you...run em or junk em... I am hoping that is just a spec of dirt ...crosing my fingers for you. Jim
Thanks. This is a new set of Richmond gears from Summit. I bought them a while back when I had the extra cash which is before we bought this new house. As I knew money would be a little tighter now. I did have to use grade 8 lock washers with the bolts that hold on the ring gear. The spool is fairly thin and the bolts by themselves were about .040" too long. Is this OK? I never had to use lock washers behind any of the big Rockwell rearends that I use to build. These were provided in the kit with the bearings, etc.
bolts see how far a bolt goes in before it bottoms out with out the washer. Don't air hammer it in just snuge. see if it is the washer thickness ...it should be noticable smaller gap then the washers thickness. Jim The could be bottoming out or there could be metal shavings in the ring gear bolt holes or just dirt too. Jim
I finally got back around to removing the ring gear and cleaning it and the spool and then reinstalling everything. The backlash is still coming up the same. Since I am racing this I kept it on the tight side but it varies from .003" to .007". I have loosened it up and it still varies .003". I have made sure of my positioning of the magnetic base dail indicator (hard to get it to stick to an aluminum hog head! I bolted a header flange up and used it to stick the base to.) I spent about 2 hours measuring and moving and still the same results. You can actually feel the difference when it gets to that spot. I will contact Richmond next. But what will happen if I run it this way? Noise? And what kind?
