Pinion depth and shims...12 bolt question

[SSGT Mustang]

Do you guys get the click-click-click-click-click-click from your 12-bolt rear end gears after a few transbrake launches? I have a 8.8 that still has the right gear pattern (and no cracks or visual anomolies), but makes a clicking noise when I spin the tire. The noise started after about ten, 7000 rpm launches......

[Dirk Olson]

I agree with Glen, Pattern in the key. I assume these are pro gears? .028 to .031 to start, look at the pattern on drive side. I like to be a slight heavy on the toe side to accomidate tooth deflection. Like about .008 on back lash on new set with good runout on spool. If runout is more than .003 you will need to open the backlash up so that you get no tooth binding. This works for me and I will get 200 to 250 passes out of a gear set then cycle them out. Hope this helps.

Dirk Olson
5036 B/S

[Bob Bender]

Originally Posted by Dirk Olson

I agree with Glen, Pattern in the key. I assume these are pro gears? .028 to .031 to start, look at the pattern on drive side. I like to be a slight heavy on the toe side to accomidate tooth deflection. Like about .008 on back lash on new set with good runout on spool. If runout is more than .003 you will need to open the backlash up so that you get no tooth binding. This works for me and I will get 200 to 250 passes out of a gear set then cycle them out. Hope this helps.

Dirk Olson
5036 B/S

x2

[Rusty Davenport]

Originally Posted by Bob Bender

x2

what do you guys mean by "run out" on the spool ????

[tj310]

Run out on the spool , gear not seated flat against the spool . Backlash will vary as the teeth move closer . ---Trevor

[Dirk Olson]

What need to do is check the spool in the case, caps torqued, no ring gear. Take a dial indicator and set it so that you are measuring the surface the ring gear mates to the surface the ring gear is bolted to, rotate the spool, any movement off .ooo is your runout.

Dirk

[Rusty Davenport]

Geeeeeeeessssssss.....you guys are the greatest....thanks for helping an old man. IF I WAS DOING THIS BY THE HOUR THE CUSTOMER WOULD HAVE TO GET A HOME EQUITY LOAN !!!!!!! HAHAHAHAHAHAH Actually it has been really interesting and I am so thankful for you guys helping me along with some others, plus I am not in a hurry. When my patience starts giving out I just cut the lights out for a few days and come back later. Thanks again all of you. Keep the info coming. This website is really a good thing.

[Glenn Briglio]

Originally Posted by Dirk Olson

What need to do is check the spool in the case, caps torqued, no ring gear. Take a dial indicator and set it so that you are measuring the surface the ring gear mates to the surface the ring gear is bolted to, rotate the spool, any movement off .ooo is your runout.

Dirk

+1 Very important to check , if this is off forget about getting consistent backlash and pattern. Also check runout on ring gear after checking spool runout. That is with ring gear mounted on spool torque to the correct specs.

[Alan Roehrich]

Originally Posted by Rusty Davenport

what do you guys mean by "run out" on the spool ????

Rusty, what you'd need to do, is take the gear off of the spool, put the spool back in the housing under a little pre-load, and use your dial indicator to check for any "wobble" on the face of the spool where the ring gear mounts. You don't want to see more than about 0.002", and of course less is better. Sometimes at 0.004", it gets really difficult to set a gear up.

This is usually not a problem. If your backlash does not vary more than 0.002" when checked at 4 to 8 places, 90 or 45 degrees apart, then runout is not likely to be a problem. I find this to be a problem in maybe 1-2 out of 30-50 spools or carriers. If it is a problem, you can often rotate the gear on the spool either 90 or 45 degrees, and solve enough of it to be able to proceed.