Pinion depth and shims...12 bolt question

[Rusty Davenport]

Taking out a Richmond 5.00 gear and putting in a used US Gear 4.88......the US gear pinion depth has been done away with by a previous owner so I am playing with trial and error even more than usual.....if I hold the same pinion depth as the Richmond gear that came out I will have to add .090 worth of shims.....is that considered an unusual large amount of shims to any of you 12 bolt experts ??? (The pinion head of the Richmond gear is that much thicker......concerns me where to start...... I always read about starting at .035)

[Alan Roehrich]

Yeah, 0.090" of shim is a ton. I'd start with 0.035", and about 0.010" of backlash, and go from there.

[tj310]

I did 2 sets last week .030 .038. gave up on pinion depth setters years ago. ---Trevor PS it's not a 3 series gear going on a 4 series carrier?

[Glenn Briglio]

Originally Posted by tj310

I did 2 sets last week .030 .038. gave up on pinion depth setters years ago. ---Trevor PS it's not a 3 series gear going on a 4 series carrier?

+1 Pattern, pattern, pattern. That's what it's all about.

[Greg Reimer 7376]

Originally Posted by tj310

I did 2 sets last week .030 .038. gave up on pinion depth setters years ago. ---Trevor PS it's not a 3 series gear going on a 4 series carrier?

In my experiences of setting up rear ends,a 3 series gear set on either a 12 bolt or an 8 1/2" 10 bolt, an.030" pinion shim is usually about perfect. For a 4.11 to a 4.88,use either a.031-.032' shim, and with gears in the 5's or a 6.14, use a .033 shim The small pinions need to be set a little deeper in order to achieve a pattern centered on the ring gear. I probably have set up an honest 100 rear ends in my life.12 bolts are pretty consistant in what shim to use.

[Rusty Davenport]

thanks for all the replies, I'm trying to read the paint on the ring gear but that is a little more challenging than I anticipated. All the preloads are perfect, just the mesh torments me......may just put it together and run it !!!!!!!!!!!!! ahahahaahahahah

[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

[Alan Roehrich]

Originally Posted by Rusty Davenport

thanks for all the replies, I'm trying to read the paint on the ring gear but that is a little more challenging than I anticipated. All the preloads are perfect, just the mesh torments me......may just put it together and run it !!!!!!!!!!!!! ahahahaahahahah

Getting the pattern you want on a used set, especially without dimensions, can be difficult. Remember that the settings are the opinion of the guy who ran the Gleason machine on that set of gears. Also, you likely will not easily get the pattern you'd get on a set of Richmond race gears on that U.S. Gear set. It may be near impossible.

[Rusty Davenport]

Originally Posted by Alan Roehrich

Getting the pattern you want on a used set, especially without dimensions, can be difficult. Remember that the settings are the opinion of the guy who ran the Gleason machine on that set of gears. Also, you likely will not easily get the pattern you'd get on a set of Richmond race gears on that U.S. Gear set. It may be near impossible.

That is really interesting....would anyone let me text the pictures of the pattern to them for an opinion ??? Phone number ???