hey all- does anyone know if you can mix a ring gear from one set and a pinion from a different set? Like if you needed a specific ratio for a certain application and nobody offered that exact ratio, could you just use any ring and any pinion with the necessary teeth counts? ie- if a 4.10 is 41 ring and 10 pinion teeth and a 3.23 is 42 ring and 13 pinion teeth, can you use the 42 ring and 10 pinion together to get 4.20? Well thanx for any ideas

 

No, you can not mix ring and pinions, not even within the same ratio.

Miles
Diff Solutions

 

alright, next question then- does anybody know if any companies or shops make custom ratios for gm 7.625" or 8.5" rears other than the usual ones (ie- 3.42, 3.73, 4.10, 4.56, etc)? This is for my full-time AWD S-10 and I'm trying to mix 17" wheels front and 18"s rear (sorry not necessarily f-body related, but nobody on any of the other boards had any ideas). Anyways I know I could just put smaller tires on the back so they're all the same size, but what fun would that be? Hopefully I'd like to stay somewhere around 235/40/17s front and 255/35/18 rear and the front diff ratios are limited to (as far as I know)- 3.42, 3.73, 4.11 and I've been told 4.56 but never seen those personally. The rear is the stock 7 5/8" but I could change to an 8.5" if I need to. Well thanx again for any ideas

ps- actually if anybody knows where to get odd ratio sets for the 4wd S- truck front 7.25" diff I'd definitely check that out too

 

there is no suck thing as a custom made gear set, there are only a limited number of ratios that would work, or be pratical. notice that all gear set teeth count are prime numbers? it's done for a reason. i guess you could come up with a combination that isn't made but i doubt if it'd be worth it or reasonable to make.

 

The ring and pinion are lapped to mate each other.So say you and your buddy each have the same 10 bolt rear end with 3.42:1 gears.You can't use his ring or pinion because they weren't lapped to mate each other...
Hope that makes sense........

 

Yea, There is a special set of 3.70's out there (10 bolt 7.5). I think they have 7 teeth on the pinion and 26 on the ring. Something close to that. I've seen'em on Ebay a few times...look beefy