View Full Version : 3.42 to 3.73 in ME 12 bolt

03-05-2005, 05:43 PM
I've recently bought a Moser Engineering 12 bolt w/ Eaton Posi, their 30 spline alloy axles, with a 3.42 rear gear, and c-clip eliminators. I was wondering if the Eaton Posi unit needs to be changed if I were to changefrom 3.42 to 3.73

03-05-2005, 05:52 PM
No it does not.......

Hope that brings a smile.

03-05-2005, 07:23 PM
Hey Tom! hows it going? I think he's still Roaring!!! LOL Hey what the cut off? is it 3.08? take it easy

03-06-2005, 12:53 AM
Thanks, I never really dealt with a rear end before. I'm very much a newbie. But I'm guessing it's not a cheap swap unless I knew how to do it myself?

03-06-2005, 08:46 AM
Most places here charge a couple hundred or less to set one up.

03-06-2005, 06:45 PM
Quick~ 3.08 to 3.90 (unless you include the thick and thin sets that overlap carrier series) then you can include 4.10 on a three series and a 3.73 on a four series....

All~ The going rates are around 200 to 250 for a bench job and between 250 to 300 for in car assembly. If you havent set one up before (or do it for a living in the first place) I wouldnt recommend it......unless you want to take the hit on gear and bearing replacement if you dont get it right the first time. I am not saying that you cannot do it, although it is rather thought of as a 'black art', but if you are familiar with dial micrometers and "rolling preload" in relation to tapered roller bearings......... go for it.

It is a fun thing to learn how to do ! Just make all measurements three times and dont forget to read the break in instructions.........

03-06-2005, 09:48 PM
Well I don't really understand what you meant by a 3-series and 4-series carrier in the quick reply but I'm sure they are the types of posi units you're refering to? So with that I'm defin. not going to do any rear end business myself. Especially for this car.

It's my first car as well as my dream car so for now I want it done correctly.

Someday I'll get a beater (another 67 Camaro perhaps) and do my trial and error on that ;) Thanks for the input

03-08-2005, 08:07 PM
"Series" leans towards the definition of which range of ratios will fit onto a certain 'carrier' with it's specific flandge height. A "three series" carrier will fit ratios from 3.08 to 3.90. The "four series" carrier will fit ratios of 4.10 and up...... with the exception of the 'thick' and 'thin' gearset's, which will fit a certain ratio on the opposite carrier series.