Axle type

[summitflier]

How can I tell if my axle is a "3 carrier" or a "4 carrier" ?

Looking through ring and pinion sets on summit racing and jegs,
I see 3:73 gear sets listed under both type 3 and type 4.

[Sklptrljay]

Originally Posted by summitflier

How can I tell if my axle is a "3 carrier" or a "4 carrier" ?

Looking through ring and pinion sets on summit racing and jegs,
I see 3:73 gear sets listed under both type 3 and type 4.

Not the expert on this, but I believe if it's an original rear end, 3.73's and up (numerically) are a 4.

They now make 3.73's that can fit either, since the most common swap is 3.08 to 3.73.

[racerop]

Here is a good link for information on carrier breaks
http://www.differentials.com/technic...carrier-breaks

[leftybass209]

Pretty much just verify what gears your truck has now. 3.73's and lower are 4 series, 3.42's and higher are 3 series carriers. As stated, most gear sizes can be found for both carriers. Best of luck with your search!

[mjgord51]

Originally Posted by Sklptrljay

Not the expert on this, but I believe if it's an original rear end, 3.73's and up (numerically) are a 4.

They now make 3.73's that can fit either, since the most common swap is 3.08 to 3.73.

Originally Posted by leftybass209

Pretty much just verify what gears your truck has now. 3.73's and lower are 4 series, 3.42's and higher are 3 series carriers. As stated, most gear sizes can be found for both carriers. Best of luck with your search!

Hows right here, Sklptrljay says 3.73's & up are 4"
leftybass209 says 3.73's & lower are 4"

Am I not seeing this right? or what?

[SS Tim]

They are both saying the same thing. Factory 3.73 and lower gears (higher numerically) use the 4 series case/carrier. Where 3.42 and higher gears (lower numerically) use a 3 series case/carrier.

[mjgord51]

Originally Posted by SS Tim

They are both saying the same thing. Factory 3.73 and lower gears (higher numerically) use the 4 series case/carrier. Where 3.42 and higher gears (lower numerically) use a 3 series case/carrier.

That makes since, I knew that LOL LOL mjgord51

[Taibo]

Confused about gear ratios? Go see these guys. That'll help!

[summitflier]

I'm not entirely sure the gear ratio determines the carrier series.

For example....
This page says 3.08 to 3.90 is 3 series.
and 4.10 and higher is 4 series (for cars) but says 3:42 and lower is 3 series for trucks and 3:73 and higher 4 series for trucks.
http://www.jegs.com/p/Eaton/Eaton-Po...363&Ntt=750876

This says it's for GM 12 bolt truck axles and supports 3:73 but is a 4 series.

http://www.summitracing.com/parts/rmg-4902801/overview/

This says it's for GM 12 bolt truck axles and supports 3:73 but is a 3 series.

http://www.summitracing.com/parts/rmg-4900721/overview/

I suppose it's possible that JEGS and summitracing are wrong but...

[mjgord51]

Originally Posted by Taibo

Confused about gear ratios? Go see these guys. That'll help!

MR Taiboo I thought this site/forum is for people sharing information to one another for HELPING some that need a little helping hand. I don't appreciate the hand slapping you just gave me. I didn't think any thing about your comment was of any taste at all ! ! ! mjgord51

[Redline novdog]

My $.02 cents would be spend the $20.00 for a gasket and couple of pints of gear lube to make sure what carrier you have. If the gears are factory the should have GM #'s on them. The carrier should have some casting #'s on it. Before I would order $3/4 hundred dollars of gears/bearings/seals/make sure visually what you have. Get some #'s and if you can't get the info you need on the internet or parts store. Ask the Guys on this site.MOST of them are very knowledgeable!!!

[leftybass209]

Originally Posted by summitflier

I'm not entirely sure the gear ratio determines the carrier series.

For example....
This page says 3.08 to 3.90 is 3 series.
and 4.10 and higher is 4 series (for cars) but says 3:42 and lower is 3 series for trucks and 3:73 and higher 4 series for trucks.
http://www.jegs.com/p/Eaton/Eaton-Po...363&Ntt=750876

This says it's for GM 12 bolt truck axles and supports 3:73 but is a 4 series.

http://www.summitracing.com/parts/rmg-4902801/overview/

This says it's for GM 12 bolt truck axles and supports 3:73 but is a 3 series.

http://www.summitracing.com/parts/rmg-4900721/overview/

I suppose it's possible that JEGS and summitracing are wrong but...

What you are seeing is correct. Since the development of the OEM gearsets and the 3 and 4 series carriers, aftermarket manufacturers have developed gearsets that are thicker and thinner so that you don't have to purchase a gearset and carrier. Currently it's possible to purchase new 3 series 4.11's or 4 series 3.08's, among other oddball combinations that don't follow the OEM rule.

Don't confuse yourself or waste shipping money buying the wrong gearset. If you are certain the carrier is an OEM piece for a 67-72 carrier, the rule as stated in my first post applies.

I hope that clears it up.

[Taibo]

Originally Posted by mjgord51

MR Taiboo I thought this site/forum is for people sharing information to one another for HELPING some that need a little helping hand. I don't appreciate the hand slapping you just gave me. I didn't think any thing about your comment was of any taste at all ! ! ! mjgord51

mjgord51, If you go back to the two posts immediately above mine you will see the humor in my post and the reason it is there. The funny part is the confusion between a numerically LARGER number actually gives a LOWER gear ratio, hence my picture of the three most confused people in our history. SSTim, and Lefty are both correct BUT racerop gave the best answer . A simple deck height measurement identifies the carrier series very quickly. If you look at any ring gear 3.42 and numerically lower and compare it to any ring gear 3.73 and numerically higher you will immediately see why that is true. It would also make it clear that there is no single carrier that can use ring gears from either series 3 or series 4 interchangeably in a Dana differential.

[mjgord51]

Originally Posted by SS Tim

They are both saying the same thing. Factory 3.73 and lower gears (higher numerically) use the 4 series case/carrier. Where 3.42 and higher gears (lower numerically) use a 3 series case/carrier.

Thank you for a clear understanding of the differences, I also Appreciate a straight answer than a belittling picture. mjgord51