[lehnerjc]

i want to replace my factory original 411 gears in my stock rear end
i have been told the 57 housing is different than 55 and 56.
and that those gears will not work right.
is this true.
also where can i find these gears that are no longer being made.

 

[Pops @ Tri-5.com]

@DZAUTO will be your best source of information on this one.

 

[lehnerjc]

@DZAUTO will be your best source of information on this one.

thanks
where are they located
i couldnt find them in my search

 

[Pops @ Tri-5.com]

thanks
where are they located
i couldnt find them in my search

He is one of our members here...By typing @DZAUTO he will be alerted to this thread, when he gets back on the site.

You could also send Tom a PM

 

[hotrodg726]

it's not a they, it's a person here on trifive.com his user name is DZAUTO

 

[Pops @ Tri-5.com]

@lehnerjc I know Tom (DZAUTO) went to the Nomad Convention in Oklahoma with @BamaNomad and @69SHEVL

I'm not sure if the event is over and he is back home or not yet.

 

[KRUNK !!!!]

what gear ratio are you looking for ? Im postive all the rear end center sections will interchange with your 57 housing......I think DZAuto will concur.....I believe not all center sections will bolt into the 55-56 housings.......any 1955-64 will bolt right in, they have for me anyway

 

[gardnerteam]

I just had my 57 Chev Bel Air rear end rebuilt last week. Ring and pinion were stock 3:55 and were Yukon Gear # YGGM55P-355, American made at a cost of $438 for the ring and pinion. Yukon Gears are mostly (NOT ALL I'm told) made in the USA. Whole job of rebuilding the rear end with all new bearings, etc, including axle bearings, new ujoints, etc, and labor was $1800. Cheaper than having my Pontiac rear ends rebuilt.

 

[DZAUTO]

i want to replace my factory original 411 gears in my stock rear end
i have been told the 57 housing is different than 55 and 56.
and that those gears will not work right.
is this true.
also where can i find these gears that are no longer being made.

FIRST,
Yes, the 55-56 and 57 AXLE HOUSINGS (NOT center section) have some differences.
But, the 55-64 removable CENTER SECTIONS are 100% interchangeable. They are also the same as 56-62 Corvette.
ANY, repeat, ANY 55-56 center is a pure bolt-in swap into ANY 55-64 AXLE HOUSING.

This is an AXLE HOUSING.

This is a removable center section.

Also, there are some differences between 55-6 and 57-64 center sections-------------BUT------- they are still physically a pure bolt-in swap into ANY 55-64 axle housing.

SECOND
The 4-series gears and 3-series gears will only mate with a 3- or 4-series internal differential case (NOT the outer case).

Here is a comparison of a posi(left) and non-posi center section.
The part which the ring gear is bolted to is the differential.

LAST
To answer your question.
To go from a 4.11 ratio to any 3-series ratio, it will be necessary to also change the 4-series differential to a 3-series differential.
MY PERSONAL ADVICE, IF THE STOCK AXLE HOUSING IS TO BE RETAINED, DO NOT GO WITH A 55-6 CENTER SECTION. The internal guts are lighter, thinner and weaker than the 57-64 center sections. IF, IF, IF you have a 55-6 center section, and you wish to retain it because it is original to the car, that's OK, BUT, just build it with 57-64 guts.

Here is a comparison between a 55-6(left) and a 57-64 outer case. The 55-6 case has had a posi unit installed in it.
As can be seen the 57-64 case is more robust than a 55-6 case.

Probably your best way to go would be to locate a very good used center section, OR, one which has been professionally rebuilt. For these early rears, the 3-series ratios that were available are 3.70, 3.55, 3.36, 3.08. For hiway driving, the 3.36 (first available in 57) and 3.08 (first available in 59 behind a 348) are the better choices.

 

[lehnerjc]

FIRST,
Yes, the 55-56 and 57 AXLE HOUSINGS (NOT center section) have some differences.
But, the 55-64 removable CENTER SECTIONS are 100% interchangeable. They are also the same as 56-62 Corvette.
ANY, repeat, ANY 55-56 center is a pure bolt-in swap into ANY 55-64 AXLE HOUSING.

This is an AXLE HOUSING.
View attachment 462181


This is a removable center section.
View attachment 462182


Also, there are some differences between 55-6 and 57-64 center sections-------------BUT------- they are still physically a pure bolt-in sway into ANY 55-64 axle housing.

SECOND
The 4-series gears and 3-series gears will only mate with a 3- or 4-series internal differential case (NOT the outer case).,,,,,,

reply as tri five iw not working right

Here is a comparison of a posi(left) and non-posi center section.
The part which the ring gear is bolted to is the differential.
View attachment 462183


View attachment 462184


LAST
To answer your question.
To go from a 4.11 ratio to any 3-series ratio, it will be necessary to also change the 4-series differential to a 3-series differential.
MY PERSONAL ADVICE, IF THE STOCK AXLE HOUSING IS TO BE RETAINED, DO NOT GO WITH A 55-6 CENTER SECTION. The internal guts are lighter, thinner and weaker than the 57-64 center sections. IF, IF, IF you have a 55-6 center section, and you wish to retain it because it is original to the car, that's OK, BUT, just build it with 57-64 guts.

Here is a comparison between a 55-6(left) and a 57-64 outer case. The 55-6 case has had a posi unit installed in it.
As can be seen the 57-64 case is more robust than a 55-6 case.
View attachment 462185


View attachment 462186

Probably your best way to go would be to locate a very good used center section, OR, one which has been professionally rebuilt. For these early rears, the 3-series ratios that were available are 3.70, 3.55, 3.36, 3.08. For hiway driving, the 3.36 (first available in 57) and 3.08 (first available in 59 behind a 348) are the better choices.

reply as tri five is not working right
thanks for a detail reponse
i didnt know about the 348.
and assume according to my info
i have factory rear with 411.
all tri five with over drive have a 411.
i have factory over drive.
the 411 is juat fun to drive
and will not chage it for a highway gear.
the over drive takes care of gas milage.
the 411 ia not manufactured by Motive or by Yukon
according to my info.
but some are laying on a shelf somewhere.
where can i cali .
i assume i have a 4 series differnial being a factory rear.
what you think

 

[lehnerjc]

i have driven a posi car and cant see any difference from mine.
of what what vale is a posi

 

[lehnerjc]

reply as tri five is not working right
thanks for a detail reponse
i didnt know about the 348.
and assume according to my info
i have factory rear with 411.
all tri five with over drive have a 411.
i have factory over drive.
the 411 is juat fun to drive
and will not chage it for a highway gear.
the over drive takes care of gas milage.
the 411 ia not manufactured by Motive or by Yukon
according to my info.
but some are laying on a shelf somewhere.
where can i cali .
i assume i have a 4 series differnial being a factory rear.
what you think

also will the thicker after market ring gear actually fit in my case

 

[DZAUTO]

i want to replace my factory original 411 gears in my stock rear end
i have been told the 57 housing is different than 55 and 56.
and that those gears will not work right.
is this true.
also where can i find these gears that are no longer being made.

Is your 4.11 rear a 55-6 or is it a 57?
It makes a BIG difference!!!

 

[lehnerjc]

57
Factory original
411

 

[mr55/56]

Have you had it apart and sure its a 4.11. I always thought my 56 was a 3.55 until it was a 3.36 and it was not quite 20 years old when I got it.

 

[DZAUTO]

57
Factory original
411

If it is a factory 4.11, than ANY 57-64 4.11 ring and pinion is a direct replacement. The 57-64 models used a SEPARATE differential for 4-series and 3-series gears.
The 55-56 used the SAME, repeat, SAME differential for 3.55-3.70-4.11 gears. The 55-6 differentials were slightly different from the 57-64 versions.

 

[lehnerjc]

Is your 4.11 rear a 55-6 in or is it a 57?
It makes a BIG difference!!!

5557 factory original

 

[lehnerjc]

1957
411 is original
From factory
10 bolt
8.2

 

[56Rick]

FIRST,
Yes, the 55-56 and 57 AXLE HOUSINGS (NOT center section) have some differences.
But, the 55-64 removable CENTER SECTIONS are 100% interchangeable. They are also the same as 56-62 Corvette.
ANY, repeat, ANY 55-56 center is a pure bolt-in swap into ANY 55-64 AXLE HOUSING.

This is an AXLE HOUSING.
View attachment 462181


This is a removable center section.
View attachment 462182


Also, there are some differences between 55-6 and 57-64 center sections-------------BUT------- they are still physically a pure bolt-in sway into ANY 55-64 axle housing.

SECOND
The 4-series gears and 3-series gears will only mate with a 3- or 4-series internal differential case (NOT the outer case).

Here is a comparison of a posi(left) and non-posi center section.
The part which the ring gear is bolted to is the differential.
View attachment 462183


View attachment 462184


LAST
To answer your question.
To go from a 4.11 ratio to any 3-series ratio, it will be necessary to also change the 4-series differential to a 3-series differential.
MY PERSONAL ADVICE, IF THE STOCK AXLE HOUSING IS TO BE RETAINED, DO NOT GO WITH A 55-6 CENTER SECTION. The internal guts are lighter, thinner and weaker than the 57-64 center sections. IF, IF, IF you have a 55-6 center section, and you wish to retain it because it is original to the car, that's OK, BUT, just build it with 57-64 guts.

Here is a comparison between a 55-6(left) and a 57-64 outer case. The 55-6 case has had a posi unit installed in it.
As can be seen the 57-64 case is more robust than a 55-6 case.
View attachment 462185


View attachment 462186

Probably your best way to go would be to locate a very good used center section, OR, one which has been professionally rebuilt. For these early rears, the 3-series ratios that were available are 3.70, 3.55, 3.36, 3.08. For hiway driving, the 3.36 (first available in 57) and 3.08 (first available in 59 behind a 348) are the better choices.

Very good information! Thanks for the photos too! My 56 has a 1964 center section, per the numbers, and it has 4:56 posi gears. I too want to change to 4:11 or maybe 3:70's as the 4:56 are quiet low. I have a 427 BB in the other end, or will have it back in soon, and it's great across an intersection, but not so good for cruising! Have had this rear end in my car for the 50+ years I have owned it. But it sat for 20+ years.

 

[jerrspud]

reply as tri five is not working right
thanks for a detail reponse
i didnt know about the 348.
and assume according to my info
i have factory rear with 411.
all tri five with over drive have a 411.
i have factory over drive.
the 411 is juat fun to drive
and will not chage it for a highway gear.
the over drive takes care of gas milage.
the 411 ia not manufactured by Motive or by Yukon
according to my info.
but some are laying on a shelf somewhere.
where can i cali .
i assume i have a 4 series differnial being a factory rear.
what you think

I had a sm319 (three speed with overdrive) and a 4:11 gear and it was terrible. They put a 4:11 in OD cars so you can start out in 2nd gear and never have to shift while driving in town. I installed a 3:06 out of a 62 car and it's so much better to drive now. I only use the OD on the freeways. as stated... any center section (pumpkin) from 55-64 will fit.

i have driven a posi car and cant see any difference from mine.
of what what vale is a posi

for a car... good in the snow or mud.