rear end gear ratio

[Deleted User]

can anyone that posts here tell me the gear ratio that would have probably been in a 1951 hudson hornet that had the hydromatic in it?

[Deleted User]

3.07:1



That was the standard rear ratio for the Hydramatic tranny.

Unknown

From what I was told The 3.07:1 is for the dual range hydramatic which came out for the mid 52's. The early 52's and the 51's used a single range hydramatic which has a 3.50 something to 1.



If the number tag is still on your differential you can determine the ratio. The number on the tag is a fraction one number over another, divide the bottom number into the top and you will have the gear ratio.



This what Ken Schulte told me when I was trying to determine mine.

Unknown

As I remember the Hudson built rear ratio was 3.54 to 1 with hydramatic. 3.07 to 1 was the Dana 44 rear.

[Deleted User]

Yep, Ken Shulte's information is correct.



I don't have all my Hudson rear end info at hand, my Dad has it "borrowed".



I think the Hudson rear ends also had a 3.:07 option pre '52 (Dana). But, the lower ratio is specific to the dual range.



Mark

Unknown

SRCraftsman2 wrote:

From what I was told The 3.07:1 is for the dual range hydramatic which came out for the mid 52's. The early 52's and the 51's used a single range hydramatic which has a 3.50 something to 1.



If the number tag is still on your differential you can determine the ratio. The number on the tag is a fraction one number over another, divide the bottom number into the top and you will have the gear ratio.



This what Ken Schulte told me when I was trying to determine mine.

This is interesting. I've heard talk about people changing the gear to a higher end ratio to compliment today's highway standards. Our '52 must be one of the later ones with the 3.54:1, as "Doc" will cruise all day at 75mph-no problem.



Russell

[Deleted User]

thanks for the information, the question is raised because my 51 now has a TH350 transmission coupled to a 350 chevy engine and it seems that when I de-accelerate it drags down, much the same as on a standard transmission when in second gear you let off the accellerator, I was hoping that it had a gear ratio that would give me better gas milage

rambos_ride

billjharris wrote:

thanks for the information, the question is raised because my 51 now has a TH350 transmission coupled to a 350 chevy engine and it seems that when I de-accelerate it drags down, much the same as on a standard transmission when in second gear you let off the accellerator, I was hoping that it had a gear ratio that would give me better gas milage

So in 3rd its really a noticeable drag down as you described? That sounds more like somwhere between a 3:7 - 4:11 ratio

Course I don't know Hudsons that well yet but I had a 307/powerglide 2:93 gears (one-wheel-wonder - no posi) stock in my 68 Chevelle - it would do 60+ in first gear no problem - I called 'em Moon Gears

Then put a mild 350 and TH350 with the same "one-wheel-wonder" rear and it pulled a respectable 14:60 in the 1/4 mile - barely shifted outta 2nd before I hit the lights

[Deleted User]

I'm still working from memory as I haven't retrieved my hardcopy info.



The Hudson rear ends (pre-late '52) had a 4:10 ratio for non-OD, 4:56 ratio for OD, and an optional 3:55 rear ratio for non OD. For Hydramatic trannies, I think the ratio was 3:08.



The late '52 to '54 rear ends were Dana 44's. The same Dana rear end found in modern Vipers and throughout all the Mopar muscle cars. You can tailor the rear differentials to whatever you like with "off the shelf" Dana 44 pieces. Ring gear&pinion as well as any of the "locker" options out there for Dana 44's - will fit in the Hudson/Dana rear ends just as easily as a '68 Dodge Charger.



In the other forum, Park Waldrop mentions ordering a new ring gear and pinion setup and gives the address of a reasonable supplier. To me, this is a highly desirable rear end as it may even be possible to retrofit flanged axles in lieu of the "tapered" axles in the rear end. The bearing retainer is the only detail to work out, axles can be had in about any length imaginable to place the flange at the same location for the brake hub. Its amazing how "standard" the Dana 44's dimentions are, relative to the bearing retainer bolt pattern and brake plate bolt pattern. I just haven't gotten around to dedicating alot of time to this aspect of my project yet.



The Dana/Hudson rear ends were: 4.55 for OD, 3.58 for non OD, and 3.07 for the Dual range Hydramatic. It was a pretty popular option to have a non-OD rear end in an OD car.



My Super Wasp has the 4.55 w/OD transmission. While that is LOW!, it does have a pretty nifty aspect. In town, it will start off in 2nd easily and make an OD shift into high 2nd. This makes it possible to operate in town without shifting the transmission manually. Only problem is, you have to remember to clutch it when approaching a stop - you'll swear your driving an automatic otherwise.



Mark

rambos_ride

`Hudsonator wrote:

I'm still working from memory as I haven't retrieved my hardcopy info.

The Hudson rear ends (pre-late '52) had a 4:10 ratio for non-OD, 4:56 ratio for OD, and an optional 3:55 rear ratio for non OD. For Hydramatic trannies, I think the ratio was 3:08.

The late '52 to '54 rear ends were Dana 44's. The same Dana rear end found in modern Vipers and throughout all the Mopar muscle cars. You can tailor the rear differentials to whatever you like with "off the shelf" Dana 44 pieces. Ring gear&pinion as well as any of the "locker" options out there for Dana 44's - will fit in the Hudson/Dana rear ends just as easily as a '68 Dodge Charger.

In the other forum, Park Waldrop mentions ordering a new ring gear and pinion setup and gives the address of a reasonable supplier. To me, this is a highly desirable rear end as it may even be possible to retrofit flanged axles in lieu of the "tapered" axles in the rear end. The bearing retainer is the only detail to work out, axles can be had in about any length imaginable to place the flange at the same location for the brake hub. Its amazing how "standard" the Dana 44's dimentions are, relative to the bearing retainer bolt pattern and brake plate bolt pattern. I just haven't gotten around to dedicating alot of time to this aspect of my project yet.

The Dana/Hudson rear ends were: 4.55 for OD, 3.58 for non OD, and 3.07 for the Dual range Hydramatic. It was a pretty popular option to have a non-OD rear end in an OD car.

My Super Wasp has the 4.55 w/OD transmission. While that is LOW!, it does have a pretty nifty aspect. In town, it will start off in 2nd easily and make an OD shift into high 2nd. This makes it possible to operate in town without shifting the transmission manually. Only problem is, you have to remember to clutch it when approaching a stop - you'll swear your driving an automatic otherwise.

Mark

Thanks Mark - that sounds more like what Bill might be dealing with in terms of his gear ratios and the behavior he is outlining

Anything above 4:x in gear ratios would not be "highway" friendly without an overdrive at least - GRrrreat for drag racing and seeing who can get to the next stoplight the fastest! :eek:

Unknown

The Hudson rear ends (pre-late '52) had a 4:10 ratio for non-OD, 4:56 ratio for OD, and an optional 3:55 rear ratio for non OD. For Hydramatic trannies, I think the ratio was 3:08.



The late '52 to '54 rear ends were Dana 44's

.



Mark:



Were does the Spicer rear end fit in? Was it used between the Hudson rear end and Dana or is it the same as the Dana?



The rear end in my 52 Commodore is a spicer since the rear cover plate is removable. I have a dual range hydramatic, with a tag number of 43/14, which gives a ratio of 3.0714 etc.:1



If the Spicer and Dana are different, how do you tell them apart?



Didn't the 51's and early 52's with a single range hydramatic have a rear end ratio 0f 3.54:1? Wasn't this ratio needed to have the engine help slow the Hudson down going down long hills, the dual range hydramatic could use a higher speed rear end because the driver could manually pull the transmission down a range when going down a hill.



If billjharris has a 51 with a single range hydramatic which should have a 3.54:1 ratio, would that not give him the engine rev's he is experiencing and swapping to a later rear end from a dual range hydramatic improve his gas milage. Also woundn't changing the rear ends be an outright swap?



I've been away from Hudson's and cars for a long time and I am just trying to clarify some points I may need in the future.

Unknown

The Dana and Spicer are one and the same. Later on it was noted as Dana/Spicer. The Dana 44's which were used in the '52s and later were used on a variety of vehicles. Changing the ring and pinion is a pain as it has to be done in the housing and the lash is adjusted by pinion shims but there are a multitude of gear ratios available.



Noted in an earlier post is a bit of misnomer. The Dana/Spicer rear end was utilized by Chrysler products throughout the 60's muscle car era but the really big block cars used a heavier version (Dana 50 for 383 and single carb 440s and Dana 60 for the multicarb 440s as well as the hemis). The Dana 60 and Dana 70 were used by Ford and Dodge for many years in their 1 ton trucks.



The Dana 44 is a good rear axle and gear ratios as well as other parts are readily available. I would swap a '52 or later axle into an earlier stepdown to avoid the tapered bearings used in the Hudson housing.