Have a 51' Commodore, 262 CU, 3 Speed Manual, believe the rear ratio is 4.11 (welded cover, no ratio tags or markings present). The car drives nicely around town, almost exclusively using 2nd gear to start from a stop, but the engine revs too high in my opinion when on Freeway especially above 55 mph (I estimate at 65mph the engine rev's are approx 3400 rpm). I sure would like to drop the revs. Driving 55 mph is dangerous in my neighborhood.

I've been toying with idea of swapping out the original 3 speed for a later model 3 speed/ with OD tranny (out of a 52' Hornet). But that would entail quite a bit of work and money. Furthermore I'd ultimately be setting aside the 3 speed which is in great shape (recently rebuilt, new clutch, etc.)

I also have a 3.08 rear-end that originally came out of a 54' Hornet (automatic car). It seems to me that the swap of the rear end would be much simpler and cost effective way to achieve the freeway goal. If my calcs are right the engine revs would drop to 2550 rpm.

Has anyone performed this swap? Any leanings you might share are greatly appreciated.

Robert, changing to the Dana 3:08 is a good idea, and not too difficult. With your 262 engine, you may find the 3:08 a bit "tall", unless you're in pretty flat land. But the good news is that with the Dana you can get several other gear sets, and a lot of folks know how to change them out . . . the Dana is used in Jeeps and some others. You may find that a 3:40 to 3:60 be better with your engine.

Park ---I do live on predominantly flat land and only occasionally head to the hills. But I've heard the 3.08 is probably too tall and would definitely tax the clutch especially when starting at the bottom of a hill. Thanks a million for the reminder that the second generation Step-downs sported Dana's whereas the welded cover rears (like the one in the 51') were "Hudson" made. Your idea of installing the Dana and changing out the gearing to + -3.55 is spot on. Sacrificing some off the line acceleration for better & easier freeway cruising is a good trade in my book anymore. Would you happen to know whether the 54' Dana would "bolt onto" the 51's leaf spring mounts and whether the driveshaft geometries are identical? I'll measure of few things but I'd welcome the opportunity to tap into the hard earned experiences of others if out there....Thank you!

Robert, it's been a long time since I did that changeover on my '51, but as I recall, the springs were not an issue. I think there was an issue with the anti-sway bar matchup , but's not a big problem. There are others on the forum who can confirm these or other small issues, but nothing really drastic.

There are differences in the bottom plates and U-bolts, as the housing tube diameters are different, if changing to a later unit you will have to get the u-bolts and plates. Not sure about the drive shaft, but I think the length is the same. I am upgrading my '53 Hornet, which has the ridiculous 4.55 rear end. I'm deciding whether to replace the gears, or the entire rear end. I have an earlier one, and have noted these differences. The Dana is more difficult to change the actual gears as you need to set the pre-load on the pinion and crown wheel bearings, and also need a housing spreader, so I am inclined to use the earlier one. I know it was not as heavy duty as the Dana, but hey, I'm 82, and not going to burn anyone off at the lights!

Geoff --You mentioned being inclined to use an "earlier one." Am I correct in assuming you're considering installing a 1st generation rear end (welded cover) with a lower number gear ratio into the 53'? If that's the case what ratio are you considering? Does someone make new gear & pinion sets for the 1st generation rearend? Thank you

Yes, the welded cover earlier diff is what I am planning to transplant into my Hornet. It has the standard 4.1 ratio, as against the 4.55 in my Hornet presently. I understand these early rear ends had 4.55, 4.1 and 3.4 ratios, the latter used with auto transmission. My Hornet has overdrive. My Jet has a 4.1 and o/d, and is a perfect match, so I reckon the Hornet will be even better. I don't thin anyone has reproduced gearsets for these early models.

The 51 Single range Hydro cars had a 3.58 ratio.

As Tom stated, the '51 3:58 ratio is for hydramatic, is a Hudson built rear end. If you find one of these "3:58 Hogshead", you can simply remove the 4:10 or the 4:55, then install the 3:58. This rear end ratio is also a little tall for the 262 but if tuned right, should pull this ratio just fine. My experience has been when changing to this ratio, you seem to be right in the middle of needing to shift gears when making a long, hill type pull, and down shifting only raises the RPM's and doesn't really add to the pulling power. This is a really easy fix, but does have some down side?, just your preference. Hope this helps.

Robert,

Years ago, I did something a bit more extreme than what has been discussed. I had a 1942 short wheelbase which originally had a 175 engine, and a 4.55 axle. By the time I got it, the engine had been changed to a 212, but the axle was still 4.55. With the long, 5 inch stroke of the 212 engine, I didn't like to drive more than 40 miles per hour.

I decided to put in an overdrive, which helped, but because of the 4.55 axle, I felt that 56 mph was good cruising speed for this setup, but not for interstate driving.

So I measured axles at a junk yard, and found that an 8 cylinder 1969 Mustang axle would fit onto the Hudson axle. I installed this axle. Only the handbrake cables needed modification. The Ford wheel pattern was the same, so the Hudson wheels fit. The ratio was 2.78. By my calculations, this gave an advisable cruising speed of 65 mph.

Soon I removed the overdrive, since it wasn't necessary. Since I did not live in a hilly or high altitude location, the amount of power was acceptable. Driving on big roads was fun, and the car was very quiet (the 4.55 axle had been a bit noisy). However, in city driving, the gearing was such that I would never get out of second gear. Therefore, it was great for long distance driving, but annoying for in-town driving.

For your car, with the 262 engine having a stroke of 4.375 inches, overdrive with the 4.55 axle would give 65 mph. Overdrive with the 4.1 axle would give 72 mph.

Dan McNichol and I drove around the country (starting in Boston, passing North Dakota, Seattle, San Diego, Austin. New Orleans, and back to Boston.) Our 1949 Commodore four door sedan is equipped with a Pacemaker (232) engine, and a 4.1 axle. This would have allowed us to cruise at 80 mph, (because of the 3.875 stroke) but we took it easy and only went 70. The engine is still in good condition. Almost all of the interstate highways have gentle grades, so our small engine in a big car wasn't a problem.

If you stay with the 3-speed transmission, the Hudson 3.58 axle would give a speed of 58 mph, or the later model 3.08 axle would give 67 mph.

As you can see, I am basing my speeds on the stroke of the engines. Often oil burning was caused in the old days by the piston rings wearing in their grooves from running at too high rpm, My original investigation of this started when I noticed that VW Beetles could go 65 mph at high engine rpm but wouldn't burn oil. I discovered that the stroke of the VW of those days was 2.52 inches. This allows a fast engine rpm with slow piston speed. Eventually they would need valve jobs, or the bearings would wear, but they never smoked out the back, like most American cars of the thirties through early fifties.

I hope this information will be helpful.

Per

Per ---Very helpful information ---thank you! I appreciate all of the responses this thread generated thus far. Tapping into the vast experiences of the forum members is a great advantage and very important especially since the pool of knowledgeable Hudson owners doesn't seem to be expanding. 98% of the herd is stuck on Fords, Chevy's, and Mopars. Not a dig ---just the reality. The problem is that Hudsons never were, nor are they now, sufficiently marketed and promoted. The valuable nugget of information on the Mustang rear end and your long road trip were really cool notes. Along these lines a buddy and I have been planning on driving my 53' Hollywood "driver" from San Fran to New York and back again in 6 days. Drive 20 hours/day quick stops for gas, smokes & hoggies. The goal is to retrace a Kerouac and Cassidy "On the Road" trek with GoPro in tow, Facebook, Twitter, and Instagram feeds. We're trying like mad to go during this COVID19 Lock down ---US roads are empty now like back in 1950's. Call out other HET members to meet us at their local gas stations in their Hudsons. Create a scene. Now wouldn't that be beat?! Name the road trip---Fabulous Hudsons Beat 2020 Virus. My wife keeps saying, "No way!, no how! that's crazy!, you better not!!" Talk about throwing fuel on the flame! What do you think?

Arrested? What's your 20 Geoff? New York? Things aren't that drastic here in CA. We're still able to drive our cars without hassle. Most restaurants are closed except drive-thrus. All gas stations are open for business ---cheapest gas I've seen in years, approx. $3.25 for Premium 91 octane. Probably much cheaper elsewhere not subject to ridiculous CA gas taxes. Stay safe!

[quote="Robert Waid" post=25857]Arrested? What's your 20 Geoff? New York?

Robert, Geoff is in New Zealand. Some countries have taken on draconic measures to contain the virus. In the Philippines, Pres. Duarte has ordered police to shoot lock-down violators dead on sight, and one man is already dead on that account. Your brake banjo bolt, Y fitting and copper washers should reach you this afternoon, according to USPS tracking........I had to stand in line out side the post office maintaining 6 foot spacing from others for several minutes before getting in and dropping your package and another package to Oz off. Everyone was in masks and gloves, me included. I fortunately have some N95 face masks from car restoration work, along with nitrile gloves.

Ken ---I didn't realize Geoff is in New Zealand. I must admit I'm a bit surprised about the apparent intensity of control being dealt out. I've been in NZ several times and even Auckland doesn't have any where near the degree of overcrowding of major cities in Asia & Europe, and the US. Anyhow, sure hope this crappy situation blows over soon.

Thanks for sending those parts.

Regards,
Robert