installing overdrive in stepdown

Unknown

Hello,I am am looking at a 1949 Hudson ,but it does not have overdrive,but would like to have as I intend to drive it at interstate speeds.In your experence, would it be a big undertaking to install overdrive , or better just to buy a car that does have overdrive. Thank You .

kamzack

I'll wade in here and give ya an opinion. If the 49 is a good solid car to start with and in good running condition and the issue of runnin at interste speeds is your only concern, then I'd install the OD trans. The non OD trans car is usually equipped with a gear ratio in the area of 4:10, OD trans 4:56. Meaning that you'll have lower rpms at speed with the OD.
The down side is that the conversion is labor intensive. In my opinion, It's easier to pull the engine and trans as a unit so that trans can be installed accurately. Input shaft has to line up perfectly as it goes past the throw bearing and cannot be wiggled to slide in. The reason I suggest removing engine and trans from the car is that it's a big challenge to do it with engine in the car. It has to come out and back in through the floorboard. Floor mat come out, seat cushiom or whole seat assembly comes out,and floor section comes out. Then wrestle the trans and bell housing out. It's a 2 man job.
Although the process may sound scary, having the Overdrive is wotrh the effort. With OD 70 to 80 mph, without 55 to 60.
Hope this helps,
Kim
Amatuer Hudson Nut

Park_W

On removing and replacing the tranny, I've found it much easier on the back to do it from the bottom (you still need to remove the floorboard panel, to get good access to the upper bell housing bolts). Taking it out the bottom does mean the car has to be jacked a bit higher so you can get the tranny-bellhousing assembly out from under the car. As for installation, install 3" pilot studs in the two topmost bell housing bolt holes in the block. That'll be a really big help in aligning the mainshaft to the clutch. Use a good shop jack or rent a transmission jack to lift and support the tranny-bell housing assembly. Much easier that way to get everything lined up and slide it into place. And one final tip ... use some wire,string or a spring to hold the clutch lever on the bell housing in place so the throwout fork in the bell housing is all the way back. Then as you work the tranny forward, watch to be sure the throwout bearing is properly aligned with the fork. This is pretty easily seen from the bottom.

As for the peripherals, one non-original thing I recommend is to place the kickdown switch not under the accelerator pedal, but so that your left foot can find and depress it. You'll be surprised how often you'll find yourself around 30 mph, in overdrive, and wanting to accelerate mildly. It's nice to just tap the kickdown with your left foot rather than having to floorboard the throttle. Everyone I've done this for (including me!) has loved it.

Jon B

GDMN, what Kim said is right: IF the '49 you're looking for is a SOLID car, the overdrive installation won't be that big a deal. But for heaven's sake, take a good look at this car, underneath, before you invest any time or money in it. The '48-54 Hudson "Achilles heel" was the perimeter frame, especially from the rear wheels back. Make sure this thing isn't Swiss-cheesed with rust, or you will be stuck with a lot of work (or money, if you take the car to a body man to fix). (If the car is solid in these areas, it won't inevitably rust there, so long is you garage it correctly and maybe spray some anti-rust stuff up in and around there.)

shadetree

50000 mile 3.58/1, rear end, good condition except i used hubs for 54 3.07/1 replacing the 3.58 for better ratio as late 52 and up. $100.00 some replace rear end rather than overdrive duncan, oklahoma may find one in your area, if interested

[Deleted User]

It was mentioned you needed to shorten the front driveshaft. This is not true, just find one out of a car equiped with a Hydomatic. Same one as for overdrive cars,
Roger

[Deleted User]

Look for a 1951 Hornet or first series 52 rear assembly, Auto-matic, 3:51 ratio and just bolt it right in. Better than overdrive. If you want more speed, bolt in second series 52 Hornet DANA rear, same as 53 and 54, 3:07 ratio and drive 80 all day with great gas mileage. Walt.

Park_W

I agree with Tallent R., and remember well my discomfort starting out on a hill in my former '51 C8 coupe with stick shift and 3.07 gears. The 3.07 was fine for the Hydramatic cars it was designed for, which had a lower first gear, but can sometimes be a bit daunting with a 3-speed stick.

Having had it both ways, I conclude it's really a matter of personal preference plus the kind of terrain one usually has to deal with. My (originally) "stick but no OD" Hornet had a 3.58 gear set when I bought it, and I found it was a really nice all-around ratio for driving hilly north Georgia. (I always thought it should have been the standard factory gear for the non-OD Hornets, but I guess they wanted to be sure they could match or beat the Olds 88s from a stoplight). So I agree the 3.58 is a good compromise if you want to keep things simple and not deal with the governors, solenoids, etc. of the overdrive approach.

But out on the open road, many folks using the 3.58 feel like the car needs one more gear. The OD approach gives you the better solution performance-wise, albeit with the extra complications. With OD you get the good start-up gearing and also a great cruising gear with the OD engaged. I installed OD in my Hornet and at first left the 3.58 gears in place. I found the car was a bit over-geared, with some of the more challenging hills requiring dropping out of OD, even at Interstate speeds. I first thought I might go with the factory stick-shift ratio of 4.10, which gives you a nice top gear in OD of about 2.87. But I wanted to do just a bit better than that, so installed the later ('52-'54)Dana axle, which has more available gear choices, and went with 3.73 gears. This has turned out to be just perfect. It seems the difference from 3.58 is pretty minor, but it moves the engine's operating speed and HP up enough to make a pretty dramatic difference in taking the hills. For my combination of local driving in moderate hills and long-distance trips on the Interstates, this has turned out to be an ideal arrangement.

So it's all a matter of what you really want, and how much hassle you're willing to undertake to get there.

Unknown

Hello,Thank you everyone for responding to my overdrive question, I never expected 2 pages of replys!!This will help finding the right Hudson for me. gdmn852

kamzack

You'll find that Hudson folk are more like family than most car gatherings. They seem to do the wave when a Hudson is back in driving condition. Makes it that much more enjoyable.
Kim