Tell me about overdrive

Unknown · March 2006

I found this on eBay. I probably won't be able to grab it, but perhaps there are other sources / alternitives. I'm wondering if I should get an OD trans.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=4625809995&sspagename=ADME%3AB%3ADS%3AMT%3A28

I have a 48 Super Six with 308. I noticed that the engine seems to "top out" at about 60 - 70, not that I plan to drive that fast all that often. It seems to be running pretty fast at that speed. It seems as thought the car would benefit from a "4th gear".

When installed, how does the user operate the type of transmission mentioned on eBay? Does one go thru the first 3 gears, then hit the floor switch for the 4th gear? Also, a reverse "switch"? Sounds interesting.

-Chris

PAULARGETYPE · March 2006

A Bit Steep At That Price I Bought One At The National In 2003 For $150 In About The Same Shape

Jon B · March 2006

Amen to Paul. Hold off on that Ebay tranny. Ask around within the Club, someone will undoubtedly know of one for sale at a fraction of the price, sooner or later. You may then elect to the transmission to a mechanic to check condition of the gears, seals, bearings. (Why go to the trouble to install it, only to have it fail three years later?)

Operation is simple. Normally, everything operates just as your 3-speed does now. However, when you enable the OD by pushing in on the dash knob, you have the ability to shift into OD. When you are in third gear (and traveling over the kick-in speed, which is usually around 30 mph, give or take), you merely lift your foot momentarily from the accelerator. There's a click, and you're in 4th gear. You remain in 4th until you 1) slow down to below about 30, and automatically shift into 3rd, or 2) tromp the pedal to the floor (to pass someone, for example) and the car downshifts into third. Really, it's quite a simple system.

Another way to gain some speed from your car (other than installing an overdrive) is to install the rear end (or entire rear axle) from an automatic-transmission-equipped Hudson, which has a favorable ratio for highway driving.

Hudsy Wudsy · March 2006

I've charged around four hundred dollars each for a couple that I've sold in recent years. But the important issue is this, mine were complete like this one on ebay. A person can spend a tremendous amount of time pieceing together enough of the needed accessories to actually make that one hundred fifty dollar overdrive trans operate. A complete unit requires an under dash cable to engage it, relay, solenoid, ceramic connectors (with or without good wiring), kick down switch, and a longer speedometer cable. The two different cables are common are common enough, but the rest can be a hassle to locate. Besides all of that a buyer has to shorten the driveshaft accordingly. I want add here that any one adding an overdrive to a car that didn't originally have one should absolutely install a ten inch clutch if their car doesn't already have one. A ten inch clutch is all the more important in a car that didn't have an overdrive from the factory because few people ever feel the need to install the correct 4:10 overdrive rear end.

[Deleted User] · March 2006

Drivng an overdrive unit VS non-overdrive is like night and day. Definately get one when you can. Niels

Uncle Josh · April 2006

The 4.56 rear is a better choice with OD unless you're running the interstates all the time. And, you could stay with the 9 in clutch.

Hudsy Wudsy · April 2006

USGRANT7, I probably should have mentioned, if you don't already know, that Hudsons (like most cars) came equipped with different rear axle ratios depending upon the transmission with which the car was delivered. I hope that others will correct me if I'm wrong about the specifics, but as a rule, Hudsons the vintage of yours came with a 3:82 ratio if they had a standard trans. Overdrive equipped cars usually came with a 4:10 rear end and Drivemaster equipped cars required a 4:56. (Drivemaster and Supermatic options were somewhat elaborate self-shifting systems that I won't begin to describe here). The only thing I want to note about these here is that when they were engaged the car accelerated from a dead stop in second gear. (Yes, I said second)! Hence the reason for the rather steep 4:56 ratio. No doubt plenty of cars were ordered with exceptions to these transmission/rear axle ratios for various reasons such as mountainous terrain driving, police/taxi, trailer towing, and just personal preference.

Non-overdrive equipped cars like yours came with a nine inch clutch, whereas overdrive and Drivemaster cars came with ten inch clutches as part of the package. I've seen the ten inch clutch in several Hudsons with standard (non-overdrive) transmissions, however. Perhaps there wasn't mush of an upcharge to have the heavier duty clutch. My point in mentioning that you should install a ten inch clutch was possibily overstated. If you have a good nine inch, use it up! I just want you to know the if your Hudsy left the factory with it's original 262 or 254 and an overdrive, there would have been a ten inch clutch between them, not a nine. Most guys that retrofit overdrives into cars like yours don't bother to change their rear axle ratios to the more appropriate 4:10 and those that do I beleive are very unlikely to go up to a 4:56. I can't blame them. Roads are better now than ever, and besides, gas is expensive and Hudsons love freeway speeds. You should, by all means, check to see which rear you have.

It sort of goes without saying, that 308 is a tad more powerful than whichever engine your car left the factory with. I would want a ten inch clutch behind it no matter what rear end I was running, but especially if I was staying with the original 3:82 rear.

Geoff · April 2006

Definitely go for the 10" clutch if you change to overdrive. I had a '50 Pacemaker which had o/d and a 9" clutch. drive anywhere more than 30 miles and you couldn;t shift gears because the clutch wouldnot release, due to hot swollen corks. Changed to 10", no more problems. And your 308 will definitely handle the 4.10 rear end with o/d - my old Pacemaker did, as does my Jet. I have a 4.1 gearset which I am going to put in my '53 Hornet just as soon as I can. It presently has the stump-puller 4.55. No car needs that low a ratio these days. In overdrive with a 4.1 rear end you have an effective overall ratio of 2.87, giving just under 2000 r.p.m. @ 60 m.p.h. - a very comfortable and economical cruising ratio. Oh, and don't use the kick-down too much with a 308 - I have seen clutch shafts corkscrewed. And I agree, the price for a complete unit is reasonable IF it is complete and working. Driving a car without overdrive is like eating a hamburger without meat!

Geoff.

Unknown · April 2006

I agree, the price is not so bad considering it has everything. The OD relays alone are going for upwards of $100 now. The solenoids are not cheap either. About the only part that is cheap is the kickdown, as a compatible part is still being produced and can be had for $10. My only question is what kind of shape are it's guts? I bought one fro $50, but paid Al Saffrahn to redo the whole thing.

PAULARGETYPE · April 2006

Just A Bit Of Info On How We Install The Elect. Side Of The Overdrive We Get A Hot Wire From The Ing. Switch And Install A Fuse And Then Run It To A Switch Mounted Under The Dash And Then To The Overdrive Sellenod When You Want Overdrive You Flip The sWitch It's Short Cut It Works Fine No Need For All The Other Wiring We Don't Use A Kick Down Switch Or The Govener You Must Use The Cable To Lock Out The Over Drive To Back Up As Is Normal

[Deleted User] · April 2006

PAULARGETYPE wrote:

Just A Bit Of Info On How We Install The Elect. Side Of The Overdrive We Get A Hot Wire From The Ing. Switch And Install A Fuse And Then Run It To A Switch Mounted Under The Dash And Then To The Overdrive Sellenod When You Want Overdrive You Flip The sWitch It's Short Cut It Works Fine No Need For All The Other Wiring We Don't Use A Kick Down Switch Or The Govener You Must Use The Cable To Lock Out The Over Drive To Back Up As Is Normal

i had the same outfit hooked up on a chev transmission that was hooked up to a mopar automatic that was connected to a nissan diesel that was under powered. (what a interesting assembly). i could split 6 speeds before i got across a intersection and the overdrive in 3rd. 3rd. was super on the highway. had the same overdrive setup on my 55 studebaker powered by a 56 packard v8. it was great. i just switched the governor wire to ground with a switch that was neatly mounted on the lower dash.

[Deleted User] · April 2006

My Wasp has the stump puller 4.55 rear end with OD and H-145 308. With most country roads having a 55 mph speed limit, the ratios are just fine and the engine seems happy right on up to 65. At 70, you begin to notice that your engine is humming pretty hard. My '49 without OD, is screaming at 60 mph, and dangerously wound up at 70 mph - 4.10 rear gear- I miss my OD!

There are two advantages to the 4.55/OD setup. 1) You have plenty of OD torque and the kickdown isn't visited unless you are going up a dang steep incline or passing. 2) You can start with ease in town right off 2nd gear, and let the OD shift into 2nd OD, works great for town traffic and lower speed limits. I can hum around town at 35-40mph and never touch the shifter either cruising or stopping/starting. The governor is set to activate the relay at around 20-25 mph with the 4.55 rear end. As the rear ratio gets lower, the activation speed gets higher unless you re-calibrate your governor.

Some time ago, Uncle Josh sent me the gear ratios for the two lever OD tranny, and I've since tried to tailor my expected driving speeds/tire sizes/engine rpms to the conditions I hope the '49 to be in - with an acceptable rear end ratio.

Here are the ratios: 2 lever Borg Warner OD tranny

1st-2.88 / 1stOD-2.16 / 2nd-1.82 / 2ndOD-1.274 / 3rd-1.00 / 3rdOD-0.70

Here is my favorite rear gear calculator: http://www.f-body.org/gears/

It convieniently has enough tranny ratios for all six OD ratios. Just enter your tire size, the six ratios above (I don't know the single lever ratios, perhaps somebody can supply those), and let the calculator help you pick out a rear ratio thats right for you. I'm going to say if you intend to go below 3.92 - definately plan for a 10" clutch.

Modern Dana 44 gear sets will work in the later stepdown rear ends with the removable differential cover. This truly opens up many choices as far as your gearing is concerned. The only other thing to be aware of is that you will have to also buy a new pinion yoke to mate up to your original universal and newer pinion spline.

Happy Hudsoning - In Overdrive!

Mark

Tell me about overdrive

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