I have been thinking (which is very dangerous) about putting two transmissions in my f3 (when i get to it). Except I would put the second one in backwards. My f3 has 4.88s and a heavy duty 3 speed. I thought I would take a four speed (crash box, spur type, bone cruncher, rock grinder) and use that. This would give me 3 gears of overdrive!! I would not be able to shift while moving but i think this could be a lot of fun. My grandpa did this in his 35 chevy in 1958........ anyone tried this??

 

There was a guy on here who did that with his truck, a 59' I believe. He has a nice write up here: https://www.ford-trucks.com/forums/5...ed-w-3-od.html

I'm glad to see I'm not the guy here who likes the idea! You might see if you can use a later model four speed with synchronized gears, that way it would be a bit easier to shift while moving. Shifting should be doable with that crash box, as long as you rev match the gears.

I've been kicking around the idea of doing this to my 73' for quite a while now, my rig has 4.10 gears in the rear and it it turning quite a few rpms on the freeway, even at 55 MPH. Besides, I like the idea of having two sticks coming up through the floor!

Sam

 

I'll check out that thread, but my first reaction would be that gearboxes are designed with bearings for power flow in a specific direction (thrust loads especially). Hard to imagine that running one backwards would last very long.

As many people with cars/trucks from the '20's thru the '60's want an overdrive that can be added to their existing drivetrain CHEAPLY, I don't know why someone doesn't make up a small gearbox that uses just enough gears to give a 25 - 30% OD ratio. I wouldn't care if I had to crawl under the truck to shift it, as long as I could do it for trips on the highway. $1800 for a Gear Vendors unit doesn't fit with my plans.

 

Advance adapters makes a small gear box that goes between the bell housing and the transmission. They call it their "Ranger OD". It's cheaper then a Gear vendor unit but it's still around $1300-$1500.

 

I don't know maybe I am the one who has lost touch with reality. These prices of $1800 or $1500 for stuff is insane. I was reading about the new create motors and they want $8000 and the author acted like that is cool. Don't these people realize times are tough? I am moving forward on my truck and I would like to add a 200R4 overdrive trans instead of my 350 but a good rebuilt unit is over a $1000....... Well smaller gears in the back is cheaper....Is it just me???

 

Nope not just you. It seems like everything is way overpriced now.

 

It really looks like a cool alternative to OD units.

I imagine that putting them both into reverse would give you one wicked low forward granny gear!! Talk about climbing walls, I bet that would do it.

The Gear Vendors unit, while expensive, seems like a good unit to use. I have been looking at them and at the A4OD to put one behind my 289. I currently have a C-4 with 3:1 rear gears. I can't decide which one to go with because they are about the same price where I have been looking.

 

The tranny shop that I had relied on for years got a big head...He won't touch anything for less than $2000....I don't care what it is, old or new.
LOL we have called him on several different occasions asking about rebuilds on random cars and trucks and his price is the same know matter what! funny thing is, he is always busy! I don't get it...

 

Look for an early (80's) Volvo Overdrive - it's the same thing as the Gearvendors - Originally called Laycock DeNormville Overdrive.

 

Jeff, ask him about the price for a rebuilt Audi, BMW, or even a Honda A/T. I saw in a magazine article, about 15 yrs ago, where an Audi Quattro's tranny failed during their test. The cost for a factory rebuilt from the dealer was over $8k then! A friend with an Acura TL had hers go out, factory rebuilt was $5500. These were both before the dollar devalued, so... Who would put that kind of money into a tranny on a ten-yr-old car?? You see a lot of those high-end cars in U-Pull-It, maybe that is why. Stick shifts for me!!

 

A friend's grandpa did that in a '36 Ford Regular. He needed a lower gear since he had a mixer feed box for cattle on the back. It went too fast otherwise. This was not used on the highway, but in their feedlot. I've heard of doodlebugs with twin transmissions.

Large trucks that have a 5x4, 5x3, or 4x4 use this same concept. The auxillary trans, or Brownies (since most were made by Brown-Lipe years ago) don't have synchronizers. You don't use the clutch to shift them. Once you got the feel for the RPMS, you watched the tach (some guys listen to the engine), foot off the feed, and it would slip into the next gear without a whisper. If you get good, you can shift both at the same time, hence the name mixer sticks. I didn't get enough driving time to do that!

 

I see a lot of these cars get "stolen", "vandalized", or have "undercarriage damage".

 

[quote=ALBUQ F-1;9740880]I'll check out that thread, but my first reaction would be that gearboxes are designed with bearings for power flow in a specific direction (thrust loads especially). Hard to imagine that running one backwards would last very long.

That is why i was going to try the crash box. I have enough of those i could just keep swapping them as they blew up!! Since we know how everyone loves those transmissions they are not hard to come by!! hahahaha

 

I would think that with a little imagineering you could take a regular three speed and mix the gears up enough to make an OD with maybe two OD gears.

I'll try and dig up a gearing calc and play with some numbers.

 

I do like this place...I tried the twin trans thing.... hell ...30 years ago..it worked for a while two things it is hard to line up properly ..and it did blow up after a few weeks of abuse ...damm it was nearly 40 years ago ,in my 50 merkury panel..and yah running backwards made for interesting shifting..it will work.. I just wasn't smart enough to figger it all out just slamed it together and hoped for the best..I couldn't weld didn't machine anything straight..and had no idea about safety...but it was fun!!!