transmission question (good one)

[MUDKICKR]

ok guys i have a question, its kinda out there but its a serious one, just want some opinions. i have an ex-cab long bed f350 trk. i was thinking the other day and was wondering if this would work. if i put a reg 2wd c6 in it and with a little driveshaft (like 6"inches if that) and mate it to a zf5 tranny. what i was thinking was building a bracket to bolt to the frt of the tranny and have a bearing in there. have a shaft made to go between the input shaft of the zf5 and the small driveshaft and bolt it all together. i would have the clutch system still in there so all id have to do is bolt it to a shaft sticking out the bracket. keep the clutch pedal in the trk and make the zf5 trans work as well.
the way i see it is it would not only give it overdrive, you could drive it like an auto (no gear changes) but when you need to pull something heavy it would make it a 15 speed trk which would make starting out with hauling heavy loads easier. and i think it would be cheaper then an overdrive unit and you would also benefit with not only overdrive but several underdrive gears as well.
please dont flame me i have been thinking about this for a little while. what do you guys think?

 

[Classicfordguy]

Would you put a flywheel in front of the zf5? That is a realy cool idea, you could then run realy low diff gears if you wanted. You would have nice overdrive choices but it might not get you better gas millege since another 18% or so of your power would be lost in the zf5.

-Rob

 

[RLDSL]

Or you could do like I'm fixing to do here real quick. I'v got a zf5 in the truck and I've got an old Spicer 3 speed brownie on the bench right now. soon as i pop some new seals in it it's going behind the zf5 . The spicer has .85 overdrive, direct , and roughly 2.83 under drive. I'll have available 15 forward and 3 reverse gears. Should be able to pick up a little fuel mileage with the double OD and perfect pulling in the mountains( especially with my 4.10 rear end ) and with that under drive, stuffing the 5er into tough places will no longer be a chore for my left knee

I really wanted to find one of the 4 speed air shift boxes, but there just aren't any around except for the newer double countershaft boxes and they'd be too heavy for a pickup.

 

[Diesel JD]

How hard is it to find something like that Robert? How much money do they usually go for? Its probably not a drop in/bolt up project is it? Would it work behind a T19?

 

[RLDSL]

How hard is it to find something like that Robert? How much money do they usually go for? Its probably not a drop in/bolt up project is it? Would it work behind a T19?

They pop up on ebay every once in an while, and I know one heavy wrecking yard in Oregon that sells used and rebuilt units. Have to do some homework to find one with the right code / OD ratio to give you good gear splits to match your transmission/ rear end. I had to pass on quite a few of the things before the right one came along. After shipping I paid about $500 for this one and it came with the crossmembers and the shifter. Gears and bearings are in perfect shape, I'm just replacing the seals and gaskets for giggles since it's on the bench anyway. Once I get it stuffed in there, I just have to get my driveshaft ends modified to fit . When I picked it up at the freight terminal I ran it by the driveshaft shop and he said no problem matching it to my f350 shafts.

 

[lotzagoodstuff]

Just wondering: what wrecking yard in Oregon are you dealing with?

 

[RLDSL]

Just wondering: what wrecking yard in Oregon are you dealing with?

I bought mine on Ebay.
Anderson Brothers in Oregon usually carries quite a few in stock. here's a link to their tranny stock page Scroll down to spicer Auxiliary. I almost broke down and bought one of the 1241P from them so I could have the air shift, but I just couldn't see hanging that much weight under there, plus the extra contershaft resistance wouldn't exactly help with fuel mileage.

 

[MUDKICKR]

yes i would run the flywheel so i would have something to mount a shaft to for the short driveshaft. what i was really going for was to have my trk an auto trk, run like a 3.55 or so gears in the axles, have 37" tires, and when i need lower gears (for hauling or pulling) use the zf5 for lower gears. i know i would have to have the zf5 in 4th (1to1) until i got onto the interstate and then i could shift into overdrive while driving, (since the clutch system would work) but i was thinking about doing it just for fuel mileage on the interstate, and for lower gears for pulling and hauling, and of course offroading.

 

[t-roymoose]

I have to stop browsing thes forums. I am getting too may project ideas. I did a 2WD to 4WD conversion on my 93 F-350. I have the old ZF5 tranny (2WD one). I have the 4WD ZF5 in my truck now. Would I be able to put the 2WD one in front on the other one and go that route? If I understand you guys correctly that is what you are saying. Andif f I am thinking corectly (it is like 3:40 in the morning), I would have like 15 forward gears (without using my T-case low range) and 5 reverse gears. I have a crew cab long bed so I have lots of room underneth. I think I would also be able to drive with one tranny in 4th (1:1) and just shift the other like normal. Then when I wanted to start messing around I could start shifting like you would a tractor. I should go to bed, my brain hurts.

 

[Exekiel69]

Here is one.

 

[discbrks]

My dad put a 'brownie-box' in an old '72 F-350 with a 390 that he still has. It has a granny-gear 4-speed (the name of it escapes me right now, but all those old 250's & 350's had them), an 18" driveshaft to the brownie box, drviveshaft out the back to the rear end. It gives you 12 forward and 3 reverse. A lot of fun to drive. I drove it to high school some 13 years ago and to see the looks on my friends faces. The BEST part is shifting while in reverse... Main trans in reverse, brownie in "low".. backup a few feet, hit the clutch, grab "direct" on the brownie and backup a little faster.... hit the clutch again, grab "Over" on the brownie and backup even faster. This thread gave me the chills!!! Man that was one cool truck!

 

[discbrks]

granny-gear 4-speed (the name of it escapes me right now, but all those old 250's & 350's had them)

Ah Ha! I remembered. NP435 - New Process 435.... just had to get that out.

 

[Greg Pettit]

A Brownie and a normal trans are two different animals.

A buddy of mine tried this idea with a gasser mid '70's 4wd 1/2 ton pickup.

He ran a turbo 350 output shaft to the input shaft of a Muncie M22.

Turns out the M22 does not like 900 ft/lbs of torque applied to its input shaft.

A diesel would be twice as bad.

Greg