Hello all,

I've owned my 71 F250 "highboy" for about a year now.
This is my 6th Ford truck and I have loved everyone of them; but this one is by far my favorite. 36"x14.5"r16.5", new 2011 mustang Sterling Grey (charcoal) paint, 360 (bore to nearly 390) with Holley 750 DP and new cam and 4 speed trans. It's absolutely brilliant, wouldn't trade it for anything.

This weekend I was driving to work and I broke a U-joint.
It was the U-Joint connecting the shortest of the three drive shafts to the transfer case. I hear it snap and begin to pull over and then I hear an explosion of sorts...

When I got out of my truck I took a look under it to find that while the drive shaft was thrashing around it snapped the tail of my transmission as well as the output shaft about 12" deep into the transmission. So I'm looking at trans options.

I believe I had the stock NP 435 4 speed and would like to stick with a manual. A lower first gear than the 2.99-1 would be nice. Does anyone know if the NP 435 with granny low (6.56-1 i think...) has the same bolt pattern and will bolt to the same bell housing? I had a granny low 4 spd in my 79 Bronco and loved it, it would be nice to have with the big tires.

Or can anyone recommend a 5 speed thats not too much more expensive? Any information would be helpful (including new clutch suggestions) as I have not had a huge amount of experience working on or installing manual transmissions.

 

If it's a Ford np435 it should have a granny- The New Process 435 Transmission - Novak Conversions according to this site the highest first the 435 had was 4:56 to 1, and that was only in GM trucks. If your first gear is that high I think you might have something else- but the only one I'm aware of with a first gear close to 2.99 to 1 is the old 3spd column shift.

Maybe you have a close ration t-19 or something similar? The Borg-Warner T18 & T19 Transmissions - Novak Conversions

Sam

 

My gearing is not that low, but it was extremely low in the Bronco.
I could only reach about 8 MPH in first in the bronco.
The truck is currently gear much higher, I can just about reach 20 MPH.

I was hoping to find something geared lower than I already have.

Does any know if they make bell housing for the T56 or TKO series that would fit a 71 360?

 

Interesting, I don't know what transmission you have in it. Do you have any pictures of it? It sounds like someone swapped in something somewhere along the line, I believe all F250 4x4s 1972 and earlier left the factory with the NP435 with granny gear.

There's an FE bell housing for the TKO, I think quicktime is the company that has it. I don't know if you'd want one though, it has a some pretty high gears for a truck. I think first is 2.87 to 1 or something like that.

What gears are in the differentials? If you have some real big tires on it you might just need to re-gear the axles.

Sam

 

T-19's were first installed in 1979 F350's. Most 4WD's used the New Process 435 (NP435-introduced in 1965) while 2WD's used the T-18 (also introduced in 1965). Some 2WD's also used the NP435.

Warner T-18 & T-19: The shift lever retainer cap threads on/off.

NP435: The shift lever retainer cap has two notches, is retained by two pins that protrude from the shift tower.

Warranty Plate TRANS code: A = New Process 435 / F = Warner T-18.

TKO = Toyo Kogyo (Mazda) 5 speed manual overdrive trans. A "weak sister" first installed in 1977/81 Couriers (rebadged Mazda B series truck), 1983 Rangers, 1984 Bronco II's.

 

Not THAT TKO, this one:

http://www.moderndriveline.com/catal...Ford_small.jpg

A 3.27 first and .68 OD. Not really the usual truck trans ratios.

For a heavy 5 speed OD truck trans for use behind an FE, your choices are mainly limited to Clark transmissions, found in mediums, usually beat to death, or the NV4500, from a Dodge or Chev, with care needed to avoid the 5th gear spline issues in some Dodges.


High Impact - NV4500 5spd

Check the link in post 5 here about the NV4500:

https://www.ford-trucks.com/forums/1...l#post10512673

 

The nv4500/Chevy tranny install is not all that hard in the highboy's. And don't have the rear lock-nut issues, like the long tail shaft ones. BUT it is not with out issues like any conversion, Like shortening jack-shaft about 9",Then moving the cross-member back about 4+" to maintain out put drive-line to rear-end angle. Then Chevy 11" clutch plate & pilot-bushing reamed out to like 3/4" Then the 4wd shaft linkage all has to be all modified. So this is most of what I can think of are the biggest issues. I do have a few pictures and info as, I did the installation. Go the link at the bottom, then to Installing a 5spd NV4500 tranny
..my 2cents
orich

 

Hi All,

Sorry it took so long.
I finally go the truck moved back to my place and got a chance to take a better look. I've also been doing some research.

This is definitely not a transmission intended for the truck...

Looks like a T10... wtf.

Linkage matches the t10, the shift pattern matches the t10 and so does the bolt pattern. Oh, and passenger side says T10. pictures below.
Can anyone confirm my belief from the pics?








Thanks

 

What about switching to an auto trans?
I have a divorced transfer case so I wouldn't have to worry about adapters, just a short drive shaft, like the one I had prior to the transmission explosion.

C6 doesn't have very low gears though. Are there other Ford AT that would bolt up to my engine with lower gears?

 

Yup, that looks like a car T10. Odd that it would be in an F250.

As for the automatic, the C6 is the way to go.

You can get lower gears in the C6, but it is not inexpensive. (E4OD parts are used)

Despite the 2.46 low gear, the C6 has a torque converter that happily slips away at low revs. That makes up for a lot of gear compared to a stick.

Some discussion of the WR C6 from some obscure website I found accidently. I can find more if you think that would be the way to go:

C6 "wide ratio" mod...worth it? - Mombu the Ford Forum

 

85,

thanks for the help.
Do you happen to know who makes a C6 with a lower 1st?
It would be interested to compare cost to the OE C6.

Found reman C6's at drivetrain.com for $743 + $100 for core charge.

I'm definitely starting to consider the C6 as a serious option.
Will it be necessary to get a new flexplate due to the change to auto from manual?

I would assume I'd just look for a C6 with a fixed yoke so I could run a shorty drive shaft to the divorced T-case.

 

Wait, found what I believe you are speaking of.
2.75 first C6 for 4x4 with "remote" T case.

C6 4X4 with Remote Transfer Case - TCI® Auto

 

The WR C6 can be a diy, or a shop that is rebuilding it if they know the right parts.

About 1/3 of the way down the page here:

C4 C6 Performance Transmission from PATC, C6 Transmission

About $250-300 in parts from them if I'm reading it correctly.

Yes, you need a flexplate for your engine, the flywheel you have now will not work.

You need to check the overall length of the C6 to determine if it will work. Some have a fairly long tailshaft housing. Changing that requires a full teardown btw.