Driveshaft questions

[spartman]

Can you guys help me?

I need to know how long the front drive shaft is from the tranny to the carrier bearing.

I need the measurements from a stick shift setup.

I got a drive shaft from an auto but it turns out to be to short.

I'd appreciate any help you guys can give.

[AlleyCat]

I'm guessing you're having a shaft made? If so and your trans has a bolt on yoke then measure the distance between the center of a u-joint cap on the trans yoke and the center of the carrier bearing bolt holes.Take that measurement and the automatic shaft to the driveshaft shop.They can build it from there.

[cdherman]

To add: measure with the vehicle on the ground, not jacked up by frame etc.

If its to live its life heavily loaded, then some shops will even have you load it, and then measure.

[spartman]

What I hope to only have to do is get the rear shaft cut down.

I am hoping that the front shaft will be stock since the distance from the tranny to the carrier bearing shouldnt have changed any.

I need to know how long that front shaft is stock so when I go back to the yard to swap mine out I can more easily locate the proper driveshaft measurements.

[AlleyCat]

spartman, unless you've changed the wheel base or moved the carrier bearing mount the rear half of the shaft is the same with stick or auto.

[spartman]

What I am doing is putting a 2pc driveshaft into my swb truck.

so no matter what the rear shaft has to be cut down.

The carrier bearing is gonna stay in the stock location.

I got a driveshaft from a bump that had an auto (the only one in the yard) and I thought the front shaft would be long enough.

It was not.


So since I will be needing to go back there I will have to try and get one from a dent so I need to know how long the front shaft is on a bump with a stick.

That way I can go out there with some idea of what to find.

I took a measure of what it should probably be on mine and it looks like about 30 inches give or take a bit.

[willowbilly3]

So you need the measurement of the front half of the driveshaft from a standard shift. That don't sound too difficult. I will see if I can find one, wink wink

[Wes]

Spartman have you considered the angles your rear shaft will be running ? any thing much over 2 degrees is going to cause you grief. Weird vibrations, pinion seal bearing wear, u- joint failure. both front and rear u-joint angles should be the same. why the 2 piece for your swb truck ?

[spartman]

The reason being is that I cannot seem to find a fixed yolk driveshaft long enough.

I am not sure why this is but it seems like anything over about 40 inches and they made it a 2 pc shaft.

If I could find a T-18 or a NP435 with the longer output shaft on the tranny Id put that in the truck in a heartbeat.

[Wes]

Ahh yeah now that you mention it I don't recall seeing a fixed shaft that long either. I had to lower the center support bearing on cheby that was lifted 4" to improve the angles.
I don't have a 2 piece ford to measure for ya. good luck let see what ya come up with

[cdherman]

The fixed shaft in my 65 (same driveline as yours I think) with T18 going back to a 9" rear, in SWB, was clearly more than 48".

I think you should keep looking or alternatively, have a new one made up. Here in KC, I found a fellow to make up a new drive shaft for $200 but it was for a slip yoke tranny. Behind a tranny with a fixed yoke, you obviously need the slip in the drive shaft. I assume that would cost more to have made up.

The part about angles is very correct. If the carrier is too far back, the angle will be nasty. The guys with radical lifts run into this problem all the time. The end up chewing up ujoints and getting vibration often.....

[spartman]

I do have a fixed yolk driveshaft from a chevy that I was going to use but its was to short.

I roughly measured the distance from the tranny to the rear and it was about 69 inches or so.

How would one determine if the angles were to far?

[cdherman]

69 inches? That seems very long (almost 6 feet) for a short wheel base truck. What kind of tranny is this? Did you do some sort of custom something and move the engine forward as well?

There are tools made to measure the angle and also general guidlines. Do a google search for driveline angle and youll get some hits with diagrams etc. Zero degrees is of course straight, 2 degrees is not that much -- I thought the acceptable was more than that, but there are limits.

[Wes]

for a cool write up on drive shatf angles check this link
http://classicbroncos.com/pinion_angle.shtml

[spartman]

The tranny is a T-18 that I pulled from a 1967 LWB 2wd F-100 truck.

I will have to go and remeasure the distance but IIRC thats what it is.

I have not moved the engine or tranny from the stock location, in fact the mounts are bad and the whole thing has actually moved back about an inch or two.