calculating trans pinion yoke clearance

how do i calculate the correct distance between the transmission and pinion yoke? there has to be a formula. if i know my driveshaft length and the suspension travel i should be able to calculate how far the pinion will push inside the trans tailshaft, right?

 

I've never done calculations to determine driveshaft length. Push the trans yoke into the tail shaft until it bottoms out. Pull it back out about 1". Measure center to center on the yoke eyes. That's your drive shaft length. Unless you've got an extremely short driveshaft and very long rear suspension travel, that method works fine.

Bob

 

Similar to bobscogin's reply, my driveshaft shop has me bottom the yoke into the trans and pull it back 3/4 of an inch. Measure from there.

 

thanks! it's a 62 3/4 ton pickup (see avatar) so the travel will be greater than the average car.

i'm ***uming that this measurement is at standard ride height with no load, right?

 

You're likely to wind up running a 2 piece shaft on that truck. A long bed GM truck with 1 piece driveshaft is getting right to the maximum length of what most driveline shops will build. Variables are which transmission you're running of course.

 

this is the way the truck was made. it was fine before the T5 trans swap and is now a few inches shorter. i just want to be sure when we get another shaft made it's going to go into the trans far enough so as not to cause any problems.

 

Where bouts in Texas are you ?

 

i'm just outside of Cleburne which is south of fort worth about 45 miles.

 

****er/Dana lit says push yoke all the way into trans ,pull out 3/4th " . Measure from center of the yoke eye to the center of the eye on the pinion yoke. That is the length the shaft needs to be. This measurement needs to be done with the vehicle's wheels on the ground or axles supported with jack stands setting the way it would be with the wheels on the ground.

 

This has been published in hot rod mags a million times over the last 30-40 years ,,

 

Dragsta,

I'm about 25 miles west of Fort Worth myself. I drive a 63 short bed daily (It's my only vehicle).



I very highly recommend using Ft Worth Gear and Axle for your driveshaft work. They've been doing mine for 20 years now.

 

Ayers: yes, i've already spoken to them. tomorrow we're going to look at that %$$%$^!!! driveshaft again and will take it to fort worth gear and axel for a new tube / balancing/ phasing.

i've got a biker friend in Aledo which is probably close to you. i've been told to buy a new truck but i reply; i'm not going to trade something that appreciates in value for something that depreciates. besides, i love my truck and i love driving it.