Driveshaft length

[huntsg]

I'm getting ready to get a new driveshaft from PST and I need to know the length of a stock shaft. I measured mine at 56 3/8" from the metal disk behind the yoke to the back of the transmission where the input shaft goes. Does this sound right?

 

[1KWIKSIX]

I'm getting ready to get a new driveshaft from PST and I need to know the length of a stock shaft. I measured mine at 56 3/8" from the metal disk behind the yoke to the back of the transmission where the input shaft goes. Does this sound right?

I'm not 100% sure, but if my memory serves me correct, think is should be 51 -1/4" from centre to centre of U joint on yokes?

 

[mikestertwo]

That seems to be a bit long. Assuming you have a 8-1/2" rear it should be in the range of 51-3/8" to 51-1/2". You measure center to center on the U-joints.

 

[TurboTnZ06]

I got a 3.5 inch alum shaft from PST. They had me measure from the end of the tailhousing to the front of the axle housing (with the car on the ground, no jacks) since I upgraded the joints as well. This is the most accurate and they can give you the right piece if upgrading both joints. Mine was around 57 1/4 for that measurement, but that is from memory and not sure how accurate my memory is these days. Basically it is seal to seal for PST measurement. It's a two man job to measure it under the car like that.

 

[49-blues]

If you go on Denny's driveshafts they have a printable form and instructions how to measure properly- I think it's from the back of the trans housing to the front face of the pinion yoke.

 

[Pronto]

Measuring depends on if you are replacing the pinion yoke with the biggie. See the instructions on any of their websites.

 

[huntsg]

Yep. I'm replacing the pinion yoke with the biggie. So I came up with 56 3/8" based on the way they say to measure. The tranny is a 200r4 and the rear end is stock. Does that sound right and how accurate does it have to be? Can it be off 1/2"?

 

[Pronto]

Right off Denny's website:
http://www.dennysdriveshaft.com/img/File/how_to_measure_diagrams/c.html


How much of a mistake am I allowed in my measurements?

NONE!!! Its too easy to get it right so why do it wrong. Never use the hook on the end of a tape measure to measure a u-joint. It is best done with a good steel machinists ruler or a dial caliper but if those tools are not available any good ruler will do as long as it reads down to 1/16 of an inch. Use the tape measure hook for the overall length only!​

 

[just plain john]

If I was buying Vendor X's shaft, I'd measure it like Vendor X says. Vendor Y might do it differently. Btw, what's a ballpark cost on the entire thing, 1350's included? I assume that would include the pinion yoke too.

 

[huntsg]

From PST the cost is $459 for the 3.5" diameter driveshaft and $115 for the pinion yoke. Yes its 1350.

 

[Dennis Kirban]

We just started to carry aluminum 3 1/2 driveshafts already had them speced out by sending a stock one so they have the figures in their system. Meaning going from a 200 4r to a stock 8 1/2 inch rear/. Stock shaft is 3 inch this is 3 1/2 meaning 1/4 inch wider all around. May or may not work with various aftermarket driveshaft loops. Company making ours been making them for 20 years. Set up will handle 700 hp to 750 hp you shave about 3 lbs in weight...balanced within the weight of a single postage stamp. Has spicer sealed universal joints and new yoke all assembled made in the USA. Its aluminum alcoa 6061 material which is what they use for driveshafts. I got the specs at work on the joints....pretty confident it is probably similar to what you are getting quoted on. Looking at 3-4 day turn around as we just last week got this project off the ground. Better welds, never rust, lighter weight, plus its not 25 plus years old.....

Looking at $439.95 and $19 shipping....

dennksirban@yahoo.com

Interesting how they explained to me how GM balanced their driveshafts by welding a weight on and if it was off they then weld another weight on the opposite side to correct it. Also GM is not nearly balanced as exact as these are...pretty impressive when its balanced within the weight o a single postage stamp. If only wheels where balance that close!

 

[huntsg]

Dennis, that sounds great. Do you also have the pinion yoke?

 

[Dennis Kirban]

Dennis, that sounds great. Do you also have the pinion yoke?

The driveshaft comes complete ready to drop in new front yoke (to trans) is included new rear universal joints included all assembled in other words a complete driveshaft like you would remove from the car.

denniskirban@yahoo.com

does not include rear pinion yoke if that is what you are referring to. That is a part we do not carry.

 

[87gnguy]

Also when measuring the driveshaft length, the Denny's website says to measure it with the full weight of the car on the suspension. When I talked to Cliff at PST and gave him the measurement of 56 3/8, he commented that the stock measurement he had was 56 3/4. He didn't know if that measurement was with the load on the suspension or off. I would think his measurement is with the load off because wouldn't you get a slightly longer reading measuring that way?

 

[87gnguy]

The driveshaft comes complete ready to drop in new front yoke (to trans) is included new rear universal joints included all assembled in other words a complete driveshaft like you would remove from the car.

denniskirban@yahoo.com

does not include rear pinion yoke if that is what you are referring to. That is a part we do not carry.

Dennis, I tried calling you today because we need to get these shafts and I'd rather buy from a vender but I had a couple of questions. I'm emailing you my phone number. Thanks, Casey

 

[huntsg]

Dennis, thanks for all your support to the community and answering all our questions. We ordered two today. Steve