Drive shaft questions

-
olddog12

olddog12

Well-Known Member
Joined
Sep 15, 2014
Messages
294
Reaction score
10
Location
Nova Scotia Ehh
Have a 73 Scamp with an A body (sbp) 8 3/4 rear and 727. Can someone post a picture of the yoke for the trans and perhaps any measurements I would need to pick one up please.
I was told there is a different yoke for sb/bb but not sure. Just know I need a complete shaft.
Thanks
 
Its not different for SB BB because a SB can also have a 727. A 727 slip yoke is bigger than a 904 slip yoke. There was no 904 made for a BB so the presumption has partial validity. So is your question about the drive shaft dimensions?
 
Ok my Duster shaft should be the same as what you need. Would you like center to center of the joint cups or from weld to weld on the tube?
 
Center to center on the cups and from center of rear cup to the end of the yoke if possible.
 
mguner said:
original driveshaft from a 69 big block dart. It is part #2852228 dia 3.25 length 47.81 pretty sure center to center is 45". Ok 44.99 so sue me! :)
http://board.moparts.org/ubbthreads/upload2/4563759-PartNoDriveshafts.pdf
Click to expand...
That chart is really confusing. 727 transmissions for cars have the mount in the same place. Why all the 727-8.75 cars have 2" variations I'm not really sure. A little short (very little) is better than too long because you don't want the spring wrap smacking the yoke into your tail shaft.
 
We just had one custom made for our 4 door Valiant. It's best to measure your car for best fit. I have several shafts for abodies with 904 and 7 1/4 axle and there are at least three different lengths...

Take a yoke and push it all the way into the trans, have the rear suspension loaded (not hanging free) and measure from the center of the front u-joint to the center of the rear u-joint and subtract 1" for installation.

We also found out that the yoke can also affect the measurement. The shop didn't have the standard 727 mopar yoke in stock, but had one a little better that would fit the 727, so we used that one, and we had to remeasure with that yoke for a proper dimension.

Here's our new shaft:

Dvsft A01 b2.jpg


Dvsft A03 b2.jpg


Dvsft A05 b2.jpg
 
I dont have a yoke is the problem.
Found a guy who has lots of mopar parts but he dosent know what most is off of and neither do I. I dont want to buy a complete shaft only to get home and realize its the wrong yoke.
 
There has been a lot of threads lately on driveshaft length because people want to know how much to shorten the driveshaft if they put in an 8-3/4. However, you've got a stock condition where you know the car, rear end, and type of transmission.

If you have a 73 Plymouth parts catalog, they list the driveshaft length (in the Propeller Shaft tab) for all the possible combinations -- and they tell how it is measured.
 
Can anyone tell me how far the yoke should go into the trans, when the car is on its wheels?
Im not sure if it should be in the trans 1" or 5" or what it should be. Rough number is fine.
 
4" is a good number depending on if you are running the seal with the dust boot or not. You do not want the boot to touch the shoulder of the yoke or you will get an annoying squeak. You also want the yoke to be able to move in and out with rear spring wrap and suspension travel without bottoming out.
 
olddog12 said:
Well the car is 40 years old, eventually everything becomes declassified I thought??
Click to expand...

Ok, per the freedom of information act:

When you measure to go with a custom one, you push the yoke in the trans all the way, measure from center to center of the front and rear u-joint and subtract an inch for installation...

So, basically you get all of the yoke minus one inch...
 
Last edited:
You must log in or register to reply here.
-

Back
Top