8 3/4 to dana60

[alfe]

will driveshaft fit when i swap to dana60?? from 8 3/4

[maxwellwedge]

Fit what? What car, year, trans?

[alfe]

Fit what? What car, year, trans?

if i change from 8 3/4 to dana 60

68 charger  trans 727

[alfe]

Fit what? What car, year, trans?

if i change from 8 3/4 to dana 60

68 charger  trans 727

do i need to shorten driveshaft

[Just 6T9 CHGR]

Moparts has a nice driveshaft length chart...which is a bit confusing

http://board.moparts.org/ubbthreads/upload2/4563759-PartNoDriveshafts.pdf

[Just 6T9 CHGR]

Doing a little research in my '69 parts book I found this...

(W) meaning Coronet (same as Charger)

measured from center to center of joints

So YES you will have to shorten the shaft

[John_Kunkel]

When going from an 8 3/4" to a Dana the driveshaft will need to be shortened 1 1/8".

The factory specified different driveshafts according to the type of U-joint but the difference between the two center-of-axle to center-of-ujoint dimensions is 1 1/8" so that's close enough.

[alfe]

THANKS

[69rtse4spd]

When I did this on my 69 back in the early 80s, used the same driveshaft. Held up very well even at the drag strip, never had a problem. Doing the same thing in the 70 right now, going to use the same shaft I have right now, as long as the u-joint is the same.

[Ghoste]

What probably happened in your case was that you took up all the "slack" (for want of a better term) in the slip yoke at the back of the transmission.  There should typically be about an inch before the yoke bottoms out in the trans.  By using up that inch you could make a longer driveshaft fit but the slip is there for a reason.

[John_Kunkel]

Lots of people have just shoved the extra inch plus into the trans but they risk damaging the transmission tailhousing. (and the damage won't always be apparent)

[69rtse4spd]

Has anybody ever thought of just maching off an inch from the slip yoke end. .

[tatrick2me]

Doing a little research in my '69 parts book I found this...

(W) meaning Coronet (same as Charger)

measured from center to center of joints

So YES you will have to shorten the shaft

Wrong! B body cars with 727's or 4 speeds use the same drive shaft with 8 3/4 or Dana 60. Been there done that.

[Just 6T9 CHGR]

Doing a little research in my '69 parts book I found this...

(W) meaning Coronet (same as Charger)

measured from center to center of joints

So YES you will have to shorten the shaft

Wrong! B body cars with 727's or 4 speeds use the same drive shaft with 8 3/4 or Dana 60. Been there done that.

But have you done it correctly?  

[six-tee-nine]

IIRC there is no lenght differece between an auto or manual setup. But as Chris stated the manual displays a different lenght for the Dana rear.

So if i'm right there are 2 possible lengths in this case :
1) Auto or 4speed with 8-3/4
2) Auto or 4speed with Dana 60

As Stated above, it wil most likely be possible to mount the longer driveshaft in between the trans and the Dana but then you will just slide the yoke deeper in the trans. Remember that this is no good since the length of the driveshaft alters under the travel of the suspension.....


Offtopic :

I've seen several guys with lifted 4x4's with their original drive shafts who popped their yoke out of the trans on fully travelled out suspension.....

[BrianShaughnessy]

IIRC there is no lenght differece between an auto or manual setup. But as Chris stated the manual displays a different lenght for the Dana rear.

So if i'm right there are 2 possible lengths in this case :
1) Auto or 4speed with 8-3/4
2) Auto or 4speed with Dana 60

As Stated above, it wil most likely be possible to mount the longer driveshaft in between the trans and the Dana but then you will just slide the yoke deeper in the trans. Remember that this is no good since the length of the driveshaft alters under the travel of the suspension.....

1):  The Dana is about an inch "longer" from axle centerline to yoke centerline than the 8 3/4.   The trans makes no difference.    While you might actually get a longer driveshaft in while up on a lift or something,   once the suspension starts working the longer shaft will bottom out on the slip yoke at the trans tailshaft at the seal area probably causing damage.
There's a chart in the Charger, Road Runner and Super Bee Restoration Guide attached. 

2):    A Plymouth is about an inch shorter wheelbase than a dodge.   A Satellite / Roadrunner / GTX  8 3/4 driveshaft is pretty close to a Dodge (Coronet / Charger ) Dana 60 shaft - but not quite.

3):    A 70 shaft is 3.25" diameter as opposed to a 69 down 3" diameter.    Bigger is better.  More strength, less vibrations.

4):    40 year old shafts suck.   Buy new.    The last of the driveshaft shops in my area stopped doing them several years ago... which is just as well.  Anything I had done there sucked.    

[Just 6T9 CHGR]

Thanks for that pic Brian....gonna save that one

[hemi68charger]

Thanks for that pic Brian....gonna save that one

Which pic Chris? The application chart or Brian's signature/avatar pic........   

[bad88t-top]

Great read here guys.  Thanks for the info.