Yoke (smooth shaft) won't slide in my tail of my Auto Transmission

[ACUDANUT]

   Any thoughts ??

[VPFD13]

The auto and the 4 speed shafts are different did you change over or were you given the wrong shaft?

[firefighter3931]

Are you trying to install a 904 slip yoke into a 727 transmission by chance ?

Is this a brand new slip yoke from MP ?


Ron

[ACUDANUT]

     I am using a 727 yoke.  It starts a tad bit but stops...On that thought, does it make a difference if the yoke has a slot in the splines and the transmission does not. ??  How abou hammering it in.

[VPFD13]

Don't hammer it!

[Just 6T9 CHGR]

I would run a hacksaw blade through each spline on both the trans output shaft & inside the yoke.....might have some casting flash or a burr on the splines.

You should not hammer anything......a little trans fluid for lubrication and it should be a smooth slide.....any binding & you will be having problems when it is installed

[Ghoste]

I ran into the same thing a few years ago.  Some yokes are cut slightly differently.  It seems to me it was a MP one that fit a spare trans I had here but not the one in the car.  In any case, I ended up having to order one from someplace else and I think it was Mancinis who got it for me.  It was made by someplace with a name like PHP or something similar.

[TNT]

Check to see that the transmission tail shaft bushing is in straight, check the machined portion of the yoke is free of defects.  I had a similar problem when my transmission was rebuilt, it turned out that the inside diameter of the tail shaft bushing was too small;   solution reinstall a new bushing or machine the slip yoke down a few thousands of an inch to obtain the clearance you need.
      TNT

[mikepmcs]

Agree with TNT, I bet the tailshaft bushing/seal etc... is either broken, bent, ruptured, punctured, torn, or twisted. 

This just happened on my buddy's oval track car.  Hammered one(drive shaft) in the previous race because it was binding exactly like yours and the following race we had to change tranny's, one because it was leaking and the other reason was the end of the tail shaft was all jacked up.  the springs from the seal were ground right in to the shaft.  See if you can get a light in there and look first, But I wouldn't hammer it hard at any cost or there will be some extra cost in the end.
Good Luck,
v/r
Mike

[ACUDANUT]

 My Bushing/seal is not the problem.  I think.... Does any one know why there is a slot in the input shaft splins but not the end of the transmission splins ??  I found this on all my input shafts and the same for the other transmissions. ??  I know the 904's won't work on the 727's. Thanks for the input.

[firefighter3516]

The reason for the slot is because some splines have what they call a dead spline and so that you cant use just any yoke. But as long as you the transmission splines don't have a dead spline on it then you can use any yoke. I have had the same problem as you on my Dakota when I put a 727 in from tci in it the old yoke wouldn't work so I got a new one and it did work there was a slight difference in the diameter of the new and old trans. I found this out after taking my calipers and doing some measuring. If you have some calipers or can borrow some you could measure the major and minor diameter of both the yoke and trans splines and see if they add up or not.

[tan top]

don't know if this is any use , heard that the MP one don't , got one from Mancini , no probs

[ACUDANUT]

  Hmmm, I am afriad to buy one from Mancini's because of the headache I might have if it does not work.  I can just see it now...Sorry sir, it apears you tried to use this and it's now considered "used"....Another 125.00 bucks down the drain.

[RD]

mike (that is your name right? been a long time),

let me know if you need help some time, i can make a trip up to see you and help you out if need be.

Jamey

[ACUDANUT]

Okay. I pulled the rear seal off the transmission and I can see the steel bushing is not perfectly round inside the tail of the 727.  This looks like it is keeping my yoke from sliding in.
** Do I pull the steel bushing out (how hard is that) or do I have my yoke taken down a few hundrenths ?? Your imput is greatly appreciated. thanks

[RD]

Okay. I pulled the rear seal off the transmission and I can see the steel bushing is not perfectly round.  This is keeping my yoke from sliding in.
** Do I pull the steel bushing out (how hard is that) or do I have my yoke taken down a few hundrenths ?? Your imput is greatly appreciated. thanks

just for others to know, i will be up this weekend to install a new bushing for Mike.

[ACUDANUT]

RD..AKA Jaime. Thanks for the help.  I look forward to seeing you and getting 'er done. Thanks RD

[firefighter3931]

just for others to know, i will be up this weekend to install a new bushing for Mike.

Excellent !