4 Speed Transmission woes..

Posted By: Nuke463

4 Speed Transmission woes.. - 02/27/10 09:18 PM

I have a rebuilt 66 4 speed trans (23 spline) that I was going to put in my 71 Bee however, the driveshaft I have doesn't seem to fit. I was told that all 71-74B body drive shafts are the same length. I am positive I have a -71-74 drive shaft. The yoke end on the drive shaft has a master key way that my tailshaft on my trans does not have. Do I have the wrong drive shaft? Does a 4 speed and an automatic for a 71-74 B body differ? Have I got the wrong shaft?

Posted By: stumpy

Re: 4 Speed Transmission woes.. - 02/27/10 09:30 PM

When you say it doesn't fit what exactly do you mean? Won't go over the trans output shaft, too long, too short?

Posted By: Nuke463

Re: 4 Speed Transmission woes.. - 02/27/10 09:41 PM

Yes...doesn't mate to the trans output shaft. This is no master key way on the rear of the output shaft. Is there suppossed to be?

Posted By: John_Kunkel

Re: 4 Speed Transmission woes.. - 02/27/10 09:51 PM

There is no "master key", the missing spline in the slip yoke is to allow air to move out of the pocket formed by the plug in the back of the yoke.

If the yoke won't go into the trans at all it's the wrong yoke, if it goes in part way and stops the problem is elsewhere.

Posted By: imfixinmopars426

Re: 4 Speed Transmission woes.. - 02/27/10 11:23 PM

find a correct 727 yoke,and try. might have a 904? or off brand yoke.

Posted By: 446acuda

Re: 4 Speed Transmission woes.. - 02/28/10 02:21 AM

Quote:

I have a rebuilt 66 4 speed trans (23 spline) that I was going to put in my 71 Bee however, the driveshaft I have doesn't seem to fit. I was told that all 71-74B body drive shafts are the same length. I am positive I have a -71-74 drive shaft. The yoke end on the drive shaft has a master key way that my tailshaft on my trans does not have. Do I have the wrong drive shaft? Does a 4 speed and an automatic for a 71-74 B body differ? Have I got the wrong shaft?

If it is a complete '66 trans with a '66 tailshaft housing then you are going to have a problem with the trans mount location ( 1-5/8" further back on '69-earlier transmission and rear shifter mount location like the '70-up tailshaft housings. On the yoke, if it is for a 518 trans then it won't fit a 727. The splines on a 518 are more square than the triangular spline on a 727.

Posted By: stumpy

Re: 4 Speed Transmission woes.. - 02/28/10 02:22 AM

Although the 727 slip yoke will fit a 518.

Posted By: peabodyracing

Re: 4 Speed Transmission woes.. - 02/28/10 12:47 PM

Nuke, as mentioned already, the transmission mount location is different. I went through this exact problem last summer with a 71 RR. I would have bet money the transmission mounting scheme was the same. A smarter guy than me showed me the difference, which is pretty subtle. Also, you'll need a shifter mounting bracket from a 71 up 4 speed car in order to put the shifter in the right location. Otherwise your shifter will be too far forward in the tunnel. These will be tougher issues to resolve than the slip yoke. I'm afraid you'll have to do like I did and locate a 70-up 4 speed and the bracket. To get going on mine I used an OD 4 speed and had the input shaft housing turned down to fit the bell housing opening. Hope to find a proper 4 speed this year. Good hunting.