727 transmission and yoke

[RSZ28]

Doing a big block swap in a 65 Belvedere. I want to keep the column shift, but it used the one year only transmission with cable shift. I found a 727 from a 65 Imperial that used the cable shift. I would like to use this if possible. When looking at the input shaft it has 19 splines on the tip and 27 splines behind the 19. Is this usual? How many spline torque converter will I need? Also, the slip yoke on the rear of the transmission has 23 splines and uses two straps to hold on the universal just like the rearend. Can I still use this yoke with a custom driveshaft to fit this yoke or do I need a different yoke? Thanks

 

[AR67GTX]

You will need a 19 spline torque converter unless you go into the transmission and substitute some parts. You should be able to use the rear yoke if it's in good shape. You will probably need to determine what type u-joint it takes and also the type the driveshaft takes - and buy an adaptor u-joint to match them up. But they seem to be pretty readily available. If you have a custom driveshaft made they can probably match the yoke for whatever u-joint it takes.

 

[RSZ28]

Another question. The output shaft on the transmission is threaded and the yoke is attached with a large washer and nut. Can you use a different slip yoke without using the washer and nut, or must you use a yoke that is held on by the nut? Thanks

 

[Glenwood]

Any pics? I didn't think slip yokes had a nut like the pre 65 trunion flange. The 64 bb 727 i sent out for rebuild had a rearend yoke bolted on in place of the flange. This was to use a ujoint with a modified driveshaft.

 

[RSZ28]

The yoke on my transmission is like the one that you said was on your '64. There is no flange, only the yoke that fits on the splines of the output shaft at the rear of the transmission, and then is held on by the washer and nut. Was there a part number on your yoke? My yoke has the number 2533178 on it and I can't find that number in my parts book. The book shows 1739915 to be correct for the yoke on the Imperial 727. The yoke on the driveshaft is 2405674. The number for a Belvedere yoke is 2405665. Can I have a driveshaft made with a front yoke so that it will mate with my yoke and then just use the rear yoke that will match the rear end? Thanks

 

[Fran Blacker]

If that trans yoke is bolted solid to trans there was a C/V joint and a center bearing. The drive shaft may have a splined part to take up suspension travel.
T

hese came out of a 66 book. Note the slip joint in upper right corner.

 

[RSZ28]

Since a slip yoke will move in and out to take up the suspension travel and mine bolts on, do I need to find a driveshaft with the CV joint and center bearing or can I just switch out the yoke that I have for a slip yoke? If not, can I then use a different input/output shaft from a later 727 transmission when I have the transmission rebuilt that uses a more common slip joint and converter? Thanks

 

[Fran Blacker]

Well you need something to take up suspension travel. Don't know what options you have. Was looking in prop shaft section for something and was looking at picture I posted. When saw your question I could see there could be a problem. I don't have an answer.

 

[Fran Blacker]

You probably should look for a later trans 68 or so with the good input shaft and a spline output shaft. Converting your trans more trouble than it's worth.

 

[Fran Blacker]

Maybe you can convert to ball and trunnion.

 

[RSZ28]

Thanks Fran. Went with ball and trunion.

 

[Glenwood]

Thanks Fran. Went with ball and trunion.

I saw the driveshafts fran talked about on mancinis site. There about $500.

 

[dvw]

You can swap the reaction shaft support and input shaft with the later 67 and up. This will allow the use of all normal 727 converters.
Doug

 

[Fran Blacker]

You can swap the reaction shaft support and input shaft with the later 67 and up. This will allow the use of all normal 727 converters.
Doug

Yes an easy switch unless you forget to tighten front band when removing front pump housing, I know.