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727 output shaft sizes help!!!!

Mike67

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I have a big block 727 that I bought and had rebuilt, bought a Speedmaster billet yoke, verified shaft was 29/30 spline. Had to push and wiggle hard to even get it to start to engage.
Checked it on my 4spd and it skipped right on.
Are there different output shaft diameters? This just ain't right...
Thanks
 
Measured the OD of the 4 spd 1.280 & 727 is 1.2850...why????
 
Just a thought, new tailshaft bushing. Changed mine, needed a good push to get yoke in.
 
Just a thought, new tailshaft bushing. Changed mine, needed a good push to get yoke in.
Thanks!
Are you talking about the seal? I can get it passed the seal but it does not slide, it's an effort to continue sliding it forward.
 
Bushing. Curious about .005 size difference?
ttool1.jpg
 
Was doing some research and over on FABO saw where someone was having a similar problem. The discussion lead to spline cut, and the difference of an A518 and a 727 which I'm wondering ifthe the yoke they sent me is for an A518??? Or if my builder installed an 518 output shaft and is this even possible???
My splines are full and flat, the yoke appears to be a little more pointed.

20200912_105500.jpg
 
This is mockup slip yoke I've used on dozens of 727's from many years '66 through late 70's. That bushing fit may be the issue. I test my new bushings for fit without the seal first, if they're tight, a little Scotch Brite on the bushing, take a little off till it fits.

20200912_143618.jpg 20200912_143649.jpg
 
This is mockup slip yoke I've used on dozens of 727's from many years '66 through late 70's. That bushing fit may be the issue. I test my new bushings for fit without the seal first, if they're tight, a little Scotch Brite on the bushing, take a little off till it fits.

View attachment 1001121 View attachment 1001122
Not a trans guy how would I go about doing that?
Thanks
 
So looking at my splines the are flat and seem to match up with the 46Re...could someone have used that output shaft in a 72 case???

No, the 46RE is an overdrive transmission, output shaft is in the OD unit not the transmission.
 
I've had a run of tight tail shaft bushings lately. Had to work the last 4-5 to get them to fit.
You can remove the tail shaft easily. Then test the yoke. Also seen the output shaft seal garter spring get pushed into the bushing.
Doug
 
As much as I dont want to, it sounds like I need to oil the tail shaft just to verify...
 
So pulled the tail shaft today, slip yoke slides right in. So it's not a bushing issue.
Test for the yoke on the 833 slides right on. The output shaft seems to be larger, trans IF PK368 1054 4367 519...isn't this a 72 ?
 
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