Who's Created/ Converted a Short 727 Using a Truck Tailhousing to a Slip Yoke?

-

PROSTOCKTOM

FABO Gold Member
FABO Gold Member
Joined
Oct 8, 2013
Messages
1,456
Reaction score
1,415
Location
West Central Indiana
Guys, I would really appreciate it if this thread can stay on topic. I am aware that a shorty kit can be had from A&A but that eliminates the governor which means manual shift only. I have several short transmission that just have the bolt on yokes (No parking brake drum types). Boring the tailhousing for a bushing or bearing in no problem for me. So basically what if any rework has been done to a stock output shaft? Or does this require a custom made shaft only?

Thanks,
Tom
 
Tom, I would think it may be a custom shaft. I know to add an overdrive on the back of a 727 there was an adapter that bolted to the back of the 727. I can’t remember if a tail shaft was supplied or we had the tail shaft shortened and splined. This overdrive also bolted to this adapter. The od unit was an American Overdrive unit. I don’t think they are made anymore. The adapter was about 6 inches long. Kim
 
So CFHJ r u saying to remove the bolt on yoke and get a splined end to fit the tranny shaft? I take it as he wants a shorty tranny. Kim
 
No but that works on the th400. I'm saying to use a splined driveshaft; like what was bolted to the trans originally.
 
He doesn’t have that because his tranny has the bolt on yoke like the rear Diff has. Unless I’m totally mis reading this. Sounds like he is asking if he can modify his short shaft or modify a long tail shaft. Or has to get something made. Kim
 
He doesn’t have that because his tranny has the bolt on yoke like the rear Diff has. Unless I’m totally mis reading this. Sounds like he is asking if he can modify his short shaft or modify a long tail shaft. Kim

He's saying use that setup. It's similar to a front drive shaft on a 4x4.
 
It's not as straight forward as you guys think. The bolt on yoke shaft has only short splines that terminate into a larger diameter part that is a boss for a roller bearing. You have to fully understand the parts to see the issues that have to be worked around.

Tom
 
All of the bolt on yoke 727s I have (3 or 4); Have a big nut in the middle and a place to bolt on a u-joint.
 
So what Rusty is suggesting u don’t want to even consider it? Lots of trucks used that system for many years. Is it not strong enough. Kim
 
I was researching something similar. To get rid of the ball/trunnion on my barracuda. There are parts available. The existing flange remains.
 
Found a screenshot. If anything it will give you somewhere to look
35C36ACA-6917-4D83-83CA-F038F7CEB851.jpeg
 
Keep the bolt on flange and have a driveshaft with a slip joint made.

I put a 454/TH400 from a 3/4 ton truck into a '73 camaro several years ago. The TH400 had a bolt on yoke and I didn't have the money for another trans or to convert it over to a slip style. I had the local driveshaft shop build a shaft with a slip joint and it worked perfectly! I think the cost was like ~$425.
 
Thanks guys for the suggestions, but I am not wanting to run a slip yoke driveshaft in a big block drag car. With the engine sitting back I am just not interested in using the full length 727 tailhousing and I don't want to get rid of the governor, or I would just go ahead and buy an A&A shorty kit. I assumed when I posted this that someone would have converted one by now. Really wasn't wanting to machine a new shaft, but it looks like that's going to be the plan going forward.

Tom
 
Thanks guys for the suggestions, but I am not wanting to run a slip yoke driveshaft in a big block drag car. With the engine sitting back I am just not interested in using the full length 727 tailhousing and I don't want to get rid of the governor, or I would just go ahead and buy an A&A shorty kit. I assumed when I posted this that someone would have converted one by now. Really wasn't wanting to machine a new shaft, but it looks like that's going to be the plan going forward.

Tom
How short do You need the tailshaft to be? IIRC, the /6 unit I have out of a B-series van is shorter than the std. 727, & has a slip Yoke. Not a stubby for sure, but may be able to use it or work with that tailshaft?
 
How short do You need the tailshaft to be? IIRC, the /6 unit I have out of a B-series van is shorter than the std. 727, & has a slip Yoke. Not a stubby for sure, but may be able to use it or work with that tailshaft?
If this is a 727 I’d like to see it. Post some pics please. Thanks. Kim
 
OK, found it, & when I acquired that thing 30+yrs. ago it appeared shorter for some reason. I had decided not to use it, after getting the parts to build it & a Transgo kit, it stayed parked in a tote & boxes ever since.
To stay on topic, a custom shaft, & TIG welding the extension housing with a section taken out may be it. There appears to be enough meat on the shaft to shorten & re-spline it with about 7.5 inches cut off, but it would need re-hardened,......not sure what the effort/cost/durability delta is on that end........
 
-
Back
Top