what yoke do i need...

-
diymirage

diymirage

HP@idle > hondaHP@redline
Joined
Oct 12, 2012
Messages
34,266
Reaction score
43,617
Location
michigan
hey guys
im in the process of installing a 360/727 combo in my duster
the tail shaft of the 727 has 30 splines
I would like to find a yoke I can use to attach the 727 to the stock driveshaft that came with the 904

does anyone have a partnumber (or better yet, the actual part) I need?

thanks guys
 
Its actually a 29 spline and all you need is a 727 yoke. I'm sure someone here has one its where I got mine for 25 bucks. The 904 is 4 inches shorter than the 727
 
strange, I counted it twice and both times I got 30
(it came from a motor home but it has the right sized tail shaft)
 
thanks Dan
the 904 is in fact shorter so I should be able to have the driveshaft cut down and the 727 yoke installed in stead of the 904 unit

im not quite sure how to get it on the spicer (that the thing that looks like a plus sign?)
 
There's only 1 slip yoke for the 727 but some have 30 splines and I'm not sure why but I've seen some that were missing a spline so their count is 29, but there are a few different U-joint sizes so not just any yoke will work. If it's an A-body car nearly all of them used the small 7260 yoke. It was even used on small block B and E bodies. Here's a picture I saved from another site that shows the 2 most popular U-joint sizes so you can measure and compare yours and figure out what size u-joints you now have so you get a yoke that matches the rearend. It's also possible to use a yoke with a different u-joint than is on the driveshaft but that means you'd have to use a conversion U-joint.

BTW: don't let someone sell you a yoke for a A518/46 series (basically a 727 with overdrive) because it may not work. I haven't personally tried it but have read that the spline count is the same and the diameter is the same but the angle they cut the splines is a little different so it looks like it'll work but won't.

You probably have the 7260 series U-joint but if your U-joint happens to be a 7290 series I have a good used yoke I'll let go cheap. PM me if you need it
 

Attachments

  • U-joints.jpg
    30.9 KB · Views: 319
Tracy , I kept this information for reference, I forget exactly where I got it. maybe you can confirm or maybe its inaccurate, but they state that all 727's are 29 spline, whether big block or small block. I haven't ran across a 727 yoke that would not fit a 67 or later trans , BB or SB. you are the trans guy , and the great guy I got my yoke from , so now I am just curous lol
A727
transmissions from their inception until 1966 have 19 splines on the
input shaft. Nonlockup
727 transmissions from 1967 onward have 24 spline input, and 29 spline output shaft
Lockup 727 transmissions that debuted in 1978 had 23 splines.
Not all 727 transmissions made after 1978 were lockup; specifically towing
package 727 transmissions commonly were nonlockup,
and would have the '67onward 24 spline input shaft. The A518
overdrive also has 23 splines. The output shaft has 29 splines.
A904
transmissions from their inception until 1967 have 18 splines in the
input shaft. Nonlockup
transmissions from 1968 have 27 splines.
Lockup 904 transmissions appeared in 1978, and have 26 splines. A500
overdrive transmissions also have 26 splines. The output shaft has 25 splines.
Click to expand...
 
73AbodEE said:
Tracy , I kept this information for reference, I forget exactly where I got it. maybe you can confirm or maybe its inaccurate, but they state that all 727's are 29 spline, whether big block or small block. I haven't ran across a 727 yoke that would not fit a 67 or later trans , BB or SB. you are the trans guy , and the great guy I got my yoke from , so now I am just curous lol
Click to expand...

The input spline info is all correct in the article and I believe your right that all 727 slip yokes are interchangeable. I've never ran into one that wouldn't fit
 
so, in the drawing posted there is mention of a conversion joint

would i be able to use a 7290 on the transmission, a 7260 on the driveshaft (should be there from the 904 correct?) and a conversion joint to mate the two together?
 
I tried the autozone and napa websites and neither one consider the part number listed in that drawing as a decent part number :(

mancini doesn't either
 
These are series numbers, you'd need to look up by application for the standard 7290 and 7260. Here are the conversion part numbers via Napa, I have used them, they work.

7260/7290= napa#347
 
so I went to napa and got what I thought was the right conversion joint
got the car running
put maybe 50 miles on it and I heard a large "CLUNK" (sounded like someone smashed a huge lightbulb next to my car) and then the car started to shake like crazy

jacked it up when I got home and sure enough, one of the caps of the joint was missing, the other was damaged

ran over to autozone to buy a new one to snatch the caps off to get the car running again and guess what?

the 7260 part measures close to 2 1/4
I measured the yoke and that is 2 1/8


great
 
Did you put the clips on the U-joints? This retains them from falling out. They will be a "C" shape and there is a groove on the cup that they fit onto. so when you press them in you need to be sure the clip groove it accessible and put them in. For the rear side, you put them on and set the u-joint into the rear yoke and install the straps. See the pic.

The clips should have come with the u-joints.
 

Attachments

  • uj-1.jpg
    40.4 KB · Views: 232
funny you should mention that

I tried to install them and noticed the grooves were covered up by the ears of the yoke
I attributed it to my in-experience and even pulled the C clips out of the old joint and tried using those because they were thinner then the new ones

I got them on, but I wasn't sure if they were in
I asked the guy at the shop that shortened and balanced the shaft and they said it looked allright to them and with a conversion joint, that's about as good as it gets

I kinda thought that if they wouldn't come out when they balanced it I should be OK


guess not
 
I did the exact same thing when I was 17. My car did just what you described at the rear end. I press the cups in until I see the groove then but the clip in, then do the other. You do need them on the ones that go into the rear end yoke, the yoke is machined for them.
 
diymirage said:
so I went to napa and got what I thought was the right conversion joint
got the car running
put maybe 50 miles on it and I heard a large "CLUNK" (sounded like someone smashed a huge lightbulb next to my car) and then the car started to shake like crazy

jacked it up when I got home and sure enough, one of the caps of the joint was missing, the other was damaged

ran over to autozone to buy a new one to snatch the caps off to get the car running again and guess what?

the 7260 part measures close to 2 1/4
I measured the yoke and that is 2 1/8


great
Click to expand...

Bummer.

BTW: The i.d. of a 7260 yoke should measure 2-1/8". If the U-joint measured 2-1/4" from outside of the retainer to retainer something isn't right. Sometimes one of the needle bearings will fall down in the cap and hold it out farther than it should be. It's too late to tell now since the cap is missing but if the new one doesn't measure 2-1/8" take the caps off and make sure all the needle bearings are in place. Inspect the yoke real good too cause if it tossed a cap it could have damaged the i.d. of the yoke making it impossible to get cap to seat right
 
I stopped by napa today and they didn't have the conversion joint I needed
it gave me some time to look at the 7260 joint and the ears seem to have taken a bit of a beating

long story short, I think ill just have a whole new shaft made up :banghead:
 
diymirage said:
I stopped by napa today and they didn't have the conversion joint I needed
it gave me some time to look at the 7260 joint and the ears seem to have taken a bit of a beating

long story short, I think ill just have a whole new shaft made up :banghead:
Click to expand...

If the rest of the driveshaft is ok they might be able to just replace the yoke that's beat up. That'd save you quite a bit
 
fishy68 said:
If the rest of the driveshaft is ok they might be able to just replace the yoke that's beat up. That'd save you quite a bit
Click to expand...

trying to save money is how I ended up in this predicament to begin with :banghead:
so instead of running a 7290 yoke on the tranny, conversion joint and 7260s all the way back im having them build me a driveshaft with a 7290 yoke on the tranny, both ends of the shaft and a conversion joint going into the rear end
that way once I find that 8.75 I want ill just remove the conversionjoint and put in a regular and be good to go
 
An 8-3/4 can have the large or small yoke on it. My 4 speed car has all large U-joints stock. Most Automatic cars had the small yoke.
 
interesting

I guess if I come across a small yoke 8 3/4 ill be all set now too :)
 
diymirage said:
trying to save money is how I ended up in this predicament to begin with :banghead:
so instead of running a 7290 yoke on the tranny, conversion joint and 7260s all the way back im having them build me a driveshaft with a 7290 yoke on the tranny, both ends of the shaft and a conversion joint going into the rear end
that way once I find that 8.75 I want ill just remove the conversionjoint and put in a regular and be good to go
Click to expand...

When things are done right you can save money without sacrificing quality. It sounds like you just didn't get the clip on to hold the caps in place and it'll come apart every time like that. Having a whole new driveshaft built is the best way of course
 
You must log in or register to reply here.
-

Back
Top