C6 yoke installation questions

[radiorusty1096]

Hello,
Re my 1970 F250 C6 transmission installation: I have some questions:

1) My newly rebuilt transmission came back with a different output shaft. The new shaft carries all the same dimensions but has no provision for the cotter pin to safety the yoke nut, as the former shaft did. Is it OK to torque the nut on and put the truck back in service without a cotter pin safety on this nut? The Ford manual calls for 380 to 470 foot pounds on this 1 & 1/2" nut. Does this sound right?

2) The spacer between the aft (7065) transmission bearing and the speedometer drive gear is also missing. (I think the spacer part number is 17288.) Without this spacer, the speedometer drive gear does not center over the speedometer driven gear and the yoke goes on the shaft too far. This causes the yoke nut to shoulder out before it actually contacts the yoke. Any idea where I can find a 17288 spacer? And will the spacer alone get me lined up or will I need to shim it up? If so, where can I find the shims?

3) When flushing the radiator/trans fluid cooler and lines I noted very free flow in the correct (aft output, forward return) flow direction, but no flow whatsoever in the opposite direction. Is there a check valve somewhere (darned if I could find one) or is something else going on?

Thanks for your help!
Russ

N420GAand F250082016.jpg

[basketcase0302]

"radiorusty1096"]Hello,
Re my 1970 F250 C6 transmission installation: I have some questions:

1) My newly rebuilt transmission came back with a different output shaft. The new shaft carries all the same dimensions but has no provision for the cotter pin to safety the yoke nut, as the former shaft did. Is it OK to torque the nut on and put the truck back in service without a cotter pin safety on this nut? The Ford manual calls for 380 to 470 foot pounds on this 1 & 1/2" nut. Does this sound right?

2) The spacer between the aft (7065) transmission bearing and the speedometer drive gear is also missing. (I think the spacer part number is 17288.) Without this spacer, the speedometer drive gear does not center over the speedometer driven gear and the yoke goes on the shaft too far. This causes the yoke nut to shoulder out before it actually contacts the yoke. Any idea where I can find a 17288 spacer? And will the spacer alone get me lined up or will I need to shim it up? If so, where can I find the shims?

3) When flushing the radiator/trans fluid cooler and lines I noted very free flow in the correct (aft output, forward return) flow direction, but no flow whatsoever in the opposite direction. Is there a check valve somewhere (darned if I could find one) or is something else going on?

Thanks for your help!
Russ

N420GAand F250082016.jpg

Well I had to look at the file pic as I couldn't remember on the tailshaft, (didn't remember mine having a cotter pin). But it does show one so maybe someone else will chime in here too. Try Green Sales for the spacer and then Obsolete Ford Parts as those two specialize in hard to find parts like that. And I'm gonna go out on a lim here about the tranny lines and say your correct about the check valve. I do remember pulling the valve body on a C-4 years ago and the check valve was a ball bearing in the valve cavity. Maybe someone else will chime in on that one too, sorry I couldn't help more.
Nice truck BTW too.
http://www.greensalescompany.com/

[Rjshove]

Just took my C6 tranny apart. It's out of a 72 f100.
The Short Tail shaft with the U joint Companion Flange was loose, nut doesn't have a cotter pin, not the castle nut type. The picture that is shown on here doesn't look like the one on mine. The C4 type looks closer!
AFTER removing the bolts that attach the tail housing to the case, the complete tail housing and shorter main shaft came out as one unit.
I removed the 1 1/2" nut that retains the flange. Flange came right off. The CR21213 seal was next. It is about 3" OD, and about 2" ID.
When I pulled the tail housing off, the main shaft came with it AND the governor assembly. Is there a Snap ring holding the governor on, which I don't remember it being on there?? And a roller bearing in the tail housing, from the inside, which is held in the tail housing with a snap ring. A snap ring was on the shaft up against this bearing, I think someone must have put this in the wrong place, because I THINK the snap ring is supposed to be holding the governor on the main shaft. NO spacers
The flange, speedo gear are held tight by the 1 1/2" nut up against the roller bearing. Don't know the torque on this, I would say 200 ft. lbs. at least.
NO internal snap ring for the main shaft? Again a question on this. I am sure, no internal snap ring, not since the way the tail housing has to come off.
Anyway, I have found NOTHING about this, or the correct way to put it together. I can only guess, and am researching as much as possible.
If I find out anything, will post it. ray

[Rjshove]

The tail housing of my 72 C6 truck is a one piece aluminum that looks like the 4wd type w/o the mounting for the shifter.
It has a internal roller bearing that is held in with a snap ring from the inside! NOT like the pictures.
Is is a zero tolerance bearing that is installed 1st! down against a machined flat of the main shaft. It is then installed into the tail housing from the inside, and then a large snap ring holds it in the tail housing.
A new rear tail housing seal is installed, slide the speedometer gear onto the shaft and then the companion flange and tighten the 1 1/2" nut to 80 ft. lbs., with a little blue lock tite!
This will hold the speedometer gear from turning. Now install the governor assembly and it's snap ring.
This tail housing is installed with out a snap ring internal as MOST C6's have!
Hope this helps.

[Rjshove]

dscf0093_0e71caa89d01a7e3f0be3e07480626842bedc78d.jpg

This is of a 4wd tail housing and is VERY similar to mine.