Transmission yolk play

[flyinlow]

How much up and down play is normal on the front of a driveshaft installed in a 727 ?  Car on jacks ,trans. in neutral.

Thanks craig

[RD]

man.. i have never thought about this.. it should be "0".  the front yoke slides right onto the output shaft and should be stabilized steadily.  if you are getting movement up and down.. my guess is your u-joint is on its way out and needs to be replaced immediately

OR

if the yoke is moving inside the rear trans output shaft housing.. then your rear output shaft bushing is shot or non-existent and/or your yoke is wallowed (we say wallered in Kansas) out and needs to be inspected OR BOTH!!!!

your rear bushing can be replaced by removing the output shaft housing (any tranny shop can do it, or I can guide you through it).  got a chassis service manual?

[RallyeMike]

Craig,

The yoke is not designed to be a zero tolerance fit to the trans output shaft or to the trans tailshaft bushing, therefore you will always have some slop in the fit even when everything is brand new. This is normal. The yoke and output shaft splines are designed to lock up when power is applied.

Theoretically, the splines and tailshaft bushing should not really wear, though if you have previously had a bad U-joint, an unbalanced driveline and continued to drive it, or really thrashed away for awhile, it could damage splines or the bushing. Then you are in for some of the work RD is talking about. As far as I know, there is no measureable service check for yoke fit or bushing wear.

If you think there might be a problem with the u-joint, when you check for movement, watch the u-joint itself as related to the shaft and yoke, and the not the yoke. If you steady the yoke in one hand and rattle the shaft with the other it might help you see just the joint movement. Better yet, it only takes 4 bolt to pull the shaft out of the car and really be able to check the U-joints.

[flyinlow]

New driveshaft 3 months ago except for trans yolk.  Ujoints are new. Dial indicator shows .070 up and down on trans yolk. Seams like alot.

[Ghoste]

I wouldn't sweat it in mine.  Is there something else going on that made you check it after 3 months?

[firefighter3931]

Like the other guys have said the yoke will have some vertical and horizontal "play" and your measurements don't seem excessive to me. 


Ron

[flyinlow]

Have a cycling noise 55-65 mph. level road maintaining speed. Goes away if you accelerate or coast. Have headers,3 inch exhaust,magnaflows,and dynomax bullet mufflers used as resonators. Tried adding an H pipe. Exhuast tone mellowed, but cycing drone noise still there. I pluged each tailpipe, one at a time to see if would help. No change. Pinion nut tight. axle play .012. May pull carrier and check backlash and wear pattern.

Any ideas?

[craigandlynda]

turn up radio.

check fluid level in differential.

[Just 6T9 CHGR]

Have a cycling noise 55-65 mph. level road maintaining speed. Goes away if you accelerate or coast. Have headers,3 inch exhaust,magnaflows,and dynomax bullet mufflers used as resonators. Tried adding an H pipe. Exhuast tone mellowed, but cycing drone noise still there. I pluged each tailpipe, one at a time to see if would help. No change. Pinion nut tight. axle play .012. May pull carrier and check backlash and wear pattern.

Any ideas?

This seems to be the vibration of choice lately...I have been "living" with mine for about 8+ years now...looking for a set in stone fix from others that have complained of this same vibration but havent found one as of yet....

[John_Kunkel]

The up-and-down play of the yoke will increase the farther out the yoke is from the trans and the further back on the yoke the measurement is taken. In any case, .070" seems excessive.