Driveshaft play at transmission end. Normal? (see video)

[Zed Head]

Just a couple of things.  Maybe we should go with factory nomenclature.  That would be "propeller shaft" for the shaft we're talking about, and "drive shafts" for the two that go the the wheels.  Some people use "tail shaft" to talk about the output shaft of the transmission, and tail shaft housing to mean the rear case of the transmission.  

 

On the measurements.  I measured in exactly the same spots as EuroDat, center to center of the u-joint caps.

 

early 240Z propeller shaft - 21.25" (540 mm)

1976 280Z shaft - 22.3" (566 mm)

 

EuroDat's late 204Z shaft - 22.55" (573 mm)

 

As for room inside the slip yoke for the transmission output shaft, the early shaft, I measured 4 11/16" by sticking a tape measure inside and eyeballing to the end of the slip yoke.  4.6875",  119 mm.  Just to give some idea of engagement.  But, I'm not sure what hits first, the output shaft inside the yoke, or the nose of the yoke on something inside the transmission.

 

Also added a picture fro the 1976 FSM showing the yoke inside the transmission and what looks like an outline of the bearing.  You could easily be only half-engaged in that bearing.  It might be wallowed out already, damaged.  Edit - also added a much better image from 1973.

 

The best route might be to remove the shaft, examine the inside of the transmission for damage, and get a longer shaft.

 

Might be overloading on data here, but it's fun to review all of this since I spend a bunch of time doing the same for the 71C case swap in the past.  Which is still sitting in the garage.

Edited April 19, 2015 by Zed Head

[Mark Maras]

 If 15-20 mm is the end clearance, I'd push the prop. shaft all the way in, mark the housing, then pull the shaft out 15-20 mm and give it the shake test. If it goes away you need a longer shaft. If it remains, I'd look at the rear housing bushing. Hope this helps.

[Tomzern]

I definitely have the forward-mounted diff. The driveshafts are angled towards the front of the car when looking straight up from under the car. Not in line with the hubs. I also have the R180 diff.

I tried the same movement when I pushed the propshaft all the way into the transmission. The play was almost gone, but there was still a little bit left.

Starting to think that maybe my transmission is shorter than the 4-speed. The shifter also comes up closer to the engine than stock. I think I will order the bushing you mentioned Mark.

I like the theory about this play being the cause of the previous shaft failing. It is the most probable cause the way I see it now. Thanks for that!☺

Edited April 19, 2015 by Tomzern

[EuroDat]

Starting to think that maybe my transmission is shorter than the 4-speed. The shifter also comes up closer to the engine than stock. I think I will order the bushing you mentioned Mark.

The 5 speed came out of 280Z and it is the same length as th F4W71B. The F4W71A which was the original transmission in your car was 5mm shorter if I recall corectly. Its so little that it won't be causing this problem. The forward position of the selector is caused by the different selector design between the 71A and the 71B's. There is about 60mm difference in the location. Some people cut the tunnel and console to get it to fit. I have done it once, but we cut, bent and welded the gear stick to get it centered.

If you want to change the rear extension housing bushing then you will need to dismantle the transmission to get to it properly. The bush was never a replacement part through nissan. The only OEM option was to replace the hole extension housing. I beleive you can use one from Opel and maybe others, but I cab find the forum right now.

If a longer propeller shaft takes most of the play out of it, I would leave it a t that.

Edited April 20, 2015 by EuroDat