Driveshaft Removal

[Datsun-Fever]

I'm in the process of changing out my U-joints, but i am having trouble removing the 4 bolts from the driveshaft-diff pinion, it looks like they have not been changed once in the cars life, so they are being extreamly stubborn, and to make matters worse, i can only reach them with my 1/2 crescent. How do you guys go about this?

[240Zdragon72]

What I had done was put the rear end on jackstands, chocked the front wheels and left the transmission in Neautral so you can spin the shaft when you needed. That helped a lot, but it took some time, unless you get a 3 foot extension for a socket wrench? Have you tried to spray some WD-40 on the nuts? That might help in breaking some of the road grime and possably rust that might have collected there over the years. Good luck, bro.

[Datsun-Fever]

Yup, the rear end is up in the air, and i just finished giving them another spray of wd40

I'm sure i'll get them off sooner or later. I do have a few socket extensions that reach, but they cant reach on the right angle. What tool did you use? Thanks man.

Oh, and one more thing, does anyone know if the 280zx drive shaft is the same as the 280z in that you can not replance the u-joints?

[webdawg1]

Might want to spray them down with PB Blaster for a couple of days (Every couple of hours) and see if they will break loose after that. As a last resort, maybe heat them up a little bit with a torch. As a general rule tho, usually the PB Blaster will break them loose.

webdawg1

[jmanz6]

You should be using metric wrenches to remove the bolts with. Otherwise you will round off the nuts and have to cut them off. Not fun...

[LanceM]

ZX driveshaft won't work, use box end wrenches. There is a point in the rotation of the shaft that will give you the most room to use the wrenches, I wouldn't even think that sockets would work. PB Blaster is 100 times better than WD-40 for penetration on old stuff IMO.

[240ZX]

Yup, the rear end is up in the air, and i just finished giving them another spray of wd40

I'm sure i'll get them off sooner or later. I do have a few socket extensions that reach, but they cant reach on the right angle. What tool did you use? Thanks man.

Oh, and one more thing, does anyone know if the 280zx drive shaft is the same as the 280z in that you can not replance the u-joints?

Regard the question on the drive shafts...I believe they are the same, not replacable. However, a good driveline shop can take care of that issue.

[Fun_in_my_z]

Have you tried a impact wrench?

[Datsun-Fever]

i wish i could use one, but im hardpressed to fit anything in there

so for now, im relying on liquid wrench and a 1/2 box end.

[beandip]

i wish i could use one, but im hardpressed to fit anything in there

so for now, im relying on liquid wrench and a 1/2 box end.

For one thing this is a car built with metric parts. If you do not have metric tools , buy some before you screw up and round off the nuts. To remove he nuts use a open end wrench or a boxend. As was posted before , block the front wheels and jack up the rear and put on jack stands so both rear wheels are off the ground. With the trans out of gear , you will be able to rotate the shaft . As it turns ,the u-joint will flex and the space will allow a proper wrench to fit the nut. If all you have is wd-40 , it is better than nothing, however P B Blaster is far far better . If you are going to be working on the z in the future buy some it will save you much pain and cash . Gary

[mdbrandy]

I just reinstalled the half-shafts on my 280Z a month ago, and in trying to figure out how to correctly torque those shaft-to-diff nuts, I came across the following technique.

At full droop of the suspension (rear end off the ground), the upper nuts at the diff are more-or-less exposed to a socket. I used a 3/8" drive socket (12 mm?), and either two or three 6" (3/8" drive) extension bars to extend out far enough that I could get my 3/8" torque wrench to work. You have to rotate the shaft to a fairly specific point to get each nut exposed right to get the socket to fit, but I got it to work for all four nuts on each side. A pain in the butt, but at least I know that they are torqued correctly. On the outer (axle flange), no such luck. Box end wrenches and pull hard.

This ought to work to get them off as well.

Good luck.

[jmortensen]

The driveshaft nuts are 12 or 14mm IIRC depending on the year, so 1/2" is not even close to the appropriate size wrench to use. If these are original driveshaft bolts the head is a D shape so you can't spin it, so you only need to worry about getting a wrench on the nut side. I use a long 12mm wrench on my 240 with a long screwdriver pushed thru the U joint to hold the driveshaft. This used to be a SERIOUS PITA when I had the MSA rear swaybar installed. Now I have the rear mounted ST rear bar which should open things up quite a bit and make it a lot easier.

Don't think you can get a socket onto the driveshaft because it runs so straight the shaft itself is in the way. Much easier to get a socket onto the 1/2 shaft because it is angled so far down and you can turn it until the socket fits on.