Wrong Driveshaft?

[hogie]

I am getting closer to finishing up my car and I tried to put in the drive shaft tonight. Long story short is the drive shaft appears to be way too long. I have about 25.5 inches between the flange at the axle and the seal at the back of the transmission.

However, the drive shaft I have is 29.5 inches long altogether and about 27 1/4 inches to the collar at the front. Also the splines don't seem like they want to engage all the way (though the flanged ends match perfect).

How long should the drive shaft be for a 72 240 with a 4 spd? I have found a bunch of threads, but none with a proper length.

Thanks

[hogie]

Please let me know if anything looks out of place in these pics.

The splines on the shaft look like they are in good shape, but don't fully engage. Even after a good greasing.

I am quite sure the diff is mounted properly as well as the engine. The fan is darn near touching the radiator so there is no way for it to move any further forward.

I thought I read that there was supposed to be a tiny F on the diff mount, but I dont see that either.

Also, I called MSA today and the drive shaft they sell is 30 inches long.

Thanks

[Arne]

Something wrong with the splines - either in the driveshaft or on the output shaft of the transmission.

A couple of comments - the nose of the driveshaft should not be painted. That is the surface the seal seats on. Strip the paint totally clean there without roughing up the surface. It needs to be clean and smooth. Also, the output splines on the transmission look rusty as well. The driveshaft needs to be able to slide smoothly back and forth on those splines. It would be best to clean the rust from there, if it can be done without disassembling the transmission or getting rust inside the gearbox. You might try removing the seal and trying to brush the splined end with phosphoric acid carefully. Don't let the acid get inside.

[hogie]

I tried the shaft on the 4 transmissions I have and it will only go in an inch at furthest. It is engaging the splines, but only just. I will try to strip the paint off tommorow.

Brake parts cleaner should do the job nicely.

I will try to get the end of the tranny a bit cleaner, but the ones out of the car are in better shape already and it wont work with them.

[Arne]

Definitely the driveshaft, then. There must be something wrong with the splines part way in. Look carefully in there for damage, FO, etc.

[hogie]

Arne, you hit the nail on the head. Whoever painted/powdercoated that put it on extremely heavy. After about 4 soakings in paint remover the driveshaft slides right in.

It looks like the collar on the shaft slides into the collar at the end of the transmission. Is it possible to put the drive shaft in too far? I know on my old hardbody that could cause problems.

THanks

[beandip]

hoge, I have a complete drive shaft on my work bench and it measures 29 3/4'' from the rear flange to the tip end of the splined front section. This shaft is from a 240Z . Hope this helps answer your question.

Gary

[Arne]

Shafts from '70 and '71 are shorter, as the diff was mounted farther forward. My spare '71 shaft measures about 28 1/2", maybe 28 3/4".

[hogie]

After a long break on this thread I have made some progress on other parts of the car and come back to this.

Unfortuneatly, something is wrong with my tranny or driveshaft. I was cruising at a steady speed in 2nd and went to 3rd slowy. At which point I heard a whirring, sliding sound coming from the transmission. A second later it felt like the rear of the car was binding and vibrating real bad. So I clutched in and slowed to a stop. The noise continued with the clutch in.

I couldnt see anything wrong and was in a bad spot on the road so I backed into a turn around. Once I went back to reverse the noise/vibration went away and I limped back home in first and 2nd. When I tried to go into 3rd a second time the same thing happened. I know 3rd isnt blown out as I used it when I first left the house. Perhaps something backed loose, but I have no clue what is causing it. The only other symptom is that I get a funny chirp sound almost like a belt squeel when I get off of the gas and stay in gear. It is extremely short in duration and may not be related.

The only thing that I can think of is my drive shaft is shoved pretty far into the tranny. I had an extremely hard time fitting it into the car. The Ujoints are newish and as of two months ago the tranny was full of fluid. I am at a loss on this one, but at least the engine runs nicely now!

[Pomorza]

After a long break on this thread I have made some progress on other parts of the car and come back to this.

Unfortuneatly, something is wrong with my tranny or driveshaft. I was cruising at a steady speed in 2nd and went to 3rd slowy. At which point I heard a whirring, sliding sound coming from the transmission. A second later it felt like the rear of the car was binding and vibrating real bad. So I clutched in and slowed to a stop. The noise continued with the clutch in.

I couldnt see anything wrong and was in a bad spot on the road so I backed into a turn around. Once I went back to reverse the noise/vibration went away and I limped back home in first and 2nd. When I tried to go into 3rd a second time the same thing happened. I know 3rd isnt blown out as I used it when I first left the house. Perhaps something backed loose, but I have no clue what is causing it. The only other symptom is that I get a funny chirp sound almost like a belt squeel when I get off of the gas and stay in gear. It is extremely short in duration and may not be related.

The only thing that I can think of is my drive shaft is shoved pretty far into the tranny. I had an extremely hard time fitting it into the car. The Ujoints are newish and as of two months ago the tranny was full of fluid. I am at a loss on this one, but at least the engine runs nicely now!

Last time my Z had a chirp noise that you described the U-joints were nearly completely blown. I would go under the car and take a nice look at the shaft again. It is possible that there's something there that's making the noise or binding the transmissions/drivetrain.

Hope that helps

Jan

[hogie]

The Ujoint feels fine...though I think the tranny is toast. I shoulda posted my response in this thread instead of the Carb problem. Oops

I jacked the car up and ran it through the gears at idle. 1rst and 2nd no problem. As soon as I hit 3 it sounds like crap. fourth sounds even worse and vibrates even more. 5th just pops right out as soon as the clutch is released.

Also, after my extremely short drive last night the tranny was quite warm. Any one else agree that it sounds blown? I had a hardbody 5spd crap out once and it sounded like gravel was running through it.

I have 3 transmissions in the attic to hopefully one of them is good...in fact one is marked 77 good in Junk yard paint on the top. Too bad I think they are all four speeds. I havent found any good ways to tell them apart externally. They all have L6 on the side with the B type shifter and a #6 towards the tail end.

[hogie]

Ok, I have the drive shaft darn near out of the car, but ran into a problem. The drive shaft flange is stuck to the rear end. All bolts are out and I can't get the two seperated. Is it acceptable to whack at the joint with a brass punch or a rubber mallet?

Also, it looks like the front differential mount is facing the wrong way. This was/is pulling the rear end and driveshaft into the 71 position! I think this is why I had so many problems with putting it in in the first place.

Right now i have the tranny half dropped and the rear diff loose. The drive shaft is pulling out of the transmission and not away from the flange. It has just a fraction of an inch not out.

If I am lucky moving this back to the way it should be will get rid of some of my noise/problems, but I doubt it.