I picked up my 1980 280ZX a few weeks ago with some transmission issues. Drove it to my house, half-dropped the transmission to change the clutch, only to discover its just fine, as is the throwout bearing. So, we correct the clutch fork's problem of not being on the ball, and reassemble. I accidentally tipped the battery over, so we got a new one.

She started up just fine, but as soon as I tried to drive it the problems started again. Like i said, engine is great, and I'm pretty sure its got a rebuild under its belt fairly recently, b/c 200k mile engines don't sound this good.

1st off, is that there is no neutral. It refuses to come out of gear. I think it can be put into other gears, at the very least 1st and reverse, but not neutral. The closest I got it today was where it wouldn't die when i let off the clutch, but there was still a grinding squeaking sound coming from the gearbox, and looking through the shifter hole I saw the drive-shaft trying to rotate in time with the squeals. So, that's one problem.

The second is when the car is moving, there is the sound that is almost identical to that of an RC car being pushed instead of using the controller, that higher-pitch scrape-whine sound. When my brother walked along with the car, he said that the sound appeared to be loudest when the front wheels passed him, and as the speed picked up so did the pitch of the whine. The steering wheel also jerks rapidly back and forth, only about 1/2 an inch, I'd say, and I believe these to be related, though I have never heard the "whine" of a power steering pump low on fluid.

Lastly, of the major issues, anyway, is something concerning the rear end. I replaced the U-joints on both rear half-shafts, as they were terribly worn. I changed the gear oil this afternoon after re-discovering this problem. Which is, bangs and pops. Very loud, to me, though my brother alongside the car heard them only about a third of the time. While under the car, we have discovered that most of the rubber is shot, including the rear control arm bushings and all. I kinda think that those sounds could be related to that. Something like, gaining tension when it starts turning, then having the bushing buckle, making a bang... but I dunno.

There you have it... three things preventing this from being my DD. Well, along with my seats not being fully mounted yet, too... which gets to wait for some insulation to finish being put down. BUT all that will be done in a day or two

Any help, experience, ideas, anything would be greatly appreciated!

 

Steering shake could be a number of things. Warped rotors, tires out of balance or severely worn are some of the most common issues.

Did you check to see if there is even any fluid in the tranny? If it's dry and it has been that way for awhile, you may have things seized up in there.

The "clunk" in the rear end may be some loose mustache bar bolts. I think there are only 3. I need to check mine, but I keep forgetting.

 

have you checked the fluid in the trans yet?


you can also get all new bushings in polly from Energy Suspension

 

Steering shake happens any time the steering wheel is turned from center, not just when the car is rolling.

Transmission fluid... that could be it, considering I did NOT plug up the rear end of it when I pulled the driveshaft and shoved it around, and nothing came out... Haven't checked it though, but I will later today/tomorrow when I get over there, as with the power steering fluid.

Rear control arm bushing set form Energy Suspension sold at Autozone is 33 dollars, so im glad that is cheap

 

dont drive it again untill you know theres good oil in there and plenty of it.

 

the extent of my driving it was puttering in about a 10-yard circle by my shop lol, but I gotcha. I'll head into town when I'm done with this DISH-network application and grab some tranny oil, and see what happens.

 

For extra protection, put 80-90 gear oil in the transmission. Castrol or Valvoline. For really good stuff, but don't kill the wallet, like Royal Purple, and the like. Good luck man.

 

DONT put GL-5 gear oil in the trans either if you can help it. the sulfur in it will eat up the brass syncros over time. Use a gear oil that is rated for GL-4

 

There was no GL4, so I had to use GL5. Flushed and refilled transmission + rear end fluids, and now there is neutral! Most of the problems are now gone, except for the screeching, and that neutral still has some noise it shouldn't, but its DEFINITELY a lot better.. And come to find out, has nothing to do with steering. It is related to the clutch, because it goes away when I disengage the clutch.

Any ideas?

 

Update: Except for feeling loose and floaty (due to bad shocks on all 4 corners, and surely degraded and crappy suspension components) the steering is fine.

I drove it today, for about 14 miles round trip into town and back. Discovered a few things. Firstly, 2nd and 3rd make no squealing noise. Secondly, 1st, 5th, and reverse make squealing noises. Thirdly, 4th is a serious pain. WHEN I can get it into gear at all, it is fine. However, when I take my foot off the gas, it disengages and goes into neutral. However, I don't recall it squealing in 4th. The squealing increases with speed, not RPM, in case that makes something click in an idea.

On a couple side notes, my left turn signal does not work. Not the bulb burned out or anything, but full-on doesn't work. It does not turn on the in-dash turn indicator nor the outer ones, but the right hand turn signal is flawless. The second side note is that the speedometer is crazy. It fluctuates by about 5 MPH at all times, just going up and down and up and down.

Lastly, a question that I will also search but since I'm typing now, may as well ask. Does a 1979 Datsun pickup have the same transmission as my car, if it is a standard? If so, I can source a transmission for 115+tax, presumably in working order. Front passenger side wrecked, drive-shaft already pulled. If its not the same, though, I think I'm going to take this transmission to a shop for inspection

 

Update, one post up. Just edited since I had an extra one on accident.

 

Another update:

ordering THIS when I measure my front sway bar.

Spoke with my mechanic about the transmission behavior, he bluntly told me that it would be cheaper to get a new tranny than have him rebuild it. Bearings are bad, and the races are probably broke on at least one, b/c of the 4th not going/staying in gear.

Picking up a 5-spd, in presumably good condition, will discuss it more when i get there to see, for 350. If all goes well, ill have it in on Friday.