ZCar Forum banner

1 - 12 of 12 Posts

·
Registered
Joined
·
51 Posts
Discussion Starter #1
Okay, now this might be a dumb question, but my 1987 300zx is having some strange noise issues (can be seen in my last post) and I’ve had several people tell me several different things. One guy told me that changing/filling up the oil in the transmission would fix the issue. I’m fairly sure the oil needs to be changed regardless of if it fixes the issue. But, I’ve got no clue in the world what type of oil to put in the thing. Any help would be greatly appreciated. Thanks! -Carson
 

·
Registered
Joined
·
3,785 Posts
Redline MT90 is a very good fluid for the Nissan transmissions. Better than a stock 80W-90 oil.

Before you do anything, crawl under and remove the fill plug. Stick your finger in the hole and see how much fluid is in there.

Don't know if it will fix your noises I didn't see your other post.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #3
Thank you! Yeah, I had no idea what on earth to put in that thing. I appreciate it.
-Carson
 

·
Registered
Joined
·
148 Posts
First, quit running this car until you have checked all the fluids, engine oil, coolant, transmission oil, differential oil. If you know the previous owner took care of these things you probably don't have to worry but check them.



Information about lubricants is in the FSM section GI. The Nissan transmissions use GL-4 oil and GL-5 goes in the differential. Red Line MT-90 is a very good GL-4 manual transmission oil. It is great for shifting and can withstand abuse.



From your previous post, your transmission is making some ugly noises when in neutral with the clutch released. Make sure there is some decent oil in your transmission.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #6
Okay, so I’ve checked the oil in my trans (Which is Manual) and there is a healthy amount in there, it is starting to have little signs of brownish gray in there from what I saw but for the most part it looks good.
I have no idea at this point what could be causing the noises, and without I car lift there’s no way I could pull the transmission to check the throw out bearing if that could be the problem.

I think over the summer I’m going to do a full car tear down and just see what’s wrong with the car and what’s not, and go from there with replacing and fixing. But it would definitely still be beneficial to know what that crazy noise is! I guess time and learning will tell. Thanks! -Carson
 

·
Registered
Joined
·
148 Posts
Okay, so I’ve checked the oil in my trans (Which is Manual) and there is a healthy amount in there, it is starting to have little signs of brownish gray in there from what I saw but for the most part it looks good.
I have no idea at this point what could be causing the noises, and without I car lift there’s no way I could pull the transmission to check the throw out bearing if that could be the problem.

Gray is not a color I like to see in gear oil. Traditional gear oils are near black, while the synthetics can be much lighter. MT-90 is a light red or pink if my memory serves me correctly. Gray is usually ground up metal from something that was a ... I would either get a professional to listen to your noise, or drain your oil. Pay attention to the drain plug. It is magnetic on the transmission and you can see how much metal has accumulated.
 

·
Registered
Joined
·
148 Posts
without I car lift there’s no way I could pull the transmission to check the throw out bearing if that could be the problem.
It is quite common to pull/replace a transmission with jack stands and a floor jack. I will not say it is pleasant, but it is the normal at home method. (I recommend 2 people)
I have done the job once with a lift and transmission jack, and the job was relatively pleasant. No swearing at all.
 

·
Registered
Joined
·
51 Posts
Discussion Starter #9
It is quite common to pull/replace a transmission with jack stands and a floor jack. I will not say it is pleasant, but it is the normal at home method. (I recommend 2 people)
I have done the job once with a lift and transmission jack, and the job was relatively pleasant. No swearing at all.
That’s very interesting to know, I’ve got some larger jack stands, but the only issue is I haven’t been able to jack the car up high enough to even get the bigger ones under there. I’ll have to look into trying that. Good to know no swearing was involved:grin
 

·
Registered
Joined
·
3,785 Posts
This actually sounds more like bearings in the transmission, or a broken gear. Pretty common for reverse to get chipped when the MC or slave go bad. Angry shifters...

You should remove the fluid and check the magnet. There are probably metal chunks on it.

The washing machine sounding noise with the clutch pedal up (people get "release" confused, best to talk about where the pedal is), is common to these transmissions, it's the countershaft bearing. It's just the way they are, they're noisy.

The other noises, especially the popping and jerking in reverse are signs that a gear is broken or a bearing is gone. Especially the jerking part. That should never happen.

"To put it simply, during normal use of the vehicle, in reverse, the car makes a very violent popping and clanking noise occasionally. When the popping occurs the car jerks a lot, but it only really happens in reverse. I thought it might be a gear slip in the transmission, but I’m not exactly sure. I thought after freeing up the brake calipers and fixing the clutch, that it might stop, but no dice on that. It doesn’t do it once any other gears, however in neutral when your let off the clutch, I can hear what sound I can only compare to that of a washing machine, it’s a heavy loose sounding spinning noise and can only be heard while the clutch is released. Some help, would be greatly appreciated. Thanks! -Carson"
 

·
Registered
Joined
·
51 Posts
Discussion Starter #12
This actually sounds more like bearings in the transmission, or a broken gear. Pretty common for reverse to get chipped when the MC or slave go bad. Angry shifters...

You should remove the fluid and check the magnet. There are probably metal chunks on it.

The washing machine sounding noise with the clutch pedal up (people get "release" confused, best to talk about where the pedal is), is common to these transmissions, it's the countershaft bearing. It's just the way they are, they're noisy.

The other noises, especially the popping and jerking in reverse are signs that a gear is broken or a bearing is gone. Especially the jerking part. That should never happen.

"To put it simply, during normal use of the vehicle, in reverse, the car makes a very violent popping and clanking noise occasionally. When the popping occurs the car jerks a lot, but it only really happens in reverse. I thought it might be a gear slip in the transmission, but I’m not exactly sure. I thought after freeing up the brake calipers and fixing the clutch, that it might stop, but no dice on that. It doesn’t do it once any other gears, however in neutral when your let off the clutch, I can hear what sound I can only compare to that of a washing machine, it’s a heavy loose sounding spinning noise and can only be heard while the clutch is released. Some help, would be greatly appreciated. Thanks! -Carson"
Dude, that is some of the most useful information I’ve heard about this whole situation, I appreciate that. I’ll have to look further into those things. Also, good to know about a possible exploding transmission. But I’ve got another question, is it possible to save that transmission at all? Maybe like just replacing a gear or bearing for reverse gear? Because, if I have to I will, but I’d rather not spend an obscene amount of money on a new tranny. Thanks for the help! -Carson
 
1 - 12 of 12 Posts
Top