Transmission noise

[Vinny720]

Alright I'm in need of some help. A couple weeks ago my transmission started making this weird noise when off the gas in 4th gear. It's not that loud but it's there and shouldn't be. It's like a rattling/screeching if that makes any sense. It does it in pretty much every gear but only when off the gas. But 4th is load and clear for some reason. Is it not enough oil? A bearing? I don't know. I have a friend with a 280z transmission that I might pick up if this is a big problem. If it's going to be something where I have to pull the trans I'm just gonna swap it because I could get it for really cheap. But if not then I'd like to not mess with it if it's something simple. Anyway sorry if I didn't make a lot of sense it's kind of hard to explain. But thanks in advance

[datzenmike]

Any transmission noise should be concern for checking the oil level right away, not driving it around. There's not much more you can do but check and or change it. Inspection is mostly looking for a leak. Have you ever changed the oil? If you bought second hand and haven't done it, you have no idea when it was done. It should be changed every 30K miles.

 

The zx s not a 'drop in' swap and involves trading the front cases and counter bearings. In addition the 720 used two different lengths of 5 speed. The zx is a long, yours may be a short.

[Vinny720]

I'm going to check/ change oil tomorrow and look for shavings. What would you recommend, swapping it out or just getting a rebuild kit. I know these little truck are simple and easy to work on but I really don't know a lot about these transmissions so I don't know what's the best thing to do.

[datzenmike]

First eliminate the U joints. Have them inspected. These can go dry and will ping and screech and make all kinds of different noises. They are also easier to change and cheaper than a transmission.

 

 

It might just be low on oil.

 

Get a couple of feet of garden hose with a dollar store kitchen funnel stuck in the end. Run it down from under the hood into the fill hole, usually half way up the driver's side of the transmission case. When it won't take more oil... it's full. If it is full, changing the oil probably won't do much. To check level, stick your finger tip in, you should be able to touch it.Two liters should be enough. GL-4 90W NOT GL-5. Oil must be 'yellow metal compatible' or 'safe for brass synchros'.