moyest

Hi folks I've posted questions on this a while back, see if you can spot the problem - When I hit 50mph I get a rumbling sound in the cabin, and vibration from the rear. Once I hit about 65mph+ it disappears. Suggestions so far are things like tailshaft, CV's/U-joints, outer bearings, etc... UPDATE: I had my car on a "rolling road" DYNO last week, and when I hit 50-60mph the guy said my rear left wheel was tramping up and down a bit (kind of wobbling). Makes sense. I guess if my rear left wheel is bumping along the road then it would feel a bit like an out-of-balance driveshaft or similar. Kind of feels like I have one square tyre! It's not tyres though, because the first thing I did was balance and rotate the wheels. SO WHAT WOULD CAUSE THAT? :stupid:

Well, in response to all of the above: The vibration doesn't come through the steering wheel as much as it comes through from behind the seats (and through them?). I also can hear the vibrations behind me (no smart remarks please!!). Tyres are fine. That suggests it must be U-joints or an unbalanced drive shaft?? Not sure. Any other suggestions? I would have thought it was quite "common" - I've driven other Z's that develop clunks or vibrations, and thought it might be a common weakness?

Help! My car has developed a vibration at about 45+mph. I notice it more when I accelerate, but I guess even when I take my foot off the gass it's still there a bit. Opinions so far include the drive shaft being out of balance, or the diff and gearbox not lining up true. I dunno!? I've heard horror stories of Z suspension or drive shafts collapsing at speed because people ignore these problems. I don't want that to happen! I also get a metalic "click"/"clunk" changing into 3rd, 4th or 5th gear (but not 2nd). So, I wonder whether the spline between drive shaft and diff is worn out? Any advice re: drive shafts/vibrations/diffs??? P.S: the vibration is NOT from wheel balancing - I checked the most obvious thing first.:stupid:

Fellas! Someone told me the "clunk" is normal. I didn't believe them. My "clunk" is even more mysterious! It developed after about 3 months of ownership (but of course it was already 30 years old). The clunk got steadily worse over about 2 months, then became a "bump" behind the seat. I had the diff mount renewed (and a few bushes) and it was all OK. The mechanic told me to REALLY tighten up the moustache bar bolts and those big ones that run right through the suspension arms. i.e: get the car on a hoist, and put your full weight into tightening them up. It worked for a while, but came back again. I took it to a local Z shop and they were miffed by it. They predicted there might be play in the diff!? The mystery remains unsolved. P.S: I get the "clunk" when I change into third or fourth or fifth (but not usually second).

Hello! I'm trying to get a bit more performance out of my 240Z. It's a 1972 model, and I want to go the "old school" route (not turbo, not EFI). You can check out pics of my Z at my website, just to get the picture (pardon the pun): www.angelfire.com/pro/240Z I was thinking triple weber DCOE40's (which are legal in my country, no problem!). I even found what looks like a good supplier for a full kit with linkages, anti-vibration mounts, and even a cold air box! But the PRICE! Woah mamma!! Check out the site: http://www.racetep.com/ztripdcoe.html Anybody have suggestions on reliable triple carbs for a decent price? Cheers!

Dear 280zx fever, Before you get into the webber 45's, you may want to check out this link: http://www.racetep.com/webcatframe.html Go to the link titled "Before chosing your REDLINE Kit". Read the info on the way the webbers are usually set up (i.e. "de-tuned"). I'm not expert, but I've been told that 40's would be fine even if your engine is pulling high revs. Like you said, it's all about jetting! Check out the rest of that site too, it's very informative! And check out MY website while you're at it!!! www.angelfire.com/pro/240z Cheers!

Greetings! I've put together a few photos of my 1972 240Z for you all to view and comment on: www.angelfire.com/pro/240z Check it out and tell me what you think. Also, I'm thinking about doing more mods on the engine, perhaps triple webber set-up? If you've done that yourself and have any advice (especially on how to save money!) let me know.