Dont even know what to title this...

My friend has a 240Sx fastback (shockah), and he says "Whenever I go in reverse, it makes a big whinning noise and the a knockish sound (not in the engine tho)." He's a little worried over it and I didnt feel like looking for problems that I eventually wouldnt even find, so I figured I would just ask you uber cool guys. lol Also I wont lie, I plan on buying the car off of him as a daily around fall (not a bad car for a flat grand).
Gracias...

Mine whines pretty loud in reverse too, sounds kind of like an R/C car. When I rebuilt my tranny the noise became a lot better. Is that thump it makes when he puts it into reverse? or while he's backing up. Unless it's really bad, it's probably not too big of a problem.

Does the noise happen every time he puts it in reverse? My car will only make the thump if I'm slowly rolling backwards and try to put in reverse. My friends truck makes the whiny noise. I'm pretty sure thats ok.

its normal

isnt reverse a straight cut gear?I know it doesnt have a synchro

Reverse gear does have a syncro, as well as a reverse idler. The noise is actually normal. Most cars today have their final drives helical cut. Helical cut gears always make whining noise.

yeah it's just normal, every car makes that whining noise in reverse (at least when you're driving 'faster' in reverse)
some really old oldtimers only have straight cut gears in the gearbox, they make that whining noise all the time

O okay then. Well he asked me if mine car made that noise in reverse and I replied w/ "If so, not like that..." So he/we werent sure. OK then everything seems to be pretty good then. Thanks alot for the tad bit of help. Should be frequenting these forums more often...

My car makes a grinding/clunking noise when I first release the clutch in reverse after I've just come to a stop going forward. At first I was worried about it, but recently I noticed that it only clunks for the first few feet and then it's smooth after that. If I take the time and come to a complete stop (like the manual says, ha) then it doesn't clunk/grind at all. I just chalk it up to an older tranny moaning and groaning...

As for the whining, reverse has a straight-cut idler gear which make much more noise and that's the cause of it, and it's totally normal. Some races cars use straight-cut gears because no thrust loads, which I suppose makes them more durable. Uh-oh the engineer in me is sneaking out.. I'll stop before I really get dorky.

As for the whining, reverse has a straight-cut idler gear which make much more noise and that's the cause of it

thanks for telling us :cwm27: