Transmission Rattle at High RPMs

[AnonymousCoward]

I just bought a used 240sx, 1996, manual w/ 200k miles.

At high rpms, mostly in 3rd & 4th gears, the gearbox area will rattle a lot. If I put my hand on the shifter it'll quiet down, and if I pull the shifter back by about half an inch and hold it then it pretty much stops altogether.

I've read that this could be caused by the rear u-joint. If so, would replacing it be that expensive?

In the near future I plan on upgrading the brakes & suspension and replacing bushings and possibly the steering rack, so I'd appreciate it if anyone could tell me if I should do any of these at the same time as the u-joint replacement.

Other minor issues: loose trunk/hood, trunk/gas button on driver's side doesn't work, window motor is dead. I assume getting these issues fixed at a dealership would be best, but if anyone has a better suggestion that'd be appreciated as well.

[compactfean]

Stock 240sx u joints are not replaceable. You would have to take it down to a driveshaft service place and have them chop off your old and install greasable, replaceable, ujoints and balance assembly....you're looking at about $150. Or you could do a one piece aluminum for $350 and up. Bushings are a major pita if youre doing all of them. Does the shifter have play in it? It sounds like the plastic ball on the shifter is gone causing it to vibrate. Just an idea.

[AnonymousCoward]

Yeah, it has some play in it. It can move easily about 1" up, 1" down, and about 1.5-2" to the left. It doesn't have any play really to the right.

Would something like this:
http://www.240sxmotoring.com/cispsoshbuni.html
fix that?


[Edit:] Also, the seller said he replaced the rear bushings recently so I'd probably only have to replace the front ones.

[compactfean]

Might help a little but I was more thinking something like this. http://www.240sxupgrades.com/19881999-n ... 86683.html your lucky because the rears are the hardest as far as the bushings.

[AnonymousCoward]

That's pretty cheap. I'll try it out.

[biggie]

Rattle is probably the shifter.

[AnonymousCoward]

Looks like they're sold out on those short shifters :/ Oh well, will try re-ordering the spec-d one in a week or so. Also, would there be any point in getting the more expensive shifters? I thought they generally went for at least $100, so these prices are pretty shocking.

Another minor issue popped up the other day. The clutch pedal stayed depressed and didn't come back up. I thought the clutch had given out, but all I had to do was manually pull up the pedal and it worked fine. It happened again the next day but the same quick fix worked. I assume there's a spring or something going out but not sure exactly what it is.

[compactfean]

probably out of clutch fluid...if that's the case then look at your slave and master cylinders. As far as the shifters go I've never heard anything bad about the cheaper ones....its a pretty simple design.

[AnonymousCoward]

Ok, so I finally got the short shifter ordered. Is it worth getting a lower rubber boot to replace the old one? That was suggest elsewhere in a guide, but they didn't give the reason why. If it'll help reliability/maintenance then I'll do it, but if it's just for cleanliness or something I might pass since they're almost $60.

I also picked up a full polyurethane bushing kit (+steering rack bushings) so I'm looking at replacing those once I install new shocks & springs. Is there any other suspension maintenance that should be done at that time too? I think I might add a sway bar too, but I'm sure there's some old, worn out parts that I didn't buy replacements for yet.

[nifares240]

if your boot is torn, get a new one or from a junkyard. the smell of gear oil will stick in your interior if the boots are torn. also, debris can fall inside the shifter/transmission assembly. you'll know what I mean when you change your shifter. get a small gear swivel wrench for those front bolts on shifter assembly because they suck.

those poly bushings are waste if you are updating your suspension arms. what you only need from that kit are control arm bushings, sway bar link bushings, and steering rack bushings. buy new control arms; press out the bushing and replace them with poly ones. the rear knuckles are pain which has the longest down time. I suggest getting a spare rear knuckle and do the bushing. and then is just a matter of swapping out.

[AnonymousCoward]

Yeah, I can't smell anything coming from it. The boot isn't torn or anything, just not sure about the rubber seals underneath it. But since I don't smell anything strange I guess it's not a big deal.

I wasn't thinking about upgrading the suspension arms yet, if ever. Maybe far into the future. If I only plan on lowering the car about 1-1.5 inches would they be required to correct the suspension geometry? I pretty much just want to upgrade the shocks/springs, but beyond that I don't really feel like messing with the suspension since I don't want to f*** it up (not a huge car guy). If control arms would be required to correct settings changed by new shocks/springs then I wouldn't mind adding them, but I just don't want to get that involved in the suspension if I don't need to.

[nifares240]

shocks and springs are fine. yet, they offer the best drivability. you don't want to go too low. bump steer will suck. 1 to 1.5 inches is not a big deal as long as you can set your toe alignment to zero degree. enjoy your car.

[compactfean]

At that hight rear camber will start to go in the negitive...about 2 degrees. Whitch is good for handling but bad for traction...either way keep your toes straight.