Manual Transmission whine

[Tulsa_S-13]

I just completed my auto to manual swap and noticed that first gear whines, almost like cars sound when you put them in reverse (that remote control car motor type of sound). I used Redline MT90 fluid. I only drove the car for about 20 feet and then killed it because i dont want this to result in any major problem unless it already is one. Any thoughts on what this could be?

Thanks, David

[intel]

same ****...... id unno.

[ucantstopthebick]

it could be your pilot bearing...does it make that same whining noise when your clutch is in?

[Chezedik]

Right, but it would make that sound in all gears, plus the KA (at least in the 240, can't speak for altima or hardbody) doesn't use a bearing to speak of, it's more of a copper bushing. I would suggest it is one of the internal shaft bearings, or your fluid may be low. As I am sure you have checked the level, try beating the crap out of it, and see if you can make it happen in another gear (or even the same after some hard driving) this can identify which bearing you may be looking for. Also, when checking level, look for particles. That may help diagnose your issue.

[youngmanvr4]

I sorta have the same problem. Only mine only does it when slipping the clutch. Which would be in reverse or first. All the way out it goes away and all ther way in it goes away.

[95lstegman]

young man, replace your release bearing.

others, take your transmission to a pro and have them tear it down and find your culprit, or just wait until it either falls apart on you or you get tired of it and find a junkyard 240 transmission and swap it in.

[KADreams]

If I put mine in neutral and let the clutch out it also whines. When I changed the fluid it got a little quieter, so I just said screw it. You don't hear about THAT many 240 manual trannies dying, so i'm not really worried about it.

[95lstegman]

KA, do you use a really rough clutch or have you ever? i wouldn't be surprised if it was your input shaft bearing. it's perhaps the most common to fail in the transmission.

[youngmanvr4]

Lol I just replaced it with a Factory Nissan one (the release bearing that is) when I did my swap. The guy I bought the engine and transmission from before said it made a sound (whine) and ACT told him to get a new release bearing. He didn't do it he just put up with so I replaced it before I put the engine and transmission in and I still have a whine. Is it hurting anything? Does it need to be replaced or just replace it if I want to get rid of the noise?

[InsanityInc]

Huh? MTs in reverse always make that noise. It's because the idler gear to create the reverse drive is a straight-cut gear, which is noisier than the helical cut that the normal drive gears use.

[TEKs240sx]

The problem is your first gear syncro. A good shop can replace all of your syncros and worn seals for $700. It sure as hell beats blowing the trans.

[95lstegman]

huh? i've never heard a synchronizer whine. and besides, it won't "blow" your transmission having old synchronizers. over time it will wear out the gears and the shift collars, and of course the symptoms will get progressively worse over time theoretically until you are forced to revmatch manually, although i've never seen anything get THAT bad. in any case the synchronizers are only there to help the gear and shaft match speeds without the driver's aide. if i had a bad bearing i'd rip it apart myself, but i've got a lot of experience with transmissions. my suggestion to you is just hang onto it and leave it alone. in a long time the bearing will probably fail, at which point you MUST stop trying to drive it, and then you'll have the choice to spend several hundred dollars having a shop fix it or spend several hundred dollars and get a fresh transmission. it will probably be about the same money either way, but a fresh transmission will probably [hopefully] have fewer miles on it. if you plan on keeping this car forever then have it fully rebuilt. there are few things in a driver's life as sweet as having a new transmission at his command. it ranks up there with finally installing an LSD, or finally getting a low-boost turbo kit working.

[TEKs240sx]

Lets say that the syncronizer seizes from friction due to misalignment which in turn seizes the input shaft and drivetrain assembly. The rear wheels lock and all of the torque from the engine is now riding on the transmission internals. Guess what.....Boom. Do your homework next time.

[TEKs240sx]

I forgot to add. Remember that this is a truck motor, plain and simple with 143 lbft of stock torque. With a flywheel spinning at 6700RPMs. Imagine a loose syncro because the car is old and has never had proper transmission maitenaince. It can happen, it has before. He just better get it rebuilt before bad things happen and they will. You cannot ignore the drivetrain. Manty of folks have lost their legs because of flywheel dismounting at high Rs. I have almost experianced this first hand. I don't mean to be confrentational but this is a serious thing not to be neglected.

[95lstegman]

damm guys. you guys seem to be way too experienced with the rare, quirky stuff. i've never seen a synchronizer sieze, although i guess it could happen. but since it only rides on the gear, if it did sieze, you'd just have a hard time shifting unless you rev-match. now if the whole gear siezed on the shaft, then you'd get something exactly like you just described. in any case, my recommendation is still to just replace the transmission unless you love this car to death and plan to keep it forever, in which case you should have it rebuilt.

[TegConvert]

actually the synchro does more than just help the gears match speeds, In fact it is the dog cut teeth on the side of the gear than the synchro grabs hold of to DRIVE the gear.

Check your fluid level. noise with the clutch released is the TOBnoise with the clutch pushed down is the pilot bushing. reverse sounds that way because reverse is almost always a spur cut gear. forward gears are usually helical, so if you are hearing gear noise going forward Id think you didnt have any fluid in your transmission.

[tonynalli]

hahaha a syncro seizing at 6700 prms..not to be an *** but if you driving that fast on a transmission thats on its last leg then...uhhh there are some things that might **** up.but if a syncro goes bad then it will more then likely crack and you wont be able to get the car into gear...i would highly doubt that your transmission would completely destroy itself and kill you..but hey...lifes a *****

[Manzai]

I'm also having the same problem in my '93 altima SE. At idle in neutral there is a rattle. Icouldn't fugure out if it was bottom end knock or not. Then I found that if i depress the clutch pedal the sound stops altogether. If i put it in gear and release the clutch, it makes a scraping noise. The scraping is present in all gears. My next idea was the throw-out bearing or the input shaft bearing. An "ASE" tech friend of mine noted that when i'm pushing on the clutch, the clutch assy. puts force on the flyheel and would take up any play that the crank's outputside bewaring would have. Any Gurus got diagnostic tips to help narrow this down? I'm going to be replacing both axleshafts soon, so dropping the transmission to look inside wouldn't be such a big deal. Anyways. . . . . any help would be greatly appreciated thnx.