Tranny noise?

If you are kyle and work at a nissan dealer then you should be able to diagnose it better than us. also, you need to add more details on when it is happening. my first guess is the throwout bearing, happens when clutch is out, but has nothing to do with engine speed. if engine speed makes it happen then check your oil. maybe it is low. maybe a rod bearing, but dought it. does the noise ever go away? bla bla bla

Check the level of your tranny fluid, first. Especially if it's been leaking. That's what I love about using Motul 300 gear oil... stuff stinks so bad there's no way you could miss a leak.

Does your shifter have any extra play at all? It might be another vibration from something else coming through the gears. When you disengage them, the vibration/noise goes away.

Try the simple stuff first, then start to worry. If the simple stuff doesn't work, honestly, do a search using "tranny, transmission, noise" and see what you find. There's been lots of posts and answers to several problems... answers by people far more knowledgeable than me

Peace Out,
Mark

goneturbo said:

If you are kyle and work at a nissan dealer then you should be able to diagnose it better than us.

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uhh... I'm in sales, I'm not a technician.

The shifter has some play, but not a lot. It's not engine noise, because it does not make the noise at all without the clutch engaged. Can tranny mounts go bad?

does it make the noise when the clutch pedal is pushed on the floor or when it is up in the air? I figured that someone at the dealer would look at your car since you work there? especially if it is just diagnosing a noise. The tranny mount bolts can break, and the mount it self can go bad. but with my experiences when mounts go bad you get more a vibration and drone than a rattle.

Tranny mounts can definitely go bad... splitting, tearing and collapsing.

Go to se-r.net and keyword search motor mounts, replacing or some combo. You'll get some good info on how to jack your engine up to take look at the mounts

I'd start there.

Peace out,
Mark

Here's what happens as best I can describe it: When driving, at rpms around 3k and higher, there is a kind of droning rattle (almost sounds like something is loose?). At first I thought it was the engine, but then i noticed that if I push the clutch pedal and keep the rpms the same, the noise goes away. So it has to be something with either the transmission or the clutch.

your first guess about the motor mount sounds like a good one. it is hard to describe the way a bad mount looks. usually it is the passenger side that goes bad not the tranny side. the tranny internals really dont rattle. the engine will "knock" when it is bad. so my best guess is the motor/tranny mounts. anyone else have ideas?

El Gabito said:

Here's what happens as best I can describe it: When driving, at rpms around 3k and higher, there is a kind of droning rattle (almost sounds like something is loose?). At first I thought it was the engine, but then i noticed that if I push the clutch pedal and keep the rpms the same, the noise goes away. So it has to be something with either the transmission or the clutch.

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I have the same problem with my G20. Exactly the same, except mine changes intensity with load. Oil is good and tranny was just serviced and no leaks. Clutch is new with new t/o. I have new motor mounts as well (poly'd), but I still had the problem after replacing the mounts. I thought of two things

1) input shaft on tranny
2) intermediate shaft bearing (carrier, on passenger side halfshaft)

I think my problem is the 2nd. Although you'd think that since you take the tranny out of gear it would eliminate the halfshaft, but the engine's position is different under load. Out of gear, the engine is in it original position, but in gear the engine is twisted slightly and that shaft bearing is bolted to the block in turn loading up that bearing. That's my guess; I have a warranty on the halfshaft so I'm going to get it replaced eventually and see if that cures my problem. I just hope it isn't tranny related.

I know I have at least one bad motor mount (front). I'm getting that replaced asap. I thought that might be causing it, but I didn't want to drive it if it was something more serious.

hurddawg said:

2) intermediate shaft bearing (carrier, on passenger side halfshaft)

I think my problem is the 2nd. Although you'd think that since you take the tranny out of gear it would eliminate the halfshaft, but the engine's position is different under load. Out of gear, the engine is in it original position, but in gear the engine is twisted slightly and that shaft bearing is bolted to the block in turn loading up that bearing. That's my guess; I have a warranty on the halfshaft so I'm going to get it replaced eventually and see if that cures my problem. I just hope it isn't tranny related.

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Where is this at? I put my car up on the rack today, and it was leaking from where the passenger side shaft came out of the transmission. I guess that may be the problem.

follow the shaft to from the tranny towards the wheel, there is a place where the shaft bolts (3 M12 bolts) to a bracket and the bracket (3-4 M14 bolts) to the block. normally. the shaft between those two is called the intermediate shaft. But anyway the bearing (its just before the inner CV) is what bolts to that bracket. Try wiggling around the intermediate shaft and see if it moves, up/down left/right. if it does the bearing is bad. Even a little movement means the bearing is bad.

sorry double post

Good explaination, as a matter of fact i think my classic has that same problem. there as been an annoying clicking ever since i changed the axles. i'll have to check it out. learn something new everyday...

I think I can help. My G20 had a very rough noise coming from the transmission so I swapped it out with an SE-R one. When I took the old one apart I found a bad input shaft bearing. This is the bearing directly behind the front of the shaft where the splines are. A few of the balls inside the bearing look as if they had gone through a blender. The transmission currently in my SE-R was making the noise when I put it away for the winter but it had not gotten that bad yet. You can tell by listening at an idle, if the noise goes away with the clutch pedal depressed then its a good chance that its that bearing.

I stated the same thing earlier, input shaft bearing = throwout bearing. i'm not blasting you whitehawk i just want EL Gabito to answer your post and do the pedal check.

goneturbo said:

I stated the same thing earlier, input shaft bearing = throwout bearing. i'm not blasting you whitehawk i just want EL Gabito to answer your post and do the pedal check.

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throwout bearing and the input shaft bearing are different things. You have to take a part (rebuild) the tranny to get to the input shaft bearing. The throw out is changed by just removing the tranny.

the bad intermediate shaft bearing should be a rubbing/whirring/grindy sound, not clicking. Although clicking can still be attributed to the halfshaft though.

thanks for clearing that up.

Thanks, i'll check it out. I know for sure I need a new seal where the intermediate shaft goes into the tranny. The tech said he thought it paid 2 hrs. Is $45/hr pretty good for dealer work? That's my employee rate.

$45 per hour is not bad. The shop I work in is $74 for customers. Its an easy job though, you don't have a knowledgable friend that could help?