Transmission noise/chatter?

[Stupid_fast]

Hello, I have just gotten my exhaust installed on my 510 wagon with 280zx 5-speed. Driving it back from the shop now that it is a lot more quiet I noticed when engine braking especially in 4th/5th there is a sort of whine/chatter from the gearbox, if I apply power/freeway cruising it feels and sounds fine.

 

I'm curious what is wrong, currently I have no carpet and the shift hole is just a bit cut hole in the tunnel (I can see the ground/driveshaft while driving (rofl) so I can hear it more clearly Is it a normal noise?

I also found out that I installed the throw out bearing backwards, and I need to pull the engine to fix that soon. Could that be causing this noise?

 

 

Transmission is used with new fluid, clutch is new, flywheel is new, flywheel bolts are NEW nissan OEM w/ blue threadlocker, t/o bearing is new(but installed wrong), slave/master cyl and soft line are new, rebuilt engine/all of that is new.

 

Bolts where all torqued to spec ... Could have come loose Maybe?! It sounds like its in the trans, though.

 

Sounds like it comes from the transmission, but the diff oil is old and diff case is wet. I'm changing that out this weekend, could it cause this?

 

Have been searching this but have not found a good answer.

 

Thanks.

[The Dat-side]

What about when you engage the clutch? I forgot where I read this but, some aftermarket clutches don't use the correct springs that go around the clutch (don't know what they're called). I'm having a similar problem, goes away when I press the clutch or at lower rpms.

[Stupid_fast]

What about when you engage the clutch? I forgot where I read this but, some aftermarket clutches don't use the correct springs that go around the clutch (don't know what they're called). I'm having a similar problem, goes away when I press the clutch or at lower rpms.

 

Only happens under engine braking = with clutch engaged and in gear over 2krpm's. I was driving mainly on backroads 2,000-3,500rpm's with gentle throttle since its a rebuilt engine.

 

I will try to get a video tonight or tomorrow. Its an OEM Nissan roadster pressure plate(30210-20111), Exedy Datsun 510 disc, AASCO 11lb 6-bolt flywheel.

 

 

Trans fluid is royal purple synchromax, fyi.

 

I thought the pressure plate bolts don't need locktite? is that incorrect? could those have gotten loose?

 

 

Mainly I just want to know if its bad to keep engine braking even with the noise, will it wear faster? I can just avoid engine braking but it can be annoying on the freeway. I am driving to long beach in 2 weeks, does this have to be done before then?!?!

 

Thanks.

[Stupid_fast]

Wait- Is my throwout bearing on wrong??? I saw some other pics on threads here showing that the lip is suppose to go IN, not out, but if I put it the other way around it would jam the bearing... Or am I looking at it wrong?

 

 

Its a NSK bearing... Should I order a new one and pull the engine?

[banzai510(hainz)]

T/O bearing photo on bottom looks Like the correct one.

[Stupid_fast]

T/O bearing photo on bottom looks Like the correct one.

 

But... Is it on the right way? In that pic its pressed onto the sleeve showing the top of the bearing that's contacting the clutch...

[datzenmike]

This looks correct... Top with rounded edge contacts the diaphragm fingers on the pressure plate.

 

 

You said the diff case is wet??? Before you do anything check the oil level in it.

 

 

While under there check all U joints for any looseness.

Check the rear tranny mount bolts to the body and to the tailstock.

Check that exhaust pipe and/or muffler cannot rub anywhere on the body, trans or driveshaft.

 

.

[banzai510(hainz)]

like I said the photo on the bottom is the correct way.

[Stupid_fast]

This looks correct... Top with rounded edge contacts the diaphragm fingers on the pressure plate.

 

 

You said the diff case is wet??? Before you do anything check the oil level in it.

 

 

While under there check all U joints for any looseness.

Check the rear tranny mount bolts to the body and to the tailstock.

Check that exhaust pipe and/or muffler cannot rub anywhere on the body, trans or driveshaft.

 

.

 

OK sounds good, at least I probably don't have to pull the engine... I'm doing the rear end diff oil, seals and lowering blocks tomorrow.

 

The driveshaft I got from the p/o looks like it was shortened and never installed... looked good.

 

Engine was just put in... All mounts are tight.

 

Exhaust was just installed by Troy Ermish ... Seems perfect.

 

I will check it all tomorrow, thank you both!!

[banzai510(hainz)]

I would look in to this whine before loweing the wagoon.But then again it might fix it.

 

Im not in to synthectic oil myself

 

I have run m clutch bolt with and with out thread locker and have been fine

 

 

datto510 had a whine on his 521 with the 5 speed. In 5th he would hear a little whine under load. He haised the carrier bearing. was fixed

[josh817]

Forgive my ignorance but he "haised" the carrier bearing? What is that? I only ask because I have the exact problem. My tranny whines in every gear except for 4th and only after it has warmed up and is under load. My 5 speed is from a 78-79 Z, I know this from the gearing it is exactly like the box I put in my Z where 4-5 are very close. Reason why I say this is because on the Z 5th always whined.

 

I don't know if I should address the problem or not because the tranny is holding up just fine even after 4 hours of 80mph. Shifting isn't difficult, has two quarts of gl4, and like I said only whines after driving for a few miles and only when its under load.

 

I do notice like in lets say first or second gear if I'm in trafic and using the engine to brake, you can hear it chatter. That's all Ive got, seems just like OP's problem.

 

PS I posted this using my phone while taking a shit so again, excuse my errors.... And odor.

[Stupid_fast]

Uh yeah, what is haising a bearing?

 

Even with all the noise, I've just learned to double clutch into every gear that would grind otherwise, I suck with manual gearbox so its a good POS to learn on.

 

Its strange because I cannot hear/feel any chatter while applying power ... even full throttle. (now with broken in engine) Only on engine braking ... sometimes when aggressively pulling out the clutch in 1st(big hill, ect) it will chatter/grind a bit, if I don't double-clutch into 5th it will also chatter/grinding noise.

 

Mine does not chatter at low speed in 1st/2nd ..

 

As for the blocks, I had the wrong u-bolts so I never dropped it. still waiting for those to arrive. New diff oil, didn't make a difference.

 

It didn't seem better or worse after 400 miles/ 6 hours drive to Los Angeles, 70-80mph the whole way.

 

 

I think the best solution is to rebuild the trans, or get another one to drop in.

[datzenmike]

A two piece driveshaft is supported somewhere in the middle by a carrier bearing. If the body is lowered it throws the drive shaft angles out so Raising the position of the carrier bearing helps to counteract this.

 

 

1st, 2nd, 3rd and 5th gears are driven by the counter shaft. Power from the mainshaft (from the clutch) is transferred by gears down onto the countershaft and depending on which of the 1,2,3 or 5th gears is selected, back up onto the mainshaft again and out the tailshaft. The countershaft runs parallel to the mainshaft and supported by bearings.When under load the main and counter shafts try to force each other apart and the bearings job is to prevent this but allow them to turn efficiently. When one or more of these bearings wears out there will be noise in any one of the 1,2,3 and 5th gears or all of them.

 

Why is there no mention of a 4th gear? Because there really is no 4th 'gear' in a five speed with overdrive. Forth is really transmitting power straight through along the mainshaft with one turn in to one turn out. It's relatively unaffected by bad bearings because there is no side load generated against the countershaft or it's bearings. This is why 4th is often much quieter than all the other gears.

 

To reduce unnecessary side loading... never tow, climb hills or pass in 5th gear. ALWAYS DOWNSHIFT INTO 4TH GEAR FOR THIS.