Rattle / pilot bearing?
 

I bought a 2004 RX-8 with 65k miles on it, and noticed a grinding in the clutch pedal, as well as a whirring/grinding noise when the clutch pedal was out. The dealer replaced the throwout bearing, and the grinding went away, but the whirring/grinding noise is still there (I told them to check the pilot bearing when they did the throwout bearing, they said it is fine, as is the input shaft bearing). Thing is, I think they are wrong, as the dealership was clearly unfamiliar with this car (Chevy dealer). When I release the clutch pedal, in neutral, I hear this noise. When I press the pedal down, it goes away. I can hear it under the car, and when inside the car, and it clearly comes from the clutch area. I also hear it (have to listen very closely) when accelerating in 1st and 2nd. I noticed that when accelerating to get onto the freeway, when I hit about 6k rpm, I hear a slight rattle in side the car. With the window down, it sounds more like a clank clank clank. I only notice in 2nd and 3rd, as I cruise at 80ish mph, and pushing 6k rpm plus in 4th and higher breaks 100 mph, which isn't a good ticket to have. This is only when the car is in gear, and high band RPM, and happens about 50% of the time. The noise comes from the same area as the whirring noise, and sounds like the same thing, just at a much higher rate of speed. I have also noticed that sometimes when I shift into 5th (and only 5th), it is hard, and sometimes makes a loud grind as it goes in gear (clutch fully pressed)

Any ideas / help would be greatly appreciated. Had a Mazda tech check out the motor, said it is in great condition, the car shifts smoothly, clutch works just fine, but this noise has me worried, and clutch parts aren't covered by warranties.

Not sure how loud your noises are but mine always used to make this noise, when I replaced the clutch it stoped. One thing you need to realize about the Rx8 is it is built for racing and is very light weight, as such you can hear lots more "strange noises" that are not muffled. I don't think you need to worry about it.

I think you will probably need to change the clutch soon, maybe 10,000 miles or so. Just keep an eye on it as long as the shifts are smooth and there is no slipping I think you will be ok. Once it starts to slip usually in 5th or 6th gear you will need to replace the clutch. I changed mine at about 56,000, so you are about ready for one.

I changed my clutch on my own it was $300 + $200 of tools (a great jack, jack stands, additional sockets, extender bars, torque wrench etc) then about 9 hours work. I think it will be over $1000 at the dealership.

It's actually my 2nd RX-8, and I love the car (first one was killed by a Fed EX truck, God rest her soul, no parent should ever witness the death of a child). I know the sound isn't normal, and I am 100% sure it's in the clutch, or one of the bearings related to the clutch. My main concern is can I wait till the clutch goes out, or should I just do it now? If I can wait, that would be great, because the clutch still has plenty of life in it, I just don't want to wait and find out I ruined something even more expensive. Currently on a fixed income (hope to change that soon), so if I can wait a while, it would be nice. If I have drop the tranny, I might as well do the clutch with everything else.

Gear turn-over noise, which is well-documented on this forum, can vary from car to car depending on tranny fluid, etc. On my 8 it's been loud at idle since day 1. You sure that's not what you're hearing?

^ +1 ,

Wrightcomputing, what makes you think the 8 is built for racing ? It's not 911 GT3.

I am pretty sure it's not a gear turnover noise, but can you post a link or two about it? I'll start researching it and post what I figure out.

Thanks.

The perfect 50:50 weight distribution, the fantastic chassis, the biggest and best brakes that have been fitten on any production Mazda, the rotary engine that is designed for racing with the linear torque curve and extremely high rpm.
Is it a Porsche GT3 no, does it cost over $100K no. but it is a sports car built for the track.

Like the advert says on any given weekend there are more Mazda's racing then any other make of car.

You''re 100% right. This thing was made for the track (and the canyons). It may not win any red light contests, but if you bought this car thinking you're going to smoke a Mustang int he 1/4 mile, you're a moron. It handles better than anything under $100k (and probably a lot of things worth more than that). It's clutch is so fine tuned, you can actually get it moving in 4th gear (not that you should). As I told my ex's husband (who thought it a good idea to challenge me in his Mustang GT on the canyons), you might take me in a straight line, but I'll drift circles around you in the curves, and in the end, I'll beat you by 5 seconds or more. Holding a line at the maximum speed is what it's all about, and this car does it better than any. A trained monkey can drive in a straight line, it takes something special to take it in the turns.

Now, back to my question, it's not a gear box noise that was mentioned above. I just want to know if I can drive the car with this noise till I need to replace the clutch. While I know there are no real definite answer's without taking it apart, any input would be very (very) appreciated.

If it isn/t rollover noise then it is internal damage to the bearings and gears in the transmission and it is too late for an easy fix :)

The transmissions can be quite noisy..especially if it has a short shifter installed...(or did) ...often the noise padding has been removed from around the shifter stalk in these cars :)

I dont know what " this track was made for the track "means, and, only a moron would attempt to take off in 4th gear, I see why he's your ex-husband. I guess you havent driven an Audi TTS, BMW 135i or the 370 Z , these are all way under 100k, yes, the 8 is a fine car, but its far from the ducks guts.
Wright, you gotta stop believing what you read in sales brochures.

That should read "thing was made for the track," and someone who can't even get proper punctuation down shouldn't judge a simple typo made at 6 AM, on a Saturday morning (something clearly only done after a long night on the town, so I was tired, LOL).

Anyhow, I have driven a TTS, the BMW, and while not the 370z, but I did drive the 350z (jumpy as hell). Anyhow, below is a quote from Motortrend -

"We noticed the same thing during our 2009 Best Driver's Car in which we had racing ace Randy Pobst give us his evaluation while carving Laguna Seca Raceway. Hit an apex and the 135i leans slowly, as if it had a 55-gallon barrel bolted on its roof. The four tires below scream in search of grip throughout the corner, progressively tracking farther off line the harder it is pushed. The 135i loves to be driven to the track, not on it.

Read more: http://www.motortrend.com/roadtests/...#ixzz1goyhVq35"

Car and driver 4 of a kind test (TT, 350z, Mustang, RX-8, and oh yeah, the RX-8 won this one)

http://www.caranddriver.com/comparis...mparison-tests


And finally, I don't see any of the cars you mentioned on this list either.

Wheres the incorrect punctuation, what makes you think I dislike the 8? It's loud mouth know it all's that believe everything they read that get under my skin. Do me a favor , don't bother responding, I have no desire to get into a pissing match with you.

Well, lets see, you don't know how to use apostrophes, nor cite things properly (I said my ex's husband, not my ex husband, as my name is Tony, not Toni). It's not that you don't want to get into a pissing match, it's that you started a pissing match, picking shots at someone who was simply (and politely) trying to answer the question I asked here, and more than once picked shots at the guy (even after I tried to politely push the discussion back to the topic at hand, which is the bearing noise), and when you got put in your place, by a person who has researched the topic in extreme depth, you didn't like it. If making sure I am informed before I make a comment makes me a know it all, then know it all I shall be, as, it is better to make sure one has facts to back up their random crap before they spew it out.

If it's a damaged bearing (my vote is pilot bearing), can I continue to drive the car until the clutch needs replacing, or will it damage the input shaft, or anything else in the gear box? I am just trying to gauge if I should fix it NOW or if I can wait till I do my clutch. The car shifts fine, smooth, etc, so I think it's okay, but I figured if I could get some opinions/info, it would be smarter than just assuming anything, cause all the Mazda Tech will say is, "it could be nothing important, it could be something bad, I won't know till I drop the transmission, and at that point, you might as well just replace everything."

Think about how the clutch works....when does the pilot bearing come into play?


When is your noise?

When the clutch pedal is pressed it goes away, when I release the clutch pedal, it comes back (in neutral). I can hear it quietly inside the car (almost sounds like 2 metal plates rubbing together), but it is much more noticeable from under the car. It's not noticeable when the car is in gear, during the low to mid band RPM, but at high band, I can hear it, as it gets louder.

I had seen on some of the forums that you can squirt lube up there, but if that's true, how do I get it inside? Would I go through the boot (where the stick comes inside the car)?

Do you know what or where the pilot bearing is ???

Did you think about my first question? Does the input shaft turn with the flywheel when the clutch is out? When it is in? When is the pilot bearing actually active?



You can answer your own question if you think about it

PS:..there is a seal on the input shaft that would keep any lube you squirted up there from getting on the pilot bearing....you could possibly lube the throwout bearing like that....but it would end up all over your clutch disc if you tried...not a great idea

Think there is a bit of confusion there ;)

I think so.

Tony, I think the bearing you refer to is the throw out bearing, and, if it was failing, the noise would be noticeable when under load,when your clutch is depressed.

Throw out bearing was replaced by the dealership when I bought the car, as that was my first guess too. Took it to a Mazda tech in West LA, it's the pilot bearing. If the sound is when the clutch pedal is in, it's the throwout bearing, with the clutch pedal out, it's the pilot bearing. As dannobre was politely pointing (thank you by the way), the input shaft goes into the throwout bearing, when the pedal is pressed, it separates the input shaft from the input bearing/flywheel, that's when the throwout bearing is being used, when the pedal is not pressed, input shaft is inside the throwout bearing, thus it's in use.

They wouldn't tell me if it's okay to wait till I replace the clutch, so do you guys think it's okay to wait to replace it, or should I just do it all right now? Aside from the noise coming out of it, the car runs fine, I just don't want to dump $1500 in car repairs right before Xmas, but if I need to I will.

In regards to if I know where they are, how they work, etc, yes, I have basic knowledge, but I wasn't sure what the difference was between the two bearings there. Any input anyone could give on wether I should replace now or if I can wait is greatly apreciated.

When the clutch is out...the flywheel and input shaft are linked by the clutch....so there is no movement at the pilot bearing. When the clutch is in...the input shaft and the flywheel move independantly of each other and the pilot bearing allows the input shaft to turn freely


If the pilot bearing is bad you get squeeling with the clutch in......so the mechanic is challenged :-)

If it's shifting gears fine, no clutch slippage, runs strong/smooth, etc, do you think I can wait till my clutch needs replacing to have them drop the tranny, and fix whatever bearing is making noise, or would you recommend doing it now? Thanks for the input by the way. I appreciate you monitoring this.

If the bearing has failed, it should be replaced asap. If not, this will put excessive load on the input shaft bearing.

I wouldn't worry about it..it isn't the pilot bearing ;)

It is most likely gear noise at idle ( because it goes away with clutch in :) )....and the noise when driving is likely something else :) The Renesis makes some funny noises in the intake tract at high loads