That mystery grinding noise typically after a clutch job - Miata Turbo Forum - Boost cars, acquire cats.

Welcome to Miataturbo.net   Members
 


General Miata Chat A place to talk about anything Miata

Reply
 
 
 
LinkBack Thread Tools
Old 10-14-2008, 10:48 PM   #1
Elite Member
Thread Starter
iTrader: (10)
 
rccote's Avatar
 
Join Date: Jan 2008
Location: Buffalo NY
Posts: 1,595
Total Cats: 17
Default That mystery grinding noise ( videos ).

I've had the noise for a while and it's driving me insane. CHHH CHHHHHH on deceleration and shifting and almost absent under 2k rpms. Sometimes it's slightly audible around 4k rpms when accelerating. Every time I let off the gas it sounds like I'm dragging a slew of chains. I can't remember when the sound started but it wasn't after a clutch job. I changed out the 1.6 diff to the 1.8 open one, driveshaft, half shafts yada yada and 3 transmissions later it's still there. I've read that it might have to do with the PPF being misaligned. I've taken the PPF out twice and I can't see how it's misaligned. I'm at the end of my rope.

Last edited by rccote; 10-22-2008 at 10:11 PM.
rccote is offline   Reply With Quote
Old 10-15-2008, 07:05 AM   #2
Supporting Vendor
iTrader: (31)
 
Savington's Avatar
 
Join Date: Nov 2006
Location: Sunnyvale, CA
Posts: 14,367
Total Cats: 1,331
Default

I assume in one of your clutch jobs or tranny swaps you've replaced both the pilot and throwout bearings?
Savington is offline   Reply With Quote
Old 10-15-2008, 10:24 AM   #3
Boost Czar
iTrader: (61)
 
Braineack's Avatar
 
Join Date: May 2005
Location: Chantilly, VA
Posts: 72,892
Total Cats: 1,792
Default

typically?
Braineack is offline   Reply With Quote
Old 10-15-2008, 03:24 PM   #4
AFM Crusader
iTrader: (18)
 
olderguy's Avatar
 
Join Date: Oct 2004
Location: Wayne, NJ
Posts: 4,438
Total Cats: 84
Default

The bottom of the ppf right in front of the front bolts is supposed to be 66.0mm + or - 5mm up from a straight line between the rails on a 1.6 setup. This is to make the universals almost not flex in a normal driving position.

The combination of a 1.8 rear and any suspension changes may alter this figure, but it might be a good place to start.

Do you have a lightweight flywheel installed?
olderguy is offline   Reply With Quote
Old 10-15-2008, 03:44 PM   #5
Elite Member
Thread Starter
iTrader: (10)
 
rccote's Avatar
 
Join Date: Jan 2008
Location: Buffalo NY
Posts: 1,595
Total Cats: 17
Default

Quote:
Originally Posted by Savington View Post
I assume in one of your clutch jobs or tranny swaps you've replaced both the pilot and throwout bearings?
I'm positive about the pilot and throwout, my transmission place gave me all my old parts back when they did my clutch.

Quote:
Originally Posted by olderguy View Post
Do you have a lightweight flywheel installed?
No.

Quote:
Originally Posted by Braineack View Post
typically?
As in ,if this kind of noise manifests itself, it's typically after a clutch job.
rccote is offline   Reply With Quote
Old 10-15-2008, 03:53 PM   #6
Elite Member
iTrader: (2)
 
Join Date: Jun 2006
Location: ABQ, NM
Posts: 1,850
Total Cats: -8
Default

Is your shifter boot worn out?


The miata tranny is pretty noisy without it.
BenR is offline   Reply With Quote
Old 10-15-2008, 03:59 PM   #7
Elite Member
iTrader: (8)
 
Join Date: Aug 2007
Location: Bellingham, Wa
Posts: 2,732
Total Cats: 3
Default

I'll unlazy myself this weekend and go out and do it. I wish I had just checked it when I had the car in the air doing the swap. Guess i was just too excited to start it up.
wayne_curr is offline   Reply With Quote
Old 10-15-2008, 04:17 PM   #8
Elite Member
Thread Starter
iTrader: (10)
 
rccote's Avatar
 
Join Date: Jan 2008
Location: Buffalo NY
Posts: 1,595
Total Cats: 17
Default

Quote:
Originally Posted by BenR View Post
Is your shifter boot worn out?


The miata tranny is pretty noisy without it.

Oh my big shifter boot is fucked but this noise has stayed the same prior to it getting trashed. I've got a lot of insulation around the turret so that shouldn't make a difference.
rccote is offline   Reply With Quote
Old 10-15-2008, 07:55 PM   #9
Senior Member
iTrader: (7)
 
nicacus's Avatar
 
Join Date: Jul 2006
Location: SLC UT
Posts: 1,133
Total Cats: 0
Default

Quote:
Originally Posted by olderguy View Post
The bottom of the ppf right in front of the front bolts is supposed to be 66.0mm + or - 5mm up from a straight line between the rails on a 1.6 setup. This is to make the universals almost not flex in a normal driving position.

The combination of a 1.8 rear and any suspension changes may alter this figure, but it might be a good place to start.

Do you have a lightweight flywheel installed?

Care to elaborate?
I have the same problem, except I do have a lightweight flywheel
nicacus is offline   Reply With Quote
Old 10-15-2008, 08:04 PM   #10
AFM Crusader
iTrader: (18)
 
olderguy's Avatar
 
Join Date: Oct 2004
Location: Wayne, NJ
Posts: 4,438
Total Cats: 84
Default

Quote:
Originally Posted by nicacus View Post
Care to elaborate?
I have the same problem, except I do have a lightweight flywheel
You get some strange noises from a lightweight flywheel on deceleration, but the two were not meant to be tied together.

I have run across many mechanics that don't understand that adjustment. It is called out in all the NA workshop manuals. It is also called out in later years, but I don't have the 1.8 series available nor the NB manuals(which I would assume to be the same) to give the specifications.
olderguy is offline   Reply With Quote
Old 10-15-2008, 08:05 PM   #11
Elite Member
Thread Starter
iTrader: (10)
 
rccote's Avatar
 
Join Date: Jan 2008
Location: Buffalo NY
Posts: 1,595
Total Cats: 17
Default

Quote:
Originally Posted by olderguy View Post
The bottom of the ppf right in front of the front bolts is supposed to be 66.0mm + or - 5mm up from a straight line between the rails on a 1.6 setup.
Yeah I'm having a little trouble visualizing that without going under the car. Do you have any pictures or something that could help? Is the straight line perpendicular or parallel to the car?
rccote is offline   Reply With Quote
Old 10-15-2008, 08:10 PM   #12
AFM Crusader
iTrader: (18)
 
olderguy's Avatar
 
Join Date: Oct 2004
Location: Wayne, NJ
Posts: 4,438
Total Cats: 84
Default

Quote:
Originally Posted by rccote View Post
Yeah I'm having a little trouble visualizing that without going under the car. Do you have any pictures or something that could help?
In the workshop manual it is on the last page of "Transmission".

If you put a straight edge from rail to rail(assuming they haven't been crushed by driving over curbs or added to with a frame rail kit) you can measure upward to the bottom of the PPF. The bolts can be loosened slightly and that point moved into spec and the bolts re-tightened.

I'll try to scan the page and add it.
Attached Thumbnails
That mystery grinding noise typically after a clutch job-ppf-spec.jpg  
olderguy is offline   Reply With Quote
Old 10-15-2008, 08:14 PM   #13
Senior Member
iTrader: (7)
 
nicacus's Avatar
 
Join Date: Jul 2006
Location: SLC UT
Posts: 1,133
Total Cats: 0
Default

Quote:
Originally Posted by olderguy View Post
In the workshop manual it is on the last page of "Transmission".

If you put a straight edge from rail to rail(assuming they haven't been crushed by driving over curbs or added to with a frame rail kit) you can measure upward to the bottom of the PPF. The bolts can be loosened slightly and that point moved into spec and the bolts re-tightened.

I'll try to scan the page and add it.
awesome that makes sense..
nicacus is offline   Reply With Quote
Old 10-15-2008, 08:30 PM   #14
Elite Member
Thread Starter
iTrader: (10)
 
rccote's Avatar
 
Join Date: Jan 2008
Location: Buffalo NY
Posts: 1,595
Total Cats: 17
Default

Badass. I'll see where this gets me this weekend. Thanks
rccote is offline   Reply With Quote
Old 10-16-2008, 01:42 AM   #15
Senior Member
iTrader: (7)
 
nicacus's Avatar
 
Join Date: Jul 2006
Location: SLC UT
Posts: 1,133
Total Cats: 0
Default

I just checked mine it's at 68 mm.
I'm going to see if I can get it to 66mm in hopes of the thing shutting up.

update:
I moved it up and got it damn close to where it should be seems to have helped quite a bit. I am going to mess with it some more tomorrow after work.
Rccote I'm curious if it will do anything for you. It only takes like 10-15 minutes tops, I didnt even have to bust out the air tools

Last edited by nicacus; 10-16-2008 at 02:22 AM.
nicacus is offline   Reply With Quote
Old 10-16-2008, 02:50 AM   #16
Junior Member
 
Join Date: Sep 2008
Location: Head Wound City, CT
Posts: 215
Total Cats: 0
Default

Out of curiosity, it doesn't sound anything like a dust shield making intermittent contact with a rotor, does it? I'm getting the oddest metallic noise off-throttle, and cannot for the life of me figure out what it is. I'll have to check the PPF this weekend.
MattEGTR is offline   Reply With Quote
Old 10-20-2008, 07:22 PM   #17
Elite Member
Thread Starter
iTrader: (10)
 
rccote's Avatar
 
Join Date: Jan 2008
Location: Buffalo NY
Posts: 1,595
Total Cats: 17
Default

Forgot my frame rails are kind of bent in and my exhaust is in the way of putting something across to get a base to measure off of. How do you guys do it accurately? nicacus, did you reposition the trans using a jack? Mine wont really budge without one.

EDIT:

Repositioned the PPF upwards and the noise is still exactly the same. I'm beyond pissed at this point. I'm starting to think those ******* didn't replace my pilot bearing considering I can't find it in the stuff I got back from them. Plus they said they couldn't replicate it when they were test driving. ****, if I know ONE thing that is consistent with my car it's that ******* noise. I can't even rev that high without a goddamn cacophony of grinding noises showering the surrounding area. 3500 is like the sweet spot and everything else after that is relatively quiet excluding gear shifting and in-gear deceleration. A little above 2.5k on decel sounds like a sort of on off CHH.....CH...CHH..CHH.....CHH..CH. Is that a PPF related quality? I'd give a mean *** bj to the one that solves this.

Last edited by rccote; 10-20-2008 at 08:02 PM.
rccote is offline   Reply With Quote
Old 10-20-2008, 08:21 PM   #18
Senior Member
iTrader: (14)
 
brgracer's Avatar
 
Join Date: Nov 2004
Location: Ambler, PA
Posts: 1,275
Total Cats: 1
Default

I don't think this is the issue, but not hard to try out so... After a clutch job on a friends car he got this weird vibration on accel around 3.5k rpm or so that we had trouble tracking down. He rotated his driveshaft to diff attachment 90 degrees and everything was fine. I've never had this issue with multiple clutch jobs, but technically, you are supposed to mark the driveshaft and diff and realign the exact same way.
brgracer is offline   Reply With Quote
Old 10-20-2008, 08:25 PM   #19
Senior Member
iTrader: (7)
 
nicacus's Avatar
 
Join Date: Jul 2006
Location: SLC UT
Posts: 1,133
Total Cats: 0
Default

Quote:
Originally Posted by rccote View Post
Forgot my frame rails are kind of bent in and my exhaust is in the way of putting something across to get a base to measure off of. How do you guys do it accurately? nicacus, did you reposition the trans using a jack? Mine wont really budge without one.

EDIT:

Repositioned the PPF upwards and the noise is still exactly the same. I'm beyond pissed at this point. I'm starting to think those ******* didn't replace my pilot bearing considering I can't find it in the stuff I got back from them. Plus they said they couldn't replicate it when they were test driving. ****, if I know ONE thing that is consistent with my car it's that ******* noise. I can't even rev that high without a goddamn cacophony of grinding noises showering the surrounding area. 3500 is like the sweet spot and everything else after that is relatively quiet excluding gear shifting and in-gear deceleration. A little above 2.5k on decel sounds like a sort of on off CHH.....CH...CHH..CHH.....CHH..CH. Is that a PPF related quality? I'd give a mean *** bj to the one that solves this.

Yeah I used the OEM jack that came with the car to push it up. It seemed to be a temporary fix though; the noise is back in full force. Mine is pretty damn spot on to the noise yours makes. I feel like a douche every time I get up above 3000 RPM people probably think my engine is about to explode. which is embarrassing when you are spanking the stupid civics/mustangs.

I know my pilot bearing was changed as I changed it myself. along with the throw-out bearing. Hell I took the damn tranny/engine out twice during the fiasco that was replacing my engine.
I am going to be putting a new high flow cat on later this week to see if it helps at all.
I just want my car to sound pretty like it used to
nicacus is offline   Reply With Quote
Old 10-20-2008, 08:29 PM   #20
Senior Member
iTrader: (7)
 
nicacus's Avatar
 
Join Date: Jul 2006
Location: SLC UT
Posts: 1,133
Total Cats: 0
Default

Quote:
Originally Posted by brgracer View Post
I don't think this is the issue, but not hard to try out so... After a clutch job on a friends car he got this weird vibration on accel around 3.5k rpm or so that we had trouble tracking down. He rotated his driveshaft to diff attachment 90 degrees and everything was fine. I've never had this issue with multiple clutch jobs, but technically, you are supposed to mark the driveshaft and diff and realign the exact same way.
I did mark mine when I took it out.. I wonder if the new flywheel changed the balance? I suppose I could try that though I am up for any ideas at this point. My goal is to get it figured out on my week off work, I realy cant stand it. I'm half tempted to drive the El Crapmino to work instead.

I will try and get vid/audio of it tonight if I remember..
nicacus is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
Project Gemini - Turbo Civic on the Cheap Full_Tilt_Boogie Build Threads 59 Yesterday 09:00 PM
1994 Spec Miata Race Car SM/SM2/SSM For Sale Quinn Cars for sale/trade 6 10-23-2016 08:58 AM
ACT race clutch and AASCO 7lb. aluminum flywheel graexodus Miata parts for sale/trade 5 10-26-2015 02:48 PM
Moroso Air Oil Separator Catch Can Aroundcorner Miata parts for sale/trade 2 10-01-2015 04:20 PM
Another Alternator thread ihiryu General Miata Chat 9 09-28-2015 11:22 AM


Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 07:23 AM.