The Subaru SVX World Network   SVX Network Forums
Live Chat!
SVX or Subaru Links
Old Lockers
Photo Post
How-To Documents
Message Archive
SVX Shop Search
IRC users:

Go Back   The Subaru SVX World Network > SVX Main Forums > Technical Q & A

Reply
 
Thread Tools Display Modes
  #1  
Old 12-17-2002, 12:05 AM
svxjoe's Avatar
svxjoe svxjoe is offline
Only SVX @ UCF (Cool!)
 
Join Date: Mar 2002
Location: Orlando, Florida
Posts: 258
Send a message via AIM to svxjoe
Exclamation Rotors Warp too Often!

I really don't like how my rotors warp every 5-6 months. I am aware when I drive of my braking, and know not to drive fast and brake hard as this prones your rotors to quicker warping.

I've asked this in the Babble Forum..... and got respones like "you shouldn't machine your rotors".

Well, I hate the vibrating of the Steering wheel when I'm coming to a stop and now (since I didn't have the back rotors machined last time I was in) I'm gettin a bit of a vibrating in the Brake Pedal and can also feel it on my butt coming from behind me.

So my question is...should I be warping rotors this often, and is machining o.k.?
Reply With Quote
  #2  
Old 12-17-2002, 11:39 AM
cbx-man cbx-man is offline
Registered User
 
Join Date: Aug 2002
Location: Kent, Wa
Posts: 146
Check out this thread. It should help you out!

http://www.subaru-svx.net/forum/show...ht=sick+rotors
__________________
cbx-man
'92 LSL Liquid Silver / Automatic Level-10 valve body mod / remote filter
'92 LSL Pearl White / 5 spd. IndigoSpeed 11# flywheel / ACPT Carbon fiber drive shaft
'80 Honda CBX in-line 24 valve 6 cylinder
Reply With Quote
  #3  
Old 12-17-2002, 12:53 PM
lee lee is offline
Registered User
 
Join Date: Mar 2002
Location: Indialantic, Florida
Posts: 2,940
machining is OK to fix a warp, up to the limits.

braking hard isn't the total problem. maybe somebody will chime in here, but there's also aspects of pad bed-down as well as long light braking can heat the rotors more than a simple hard stop. I'm far from an expert, so...

one last point, and really why I'm writing. Have you checked your sway bar bushings. I thought i had warped the rotors, turned out my bushings were either dead or dying (right and left side respectively). I managed to ignore the symptom long enough until I thought I had a bad CV joint coming on. I finally actually jacked the car up and looked around - turned out to be the cheapest fix I've experienced to-date on the SVX.

Of course if replacing the rotors has each time fixed your problem for a while, then my idea falls into the probably dumb response category.
Reply With Quote
  #4  
Old 12-17-2002, 02:52 PM
Uncamitzi's Avatar
Uncamitzi Uncamitzi is offline
Member #447
 
Join Date: Dec 2001
Location: Salt Lake City, Utah
Posts: 1,902
Send a message via MSN to Uncamitzi Send a message via Yahoo to Uncamitzi Send a message via Skype™ to Uncamitzi
Registered SVX
Hmmm Recurring theme...

I think someone (Beav?) said that it might be that you have over torqued your lug nuts... should be around 70-80 ftlbs.... 75 being a good number to set. I tried it, did some hard braking to heat up the rotors and they did true up..... The guys at cosco had the nuts at about 120ftlb...... I think they were afraid that I wouldn't check them after 20 miles.... I guess most of their customers don't and costco doesn't want a lawsuit for a wheel coming off
__________________
Mitch Hansen
"uncamitzi"
This is a Dark Ride
92 Teal SVX LS-L 128K tranny swap with 4.11's
Well.. my days of not taking you seriously have certainly come to a middle .
Reply With Quote
  #5  
Old 12-17-2002, 02:56 PM
Andy's Avatar
Andy Andy is offline
Registered User
 
Join Date: Apr 2002
Location: Guernsey, Channel Islands
Posts: 2,606
Send a message via Skype™ to Andy
It worked for me too. rotors now straight and true since re-torquing the nuts. A cheap fix worth trying first.
__________________
Andy

------------------------------------------------------------------------------------

If I would be a young man again and had to decide how to make my living, I
would not try to become a scientist or scholar or teacher. I would rather
choose to be a plumber or a peddler in the hope to find that modest degree
of independence still available under present circumstances.
-- Albert Einstein, The Reporter, November 18 1954
Reply With Quote
  #6  
Old 12-17-2002, 03:23 PM
svxistentialist's Avatar
svxistentialist svxistentialist is offline
Jersey Girl
Alcyone Gold Contributor
 
Join Date: Mar 2001
Location: Ireland
Posts: 8,270
Send a message via Skype™ to svxistentialist
Registered SVX
Lugs, Nuts?

Enlighten me here if you will.

Are we talking here about torqueing the wheel nuts that hold on the rim?

Or are we talking about torqueing the studs that hold the disk[rotor] bell to the hub??

Which?

Joe
__________________
Black Betty [Bam a Lam!] '93 UK spec, still languishing Betty
Jersey Girl Silver '92 UK [Channel Isles] 40K Jersey Girl @ Mersea
Candy Purple Honda Blackbird Plum Dangerous
White X2 RVR Mitsubishi 1800GDI. Vantastic

40,000 miles Jersey Girl
Reply With Quote
  #7  
Old 12-17-2002, 03:26 PM
Andy's Avatar
Andy Andy is offline
Registered User
 
Join Date: Apr 2002
Location: Guernsey, Channel Islands
Posts: 2,606
Send a message via Skype™ to Andy
Just the wheel nuts. I know, it sounds too simple but it worked for me. Must be something to do with thermal expansion I guess.
__________________
Andy

------------------------------------------------------------------------------------

If I would be a young man again and had to decide how to make my living, I
would not try to become a scientist or scholar or teacher. I would rather
choose to be a plumber or a peddler in the hope to find that modest degree
of independence still available under present circumstances.
-- Albert Einstein, The Reporter, November 18 1954
Reply With Quote
  #8  
Old 12-17-2002, 11:21 PM
Uncamitzi's Avatar
Uncamitzi Uncamitzi is offline
Member #447
 
Join Date: Dec 2001
Location: Salt Lake City, Utah
Posts: 1,902
Send a message via MSN to Uncamitzi Send a message via Yahoo to Uncamitzi Send a message via Skype™ to Uncamitzi
Registered SVX
Re: Lugs, Nuts?

Quote:
Originally posted by svxistentialist
Enlighten me here if you will.

Are we talking here about torqueing the wheel nuts that hold on the rim?

Or are we talking about torqueing the studs that hold the disk[rotor] bell to the hub??

Which?

Joe
Joe, that's right. Just the lug nut holding the wheel to the rotor.. as in changing a flat..... ( I know that means something different over there. something like moving to another apartment..) Do search on lug nuts... Beav described it much better than I ever could.
__________________
Mitch Hansen
"uncamitzi"
This is a Dark Ride
92 Teal SVX LS-L 128K tranny swap with 4.11's
Well.. my days of not taking you seriously have certainly come to a middle .
Reply With Quote
  #9  
Old 12-18-2002, 04:18 AM
svxistentialist's Avatar
svxistentialist svxistentialist is offline
Jersey Girl
Alcyone Gold Contributor
 
Join Date: Mar 2001
Location: Ireland
Posts: 8,270
Send a message via Skype™ to svxistentialist
Registered SVX
Re: Re: Lugs, Nuts?

Quote:
Originally posted by Uncamitzi


Joe, that's right. Just the lug nut holding the wheel to the rotor.. as in changing a flat..... ( I know that means something different over there. something like moving to another apartment..) Do search on lug nuts... Beav described it much better than I ever could.
Thanks Mitch,

That's what I thought. I will try this because the physics behind the idea sounds realistic. Does not explain why with the wheel off, and hub spinning the rotor has highs and lows, valleys and so on though.

I have had these machined off the fronts to great improvement, and I still have a slight judder at 70+, which I think may be the back. Will get these done next. Meantime I will torque all nuts to 75 for the sake of even expansion under heat.

Motorcycle rotors are "free floating", gripped loosely to the hub to cope with just this problem. I can't see that re-torqueing will flatten a rotor that has warped, but it could improve a situation that is caused by uneven expansion under heavy heat load.

So the total answer would be new or skimmed rotors, follow up with correct sequential torqueing all round. One final finesse. Do the initial torqueing with the wheel in the air, i.e. jack up the wheel you are torqueing for best effect.

Joe
__________________
Black Betty [Bam a Lam!] '93 UK spec, still languishing Betty
Jersey Girl Silver '92 UK [Channel Isles] 40K Jersey Girl @ Mersea
Candy Purple Honda Blackbird Plum Dangerous
White X2 RVR Mitsubishi 1800GDI. Vantastic

40,000 miles Jersey Girl
Reply With Quote
  #10  
Old 12-18-2002, 11:04 PM
James Scott James Scott is offline
The Molinator
 
Join Date: Nov 2002
Location: Fresno, CA
Posts: 1,002
Talking warping rotors

For what it's worth -
I had warped rotors about a year ago, shaking the brake pedal. I thought it was the front rotors because they take most of the stress, of course. I purchased cross-drilled front rotors from Motorsports.com who I located through SubaruSVX.com.I was not thrilled with the quality (had to drill two holes they forgot!), but eventually mounted on front - NO IMPROVEMENT! I found out that if just the pedal vibrates, then that means it's the rear. If the steering wheel shakes, it's the front. (These rotors cost $400!) I checked with my local AutoZone - picked up rear rotors for $70. each. PROBLEM SOLVED! Braking is totally smooth now for over 9 months.

I did start torqueing my lug nuts as suggested by others. I do think it is a definite factor. Someone told me that the reason my rear rotors warped may have been because the ABS system may have favored the rears too much?! I also had turned front/back rotors about 6 months prior to problem- this can speed warpage. Someone told me to grind (not turn) rotors!(??) Gooday, Jaime
Reply With Quote
Reply

Thread Tools
Display Modes

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

Forum Jump


All times are GMT -6. The time now is 05:52 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
© 2001-2015 SVX World Network
(208)-906-1122