Notices
Racing & Drivers Education Forum
Sponsored by:
Sponsored by:

Advice on wheel heat issue

 
Old 03-03-2009, 03:49 AM
  #1  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: Livermore, CA
Posts: 17,116
Default Advice on wheel heat issue

During my last DE at Thunderhill, my 964 rear wheels got so hot that the wheel balancing weights melted off the wheels. The tape holding them on, not the lead itself. Also, there was a significant amount of axle cv grease coming out of a small hole in the center of the axle into the wheel hub (outer).

I'm running with the brake dust shields, and have upgraded the rear brakes to the 993 calipers, same sizes as the late model 964, and have the correct bias valve. Also, just porsche OEM pads.

Any advice would be greatly appreciated.
sundog is offline  
Old 03-03-2009, 08:57 AM
  #2  
Geoffrey
Super User
 
Geoffrey's Avatar
 
Join Date: Dec 2001
Location: Kingston, NY
Posts: 8,305
Default

I would have a look at your drive axle assembly. Once the grease begins to push out the center vent hole, it has been compromized and turned into more of a liquid than a paste. If you continue to run, your CV joint will fail.

Use aluminum tape on the wheel weights to keep them on. This is common practice with track wheels and weights.
Geoffrey is offline  
Old 03-03-2009, 09:16 AM
  #3  
Veloce Raptor
Torque Monster
Rennlist Member
Small Business Sponsor
 
Veloce Raptor's Avatar
 
Join Date: Aug 2006
Location: In a race car...
Posts: 39,070
Default

Also consider removing the dust shields IMO.







Professional Racing and Driving Coach
Veloce Raptor is offline  
Old 03-03-2009, 09:51 AM
  #4  
onefastviking
Addict
Rennlist Member
 
onefastviking's Avatar
 
Join Date: Apr 2008
Location: Texas
Posts: 3,491
Default

Do you have an early 964 with the small single piston rear caliper ? If so consider replacing to the later style.
Also, are you possibly braking too hard ? Too much ?
onefastviking is offline  
Old 03-03-2009, 10:40 AM
  #5  
Jarez Mifkin
Addict
Rennlist Member
 
Jarez Mifkin's Avatar
 
Join Date: Jul 2004
Location: Mount Juliet, TN
Posts: 1,802
Default

Originally Posted by Geoffrey View Post
I would have a look at your drive axle assembly. Once the grease begins to push out the center vent hole, it has been compromized and turned into more of a liquid than a paste. If you continue to run, your CV joint will fail.

Use aluminum tape on the wheel weights to keep them on. This is common practice with track wheels and weights.
+1

CV joint failure's in the form of grease ejaculation cause the brake rotor to be deemed worthless and can/will cause an unsafe situation.
Jarez Mifkin is offline  
Old 03-03-2009, 12:06 PM
  #6  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: Livermore, CA
Posts: 17,116
Default

Originally Posted by Geoffrey View Post
I would have a look at your drive axle assembly. Once the grease begins to push out the center vent hole, it has been compromized and turned into more of a liquid than a paste. If you continue to run, your CV joint will fail.

Use aluminum tape on the wheel weights to keep them on. This is common practice with track wheels and weights.
Thanks for the advice Geoffrey. I'm ordering a new boot kit from EBS racing, and will also get some of the Neo Grease. Aluminum tape, what a great idea!
sundog is offline  
Old 03-03-2009, 12:06 PM
  #7  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: Livermore, CA
Posts: 17,116
Default

Originally Posted by Veloce Raptor View Post
Also consider removing the dust shields IMO.







Professional Racing and Driving Coach
That is on the list for the next DE in late March. Hopefully keep them cooler.
sundog is offline  
Old 03-03-2009, 12:08 PM
  #8  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: Livermore, CA
Posts: 17,116
Default

Originally Posted by onefastviking View Post
Do you have an early 964 with the small single piston rear caliper ? If so consider replacing to the later style.
Also, are you possibly braking too hard ? Too much ?
I had that setup, but replaced them with 993 calipers with the 2 piston rears. They are the same as the stock 92-94 964 rears, but cheaper.

Braking too much, I don't know. My instructors kept yelling, brake, Brake, BRAKE BRAKE! So maybe not?
sundog is offline  
Old 03-03-2009, 12:09 PM
  #9  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: Livermore, CA
Posts: 17,116
Default

Originally Posted by Jarez Mifkin View Post
+1

CV joint failure's in the form of grease ejaculation cause the brake rotor to be deemed worthless and can/will cause an unsafe situation.
Oh, that's not good to hear. I've already got a list as long as my arm of things to do before the DE. Is it a warping issue, or a glazing issue? Can I visually check them?
sundog is offline  
Old 03-03-2009, 12:11 PM
  #10  
Geoffrey
Super User
 
Geoffrey's Avatar
 
Join Date: Dec 2001
Location: Kingston, NY
Posts: 8,305
Default

It is the outside joint that is probably the problem, and they are not designed to be replaced.
Geoffrey is offline  
Old 03-03-2009, 12:19 PM
  #11  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: Livermore, CA
Posts: 17,116
Default

Originally Posted by Geoffrey View Post
It is the outside joint that is probably the problem, and they are not designed to be replaced.
Yes, I searched and found the thread about you rebuilding the CV joint. I don't have the access to the machine tools yet, and it's a Tiptronic for now, so the axles are different. I can probably get one from Parts Heaven if it's shot though.
sundog is offline  
Old 03-03-2009, 01:08 PM
  #12  
JackOlsen
Super User
 
JackOlsen's Avatar
 
Join Date: Jun 2001
Location: Los Angeles
Posts: 3,894
Default

What pads are you using? Did you experience brake fade? If you did, what brake fluid are you running and when were the brakes last bled?

Another possibility is a sticking caliper.

Thunderhill is not easy on brakes, but I doubt your problems are from your wheels getting too hot.
JackOlsen is offline  
Old 03-03-2009, 01:14 PM
  #13  
sundog
Workin' It, Daddy!
Rennlist Member
Thread Starter
 
sundog's Avatar
 
Join Date: Jul 2005
Location: Livermore, CA
Posts: 17,116
Default

Originally Posted by JackOlsen View Post
What pads are you using? Did you experience brake fade? If you did, what brake fluid are you running and when were the brakes last bled?

Another possibility is a sticking caliper.

Thunderhill is not easy on brakes, but I doubt your problems are from your wheels getting too hot.
I'm using stock OEM pads. Will replace them after the next DE. Or maybe I should do it now.

No brake fade, using ATE Blue, bled right before the DE.

Calipers have less than 2K miles on them. Still a possibility of them sticking?
sundog is offline  
Old 03-03-2009, 01:25 PM
  #14  
JackOlsen
Super User
 
JackOlsen's Avatar
 
Join Date: Jun 2001
Location: Los Angeles
Posts: 3,894
Default

If they're sticking, you'd likely be able to see hotter-than-normal temps in street driving, too.

My guess is a cracked and/or leaking CV boot -- and that the weights fell off for no particular reason other than that wheel weights sometimes come off.
JackOlsen is offline  
Old 03-03-2009, 02:18 PM
  #15  
RedlineMan
Addict
Rennlist Member
 
RedlineMan's Avatar
 
Join Date: Dec 2003
Location: Vestal, NY
Posts: 4,534
Default

Hey;

I would first want to determine where the heat is coming from. If it is the brakes, then I would get those dust shields off, and I would strongly suggest new pads. Factory pads often create excess heat because they simply do not have the bite of a real track pad. When you have increased friction coeficient, you find that you have to brake with less force. The increased efficiency of the performance pads often leads to lower temperatures.

Inner CV joints often get most of their heat from the engine/transmission itself, and lower amounts of air flow, and often are the first to fail for this reason. The wheels are likely getting their heat from the brakes, and that amount of heat certainly won't help the joint grease (or any other component) on either end. Do yourself a favor and use a really good grease like Krytox or Neo when you service the joints. It will hold up much better than other more generic lubes.

I'd also wonder about the rear axle bearings if it is all getting that hot.
RedlineMan is offline  

Thread Tools
Search this Thread

Contact Us - About Us - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: