Timing belt broke 140 miles from home.
08-01-2012, 01:45 PM
#31
Rennlist Member
Bill,
I'm surprised if the standard Gates belt is aramid reinforced. The generic of Kevlar is produced in the far east - last I knew - and was nearly as expensive as Kevlar. Guess we'll have to let Roger be the determinant in what the standard timing belt is reinforced with - both Porsche and Gates!!!
Cheers, and thanks again for representing our community so well last Friday.
Gary--
I'm surprised if the standard Gates belt is aramid reinforced. The generic of Kevlar is produced in the far east - last I knew - and was nearly as expensive as Kevlar. Guess we'll have to let Roger be the determinant in what the standard timing belt is reinforced with - both Porsche and Gates!!!
Cheers, and thanks again for representing our community so well last Friday.
Gary--
08-01-2012, 04:15 PM
#33
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
That's not what Gates says about timing belts.
http://www.gates.com/brochure.cfm?br...cation_id=3487
TIMING BELTS
Gates timing belts are OE-equivalent or better in service life and performance.
- Aramid reinforced nylon jackets and backside jackets for longer wear.
- High grade HNBR rubber for superior heat and contamination resistance.
- Premium high strength tensile members.
- Unlike some competitors, Gates does not substitute inferior belt constructions for premium constructions specified by the OEM on any application.
- Most extensive coverage in the industry. Import or Domestic.
All I know is they do not stretch.
http://www.gates.com/brochure.cfm?br...cation_id=3487
TIMING BELTS
Gates timing belts are OE-equivalent or better in service life and performance.
- Aramid reinforced nylon jackets and backside jackets for longer wear.
- High grade HNBR rubber for superior heat and contamination resistance.
- Premium high strength tensile members.
- Unlike some competitors, Gates does not substitute inferior belt constructions for premium constructions specified by the OEM on any application.
- Most extensive coverage in the industry. Import or Domestic.
All I know is they do not stretch.
08-01-2012, 06:29 PM
#34
Rennlist Member
Their statement of "premium high strength tensile numbers" is what counts! Still not sure aramid is used as the tensile reinforcement!! Would like it to be, as I installed a new Gates (non-racing) belt on the '94 this winter along with Ken's tensioner.
Gary--
Gary--
08-01-2012, 07:14 PM
#35
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
OK, I could have misunderstood that description. I can't find the article I read some time ago on actual belt manufacturing and construction. Regardless, the Gates belts are very, very strong, durable and do not stretch under any condition they might encounter in our cars. They may break if creased, but it would take a whole lot of force to break a running belt that had not been abused in that way. The teeth tend to strip off if, say, the oil pump seizes. My current Gates belt is approaching 60K miles. Coming up on 5 years too, so I guess I don't get to see the effects of prolonged aging this time. Never had to tension it once and would have been worried if I had to out beyond the initial "settling" period. Even then, the tension drop was minimal and required no adjustment.
08-01-2012, 08:23 PM
#36
Rennlist Member
Even at 9 years I am surprised to hear of the belt 'breaking'. I was thinking that perhaps the water pump or a cam was seizing, but I would think that would strip teeth rather than snap the belt. If there is enough left of the belt it would be interesting to see photos.
08-01-2012, 09:26 PM
#37
Inventor
Rennlist Member
Rennlist Member
I doubt also that it was the belt per se.
Most likely, bent/broken pre-tensioner shoulder bolt, or it's plastic bushings.
There is a lot of leverage on the bolt because of the long arm.
Before '86, the push rod is off-center where it pushes the arm, too.
Most likely, bent/broken pre-tensioner shoulder bolt, or it's plastic bushings.
There is a lot of leverage on the bolt because of the long arm.
Before '86, the push rod is off-center where it pushes the arm, too.
08-01-2012, 09:45 PM
#38
+1 to Bills comments in his post 35, I use Gates T/B and no adjustment required outside of initial check.
Just completed my 12 month service and T/B check and no adjustment.
Tails 1990 928S4 Auto
Just completed my 12 month service and T/B check and no adjustment.
Tails 1990 928S4 Auto
08-02-2012, 10:17 PM
#39
Rennlist Member
Thread Starter
Join Date: Aug 2004
Location: Boston, Fort Lauderdale
Posts: 901
Likes: 0
Received 3 Likes
on
1 Post
Spoke with the mechanic this evening, Said that the plastic bushing in the factory tension-er let go and the belt was running "cocked" So that explains it,
Thanks for all your concerns.............
Rick
Thanks for all your concerns.............
Rick
08-03-2012, 12:48 AM
#41
Rennlist Member
Another vote for Bill's view on this... Last August I helped a local (Rusty) replace the timing belt on a 91 S4 he had bought out of CA with 43k miles. The previous owner had records and none of the belts had ever been changed. The timing belt was 21 years old and in very good condition.
I've also seen original belts, like the one at OCIC in 09 that looked horrible through the vent hole, cracked and obviously about to break. Not sure what makes the difference.
I ran my last belt on the 86.5 12 years and about 30k miles. I'm replacing it now, it was in very good condition.
I've also seen original belts, like the one at OCIC in 09 that looked horrible through the vent hole, cracked and obviously about to break. Not sure what makes the difference.
I ran my last belt on the 86.5 12 years and about 30k miles. I'm replacing it now, it was in very good condition.
08-03-2012, 01:56 AM
#42
Under the Lift
Lifetime Rennlist
Member
Lifetime Rennlist
Member
I've not seen one of these bushings "let go". Usually they wear enough so the clearance allows the tensioner arm and roller to "****" inward and the belt mistracks over the front of the roller and the front edge of the belt rubs against the arm and gets shredded up a bit.
