Shock loading in road race conditions is why the guys at SPEC say you should
use a clutch disc with springs
Sent from my iPhone
On Jul 14, 2015, at 4:19 PM, "Peter Vucinic"
<pvucinic@netspace.net.au<mailto:pvucinic@netspace.net.au>> wrote:
Scott,
To answer some of your questions.
Would lower oil temps stops ?gear teeth breaking off? Short answer NO. However,
you should look at the differential as a complete system.
If you had tooth failure It could be due to a number of things: -
1. Long Term Use/Operation Fatigue Failure
2. High instantaneous/shock loading Failure
3. Improper backlash/clearances ? Causing Tooth Failure as a result of
incorrect tooth loading
4. Improper lubrication/type/grade/flow/level/operating temperature
The beauty of synthetic oils is that it allows the system to run at MUCH lower
temperatures (And operate at higher temps of course) as a direct result of the
synthetic oil being able to FLOW/POUR with less resistance. Just like mixing a
cake! The thicker the mix, the higher the work load required to mix, the more
friction, the hotter the mixing temps.
The other side of the coin, in general, Synthetic is that is has LESS
mechanical dampening for high shock loading than traditional mineral based oils
for the same grade product. Even on synthetic engine oils you will see
description such as ?made for modern/tight clearances? etc. etc. Reduced
operating clearances and high oil shearing applications etc. is synthetics
domain.
So, when you look at the system as a whole. YES, it?s important to have the oil
in its optimum temperature range. BUT all the other factors are equally
important. The oil is not mutually exclusive in the equation.
Hope that helps?
From: Scott Janzen [mailto:sjanzen@me.com]
Sent: Tuesday, 14 July 2015 4:44 AM
To: Peter Vucinic
Cc: 'Jason Ostrowski'; ''Friends of Triumph' Triumph'
Subject: Re: [Fot] Gt6 differential failure
so, while I respect the need proper operating temps, if the failure experienced
is not bearing failure, but simply gear teeth breaking off under load, would
lower temps help?
I run Redline synthetic.
On Jul 13, 2015, at 2:32 PM, Peter Vucinic wrote:
Get the oil temp down and use full synthetic.
I did much testing on my road going TR4 diff. Even a road car, at highway speed
cruising, the oil temp is 180-200F.
With the diff ?tucked up? and limited air flow. You are starting with a problem
before you start!
"You can Make a Small Fortune From Motor Racing. As long as You Started With A
Lage Fortune!"
Kind Regards
Peter Vucinic
TR4 - TR7 V8 - Spitfire MkII
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From: Fot [mailto:fot-bounces@autox.team.net] On Behalf Of Scott Janzen
Sent: Tuesday, 14 July 2015 12:20 AM
To: Jason Ostrowski
Cc: 'Friends of Triumph' Triumph
Subject: Re: [Fot] Gt6 differential failure
thanks, Jason - yes, I was banging through the gears, and there's now a steep
150' +/- DROP at this track, downhill turn, where I was in second gear at 7,000
RPM, first accelerating, then letting it slow me down as I approached the sharp
right to the uphill climb. I'm sure that did not do the diff any good.
Somehow the idea of putting a Subaru diff in this car does not feel very
"vintage".
Question - has anyone checked the oil temp, and would cooling make a
difference? I do run Redline 75-85 gear oil.
I will report back and send carnage photos when I get it out.
On Jul 13, 2015, at 10:12 AM, Jason Ostrowski wrote:
I agree that it is consumable.
A change to something different would seem to lead to a redesign of all the
parts that mate to it and that could turn into a whole new set of other related
projects.
Likely a costly and complex endeavor to say the least.
Knowing you, I assume you are using a quality oil already as Steve recommends.
I notice you are racing faster lately and seem to be doing great with the car.
Begin Public Service announcement to all FoT...
That being said, (especially the faster you go) don't forget to remind yourself
regularly about how you need to treat the drivetrain.
Perhaps most importantly on this issue is careful driving with a constant focus
to smooth transition between the gears.
And really important is super smooth take-offs.
I'm lucky to have John Reed (best GT6 racer of all time) at the track with me
most of the time.
He is never afraid to remind me of this.
And does so on a regular basis when I'm leaving the grid.
Even after all these years of coaching he will still often yell at me through
my helmet prior to taking off.
something like....
"Ride that F$#&%ng clutch baby!!"
or "Easy take off".
Wisdom I'm not afraid to admit I need to be reminded of in a tense moment
taking off to hit the track.
One slip of the foot or abrupt start is all it takes to do damage to the
differential.
I can trace most of my differential failures back to sketchy shift transitions
or abrupt starts...
We all hate to admit that an equipment failure is our own fault but, speaking
for myself, I know it often is.
This was an FoT Public Service Announcement...
Brought to you by Friendly Ghost Racing.
Jason Ostrowski
Friendly Ghost Racing
1969 Triumph GT6+ Racecars
n@me.com>> wrote:
Mine disintegrated in a big way in the last race yesterday at Pitt Race. Last
one did the same thing about 3-4 years ago.
Should I just consider this a consumable item, or swap to something stronger?
What are other vintage racers doing?
Sent from my mobile device
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