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I wonder if the cold had anything to do with it. 250wt has got be nasty at 20 degs.
Thats what I was wondering, i bet the pinion bearings got wiped out before the oil got heated up enough.
 

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Discussion Starter #63
Jorden Pelegrino said during the KOH Experience that his rear diff got to 370 degrees before it seized. Tony stated that they were "Obviously" going to the manufacturer for answers.
We had heard earlier that he lost oil due to leaky seals in his "Prototype" diffs that 4 of the T1 trucks were also using. That info came from a secondhand source so take it for what it's worth.
 

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I wonder if the cold had anything to do with it. 250wt has got to be nasty at 20 degs.
You'll see trophy trucks running the truck on the stands before starting the races, do ultra 4 guys do that to warm up the gear oil?
I’ve seen them doing it in past years. Didn’t wander thru the staging lanes this year though.
Thats what I was wondering, i bet the pinion bearings got wiped out before the oil got heated up enough.
I've never seen a u4 warm up the gear oil before a race... but you know what, I will be doing this on cold days. Inline for KOH to start takes 2-3 hours, you would have to have your pit crew at the car with a jack and stands.

Nick nelson said he felt his rear end shimmy right off the line. It makes total sense that it got wiped out when he pounded the throttle. Being first in line means it sat cold and unmoved for at least 2 hours before mashing the gas 100%.

the things you can learn watching and reading. I wonder what GW would say about this... I might call them.
 

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I've never seen a u4 warm up the gear oil before a race... but you know what, I will be doing this on cold days. Inline for KOH to start takes 2-3 hours, you would have to have your pit crew at the car with a jack and stands.

Nick nelson said he felt his rear end shimmy right off the line. It makes total sense that it got wiped out when he pounded the throttle. Being first in line means it sat cold and unmoved for at least 2 hours before mashing the gas 100%.

the things you can learn watching and reading. I wonder what GW would say about this... I might call them.

I have seen numerous cars on jacks getting their diffs warm before ultra4 races. :confused:
 

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I've never seen a u4 warm up the gear oil before a race... but you know what, I will be doing this on cold days. Inline for KOH to start takes 2-3 hours, you would have to have your pit crew at the car with a jack and stands.

Nick nelson said he felt his rear end shimmy right off the line. It makes total sense that it got wiped out when he pounded the throttle. Being first in line means it sat cold and unmoved for at least 2 hours before mashing the gas 100%.

the things you can learn watching and reading. I wonder what GW would say about this... I might call them.
This year was the coldest to date. But I will say. Dave had us line up at 7am. Much later than past years. But even than. These diffs sat in sub 30 deg weather all night. It'd take sometime to warn them up on stands, than sit again for at least and hour. That oil would be crazy thick at start, and they just hammer down.
 

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I've never seen a u4 warm up the gear oil before a race... but you know what, I will be doing this on cold days. Inline for KOH to start takes 2-3 hours, you would have to have your pit crew at the car with a jack and stands.

Nick nelson said he felt his rear end shimmy right off the line. It makes total sense that it got wiped out when he pounded the throttle. Being first in line means it sat cold and unmoved for at least 2 hours before mashing the gas 100%.

the things you can learn watching and reading. I wonder what GW would say about this... I might call them.
Pretty sure the dude who runs/owns Gearworks was Nick Nelson’s co-driver.
 

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I have seen numerous cars on jacks getting their diffs warm before ultra4 races. :confused:
In 3 years I haven't that I recall. Maybe I am focused on my own stuff...

....That oil would be crazy thick at start, and they just hammer down.
yup... instant issue a la Nelson

Pretty sure the dude who runs/owns Gearworks was Nick Nelson’s co-driver.
I wonder what he would say about warming the oil and ambient temp vs all the KOH early rear diff losses.
 

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This year was the coldest to date. But I will say. Dave had us line up at 7am. Much later than past years. But even than. These diffs sat in sub 30 deg weather all night. It'd take sometime to warn them up on stands, than sit again for at least and hour. That oil would be crazy thick at start, and they just hammer down.
This makes zero sense to me.
 

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It's the 250wt oil. Not 75-90. The GearWorks stuff requires a super thick oil. at room temp it barely wants to move out of the oil jug.
I understand that. Heavy weight is needed because of heat generated correct?

Are the bearings burning up in a mile? 2 miles? Instantly?

Does cold oil not splatter/sling enough to coat a pinion bearing? Just sits in the bottom of the diff waiting to get warm enough to move?
 

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I understand that. Heavy weight is needed because of heat generated correct? I dont know, I just put in the oil GW tells me

Are the bearings burning up in a mile? 2 miles? Instantly? Both. Nick Nelson reported feeling it right off the start line. My guess is its so thick its forcing defection but that might be dumb. I think its safe to say the damage starts at the start line, jamming 650 to 800 HP down the 3rd's throat

Does cold oil not splatter/sling enough to coat a pinion bearing? Just sits in the bottom of the diff waiting to get warm enough to move? only happened in rear LP, not in front HP. I am sure there is a reason, it could be more force on the rear or design.

All great questions.
.
 

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I understand that. Heavy weight is needed because of heat generated correct?

Are the bearings burning up in a mile? 2 miles? Instantly?

Does cold oil not splatter/sling enough to coat a pinion bearing? Just sits in the bottom of the diff waiting to get warm enough to move?
I'm assuming it would get slung off, and take a long time to drain back down to the gear to get slung back up to the pinion and help with lubrication. See the Banks youtube channel for the gear oil stuff he's been doing. If it's as thick as molasses when they start, I can't see it draining back down or effectively getting into the pinion bearing to provide much lubrication until it warms up.
 

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I understand that. Heavy weight is needed because of heat generated correct?

Are the bearings burning up in a mile? 2 miles? Instantly?

Does cold oil not splatter/sling enough to coat a pinion bearing? Just sits in the bottom of the diff waiting to get warm enough to move?
There's a video on FB, I'm trying to find it. They are trying to pour 250wt into a diff when it was cold, not even freezing. Hold the jug upside down and it doesn't come out of the 2" opening. The shit is crazy thick.
 

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I'm assuming it would get slung off, and take a long time to drain back down to the gear to get slung back up to the pinion and help with lubrication. See the Banks youtube channel for the gear oil stuff he's been doing. If it's as thick as molasses when they start, I can't see it draining back down or effectively getting into the pinion bearing to provide much lubrication until it warms up.
There's a video on FB, I'm trying to find it. They are trying to pour 250wt into a diff when it was cold, not even freezing. Hold the jug upside down and it doesn't come out of the 2" opening. The shit is crazy thick.
Searching and I found this video.
https://www.youtube.com/watch?v=Y-FYdAzLjg8
 

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i bet the TTs lasted longer because of the 20mi sprint doing little damage, then it had chance to heatsink and get warm, then fail at the end of the race due to previous damage.
 

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I have seen numerous cars on jacks getting their diffs warm before ultra4 races. :confused:
I had new GW HP10s this year with 250wt oil. I used immersion heaters in the diffs just before lining up to bring the oil temp up to 70-80F. Made it work just fine vs. driving thru tar the first 10-15 mins.
 

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When will someone install a block heater in the diffs and plug it in before race. Or wire it up in a toggle switch to warm it up
 

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When will someone install a block heater in the diffs and plug it in before race. Or wire it up in a toggle switch to warm it up
Thats the main thing ive been thinking about hah, Or maybe have a propane shop heaters pointed at the diffs for awhile before the start. that 250wt shit is nasty thick even when its 60 degrees. Its gotta be like nearly solid at 30 degrees, the ring gear probably just digs a hole in it and nothing makes it to the pinion gears for the first 30 minutes of the race. also i bet its a huge horsepower killer until its warm.
 
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