Diff oil surge.....? HELP HELP

[Adoom]

My expensive new T series trd lsd started howling last two times at manfield.

The oil level has never been low.
I pulled it out and had Miles Udy(He assembled it 700ish kms ago) look at it.
He pointed at some blueing on the pinion gear teeth and said it had over heated probably due to lack of oil and high power(143kw atw).
"Its never been low " I said.
He thinks it must have been oil surge in the axle casing on fast corners because I have semi slicks.
He also runs the same diff in an AE86.
$400 plus I have to find another 3.9:1 R&P to fix it. But that wont stop it happening again.
He suggested running a diff oil cooler$$$$$

Has anyone else had similar problems with a T series diff when racing?

[toyae86]

what about welding baffles in to the tubes to stop oil draining away

[Adoom]

They all have baffles. I want to know if anyone else has had the same problem.

[KinLoud]

Did you give it a chance to run in before you gave it death at the track?
The wear/contact pattern on the teeth needs to be established before you use it for continuous hard use otherwise it can overheat in localised areas - similar to your description.
Best explanation - accelerate through the gears hard then coast and/or drive slowly with low power for a minute. Repeat for a couple of 15/20 minute sessions.
This gives the extra heat from running in period to dissapate into the mass of the crown and pinion and so creates the contact/wear pattern without overheating and so damaging the contact areas.
Once the contact areas is smooth and established there will be much less heat generated and you can drive it hard continuously.

Ken
Ham
021 408 863

[85AW20v]

We had the same problem in my brothers starlet on Targa a few years ago. He talked to the guys who built the car - Tony Head from Hamilton - and they'd had the same problem when running at Manfeild. They stopped it by jacking up one side on the car, pulling the axle and filling the diff from there. Allows you to run more oil and keeps the diff immersed. It's the wide radius corners that do it - all the oil goes to one side until you're on the straights again.

Don't know if it was a T series diff but is out of an AE86. Kinloud might remember what diff head we were looking for a while ago.

[KinLoud]

Yeah Simon it was a T series crown and pinion 4.78 ratio from the front of a 4wd LiteAce.

Ken
Ham
021 408 863

[Logan]

I run 2L or so of oil in mine now. Gotta make sure you axle seals (or to not care) are up to the job.

T diffs DO have factory baffles in them to stop oil going up tubes.

I also run respectable power thru a welder 4.6 and it handles it fine. I do recall before i rebuilt my diff with the 4.6 and only used to run 1L of oil I could not touch the diff housing after a 2lap sprint race, now its touchable but dam hot.

[Adoom]

Did you give it a chance to run in before you gave it death at the track?
The wear/contact pattern on the teeth needs to be established before you use it for continuous hard use otherwise it can overheat in localised areas - similar to your description.
Best explanation - accelerate through the gears hard then coast and/or drive slowly with low power for a minute. Repeat for a couple of 15/20 minute sessions.
This gives the extra heat from running in period to dissapate into the mass of the crown and pinion and so creates the contact/wear pattern without overheating and so damaging the contact areas.
Once the contact areas is smooth and established there will be much less heat generated and you can drive it hard continuously.

Ken
Ham
021 408 863

I did about 300kms easy driving before going to manfield when the lsd was first built about a year ago. I must have had at least 4 trouble free trackdays before I had any noise.
Between the last time it ran with no trouble and the first howling day:
I changed to semi slicks.
I changed the rear end to parallel 5 link setup.(This involved welding brackets to the axle casing. I did not change the oil after doing this)

Both howling days I had a 'missfire' which turned out to be the changed fuel hose plumbing showing up the inadequacies of my low pressure fuel pump(I was running out of fuel).

But you are possibly right

[Dunny]

Overfill the diff - your crownwheel and pinion will be the problem and won't be fixed as the damage is done, either put up with it or put a new C/W & P on it.

I learnt the same lesson back when I had my KE70 (T series rear, not that it matters) on the track with oil just to the 'fill' level, it just doesn't cut it for track use, C/W & P is too long without oil in the corners.

Power has nothing to do with it

[Drifter4ag]

yeah .. as has already been said its probably dead anyway now .. but willbe fine to drive on for a while ... allways overfill your diff... we learnt that lesson when we started drifting ! Down the axle tube with 2litres plus is the way !!!

[Adoom]

Down the axle tube sounds impractical......Why dont I just weld another filler higher up on the diff?