View Full Version : R180 behaviour on wheel lift?


hmhaga
01 December 2007, 01:29
I have a 6MT DCCD gearbox with an R180 setup off a 00 Type R. How exactly is the R180 rear diff supposed to behave when one of the rear wheels lift off the ground during acceleration (due to uneven surface in this case)?

911
01 December 2007, 09:33
If the rear diff is plated LSD and set quite tight, you will not notice the loss of drive being on 3 wheels.
DropShots.com (http://www.dropshots.com/911#date/2003-01-04/12:20:18)

Wait till the last bend in the vid. The rear comes off the ground but no drive lost to the loaded rear.
If the lsd is a viscous type thie drive is easily lost as the setting is so soft.

hmhaga
02 December 2007, 18:09
Thanks for your feedback. I thought all R180 LSDs were plated?

I'm certain I lost drive with one of the rear wheels off the ground, I didn't expect this to happen :( The differential is off a low mileage car, but I had the seller rebuild it to 3.9 ratio to fit my car. Any chance that it was set up incorrectly during this rebuild?

Anyone who has any experience with the STi Pressure Ring Set?
RalliSpec - Differntials (http://www.rallispec.com/prod_diff.htm)

911
02 December 2007, 18:17
The pressure on the pack of discs can be set loose or tight, so the rebuilder could have set them light?
I think you are correct, all R180's are plated.

The only person I know with experience is David at API. He set my R160 up for hillclimbs (tight)

John Stevenson
03 December 2007, 21:49
The pressure on the pack of discs can be set loose or tight, so the rebuilder could have set them light?
I think you are correct, all R180's are plated.

The only person I know with experience is David at API. He set my R160 up for hillclimbs (tight)

Early R180s are all plates, Bugeye STi is Suretrack ( UK cars are anyway)

The rookie
06 December 2007, 16:35
If the R180 is out of an 00 type-R as you say, then it should be a plate diff, it should grip and go but they are set up with quite a lot of preload and if run wth the wrong oils the plates can get knackered, with the gearbox in neutral (or better still with the prop off the diff as there is some preload on the DCCD clutch pack), jack one rear wheel (handbrake off!) and use a driveshaft nut and torque wrench to trun the rear wheel and measure the effect of the preload, anything less than about 40lbft (i'm told) is not good, should be about 60lbft from new.

Simon


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