Center differential dead ( '02 WRX Wagon )

[Rui Pedro Mendes Salgueiro]

If its high-speed hours upon hours I think it can have
a significant detrimental effect. Try touching the rear
differential after driving for half an hour, or so, at 70mph.
Its hot, very, very, hot, I might add.

So ? As long as the temperature of the lubrificant doesn't exceed
the temperature that is it is rated for...

If you happen to
go more than 70 mph then the effect is even worse.

To put this in perspective:

Some time ago I searched the net a bit for endurance speed records.
The following is a non-exhaustive list:

- August 1983: Mercedes 190 E 2.3-16, 201 hours, 39 minutes and 43
seconds 50,000 kilometers (247.94 Km/h average). Nardo, Italy.

http://www.germancarfans.com/classics.cfm/classicid/5040331.009/page/2/lang/eng/mercedes/1.html
http://www.benzworld.org/news/news.asp?id=238

- Saab at Talladega (1986 and 1996):
1986: 100,000 km with an average speed of 213.299 km/h = 468.825 hours
1996: 226.45 km/h over 25,000 miles/40,000 km. = 176.639hours

http://www.thecarconnection.com/Vehicle_Reviews/Luxury_Cars/1999_Saab_9-3.S183.A800.html
http://www.saab.com/main/GLOBAL/en/awards_9000.shtml
http://www.swedecar.com/saab_history.htm
http://business.fortunecity.com/bechtel/441/17.html

- 2005 - Mercedes E 320 CDI 100,000 miles (160,934 km)
Standing start 224.823 km/h ??? 139.699 mph*** World record **
Laredo, Texas 715.825 hours = 29.82 days ~= 1 month !

http://www.germancarfans.com/news.cfm/newsid/2050502.003/mercedes/1.html

The above URLs are some months old. I hope they still work. If not, try:
http://www.archive.org/

As you can see these cars had no trouble running their transmissions at
full speed for many km.

BTW, the 1983 record was at Nardo which is a 12km-perimeter circle,
so almost a straight. But Saab ran at Talladega , which has corners
(it is described as a 2.66-mile tri-oval). This is a bit more effort
to the differential (since the wheel speeds are very slighty different).

http://www.talladegasuperspeedway.com/track/index.jsp
http://maps.google.com/maps?f=q&hl=...ll=33.568289,-86.067238&spn=0.021598,0.032187