legacycentral bbs

So, I've been reading up a bit on the all-wheel-drive system and from what I'm gathering, it's not a good idea to do donuts. There was a post that described the workings of the 4eat center differential and it said that when the front wheels and rear wheels are spinning at significantly different speeds for over 30 seconds, you can do serious damage to the diff.

Do you guys have any further input on this? Is this the same with the manual transmission cars?

I did donuts in the snow and I've done them every chance I can and my transmission felt no different.

Really..... Do you have 5mt or 4eat?

Does my 5mt have a better center diff? I've been wanting to do doughnuts in the snow when I get the chance... but would hate to cause severe wear from something silly...

*I did them before my overhaul on dry asphalt with bits of grit on the road and nothing horrible happened.

I don't know if it's "better" but I know it's different. I think one is a mechanical diff and one is a viscous slip unit. I'll try to find the post where some guy explained it.

I'm sure it is not "good" for it. But I doubt that it would do much damage if it is not done to excess. If your doing donuts for 5 minutes or something at WOT that would wear on it hard. You just don't want to overheat it just like the tranny its self. The diff basically is another automatic transmission.

I have a 4EAT..and of course I won't WOT it for like 10 minutes, but doing donuts at slow speeds isn't going to make my tranny break.

Spinning tires is probably going to ruin CV boots before it damages the center diff. That being said, I can break pretty much any gear in pretty much any car screwing around with it. I do donuts all the time in my field with the AWD BJ wagon (5sp). I have never had a problem other than the huge dent in the unibody from the woodchuck holes. Car still runs and drives fine....I really don't care if this engine or tranny blows up so I've held it at about 5500 RPM (for about 30 seconds at a time) while sliding in 1st and 2nd gear. Drives like a charm.

forget wear i read it im sure it was on hear some wear but there were several accounts were the 4eat actually did better in the snow than the 5mt. not a substantial amount just barley noticeable., though you have to factor in the drivers capabilities as well.

the real damage will accrue when you hit a patch of the sticky asphalt causing a sudden jerk of force to your drive line which can break all kinds of things.

ej22t kid wrote:forget wear i read it im sure it was on hear some wear but there were several accounts were the 4eat actually did better in the snow than the 5mt.

Sure doesn't seem to be the case with my cars. My wife's 97 Outback is a 4EAT, mine's a 5MT, and both have same age/brand snow tires. My 5MT seems to do better than her car.

who cares what it does, it is too much fun not to do them.

+1

haha, +1

Ok serious now, I've done it a lot and all my cars have seemed fine afterwords. But, I don't spin minute after minute - I take breaks, coast around a bit, and let the viscous goo or solenoid coupling cool down (depending on which tranny you have). Best not to put ANY part of the car under unusual load for long without breaks. Like people said, I'm sure it's not "good" for it but it's "ok" and definitely worth it!!!!

I doubt anyone on here would notice if their viscous coupling degraded anyway. Wouldn't be surprised if someone told me they wear out naturally after 15 years.

Anyways, don't worry about the diff, worry about curbage. Every winter the "I ate curb" threads flood every Subaru board.

Kiddies: Research your parking lots BEFORE the snow covers all the curbs and medians!!!

Bottom line...

Have as much fun and break as much stuff as you can afford.

Quote worthy?

i would have to say that is quote worthy.

i was doing doughnuts in the mt. baker parking lot the 1st time i drove it up there... held 2nd and bounced it of the rev limiter

I don't ever hit curbs when Im screwing around, I hit them when I have a catastrophic blowout on a steering tire on my way to work (late)... but yes. always know where youre sliding, and whats there... many small items have been overlooked and caused thousands in damage to cars over the years... I remember once I bumped one of those barrels full of sand next to a stop sign at an intersection (I was going through the side without a stop sign) and I just had the rear end hanging out... cost me a scratch, and a ding in the rear bumper.... back to the donuts thing though... 5mt vs 4eat, I say the MT factor adds clutching, so you CAN push more force into the donut... but again, thats all driver... they both f-ing rock, so just do donuts and if something breaks find out why, fix it and tell us.