now what? almost lost control of the X5
 

So this morning I was coming home from work and its was slightly drizzling outside. I am going about 65 on the hwy and all of a sudden the rear end just started to slide. I let up on the gas and it recovered. I slowed down a bit and then got up to about 55 and again teh rear end started to twitch. At taht time i figured maybe its a slick spot or something.

I left the house awhile ago and as soon as i hit around 55 (still raining) the rear tried to swing out again. I got a good 1 or 2 inch left to right slide and now even at slower speeds 35-40 the rear just feels really loose and like its ready to just swing out any moment. any thoughts? Its at home right now. Drove the dodge truck to work

You didn't Armor-All the tires, did you? (j/k)

I'm assuming you have plenty of tread on your tires? Is/was the DSC off?

The general concensis should be, especially in normal dirving situations with bad weather, to KEEP DSC ON. Even more true in cars like E46 M3's, but still holds true for most in the X5 as well. Although the E53 is way more heavy and with "better control" via xDrive, you should still keep DSC on. Turn it off to do doughnuts in a snow-filled parking lot or to get loose in deep snow but otherwise keep it on. It'll save your ass in bad weather for sure.

Not that the OP said he had it off, but just my 2 cents.

Good luck with your car dude. :thumbup:

That handling characteristic (even in the rain) is not normal at all. I've never had the ass-end try to come around like that even in snow (at least not unexpectedly). Check the inside tread of those rear tires. I'd bet due to the negative camber setup, the tires are shot and this will keep happening to you. Let us know what you find out! :thumbup:

Could it be something to do with the rear alignment....?

nothings changed in the last 2 weeks.. i will check the tires in the AM, I cant recall how worn they are, but I do know for sure they are not at the wear bar yet

Yes, but check the inner edge of the tires and look for extreme wear. Don't be fooled by the outer edge near the outer rim or the center of the tire, focus on the inner edge closest to the center of the vehicle. If you find the tires badly worn on the inner edge, then that can be the source of your handling problem since the pitch of the camber settings on some of the X5's are extreme at the rear and the rear tires wear out quickly on the inner edge of the tires. :(

also check the age of the tires. the rubber will harden with time. after the DOT there is a 4 number code, tell us what it is...

Was it actually a slide or just the feeling of the back end twitching?
It may be worth checking the rear subframe bushes.
When these wear they cause the car to wander as the subframe moves.
I'm thinking that this could be made worse in the rain at speed if you get a build up of water infront of a rear tyre that stresses the bushes momentarily.

From a physics standpoint, simply not enough rubber touching not enough road. What would be the reason for this? Worn tires, wrong tire pressure, worn suspension parts or poor alignment. Unfortunately our X's came with the last of the 4 from the factory (extreme negative camber).

Tires have grooves on them for one reason only . . . traction in inclimate weather. Tire grooves are designed to take moisture out both sides of the tire usually and in assumption that there will be equal pressure across the contact patch. I'll bet they never studied what would happen if you cock it sideways about 4 degrees and see if it can shoot all of the water/snow out one side of the tire only because the other side is barely above the wear markers or completely sealed to the pavement.

Well the good news is because of the negative camber it's unlikely that we'll ever roll one of these over . . . on dry pavement at least.