Ass Bounce on Take Off?q

[Jehu]

With the new clutch and flywheel it was easy to stall upon launch.I have always had a heavy foot and may have learned to overcompensate for the sensitivity by stomping on the gas too much.Many times i was chirping the rear wheels as i;d take off from a stop but today i noticed the rear wheels were bouncing if i stomped particularly hard on the gas from a stop.When i got home i thought i noticed the car sitting lower on the rear wheels even a little lower on the right/passenger side but still the wheel well rim is now down over the top of the tire... this isn't meant to be is it ? What does it sound like I've done? Busted a spring? blown out the shocks? i don't hear rubber rubbing . I first thought the bouncing rear wheels was just hitting ripply, sandy pavement, now I'm not sure. Any ideas?

[califblue]

make yourself a clutch stop...end of problem...the stock POS goes all the way to the firewall...just ask Gayle I just made her one:D

total cost $.43

[Robin-535im]

Loose Ass can come from subframe bushings that have torn.

You can pull the cover plate and have a look, have someone jump on the bumper while you watch/feel how much movement there is at the subframe mounting point. IIRC there are two 13mm bolts and a big 22mm nut that hold the cover on. Have to put the 22mm back on after pulling the plate so the bushing is held in place.. otherwise it will have free reign to move when you jump on the bumper.

The other bushings are pretty tough and fairly small.

Upper rear shock tower bushing could also have gone south too. Pull the seat back and inspect it, do the same watch/feel test while someone jumps on the bumper.

HTH

- Robin

[Jehu]

Thanks very much.Good ideas.. Would these be likely to have torn from my launching hard from stops for the last few weeks?

[Alexlind123]

make yourself a clutch stop...end of problem...the stock POS goes all the way to the firewall...just ask Gayle I just made her one:D

total cost $.43

Umm, this doesnt answer his question in any way.

[Jehu]

Well if it helps me to properly use the clutch pedal so i don't either stall or launch it will help after i've fixed whatever it is i've done from being a dope.

[indierthanthou]

ill have to see that. just a bolt that the pedal hits?

[califblue]

ill have to see that. just a bolt that the pedal hits?


yes 1/4" bolt double nutted and a lock washer on the inside just adjust it to your prefrence ( there is a pre exsisting threaded bracket wtih a rubber plug...just remove the plug)...I also have a metal cap plug that i put on the bolt head for a larger contact patch( it ried a rubber one but it wears to quickly and if you send me your address and i will send you several)

or you can buy one from Bav Auto for $79

[Blitzkrieg Bob]

would be more effective

[Alexlind123]

would be more effective

I was thinking the same before i scrolled down and saw your post. The clutch stop is nice and all, but it just keeps you from pushing the clutch unnecessarily far down. It has nothing to do with clutch engagement. I would get one if i drove a manual though.

[AngryPopTart]

By the looks of these, it almost seems like there wouldn't be a huge difference in comfort if you just used solid metal bushings. Has anyone done this? Seems like it would be better than the movement you get from them being worn out.

[Paul in NZ]

sheesh a 540 should take off at idle.....if you cant manage that you need to practise,and learn where the clutch takes up,let it out to there,hold it there for an instant while you feed in some gas and then let the clutch out the rest of the way...try a few take offs just idling you will learn some clutch control.then you shuld be able to do smooth starts using hardly any throttle,your gas consumption could even go down a bit!A clutch stop wont teach how/where to make those small adjustments to the clutch and throttle.Once you have that down pat learn to stop without having the car dip at the last second,or driving the car without making your passengers head jerk back and forth...

[Qube]

Are you just talking about wheel hop or am I misreading? Maybe you need to buy the new rear adjustable Koni's I'm selling :)

[Jehu]

Are you just talking about wheel hop or am I misreading? Maybe you need to buy the new rear adjustable Koni's I'm selling :)

Wheel hop is exactly what i am saying. Is that blown shocks? Can i use them with these factory lowered springs? How much? BTW if the shocks are junked can i still drive it? Will the wheel soon begin scraping the wheel well or will the spring at least allow me to get around till i get them replaced?

[Ross]

Wheel hop is what it sounds like to me as well. Blown shocks will allow the axle to flop around, the tires are alternately grabbing and letting go.
This is VERY hard on driveline components.Fix the rear suspension before you break something or burn up that new clutch.

[Jehu]

While i have been spinning thw rear wheels a lot on starting from stops the wheel hop just started yesterday on my way home .I first thought it was just sand on ripply pavement but when i got home and saw the fender cut out covering the wheel i figured the shock had croaked.

Here are pics i just took. It actually doesn't look as low as i thought it did last night now that i see it in the light..Could the shocks still be gone endangering the rear end as mentioned?

http://img301.imageshack.us/img301/5134/rear003lc3.jpg

http://img301.imageshack.us/img301/1270/rear006sv9.jpg

[Ross]

Every time you feel the "hop" the drive line is shocked. The rear end is probably least likely to break. The clutch, driveshaft and CVs take the brunt of it.
I have had catastophic failure of all the above in various cars over the years induced by beating it like you seem to be.
If you're gonna pound on it, at least fix it so the wheel hop quits.

[Jehu]

Its only done this twice yesterday. I took it to my shop guy today and he says it sounded to him like it was just a combination of my florring it in anger over sand covered ripply pavement.Never having had it happen before i had to think the worst.I'm still going to have the struts and shocks replaced next week.He's just going to use OEM BMW parts.A tune up and a fix the power steering fluid leak/hose whatever. Maybe by them we'll have a 50 degree day and i can polish it up.Looks so trashy in the bright Sun.I'll have him check the drive line parts and see if i injured anything .Sometimes i just lose my head and transfer all my frustration thru my gas pedal... I forget it'll only hurt worse when i get the Bill.

[danielhstout]

If your car is lowered than you should probably use sport shocks. OEM replacements will likely blow soon; also consider your driving style.


By the looks of these, it almost seems like there wouldn't be a huge difference in comfort if you just used solid metal bushings. Has anyone done this? Seems like it would be better than the movement you get from them being worn out.

Maybe urethane but not metal. Even urethane can make the ride pretty harsh.

[Jehu]

If your car is lowered than you should probably use sport shocks. OEM replacements will likely blow soon; also consider your driving style.



Maybe urethane but not metal. Even urethane can make the ride pretty harsh.

The car came lowered from the factory. It does not have an after market lowering kit. If the shocks BMW used are no different weather this lowering option was installed i can't see there being an issue as these have lasted this long.he will install what i bring if i want to go that way but i asked him specifically about this, weather becaseu it is lowered, the sport option so called, did i need to have shorter shocks and he said it did not require shorter shocks, or that whatever part number is specified fro cars with this factory option will still be available and is reccomended. If you can articulate why this is not optimal by all means do.I'm not saying you aren't correct but anytime an opinion is offered which calls the Factory design into question i feel i require soem substantial facts .

[Paul in NZ]

the traction control should stop driveline abi=use over sand covered ripply pavement,or do you have that off all the time.

[Jehu]

the traction control should stop driveline abi=use over sand covered ripply pavement,or do you have that off all the time. I have been shutting it off alot because it seemed i could get going from stops better without it on.I can't recall if it was on or off but it seems to actually engage if the tires spin anyway doesn't it ? I mena the indictaor light goes out when the tires spins i've noticed indicating the system is on.