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View Full Version : Guibo - Flex Disc replaced... but...



Tiger
03-12-2008, 03:33 PM
Sounds like thrust arm problem... especially if you are just coasting. Vibration under acceleration is flex disc... but when you coast, it is suspension or engine vibration you are feeling.

rcbrown23
03-12-2008, 05:37 PM
I bought the part myself with full intention of doing it myself, but got under there and just decided to take it in. My local mechanic said he'd do it for $150, so I couldn't beat that.

Picked up the car just now (as they were closing), and now the strange part:

It used to vibrate (badly) upon acceleration. Of course I took it down the street after pickup, and the vibration was gone. Took it home.

Now it ONLY vibrates between 31mph up to 42mph. Everything else is smooth as can be. AND, it now vibrates between those speeds even when I'm just coasting or braking, whereas before was only acceleration.

Only in those speeds, no matter what gear I'm in. All other speeds are smooth.

I'm going to take it back up there tomorrow, but wanted to see what you guys thought the problem could be so I can pass along the info.

Maybe it's not bolted tight enough? could it be on backwards? anything??

Only the Flex Disc was changed. They said they looked at the center bearing (at my request), and it looked great.

rcbrown23
03-12-2008, 08:02 PM
After reading the description HERE (http://www.bmwe34.net/e34main/maintenance/suspension/upper_arm.htm), I see what you're saying, and thanks.

But... I don't get it. The car drove perfectly, then I take a hard left turn and something "falls apart". After help from the forums, I look under, and sure enough, it's the guibo (pretty much in pieces).

I only drove the car 2-3 miles, and very slowly, to the shop after the break. Other than that, it hasn't been driven.

How could the thrust arm just go out like that? I just got under there and looked, and the bushings don't seem to have any breaks or cracks in them (at least from the outside).



I did just drive it though, and can tell that the vibration is a bit different. Before, I could feel it in the shifter. Now I can't.

This sucks.




Sounds like thrust arm problem... especially if you are just coasting. Vibration under acceleration is flex disc... but when you coast, it is suspension or engine vibration you are feeling.

Jehu
03-12-2008, 08:32 PM
Don't despair. Once my car had this same shudder going up thru a similar speed range. One thing I had was an after market wheel and I learned about Hub Centric Ringsmgot a set ,put them on and shudder gone....for a while then it was back. That was remedied after replacing the Thrust Arms with Bushings, yes arms and bushings not just the bushings. Driving it with the severe shudder must have damages the ball joint and torn the bushing which now that the forces weren't being released with the wheels revealed damage done before.

So now great new Thrust arms and bushings, Hub Centric Rings but i have a little vibration when braking.... New Rortos and pads. No problem but when i take it up the highway to Bed the pads and rotors... wtf? Wild shudder again... mystified was I untill I tried just swapping the rear tires to the front. Turns out the tires on the front had worn unevenly . Once newer tires were on the front the car again drove smoothly. Check your tires.If you have non stock rims they require hub centric rings though that would have been evident by now. A bad tie rod end,lose might also contribute. Good luck. It is possible to return your car to a condition where the ride is as it was meant to be.