Outer Limits 4x4 Board

hey
my sierra recently took up a bad habit of really bad vibrations under heavy braking. and wen i turn left under braking. sometimes it feels like its comin from the from left wheel, sometimes it feels like its comin from the rear in the middle. like its drive shaft. its only started since i got the new exhaust. i cant see how that would effect anything. and ive check it out and its not hitting anything.

things i've thought it could be. havnt checked anything yet cause havnt had time.

1. front wheel bearing. i no there on there way out.
2. extractors hittin the engine mount under braking or turning left.
3. drive shaft uni's.

ive got a 1992 sierra with a 1.6 efi vitara engine.
and the exhaust i got is a 2 inch with redback extractors, cat and sports muffler. if that means anything.

any help would be greatly appreciated


me217

You are gonna have to eliminate things one at a time...
If the wheel bearings are worn then replace them and go from there.
Could be a big clod of mud stuck on the inside of a rim...Could be a warped brake disc.
Could be lots of things, so eliminate the obvious first.
Jas

i've done the mud in the rim thing before - felt like a freakin idiot when i went to get the wheels balanced and they were like "er, you know theres like, 1kg of mud in this rim right?" lol

i've also heard of an egged tyre, where the tread delaminated from the carcass.

A busted engine mount also gave me weird vibes once...

And recently in my roady car (mazda 323) worn brakes caused a shudder.

alien wrote:i've done the mud in the rim thing before - felt like a freakin idiot when i went to get the wheels balanced and they were like "er, you know theres like, 1kg of mud in this rim right?" lol

i've also heard of an egged tyre, where the tread delaminated from the carcass.

A busted engine mount also gave me weird vibes once...

And recently in my roady car (mazda 323) worn brakes caused a shudder.

I've had all four at various times in different cars i have owned!

Have you driven across a river or creek after a long downhill run recently? Did you see steam coming from the front discs as you hit the water? If the answer is YES, you discs are warped to shithouse, just like mine. If your wheel bearings are shot, it makes the vibration even worse, close to what some call the DEATH WOBBLE...

nope havnt dont any 4wding lately. bit of a run in mud but that wasnt deep. and the vibration is gettin alot worse. sometimes i dont even need to brake it just does it..

me217

update: new wheel bearings all round. still doin it. one of the tyres has bin scrubbing the leaf spring under full lock but its making the noise even on the highway. with bumps and theres no other scrubs marks. but it sounds like the tyre scrubbing. im gonna try abit higher tyre pressure as i am only runnin 26 i doubt it will help but im out of ideas.

just tried the higher tyre pressure and no luck.


me217

alien wrote:i've done the mud in the rim thing before - felt like a freakin idiot when i went to get the wheels balanced and they were like "er, you know theres like, 1kg of mud in this rim right?" lol

i've also heard of an egged tyre, where the tread delaminated from the carcass.

A busted engine mount also gave me weird vibes once...

And recently in my roady car (mazda 323) worn brakes caused a shudder.

tyres look fine and there only a couple of weeks old.
engine mounts are all fine.
and we checked the brakes when we did the bearings and there fine. disc rotors had one or 2 pits in them.

the sound has only started since the exhaust went in. so im guessin its something to do with the extractors cause there so close to the engine mount.

me217

unbolt the exhaust/extractors and see how it runs - itll be loud as, but worth a shot? lol

did u clearance the engine mount to fit the extractors?

also check where the exhaust runs round the rear shocks. mine is very close

theres heaps of room at the rear shock. and the exhaust shop fitted the extractors and they chopped the mount to fit. but ive sprayed abit of silver paint on the extractors and mount to c if it scrathes it off that'll tell me if its hittin.

me217

me217 wrote:theres heaps of room at the rear shock. and the exhaust shop fitted the extractors and they chopped the mount to fit. but ive sprayed abit of silver paint on the extractors and mount to c if it scrathes it off that'll tell me if its hittin.

me217

Just hope under it when its cold and give the whole exhaust system a bit of a hardcore shake in all angles. You should be able to hear/tell if anything is rubbin'

Dan