I have an 87 Iroc with nothing done to the suspension. When I hit 75 mph my car begins to get really shaky. What can I do to fix that?

 

check tire and drive shaft balance

 

How would I check the drivetrain? Like what in specific?

 

I think you would need to bring it somewhere to have the wheels and drive shaft checked, but you could also check to see if the front end needs new bushings, check to see if the bearings are bad, if the front wheels can be moved alot when there in the air then its probably in the bearings etc. I would check the wheel balance first though, or see what others have to say.

 

Alright I'll get it checked out. I wanted to just replace some parts from the front end, but I'll get it checked it first. Thanks

 

Take it to a tire shop and get the tires balanced. It's about $30 bucks.

 

Check all your ball joints, and the link between suspension to chassis. If it is not tight, there are some risk, including shimmy. I experienced that on a Firebird and it is crazy. You can do a full check of your car for about 20$ including a suspension check. Anyway if it is only at 75mph and over, it is more likely to be the tires (or the dirveshaft).

 

I just put rims and they were balanced when I got them. Haven't done anything to the front ones, so I don't think they need to be balanced. I'll take a look at the driveshaft.

 

its also possible that you're alignment is slightly off. i had that problem. turned out the ball joints were bad too, so i replaced all the steering linkages, ball joints, and got an alignment and now its perfect.

 

Yes it is. I'm gonna get it aligned this weekend so I'll let you guys know if it was that.

 

It's most likelt being caused by the tires needing balanced and being amplified by worn out parts.

 

I got it aligned and the wheels are balanced. Haven't ran it fast yet, but I'm planning on changing the worn out parts in my suspension

 

i have the same issue but around 65 then 70 it's far less around 75 is gone completely .
its done the shake ever since i got it i didnt notice it when i test drove the car mainly it wasnt running correctly so it didnt have the guts to get to passed 50 lol.
if the car wasnt rust free with decent paint id most likely have just stripped it and got another one.


ive done an alignment digital rack by someone i trust
new tires digitaly balanced cooper cobras
4 new rotors just incase one was out of balance or warped and 4 new calipers all raybestos
all new suspension ie shocks struts strut mounts
all bushings idler arm centerlink and inner and outer tierods even the steering box and springs and spring mounts energy suspension for all rubber replacments moog steering parts
all new wheel bearings timken brand
aluminum 1le "from a real 1le car " drive shaft with new U joints and high speed balance and so its not that
replaced the rear axle timkin bearings again new posi unit and gears all new interals basicly
steering column to fix what was got broke from it shakeing so bad

ive had 4 alignments done and nothing changes it so its not that even my alignment tech has no clue what else it could be

ive changed just about every part that moves going down the road and even with it being much less and not as dangerous as it was its still not how it should be

i just gave up and stopped doing the speed limit as nothing seems to cure my 57-68mph shake it bounces the dash pretty good around 60-65 our local speed limits . but i do 75 and its smooth as ice
after spending more then 2000 on parts i gave up and avoid doing driving at thouse speeds other then that its smooth as ice
around here you spend 600 and you get a waiver for E-check

my only advice has been from a chevy dealship said i need to find someone that still has an on car balancer thats how they used to balance these cars back in the day

no place has them anymore apperently

only clue ive got is when on an dyno it dosnt shake at all so its something with the front end .
rotateing the tires around dosnt help
under wide open throttle there is no shake
also when going up hills no shake
but going back down i get the shake
its no longer the major dash breaking shake its now a much less harsh one but its still there


i hope others can fix theres but apperently this one just wont stop

 

Damn that sucks. I'll let you know how it goes with my car.