Alright so here's the deal. I just bought a 240 off some guy and he told me that it shook REALLY bad on the freeway because the motor mounts were shot. All was fine because i figured i'd upgrade motor mounts for an SR swap anyway.
The problem is that at around 70+ the car starts shaking VERY dangerously to the point where i absolutely cannot go any faster as the car will shake to death.
Fast forward to today. I changed all three mounts (motor and transmission) and the car STILL shakes rediculously on the freeway. An observation that my buddy and i made was: With the car on all four jackstands, we put the car in gear and took it to 5k rpms through every gear. By the time we hit third gear, both rear wheels were shaking to all hell even while the car is off the ground. What could be causing the rear wheels to shake like this? Any input would help, thanx!
Just replaced my motor mounts, car still shakes bad on freeway
-
0ptimus prime
- Posts: 28
- Joined: Mon Oct 24, 2005 1:18 pm
-
0ptimus prime
- Posts: 28
- Joined: Mon Oct 24, 2005 1:18 pm
Re: (SeVa-S13)
nah bro, they're on older datsun wheels. The offset isn't very low at all; probably close to FWD offsets. But the rims don't seem to be bent. As for as i can tell, the tires don't seem to have any bumps or anything either. I don't know what could cause both tires to shake to all hell in mid air. I'll check out the bushings and maybe get a video clip of how it looks.
-
sensibleS13driver
- Posts: 3012
- Joined: Tue Sep 21, 2004 7:20 am
Re: (SeVa-S13)
I think hubcentric rings make no difference, just speaking from experience, but any tire place will tell you you need them. I'd get the tires rebalanced 90% of the time thats the source of freeway vibration.
-
FattyMcBaggins
- Posts: 640
- Joined: Sat Jan 22, 2005 6:10 am
- Car: 1990 Nissan 240SX
- Location: San Antonio, TX
Re: (SeVa-S13)
But how would the tires make his car shake when he said that the rear end shook violently even while it was on jack stands?
Re: (tenkawa_akito)
agree. Also old Datsun wheels should be fine on a 240.tenkawa_akito wrote:get your wheels rebalanced
Re: (FattyMcBaggins)
when things spin really fast imbalances make them shake...If you say the problem seems to be in the rear you could try the ol tire swap and change the fronts for the back, and visa versa, that way you can tell if its an alignment/suspension thing, or a tire/wheel thingFattyMcBaggins wrote:But how would the tires make his car shake when he said that the rear end shook violently even while it was on jack stands?
as far as hub centric rings go I don't think they would cause shaking would they? from what we learned in suspension class the deal with them was to properly transmit the load of the vehicle from the rim directly to the hub, so that the lugs simply hold the tire on, but do not support the weight of the vehicle...
Re: (Red coupe)
Nonhubcentric wheels are the most common source of shaking at highway speed for aftermarket wheels. If the the center bore and hub don't fit right, then there's play in the wheel's fitment and while you can bolt it down and it won't come off, you'll never get it exactly centered: it'll be like rolling on an egg in theory.