as3.0cl

iTrader: (2)

the car vibrates from a stop and also around 65-70 mph once we hit 80 it either goes away or gets slightly worse. it doesn't happen every time but it happens more often then not. we just ordered the F-sport springs and may be able to install them this weekend and we will report back on what we find. me and my father both believe it is drive train wobble. we can do all 4 sides in about 2-2.5 hours. i have done to many spring changes on lexus' and acura in the past 3 months haha.

My father has the GS i have the IS..his 07 GS350awd is right now on NF210's

i believe if we can get the front up an extra quarter of an inch we might be ok....also what i notice is how the springs are seated on the bottom and top hats. the F-sports seem to have a full complete coil that sets on the mounts where as the NF 210's only about half a coil is sitting on the mount. i almost think to a point that since the seeting of the spring isn't all around the bottom and top hats the spring actually vibrates or is weak.

also i hope the rear end of the car come sup a bit more then the NF's to even out the car and reduce the camber angle. we drive these cars daily even through winter storms so hopefully the F-sports will solve these problems and get rid of the awd look

stvincent

iTrader: (5)

yes.. actually the speed range doesn't matter.. this is the typical drive train vibration issue with the lowered awd models.. you can notice it right after the installation, even before springs settle.. if you don't have any issues, consider yourself among the lucky ones.. i'm just hoping there won't be any long-term damage..

bigalexus

The drop looks great! I'm curious did you get a Wheel realignment after you did your drop?

Yang1815

iTrader: (1)

Good luck with the install and hopefully get rid of the vibration.

Hmmm... I have noticed vibrations in the winter at times before the car's warmed up on stock springs but nothing different since the F-Sport springs were installed. I thought the vibrations come from being an AWD and not necessarily being lowered or not.

No I have not but I should.

stvincent

iTrader: (5)

it's possible that extra 1/4" might make the difference, but i think no one can say for sure that it will help with the angle.. as far as sitting goes, i had tein s-tech springs before, now with coilovers.. vibration issue is pretty much identical.

sorry OP to drag in another vibration issue discussion here, i know this has been beaten to death..

Yang1815

iTrader: (1)

Not a problem. Did you have the vibrations with stock springs?

nardeezy

Okay so stvincent, as3.0cl and myself have the same issue? I always thought it was wheel balancing and vehicle sensitivity. Adjusting/leveling the front and rear ride heights may resolve it? The reason I don't think it's lowering is because when I remove my iForged wheels and re-install the stocks the highway vibration is gone but the 0-15mph wobble still exists. Actually, I think the wobble has always existed (even with the stock springs).

I bet those BC coilovers would fix and prove the root cause? With the coilovers you can play around with different ride heights. stvincent, it says on your profile "BC coilovers", do you have them installed and have you played around with different height settings?

nardeezy

stvincent and as3.0cl, check this out: http://my.is/forums/f157/awd-is250-a...ration-392769/

Sound familiar?

telmz1

iTrader: (1)

Nardeezy - I have this problem as well on my 06 GS300 AWD. I had DF210s and now BC Coilovers but the problem is still there. I raised my car as high as I could with these coilovers and I still had those vibrations/wobbling from 5-15 mph. I think what I should have done was trade in this AWD and get a CPO RWD and eat the difference so I don't have to deal with this anymore. No need for an AWD here in Las Vegas.

as3.0cl

iTrader: (2)

honestly only a few people have this problem, maybe we are the few that can feel it and point it out idk....maybe our cars were from the same assembly plant and the drive train is slightly shifted.

as far as the awd IS is concerned. i'm on F-sports and i have no drive train wobble what so ever. there is guys in the IS forum with BC coils that are awd and has vibrations.

i just want o make it clear that at a dead stop there has always been an ENGINE vibration, not an actual drive train wobble vibration.

all we are doing is trying the F-sports on the GS and see what happens. if it was rims and tires the steering wheel would shake and that does not happen. the rims and tires have been road forced balanced.

stvincent - even with the BC coils you are having drive train wobble?

we all know this topic has been beaten to death but it escapes me on how some cars has it and others don't?

stvincent

iTrader: (5)

no, didn't have any problems before.

i can understand, but i have same vibration whether i'm on stocks or DPE wheels. it's very unlikely to assume that all other lowered AWD IS and GS's have the same unbalanced wheels. btw nardeezy, i have same size wheels and tires all around. the reason i believe vibration is caused by lowering is pretty simple. before i went to the shop to have springs installed, i did not have any vibration. after springs were installed, i had vibration.

i had friends seating in my car complementing how smooth the ride is on the highway. this was after springs and DPE wheels were installed.. on the other hand, i also had friends aksing me if i have any problems with tires when i step on the gas hard to pass.

yes, i installed coilovers myself, but did not try raise it back to stock height. whole purpose of getting these coilovers was to go even lower. it didn't matter if i still have vibration or not. please check the 'suspension' sub forum and check the AWD coilovers.. CMS replied regarding this issue, and i totally agree with them..

yeah, that's the same problem we are discussing here.. i just don't know what skipping feels like, prob the same i was trying to describe before..

ok.. this is where i'm getting lost again. when the car is raised back to stock height, i assumed the vibration would go away. i hear you though.. i love my car now, but was initially trying to order RWD from florida.. they wouldn't budge with the price since it had to be special ordered.. however, i couldn't complain for the price i got on AWD..

i just wanted to confirm the long-term effect of vibration, that is all..

stvincent

iTrader: (5)

yup, the car trembles as i step on the gas hard.. same here, i don't understand why some cars have issues, some cars don't..

Yang1815

iTrader: (1)

It's kind of like rattles, some have them, some don't. Some get them fixed, and some don't. Good luck y'all!

telmz1

iTrader: (1)

i adjusted the BC Coilovers to go as high as it could but it was still lower than stock. I think stock was like 4-5 fingers all around, with the coilovers I was only able to get it at about a 3-4 finger gap.

This is probably the reason why the AWD stock heights are higher than RWD? Lexus probably felt the wobbles and increased vibrations as well.

But yeah - I don't get why some get it and some don't - just like rattles. I'm afraid to say this but I have zero rattle problems, but after saying this I'll probably start having it tomorrow.

nardeezy

Technically, I can't seem to find out why a lowered ride height would cause the car to wobble from 0-15/20mph.

If I'm on the stock wheels and I accelerate with WOT from a cruising highway speed I don't get any vibrations, but with my iForged wheels I do. To be honest, I believe I always felt the 0-15/20mph wobble, even with the stock springs.