LOWERED SHAKING WHILE ACCELERATING PROBLEM

It’s not that low. I’m just looking for what I already read. I know what I read mostly, it wasn’t a huge deal. It happens to all 3GS when you lower them. It’s a very subtle shake when accelerating. It’s not huge. At all. You can fit 2-3 fingers around the entire cars wheel wells so mines not even nearly as low as most I see in the marketplace with coils. It’s down about an inch on the front about 2 in the back. I just wanna find the post I searched all morning before I made a post hoping to find someone or the person who was quoting @Silvertune I can vaguely remember the post someone NOT silvertune said “if you guys are having problems with the 3g lowered shaking under acceleration check the axles, I had this conversation with silvertune and of course he was right he said put something like some washers somewhere on the axles” it was witty like that. Like they were referencing a conversation they had with silvertune and in that Convo silvertune answered it dude applied it and “Silvertune said to put * and of course he was right” is what it said the asterisks has something about washers on the axles I just don’t remember specifics. I’m just trying to find that post since my memory only remembers that much.

Anyways I don't think my car is low enough for that to apply. Long story but the alignment wasn't up to par and I had to take it back they left some stuff loose and it caused some other stuff to come loose while diving. After that they tried to say it was because of the new parts which I am testing this weekend and promised replacements if any fail so I'll figure that out but had to adjust some stuff after i got it back because they adjusted things incorrectly so the alignment is NOT what it was (since they screwed up they promised me a free alignment since the last correction I had to undo). But I wanted to eliminate all possibilities. I think it's something to do with the alignment again. That being said they did say there is some play in my tie rod ends, and rear sway bar links are a little loose. So need to replace those soon.

But I paid them to do a (coilover adjustment, alignment, and mount and balance a rim (had a destroyed rim from a pothole replaced). I wasn't positive I had the ride height set perfectly so asked them to check. (car was leaning due to busted struts and front sway bar end links I replaced so I was used to it leaning towards the front passenger sort of, so it felt wierd to me straight, I measured a million times just wanted someone to double check to be sure.) When I got the car back the spring was less than pre-loaded. So it seems they adjusted it wrong, and also left the bottom coilover loose enough to come off when driving I heard it pulled over, jacked the car up, locked it all down, and drove it back. Then expressed my dissatisfaction. They said they never removed my front wheel so I must've left it that way which I don't believe and even if true that means they charged me for something they didn't do hence the "Aftermarket coilover adjustment" on my receipt because if they did they would have needed to remove the wheel to adjust the coil cant spin the bottom without separating it from the hub. So i caught that lie right away. (Mind you I know they were "having a day" because I was quoted 1.5 hours and got my car back 5 hours later so clearly that day wasn't going as planned for them.) To make up for this they said they would fix the problem immediately and also give me a free alignment the next go around. However they brought up an issue with my new coils this second time. So now I need to test the coils because they are blaming this shake on a gas problem with my new coils, I know I cant fully trust them though, because I caught that already but the actual technician I talked to this time and not the guy that i caught in the first go around. He seemed more genuine and went through his entire process with me. So I want to eliminate all shaking issues before I go back and bring this up AGAIN. I'll never go back there after this but want to hold them accountable and make sure all components especially the very expensive new ones are working properly. The reason they believe something is wrong with the coils is because they jacked up one side and said it shot the tire down the other side it came down slow. They were both set to the same dampening so they should've reacted the same. So if that is true it could cause the shake perhaps, but I contacted D2 and they were with me virtually through fixing the preload setting the alignment messed up, so the shake could also be because the alignment is now slightly off because they left the spring not totally snug (this is after the 2nd time with this shop) I had to snug it up so it would be at 0 preload, they had it loose like negative preload opposite of compressing the spring It could slap between the upper mount and locking nuts. The car was at least going very straight with a subtle shake after the first adjustment, until I heard it slap on the road, after the second adjustment I contacted D2 and moved that nut slightly so I know that effected the alignment, I had no choice though the nut was incorrect. Now the car pulls slightly left, and the shake is worse than the first alignment. I know some of this is due to the adjustments that needed to be done. But, I remembered that post and wanted to ensure that subtle shake I read about wasn't adding to the problem. Before I do all these tests take it back, and maybe still have the shake or whatever.

However, I cant say that is my issue due to all these variables hence why I was just trying to find the post. So, before I get a bunch of threads I was just looking for the information I found previously to help my process of elimination since I clearly have a company I couldn't trust. I need to see everything for myself. So this weekend I am removing the front coils marking where they are set to to try and maintain what ever alignment is there, then I might just say screw the free alignment from them and go somewhere else. Because I've had to go back and check their work twice and found mistakes....twice. The first mistake was straight up life threatening one of my wheels had loose lugs on top of the loose coil. So I was NOT happy.

Your car is too low, it's as simple as that. The inner CV joint is a tripod joint and when it reaches a high enough angle it side loads the axle cup and it shakes the entire drivetrain. The drivetrain moving back and forth is the "shake" you're feeling. If you want to understand this issue, look up videos of CV joints that show how the output rotational velocity of them becomes a sine wave when an angle is introduced. While your axle is a different type of joint the same concept applies. The cyclic loading of the axle is the physics behind this issue.

The only fix is to raise the car up to a point where the joints are able to do their job. Solid engine mounts can help quite a bit by arresting the swaying of the drivetrain, often making the car tolerable to drive around but if you dig into a corner and the suspension compresses the dash will start doing hopscotch again. Worn stock axles or any aftermarket garbage will make the problem worse. Rubber control arm bushings, not having the factory strut bar, all the supporting systems contribute to just how much of a shake you end up with.

The washer mod is for people who end up so low the tripod joints will actually run on the end of the cup, I know of 1 case where the axle actually came apart.

It's a bummer but welcome to owning these cars. Every time you see someone flex their slammed 3g you can scoff in your head because you know how much of a piece of shit they all drive like.

For me, tolerable is zero shake, ever. My cars don't creak, rattle, or leak fluids. They're quiet, get good mileage and above all else, are smooth.

But I go way deep in these cars well, I address the big picture whenever I get one and it's a lot of detail work. As far as suspension goes a 2-2.5 finger gap with 26 inch tires is usually where my cars end up. Lot of guys run smaller tires on wheels that don't fit right with crap alignment specs and have to drop the car way too far to think it looks decent. Others are just juvenile and think having a slammed car is "cool" even if the user experience is trash. The 3G is a cheap, loosely designed car that was made to try to dig Mitsubishi out of financial oblivion. Unlike most other platforms the designs are half baked and only work okay at the stock parameters. As such it takes a lot more from you to cover the context and supporting systems to make up for the shortcomings revealed by moving the car outside those stock operating parameters.

OK so last night I removed the Front coilovers according to D2 instructions. Tested the struts took the springs completely off and compressed the struts to make sure that they both react the same when set for the same dampening. Both the struts pass this test. They both felt the same smooth while compressing, and then bounce back up the same. I then reinstalled the spring, absolutely, ensuring that the pre-load is set to a definite 0. This actually resulted in it being slightly higher in the front end so I went back and measured everywhere after getting the car back twice. It was 3/16 of an inch shorter on the driver rear. So I corrected that as well.

this resulted in the car, having a 2 to 3 finger gap around the entire vehicle. it does seem slightly shorter in the back, than in the front.

I took the car on a test drive this morning. The shake is less significant. However, it is still there. I know the alignment change slightly because prior to this the car very slightly pulled to the right now, it slightly pulls to the left. I’m thinking the back may be dropped too low however, I have had two other people say that they have it lower and swear there is no shake. So I’m curious if I’m there or very close and the getting worn tire rod ends may have something to add to this. That is on my list of next replacements, that and rear sway bar end links but may go anti sway bar as some have pointed out is a good mod. Idk gotta look into that tbh.

However, I’m also thinking I may raise the back up a bit, and that would get it closer to stock parameters because the way the car sitting now it almost leans towards the back, but the way the 3G is designed with that bottom lip. It doesn’t look like it leans towards the back, but you have more of a gap in the front that you do in the back so it is it’s just that lower lip giving the back end raised effect.

So I suppose what I’m curious is does dropping the back really affect the CV angle? I assume so, but before I take it more out of the alignment specs want to be sure. Or does that have more to do with the front? Would raising the back help arrest this shake?

I kind of wanna raise the back anyways since I raised the front a little after testing the struts, because I think the car looks better angled more forward than leaning back regardless.

However I’m not gonna go much further up in the back I’m gonna measure again, and raise it what I assume is going to be about 3/16 to 1/2 inch in the back then after that I think it’s gotta be other things. Right? After that it will be an even 2-3 finger gap around front and back in the back rn it’s hard to fit the 3rd half finger as you can see depicted.

At that point I believe I won’t go any higher or lower and just get the poly engine mounts. I already have poly in the rear.

Okay, I raised the rear 5/16” and that eliminated almost all of the shake. You can still start to feel it very slightly around 60-70 but it is super subtle. So I think the poly will arrest it the rest of the way. Also need to get an alignment again but have a freebie so may use that. I don’t want to go any higher than this really. So I think this will be the ride hight moving forward. Will update when I get the poly mounts and how that effects it.

Then as for Tires mine are about 25” total. The rim is stock size, and I ran these rims with the stock suspension and no shake. Tires are also stock size, so I can use my alloys as spares.