NoTLoud

I am noticing this issue seems to becoming more intermittent. Sometimes when I am accelerating, the car drives like I would expect it to, while other times, it will shake horribly when accelerating. It's gotten to the point where I can tell almost immediately if the car is going to feel like shit when I hit the accelerator pedal.

I can't think of anything else outside of the mounts which would cause an issue like this. My biggest dilemma is that they were "replaced." If the shop is telling me correctly, they are not the liquid filled, OEM mounts. I am wondering with all the other stiffening of mounts I have done if the liquid filled mounts make that big a difference.

I may try and look at the condition of the sub-frame bushings this weekend. That would be my only other thought at this point. I just haven't seen anything pop-up on the forums about them before, so it doesn't seem to be a common issue.

jimmyfu

Sorry, not sure if I missed it or not, but were you able to at least check the side motor mount with the bracket off, so you can inspect underneath the dust boot?

UA7X

I'm with jimmyfu - check that side mount and see it's physical condition. Super quick check - loosen the center bolt, remove the two bracket bolts, then remove that center bolt. Dust boot slides right off, and there's your mount. Take a pic so I can see it!

The subframe mounts *can* break, but the only time I've ever seen it was on a car that was in an accident that literally bent the subframe and the knuckle and the strut. So I think this is a lot less likely to be your issue.

If your mounts are aftermarket and they don't have fluid, that's probably the cause - the fluid really does make a huge difference. I would start by replacing the front mount with OEM (assuming your side mount is ok, check that first). If you can get a decent angle, try posting a pic of your front mount too.

NoTLoud

I will try and get a better look at both this weekend! It has been a busy past couple weekends, so I hope to get some work done this weekend.

Both have the heat shield/dust boot that say SEP on them, but obviously that doesn't indicate whether the actual mount is OEM. I need to check the front and see if it has the factory markings. I have an OEM rear, so I imagine the paint markings should be similar. I just couldn't get the bolts to move when I tried to take the front mount off before. I could have been turning the bolts the wrong way though. Wouldn't be the first time I was a dumb ass when working on a car.

jimmyfu

Righty loosey, lefty tighty!

In all seriousness though, I think I used an 18" breaker bar to break the front mount bolt to the bracket.

UA7X

Pick up a can of PB Blaster or something similar. Spray the bolts and let them soak for 10 minutes or so. That should help loosen them up!

NoTLoud

I'll give them another try. I have a battery powered impact gun now, so I should be able to get the bolts off. Just gotta be careful to not strip the heads off.

Honestly though, I am really beginning to think it's the front mount.

I looked at it after I got home today. I saw no paint markings where the metal bracket attaches. My rear mount has pink paint markings on the studs coming off the mount. Is there supposed to be markings there?

The other day when braking, I noticed my car felt like it was rubberbanding itself back and forth. It will do the same if I let of throttle while in lower gears. Not all the time, but I have noticed it a couple times.

NoTLoud

What about issues with the intermediate shaft (between the axles, not steering column)? I am having troubles finding specifics on it, but it sounds like it could cause issues with vibrations under acceleration.

It appears to have a bearing inside it. I think there may be some play in that. If I move the wheels forwards and backwards with the car in the air, the wheel will move some before it engages anything. So if I move the wheel back and forth (forward to reverse), then there is play in between before it seems to catch anything.

UA7X

I've never seen an intermediate shaft go bad, maybe it's possible but it's pretty unlikely to be your problem.

That movement / play when rotating the wheels in the air is normal, nothing to worry about there.

NoTLoud

Okay! I got my side mount off this weekend.

Quick walk through of my findings:

Bolts going through mount and into frame were had the ever living shit torqued out of them. My ~700ft/lb battery powered torque gun, struggled to remove the bolts. I imagine it's a similar issue with why I couldn't get my front mount bolts loose with a larger breaker bar. Granted, I could be running low on battery, but those bolts were in there. I had to remove my swivel socket and use just a normal extension to loosen both bolts.

Side mount looked fine. As far as I can tell, it's OEM. Gold paint marking on top metal tab. The middle of the mount felt squishy. Arrow indicator on it.

One of the bolts was horrendously rusty. I'll be ordering two new ones tonight. Down it's causing any issues, but it's bad. I will try and get some pictures up after work.

I didn't mess with the front mount because I didn't feel like jacking the car up, removing the plastic that covers the tranny, putting the car on stands, then putting the jack under the tranny. I do see the "FREPAT" marking on the front mount, which seems to indicate that it is also OEM.

Rear mount has the same markings as my new OEM rear mount sitting in my room.

I don't know why the shop I took the car to was saying the mount were not OEM. That's a mystery.

Is there any possibility that over-torquing the front mount bolts is causing issues? I could try them again, but my guess is they're torqued to hell as well. As mentioned, I tried getting them off with my larger breaker bar and I couldn't get them to move.

NoTLoud

Thanks for the confirmation on the intermediate shaft. I have seen another thread where someone mentioned they still had vibration under acceleration after replacing both axles and replacing the intermediate shaft solved their problem.

Thinking about it again though, it would not explain why I am able to replicate the vibration when the car isn't moving.... I think I am just looking at every single possibility and jumping on it right now in hope it's the answer.

UA7X

Paint markings don't necessarily mean the mounts are oem. The reason you see paint marks on oem parts is because when the car is assembled at the manufacturing plant, they mark components and bolts to indicate that they were properly torqued to spec. But obviously anyone with a paint marker can add markings during service.

The rust on the bolts is probably what gave the impression that the bolts were over-torqued. Rust buildup will cause bolts to become harder to remove. I've never been to NC, but I'd imagine you have more rust than what I see in Arizona, so if it's an issue out there you may want to apply anti-seize to the new bolt threads. Couple of pointers when using that stuff: a little dab is all you need, and be aware of where it ends up - a little bit on your pinky finger and all of a sudden you have smudges all over your car and your clothes and your tools and your face and etc etc. It will make a mess lol. So I recommend wearing disposable gloves, then apply and install the bolts, and then throw the gloves away. The rusty bolts definitely aren't causing your problems though.

Common problems that come from rusty bolts:
- The bolts become difficult to install or remove
- They break during installation or removal
- They disintegrate while installed
- The bolt head rounds off during removal
- And my favorite: they become one with the component

Over-torquing is also not going to be the cause of your problem in this case. Common problems that come from over-torquing:
- The bolts break during install
- The bolts are difficult to remove
- The bolts pull the threads out of the component during install or during the next removal
- The bolts damage the component (not the case here, btw)

Also yes, the intermediate shaft is not moving while you're at a stop, so it shouldn't cause any vibration at idle.

I had another thought, if it turns out that your mounts are still good and don't need to be replaced. You could try "neutralizing" the mounts. I haven't been able to find the official procedure in the shop manual, although I'm fairly certain there's a ServiceNews Article on it which may be somewhere in the sticky thread https://acurazine.com/forums/third-g...letins-588838/ if you're willing to hunt for it. Basically, you would slightly loosen the center bolt on each of the main mounts, then start the car and shift back and forth between Drive and Reverse a few times (pausing a bit between each shift to allow the gears to catch and settle), then go back and tighten down all of the bolts.

NoTLoud

It's strange. Both bolts took all my torque gun had in it to get out. One of the bolts is very rusty and the other is fine. My guess is water just got into the hole and sat there over the years.

Overall, my car is in nearly mint condition. I do not see a spot of rust anywhere on it. None of the other bolts have been an issue removing. The only rust I have found is on the exhaust and J-pipe nuts. One I had to use a more persuasive technique on, but I have ordered a bunch of new nuts for the J-pipe with my latest order from Delray. One of the nuts it currently missing, but it doesn't seem to be causing any issues. Anyways, the condition of my one side mount bolt was surprising given the condition of many others I have seen on the car. New ones will be here today. Have a new tailight coming in today as well as my driver's side one is slightly cracked and I want the exterior as perfect as I can get it.

Bolt went back in fine, which was surprising because the threads on the bad one looked rather useless.

I will definitely look at neutralizing the mounts. It may solve the issue. It's hard to explain exactly how the car feels, but everything seems to point to a mount issue.

UA7X

Do you have a lot of noise with the vibration? I forget if you mentioned that earlier. How is your exhaust condition besides that missing bolt - any dents or bends? The exhaust flexes a bit with engine movement (this is normal), but if any pipes were bent and made contact with the vehicle frame when you rev the engine you would definitely feel vibration, although you should also hear noise (I would describe it as a low pitched almost hollow tone).

WDPanda

My flywheel became unbalanced and would vibrate at 1.5-2.5k rpm at idle too. I also just threw on my summer tires but my intermittent vibration stopped on my old 06 after I changed those 2 things.

Le7316

NoTLoud, I see that you've replaced both front axles and a lot of bushings, mounts etc..but do you still have the shaking on your steering wheel at 70 to 80mph ?

NoTLoud

I apologize I have been absent for awhile. Work has been quite a bit busier and I would spend the most times on the forum while at work. :P

I did not see anything obviously bent on the J-pipe. I have 6 brand new OEM nuts to throw on it sitting in my apartment right now. Just need to crawl under the car and replace them at some point.

How did you determine the flywheel was the issue? I still haven't tested taking the serpentine belt off and trying to replicate the vibration while in Park or Neutral.

I don't have any shaking in the steering wheel, especially with the OEM wheels and not my XXR junk wheels. Any shaking/vibration I feel at high speeds is through the floor pan. Make me think something is up with the engine.


I was told to check by fuel injectors by someone who is fairly knowledgeable on these cars. The more I think about this issue, the more I am thinking that one of my cylinders is not firing correctly. When I replicate the issue at 1100RPM in Park, the vibration or pulsation is like a heart beat. It is not a constant, it's more of a pulsation, in and out. My theory at the moment is that pulsation is a result of a cylinder not firing 100% properly. I have also noticed that the car does seem to lack some power in those lower RPM's, but at this point, I may just be imagining things. When the shaking is occurring during acceleration, it does feel like the car is bogging down.

Another weird thing. The more people I have in the car, the less I notice the issue. No clue on this one.

Issue does seem to be worse when going uphill.

Also noticed, if I feel the car starting to shake during acceleration, pushing the gas a little harder will cause the issue to go away.

NoTLoud

This one is really starting to haunt me.

I haven't been working on the car very much recently. I have lost a lot of my motivation that I had when I first bought it. My sound system is still halfway complete after 10 months and the car still shakes. New problem now is there is a vibration in the floor at highway speeds. Steering wheel isn't shaking. Accelerator and brake pedal almost feel gritty when I press them. Not really sure how to describe it.

I did take the car to the dealership this weekend. The car dropped itself out of gear 3 times on the way over, so that's also happening now. I am fairly certain the issue is the gear/neutral position sensor based on the garage post and what the transmission builder told me.

Tech at the dealership showed me there is some play on the inner joint of my passenger side axle. It wasn't anything too crazy, but based on what I saw, the passenger side was definitely worse than the driver. I'm kicking myself now because I wish I had checked for play prior to installing the Raxles. Replacing the axles made no impact on the issue. What I am wondering now is if that play existed prior to installing the new axles. I don't want to call up Marty at Raxles and tell him "Hey this one is bad" only to get another one and have the same issue. I guess it's worth a shot, but I am not even sure he will honor his warranty since I'm lowered.

Honestly, my last thought is the intermediate shaft. Both the tech at the dealership and the transmission builder both said they almost never get replaced. However, since my issue with the shaking/vibration has continued even after axle replacement, I'm not sure what to think. I think the play in the axle is basically the only lead I have right now. Since the issue continued before and after axle replacement, the only common component remaining is the intermediate shaft. I know on another thread, and I have read pretty much every thread on this forum for shaking issues, someone mentioned the intermediate shaft fixed their issue. The shaking is only during acceleration, which certainly is a symptom of a bad axle, specifically the inner joint, looking at Raxles site. The vibration in the floor of the car can obviously be a ton of things, but it would make sense for the axle to cause that as well.

Question now becomes do I take the ~$210 gamble? It's also not going to be super fun to replace. Removing the lower balljoint to get the axles out was a nightmare last time. I also have to remove the J-pipe, which I tried replacing the nuts on this weekend and the entire stud was coming off on some of the nuts. Reason I was replacing is because I noticed one was missing, thought I'd just replace them with the OEM nuts.

Curious to see if anyone has any thoughts.

NoTLoud

I've decided to go with a new intermediate shaft to see if it will fix my issue.

I also will be getting a new passenger side axle from Marty at Raxles. I had a 30 min discussion with him on Wednesday this week. He made a good point - and one I had been thinking about - I had the shaking issue before and after replacing my OEM axle with his. What Marty said was "Well it's almost impossible to replicate the same issue across two different axles." I had been thinking this too, what is the common component here? If I replaced both of them, then why did the issue persist? And what are the chances I received a bad axle from Marty?

I know I am not the only one on the forums who has had issues with shaking during acceleration after replacing both axles. I have had many shops look at the car now and all told me it was the axles. There is one thread on the forums where people confirm the intermediate shaft fixed their issue: https://acurazine.com/forums/3g-tl-p...-blown-854928/

When replacing my passenger side axle, I noticed a good amount of grease near where the intermediate shaft bearing is. Based on the thread linked above, it sounds like it may be exactly what happened to the original poster.

Circling back - I first noticed this issue when I lowered the car AND replaced my front LCA Compliance Bushings. I am theorizing that stiffening up the torn bushings is what really started to expose the bad intermediate shaft bearing. I drove that car for one day between lowering and having the compliance bushings done. I only noticed the shaking the day after I got the compliance bushings done.

Another potential key to the issue - with a bad axle, typically I would expect the issue to get better/worse when turning the car a different direction. I notice NO DIFFERENCE between turning right or left in the amount of shaking that occurs. The intermediate shaft remains straight at all times. Hm...

If anyone is still reading this, I'm curious to your thoughts.

jimmyfu

I had the issue only after after replacement of the axles, but it happened a month after. Are you installing the axles yourself? I'm not good with that big of.a.job, so I had a shop do it for me, but I think they would have been able to see the intermediate shafts after removing the problem axle.

Before I oked the fix, they did say that they thought it was either some axle support thing or the axle, but wouldn't be sure until they took it out. I oked it and after replacement they said the support was OK.

HOWEVER after replacement of just passenger side, there was still.some shaking which the shop thought may be due to drivers side. I replaced the passenger last week and yesterday got the car back after the drivers side replacement. Smooth as a dream now and I have no hesitation of going into 2nd gear or fear of vibrations.

NoTLoud

Mine was happening before and after, which does make me think something else is at play here. There was grease caked up around the intermediate shaft where it meets the axle, which is where that intermediate shaft bearing is.

Not sure what the axle support would be, maybe the shop was talking about the intermediate shaft/half shaft. I dunno.

Glad your car is driving better now! Unfortunately, I think mine is doomed to always have an issue. We'll see...

NoTLoud

7 months later, I have FINALLY fixed the issue.

Despite multiple mechanics thinking it was the axles and multiple mechanics also telling me they have never replaced an intermediate shaft... it was the intermediate shaft.

It makes sense that the symptoms were typical of a bad inboard axle joint because the intermediate shaft bearing if right where the passenger side axle connects. I will try and get the video up later today after work, but there was significant play in the bearing. Before I replaced it, you could definitely see there was more play on the passenger side inboard axle joint than the drivers side. The bearing also looked like it had sprayed grease everywhere near the bearing. The shaft itself was pretty dirty and covered with grease.

I want to thank this thread: https://acurazine.com/forums/3g-tl-p...-blown-854928/. Without it, I am not sure I would have had any real leads. I also gotta give a shout out to Marty at Raxles. He sent me a new passenger side axle under warranty. He also helped me pull the trigger on buying the intermediate shaft because he explained that it would be near impossible to replicate my issue with two different sets of axles. I was having this issue with my OEM, which is why I replaced, and my set from him. I know some of you have had issues with his axles, but now that I have the new intermediate shaft in, my car feels much smoother.

Overall, my car is 95% smoother on acceleration now. I am quite happy, I just hope the fix is not short-lived. There is still some very minor shaking, but I am wondering if it is my rear engine mount that needs replacing now. I am still so nervous when I go to accelerate from a dead-stop because I am so used to the car shaking. I think I am just having some phantom shakes now. Next up is new pads and rotors in the front, possible a(nother) new lower passenger ball joint, and checking out why the car is making a grinding noise from the passenger front wheel. Oh, and figuring out why the car is pulling to the right, even after multiple alignments.

UA7X

Glad to hear you have found and fixed the problem! And thanks for posting the solution - not like most people who ask for help and then disappear once they have the fix without even sharing the results!

As far as your pull even after alignment, that's pretty commonly caused by tires. Does it always pull in one direction? If so (assuming your tires are not directional), try rotating just your front two wheels from side to side. If the pull gets better, or if it starts pulling in the opposite direction, then it's a tire-pull, and the solution would be to replace the one or two tires causing the problem.

NoTLoud

Thanks UA7X! Appreciate all your help and insight along the way!

Sent you a PM on the pulling issue. I also started a thread here when I first noticed the issue: https://acurazine.com/forums/3g-tl-p...issues-961990/

jimmyfu

Oh man! I'm finally glad you got this resolved too! Did you end up replacing the axle anyway when you did the intermediate shaft, or did you just use the same one? I'm curious if the intermediate shaft would cause damages to the axle being used or not.

NoTLoud

It's one issue down! Yep, Marty at Raxles sent me another one under warranty. I really don't think the axle was the issue, but figured I'd replace it if I was gonna be in there anyway. Not sure about causing damage or not, potentially it was causing some uneven wear on the inboard joint from shaking around like it was.

Just hoping everything will stay smooth! I can still feel a very slight shake, but 95% smoother and nowhere near as bad as it was. Depending on how lazy I am when I get home, I'll post a video of the play in my old intermediate shaft. Seeing that play, I was pretty sure the intermediate shaft was going to fix my problem.

NoTLoud

As promised, I finally got around to posting a video of the bad intermediate shaft bearing:

For anyone else who is having the issue of the car shaking during acceleration, inspect this shaft first. You can see mine has a bunch of grease around the bearing that collected dirt. I am guessing that if the bearing goes bad, it's going look similar on your car, where the bearing has sprayed a bunch of grease everywhere.

Oh, and sorry about the vertical video. I gotta stop doing that.

NoTLoud

I think I may have finally, finally, solved the issue with the shaking during acceleration.

I did a ton of work to the car over the Thanksgiving holiday. List included:

• Valve adjustment, along with new OEM seals for everything I opened up. I also did a good deal of cleaning on the throttle body and intake manifold.
• "Rebuilt" the power steering pump with OEM seals. Replaced all but 2 seals that I couldn't really get too and didn't appear to be causing the slow leak I had. Did not replace the bearing.
• Replaced the rear mount since I had bought it months ago. Old one looked fine, but it wasn't going back in with the hassle it took to remove it.
• PCI Compliance bushings along with new OEM bushings for the other two bushings on the LCA.
• New StopTech drilled and slotted front rotors with Akebono pads.

After a couple days of driving, I do not notice the shaking during acceleration any longer! I know I said the intermediate shaft helped (and it did), but I still had some noticeable shaking after the install, especially under heavy acceleration.

It appears the Raxles were not the ultimate cause of the issue. I still need to call and talk to Marty about the whole ordeal.

So, interestingly, my family also owns a 2013 Honda Pilot and I felt the same type of shaking in that car during acceleration. It had also just had the valve adjustment performed and some valves replaced. Long story short, my Dad started the car while doing the timing belt and it bent some valves.

I am still not 100% sure what fixed my shaking issue, I did all of the work mentioned above over 5 days without driving the car in between. I suspect maybe the PCI compliance bushings played a big part, but I don't know. The shaking during acceleration seems to be a common issue for those who lower this car, so hopefully the information in this thread can help someone out in the future.