How big is the lift you installed on your Gen3? If it's OME 2" lift, it would not cause excessive angle on the driveshaft. I have 100k driven after installing OME lift on mine and I never had any issues. Camera is a good idea. How about one of those GoPros with a magnetic mount? I've seen them in Costco (didn't pay aytention to the price though)

 

After giving up for a while, I'm back at it trying to tackle my vibration issue again before winter hits. Unfortunately my vibration issue just recently spread into 2WD as well making things a little more urgent. Here is where I am at:
Recently I stumbled across a very cool article talking about the frequencies of vibrations and how the driveline, tires, engine, etc. all produce different frequency vibrations when going say 60mph (I'll post the article below for you readers out there).

https://www.brakeandfrontend.com/dri...th-vibrations/

This is going to sound crazy but I also found an iPhone app that allows you to take frequency readings of vibrations using your phone's internal accelerometer. After several tests I found there were clear consistent spikes on the frequency of 28 hz. I was able to calculate my tires frequency at 9.2hz at 60mph using a formula from the article. Since my diff ratio is 4.9 a simple multiplication of 4.9 x 9.2hz has a driveline vibration at 60mph (which I previously suspected) at 45 hz. which is far above the 28hz I am getting from the tests... In the article it talks about first, second, and third order vibrations all being multiplications of the tire frequency. Now seeing that 28hz (my reading spike) divided by 3 equals just about 9.2hz (my tire frequency) I am now hypothesizing that something connected to the wheels (axle shafts..) that have the ability to vibrate at 2 and 3x the speed of my tire may be at fault.

I hope you're still with me...Now if you look back to my initials posts you will see that my front axles were recently replaced when I had my OME lift done. & because of this I have yet to question these "new" axles. However after reading numerous forums online about aftermarket axles causing vibrations and how OEM axles made these vibrations go away, I think these axles may be the next part to replace. Not to mention that my own "frequency" tests point to them as well. Since Mitsubishi wants $1100 a piece for new axles. (yes you read that right, $2200 total). I think I will find some low mileage OEM axles from a junk yard and test my theory of the axles being bad or low quality. If anyone has any suggestions about what else could cause a vibration that is exactly 3x that of the tires let me know! As of now I am going to trust my gut and replace these axles as soon as I can. Is there anything special I should know while replacing these front axles? I have watched a few videos and it doesn't seem too difficult as long as I take my time and don't rip the seals on the diff.
Thanks for reading my rant. I am just hoping that after I solve this I will be able to help some other Montero owners out there too!!
Cheers!
-Chris

 

Chris.......I bet ole Tesla would be saying, "Dude!!!! GettyUp Mannn! Thats radical!!!!" You have definately gone deep down the rabbits hole on this one, amazing that you keep scratching and digging for answers. I think your onto something........and maybe all Physics books will add a new chapter to cover your work.

You think the non stock rims and large thumping tires could be affecting the drive shafts? I wonder what would happen if you could borrow a set of standard rims/tires.....would that make the problem go away?

This is getting pretty deep for sure. I hope you can solve this mystery.
Pie = 3.1427......

 

1960studebakerHawk,
You're totally right about Nikola Tesla . Although he would have probably connected some magnetic coils and figured out my issue right away haha. I did take a few physics classes back in college but I'm pretty dang rusty. Really I'm just tired of throwing parts at my Montero, so I'm hoping that even my amateur testing can get me a little closer to the answer than my previous full on guessing.

As for the bigger tires/ wider wheels affecting the drive shafts that is totally a possibility. From what I have seen from other forums, aftermarket CV axles don't handle lifts, bigger tires etc. as well as the OEM ones. That's why for $100 bucks it may be worth buying some used ones to see if this is true. Especially since all of this started after the new ones were installed with the lift.

I do have my factory wheels and tires sitting in my garage though so I might just throw those on this week and see what happens. Thanks for that suggestion. I'm surprised I haven't thought of that yet!

 

I just read through the entire thread and I'd have to say you have quite the head scratcher going on here. Interesting to note I have had a very similar shudder/vibration going on for quite sometime that has slowly gotten worse but I suspect it's the torque converter in my case, however it could be the drive shaft because the guy I had replace the center support bearing and all three U-Joints dinged it real good with a mallet, he said he spun it up and there was no vibration but hey I was glad he only charged $100 flat for the job. As such I would suggest you look into the torque converter, especially because you say it now does it in 2WD.

I don't remember it being mentioned before, but have you check your rear drive shaft for damage or missing weights?

 

Chris......Great that you have that set of standard rims/tires that you can try out......Im real interested as to what develops with your situation....very perplexing. Might have to add a large Tesla coil as you said, and maybe snag a flux capacitor from a rusty DeLorean (but heck, their stainless steel, and dont rust....ha ha).

Naeos mentioned the torque convertor.......now, if your going down a hill, and have that vibration problem happening, if you were to pop her into Neutral, and the vibration stopped, wouldnt that help add merit to the torque convertor suggestion? Just a wild idea here.

 

Naeos,
Sorry you’ve got a similar case, these vibration issues are a PIA. I suspected the torque converter in the past and it’s not 100% ruled out however the fact that it still is much worse in 4wd doesn’t make sense to me. Plus today I drove down a hill going 50mph in Neutral and there was still a vibration. good luck with yours! Have you by chance installed non OEM aftermarket CV axles like me before?

 

Just tested this out today and I am still getting the vibration in Neutral down a hill... so probably not the torque converter.

To further my Hz. rant, again I’ve been observing the vibration/shake at exactly 3x the frequency of the tires. I also just read today from another Mitsubishi forum that practically all of the after market CV Axles for these Monteros come with... 3 BALL CV JOINTS!.. hmmm I’m seeing a lot of 3’s here. So if one of these joints were truly faulty it could indeed vibrate at 3x the frequency of my tires...

Supposedly the OEM axles come with a 6 ball CV joint that is much stronger, so I will order some used ones ASAP and throw them in. I’ll also try my stock rim & tire setup and report back. Thanks for all of the responses guys it really gives me some motivation to keep tackling this thing.

 

Now that is real interesting......non OEM CV joints have only 3 ***** instead of the OEM 6. That could very well be your problem. Plus the fact that your rig was lifted a couple inches could add more stresses on the CV joints, maybe adding to the noises. Im betting its these 3-ball CV joints.

 

Issue solved! My vibration stemmed from cheap aftermarket CV axles. My shop laughed at me for thinking that was the problem but I ended up being right! Haha & man does it feel good to be right sometimes. All in all though my shop was great and ended up doing the repair for free which I really appreciate.

Below is the full story:

Ordered some used OEM CV Axles from a junkyard with only 40,000 miles on them. Had my shop Install them since they were willing to warranty the ones he put in a few months ago (considering they were the issue causing the shaking). Well.... The shaking and vibration completely went away and I now have my 4WD back!

Warning to others buying aftermarket cv axles for these Monteros. It is probably worth rebooting OEM ones instead of going aftermarket. You may get lucky with a different brand than what my shop used (Import Direct). But in my opinion it’s not worth doing the job twice.

STAY AWAY from Import Direct CV axles from O’Reillys!

Anyway, thanks for all of the support guys & what a relief to finally fix it. I hope this helps others who come across a front end shaking vibration. Unfortunately for me, I had a bunch of work done all at the same time, so I was really guessing for a while until I suspected the Axles. I’m learning that OEM parts are the safer way to go most of the time.

-Cheers 🍻