Why does my gen 3 feel like crap on highway?

[1morebike]

My 2003 gen three is awful on the highway and I can't pinpoint why. First the drivetrain feels like it has bad ujoint (I know it has CV joints but that what it feels like) my mechanic has checked the drivetrain and days it's fine. I had all my fluids changed and used Montero fluids. I have Cooper at3 tires with maybe 20,000 on them and have rotated them regularly. The tires are noisy ass heck I had a set on my gen 1 Montero and they were great. I had a problem with my driver's side brake being seized twice but that I believe has finally been sorted out. On the highway the truck wanders all over especially if the road is rutted at all. 70 miles per hour feels like it's at it's top end if I hit 80 it's starts to rumble pretty bad. I have a set of ome socks and springs sitting in the garage just trying to find time to get them in and I think I'm giving up on the tires and going to buy something else. Any other ideas of things to check? Oh the truck has 152,000 on it and the previous owner took really great care of it except for not running Montero fluid in the transmission.

Thanks

 

[Inyo_man]

When is the last time the wheels were balanced and the rig was aligned (four wheel alignment on the Gen. III)?

 

[Tliska10]

I have Cooper at3also and they are stupid loud on the highway

 

[1morebike]

I had the tires balanced 6 months ago and the alignment seems good. The tires came from pep boys I guess. They just seem to be so much louder then my old ones. Even louder the Cooper St tires I had on my landcruiser. Maybe it's just the tires...only one way to find out I guess.

 

[Swank Force One]

Gen3s are extremely succeptible to tire noise. I would expect the same tire to be way louder on a Gen3 Monty than any Land Cruiser.

We have Cooper ST Maxx on our FJ80, STT Pro on our Gen2.5 Monty. Both are several magnitudes quieter than the Duratracs were on our Gen3.

 

[Toasty]

Gen 3's are picky on tires and wheels, i would start there for sure.

 

[1morebike]

Looking pretty hard at the nokian rotiiva at tire for my purpose it seems like a great tire.

 

[Doing_Dirt]

Looking pretty hard at the nokian rotiiva at tire for my purpose it seems like a great tire.

I had those Nokian MT's on my Ford Expedition. Little road noise, couldn't tell you about performance, that truck was only 2wd.

And my gen 3 Montero shocks are original from 01 so they are beyond shot out, but rides fine with new BFG KO2's.

 

[Salonika]

“Alignment seems good” doesn’t cut it.....you need to have it checked out by a shop imo. A good shop will tell you if something needs to be replaced because they won’t be able to do a proper alignment otherwise. Best to have it done at a shop that does nothing but alignments, that way they aren’t trying to sell you on repairs. I believe worn control arm bushings or ball joints can cause your symptoms.......could be tie rod ends as well.

 

[coffeegoat]

Wheel balance is also extremely important on the Gen III, I've lost count of how many people have asked similar questions and then after finding a good tire shop to do the balance report all the problems went away. It's pretty annoying, but for whatever reason they are picky about wheel balancing...

 

[Toasty]

Improper wheel spacers and guys using improper hubcentric wheels does it too.

 

[1morebike]

I still have the original wheels on it so I'm good there. I haven't been happy with these tires for awhile so I think I'll get my shocks and springs in, get new tires, and then get a good alignment. Now all I need is $$$

 

[offthepath]

I have AT3s on mine and they are LOUD. Disappointing because I like the tires performance otherwise.

+1 on getting an alignment. It really is impossible to tell what could be worn unless its on a rack. I had mine aligned a while ago and the tech said the inner tie rods were bad. I replaced them and could not detect any damage, but after that it aligned fine.

FYI with the OME lift kit mine does track some on rutted asphalt. Nothing like you describe, but it will pull from time to time. I suspect its because the camber is nearly out of spec with the lift kit.

 

[Monty85]

“Truck wanders all over” ... this sounds like you need new shocks. Does it happen when just one side goes over a bump or pothole ?

I had my right rear shock go bad and whenever I hit bumps on highway, it was scary. Truck wants to fishtail.

For other issues, everyone pointed you to some possible causes already

Goodluck with repair ! Gen3 is nice and comfy when you don’t have these issues. I feel like it rides like car compared to other trucks.

 

[plh]

Tires, tire width, ball joints, bushings and alignment. Make sure that when you go for an alignment that you go to a real alignment shop. Someone who understands and knows how to set camber. Most places these days set toe and call it good (it won't be). Have a few extra camber bolts available. They are known for being seized an will brake.

I use a frame shop locally. http://www.frameandaxle.com Search for something similar in your area.

KO2s are pretty reasonably quiet on my '05. This chassis is not forgiving with certain tires. I ran 235 width tires for 35k miles - never again! Squirly as heck. Nothing narrower than a 265 should be run on these trucks. Happy with my 285s