Final call for help - suspension issues (1 Viewer)

[Joshuak172]

Hey folks, I have a 2006 land cruiser with 153k miles. It has a harshness felt at all speeds which just feels like the suspension is wound too tight. On the highway there is a constant low level chatter from bumps in the road even if the road appears smooth. There is also a low level rumbling I hear/feel at higher speeds 40mph+. It originally had AHC and the vibrations/harshness has persisted despite all I have done:

converted AHC to conventional OEM suspension (shocks, springs, tbars)
front and rear sway bar bushings
New front and rear OEM upper and lower control arms
new OEM pan hard bar
new OEM front and rear driveshafts
new OEM engine mounts
new OEM steering rack
new OEM CVs
new OEM inner, outer and needle bearings
new OEM hub flange
new toyo AT3s set at 35 psi road forced


I really can’t think of anything I haven’t touched and although I did most of the work myself, the vibrations never seem to have changed much at all. Yes it has the frame mounted vibration damper. I’m really at wits end at this point. Despite my wife thinking I’m crazy it really is bothersome on the highway, maybe has something to do with multiple TBIs over the years. Any thoughts on what I’m missing?

 

[xplore]

How long has that new suspension been in? Does it feel less harsh when you load it down with more weight?

What there ever a time that you didn't experience the rumble over 40mph?

Have you changed out the front diff bushings? You replaced the engine mounts but have you addressed the transmission mount?

 

[Joshuak172]

How long has that new suspension been in? Does it feel less harsh when you load it down with more weight?

What there ever a time that you didn't experience the rumble over 40mph?

Have you changed out the front diff bushings? You replaced the engine mounts but have you addressed the transmission mount?

Suspension has been in since April or so. I haven’t necessarily loaded it down with more weight besides the family which maybe adds up to 300lbs or so.

The rumble over 40 is pretty persistent.

I also switched out the trans mount but not the diff bushings. I do have the diff bushings, just haven’t had a chance to switch them out. Really thought it was a low probability that it’s creating my issues.

 

[xplore]

Suspension has been in since April or so. I haven’t necessarily loaded it down with more weight besides the family which maybe adds up to 300lbs or so.

The rumble over 40 is pretty persistent.

I also switched out the trans mount but not the diff bushings. I do have the diff bushings, just haven’t had a chance to switch them out. Really thought it was a low probability that it’s creating my issues.

The diff bushings are a lower probability, but it's just something that you hadn't listed. I would expect bad diff bushings to cause a clunk when going into drive and reverse, but I've heard of all kinds of weird stuff.

When did the rumble start? Did anything change at all? New tires?

Have you looked into the transfer case output shaft bearing? Does that have any play in it at all?

Who installed the new drive shafts? They could be out of balance as well.

 

[Trunk Monkey]

Tires? Out of balance, damaged, etc.

 

[unleashd]

Where in VA are you located? I am in Herndon, and could help identify the cause with my little knowledge. I recently converted from AHC to LC conventional to IM Stage 2.

 

[YvesNL]

If you haven't done it already check your u-joints. These can give a strange vibration/rumble.

It might not seem like they have play when the driveline is under tension, get one or all wheel off the ground and check for play in the U-joints. Use a crowbar, tire iron or similar to check for play, any play is bad.

When these are bad it can cause a vibration like you describe, even when the road is flat.