100 series harsh ride small bumps.

[bushcar69]

hi.
Im in desperate need of help. My 2001 100 series has a very harsh ride over small bumps and almost all offroads. Anything from like a 15mm stone, garden hose joins on the tar mac everything small. bigger bumps it ride so well. It feels as if the tyre pressure is at 1000 psi. It travels through the cab and shakes the whole interior including the dash. It is not a metal to metal or knocking noise but almost like a double rubber vibration if you know what i mean. Things i have changed and checked. All control arm bushes replaced, including torsion anchor bushes. Shocks new. All ball joints and rack ends changed, all cab mounts changed, engine and gearbox mounts are good still. Tyre pressures have been put at 20psi for testing. Nothing loose underneath. The Back springs i put in are westcoast +50kg, because the ones in there were way to soft and the bumper rubbers kept bottoming out. Front torsions i think are still stock, got the vehicle second hand so not 100% sure.
Any help would be great thanks.

 

[DuckLN]

I’ve theorized that the weight of the tire has a lot to do with the comfort of the ride. My d rated oem sized ko2s are something like 17 lbs heavier (each) that the michelin ltx-at (or about 50%). Ive replaced lots of bushings as well and still have a mule wagon ride regardless of air pressure.

 

[nukegoat]

Is the vehicle lifted?

 

[bushcar69]

its lifted maybe an inch or 2. Is it possible that the torsion bars have gone hard or have lost their springiness and causing to harsh a ride ?
The tires on there are 275 70 r16 bridgestone duelers A/T 694.

 

[Mike NXP]

I feel your pain, mine is stock height, all new suspension,bushings,etc. and I just feel every crack in the road. I am more convinced at this point that it's many different pieces of my interior just making noise and rattling away, just gotta ride it out

 

[Brandon Ryder]

What do your control arm bushings look like? Especially lower control arms.
What shocks did you put on?

 

[bushcar69]

All control arm bushes front and back, top and bottom all new. Shocks I had still good Toyota on, then changed out to westcoast, no difference. I even ran for a short test with no front shocks. Im beginning to think because of the age of the vehicle its just the interior, maybe behind the dash and all the panels are slightly worn mountings ???

 

[Brandon Ryder]

does it feel harsh or just make a lot of noise? there was a guy on here just yesterday that went through his interior and added felt and dry lube to stop the creaks and cracks to silence the noise. I'll try and find it...

How I fixed a lot of interior noises my 2001 LX

In case anyone is looking for a Corona virus project that doesn’t cost a lot of money… After many months of fixing a rattle only to find another rattle, I have successfully gotten my 2001 LX as quiet as my son’s ES350 or GF’s 350IC. Yes, I understand it is 19 years old now, has 123,000...

forum.ih8mud.com

 

[jlovold]

Were the bushes torqued with the wheels on the ground, or with wheels hanging?

 

[MJK]

My 2001 100 series has a very harsh ride over small bumps <snip> bigger bumps it ride so well.

Check the front diff bushings (there are 3), especially the lower one on the driver's side and the pillow on the front of the diff cover.

I just replaced mine and it really made a big different in the behavior you describe above.

 

[bushcar69]

Can anyone tell me the diameter of stock torsion bars for my diesel 2001 100 series ? current diameter is 30mm. im wondering if these are aftermarket and may be to stiff.

 

[jlovold]

Bushing Testing and Diagnosis - Know Your Parts

Bushings don’t need scheduled maintenance, but do need to be replaced when they break down. Here’s a guide to diagnosing failed bushings.

www.knowyourparts.com

When installing control arms with rubber bushings, the pivot bolt must be tightened with the weight of the vehicle on the wheels. If they are not, then the bushing will be quickly destroyed.

 

[AlabamaLX]

Check the front diff bushings (there are 3), especially the lower one on the driver's side and the pillow on the front of the diff cover.

I just replaced mine and it really made a big different in the behavior you describe above.

X 2 on the front diff bushings.

I've always run SL 275/70R16 Michelin LTX tires. If I run anything other than the recommended 29 PSI front/31 PSI rear, the ride seems harsher than it should be.

I recently installed the part-time 4WD kit from @cruiseroutfit and it really made a difference in the ride. I can run the tires at 40 PSI now and the ride is smooth. This points me to the bushings being the culprit.

I also have the Timbren SES installed (Front and rear), so my set up will be a bit firmer than stock.

 

[bushcar69]

All diff bushes are in good soft condition. i ran it with front prop shaft removed still no difference. control arm bushes torqued with vehicle weight on wheels.

 

[Rolocado]

All diff bushes are in good soft condition. i ran it with front prop shaft removed still no difference. control arm bushes torqued with vehicle weight on wheels.

You'll be amazed at how much shocks impact small bump feel. I ran toyota shocks with cranked Tbars and OME rear springs and unless I was at 18PSI could feel every crack. I put Stage 1 Icons in and the difference is night and day. Not saying you have to spend a bucket of $$$ on high end shocks, but at least replacing the OEM ones if they haven't in a while.

 

[bushcar69]

You'll be amazed at how much shocks impact small bump feel. I ran toyota shocks with cranked Tbars and OME rear springs and unless I was at 18PSI could feel every crack. I put Stage 1 Icons in and the difference is night and day. Not saying you have to spend a bucket of $$$ on high end shocks, but at least replacing the OEM ones if they haven't in a while.

I took the vehicle for a test around the block without front shocks and it made no difference . Do decent Shocks actually absorb the small impacts and stop them from transfereing up into the cab ? My last resort was to pull the interior and dashboard to try find where it could be loose.

 

[Mike NXP]

You'll be amazed at how much shocks impact small bump feel. I ran toyota shocks with cranked Tbars and OME rear springs and unless I was at 18PSI could feel every crack. I put Stage 1 Icons in and the difference is night and day. Not saying you have to spend a bucket of $$$ on high end shocks, but at least replacing the OEM ones if they haven't in a while.

I am at stock ride height with all new Toyota OEM Suspension and it still rides like s***. So yeah for sure the shocks help but like you said don't run out and drop cash on suspension unless you know that is the culprit.

 

[Rolocado]

That's just what I've experienced in trying to get my cabin noise dialed in. I slowly went through my suspension and bushings, etc and found the biggest improvement in new shocks (like I mentioned, I got Icons). Maybe there's a Mud member close to you that has another set of shocks lying around to see if they help at all

 

[ClassyJalopy]

Are your tires 10 ply rated? Or load rating E?

 

[MJK]

All diff bushes are in good soft condition.

Perhaps I am misreading your meaning, but you are looking for overly complaint bushings, not too hard. It all needs to move, but any slop/looseness is what you are trying to eliminate.

I recently had similar symptoms. Here is the advice I would give myself:
1) jack the front up and forcefully wiggle tire 3/9 o clock, 6/12 o'clock, pull in/out, and pry bar up from underneath the tire. Be firm, and look for any movement in tie rods and ball joints.
2) Lay down in front of the truck with the skid plates off, and someone you trust start it and put it in drive and reverse a few times with their foot on the brake. Again, look for any movement (diff, driveshaft, axles).
3) Push firmly and repeatedly down on each of the front quarter panels like you are checking for blown shocks. Any clunking/popping/squeaking?
4) visually inspect and try and move anything rubber you can (LCAs, UCAs, sway bar drop links, etc). I'd be suspicious of anything that looks even mildly cracked, torn, distorted or dry rotted. In my experience things that look questionable when installed are often worse than I expected once removed.
5) I'd also check/repack wheel bearings and grease driveline zerks as part of normal 'new to me' baselining. This is an excellent time to check all of the above.

My front diffs bushings looked OK, until I did test #2. Then, I was more aggressive in checking them than I had been previously. A pry bar moved the drivers bushing more than it should have - I previously just visually checked it and tried to move it by hand. I also took the bolt out of the pillow mount and an extension in the bolt sleeve could move without much force at all - again, looked fine before.

I don't mean to suggest you should focus on the diff - just sharing as an example of the process. Don't be afraid to poke around a little aggressively. The front suspension holds up thousands of pounds. You aren't going to hurt anything with some light persuasion.