Loose Suspension/Rattle Noise - Can’t Figure It Out

[PeterTheBeater]

I’ve got a 1997 fzj80 with about 255k miles.

35’s, fox shocks no bypass, dobinsons 3” - 3 1/2” heavies.

Recently, decided to splurge out and get delta control arms to fix the caster, got 3L’s which brought my caster back to +2.5*. As well as rear panhard bracket.

I’ve pressed the bushes in myself. (Rubber bushes, not Toyota ones, but look very close and they are pretty soft). Used all new Toyota bolt hardware, torqued at ride height to spec.

After install and drive, noticed my front panhard bar had a crack in it, so I’ve removed:

Steering stabilizer, front steering arm, steering box, loosened the brake lines bolted on the inside of the frame rail, also replaced the battery. Welded in a delta vs steering bracket reinforcement, torqued to 100lbft the steering box with new longer 1/2-20 bolts & nylocks.
Torqued all tie rods 67ftlb. Steering coupler bolts torqued as well.

At first, I was getting this loose suspension rattle (like something is bouncing around, binding) and grinding noise when braking. The grinding noise turned out to be the driveshaft, which I’ve removed and got a DC coming.

However, can still feel this “loose” part/noise, can almost feel it in the steering wheel & foot rest. I’ve triple quadruple checked all the bolts and everything is tight (I was surprised that the control arm bolts were loose in the bushings, even OEM arms).

I’ve also check all the brakes (like calipers and rotors), wheel bearing play, loose components in the engine bay. Knuckle steering arm bolts & studs. Kind of at my wits end (no pun) and not sure what to do or what else to check.

Help.

 

[george_tlc]

So, lots of changes. WHEN did the 'noise' actually start in this adventure down the rabbit hole?

cheers,
george.

 

[PeterTheBeater]

Yeah…I’ve been going down a rabbit hole trying to find it.

Noise started after repairing the panhard bar bracket and putting everything back together lol

Yesterday I dropped the new control arms to see if the bushings tore up or something. I did find few small cracks on the outside but they’re in tact. I thought maybe the new control arms are bouncing around. I took a picture pushing the insert down with a bolt.

 

[george_tlc]

It would be from the rear, but verify that the BIG panhard bolt that holds the panhard to the DV bracket is not nicking/rubbing/hitting the DS coil when it cycles up/down. The clearance is tight with the Dob dual rate coils - tight to the point of touching. Either some thick washers on the head end or reverse the bolt so the head is facing towards the coil.

Also, check exhaust rubber mounts. Both mine were 'ripped' after years of use - there are two. They can look ok, but if you move the exhaust around (muffler etc) you can tell if they have separated.

And yeah, the bolts through the the bushes better be able to allow the bushes to rotate on the bolts

cheers,
george.

 

[PeterTheBeater]

It would be from the rear, but verify that the BIG panhard bolt that holds the panhard to the DV bracket is not nicking/rubbing/hitting the DS coil when it cycles up/down. The clearance is tight with the Dob dual rate coils - tight to the point of touching. Either some thick washers on the head end or reverse the bolt so the head is facing towards the coil.

Also, check exhaust rubber mounts. Both mine were 'ripped' after years of use - there are two. They can look ok, but if you move the exhaust around (muffler etc) you can tell if they have separated.

And yeah, the bolts through the the bushes better be able to allow the bushes to rotate on the bolts

cheers,
george.

Oh duh, makes sense for the bolts.

The rear panhard is actually super close to the coil, but it does clear it. I think I can try to space it with a washer and see if that does anything.

The exhaust bushings are fairly new and intact.

The noise does feel and sound like it’s coming from the front.

 

[alia176]

if you're feeling something near the foot rest, check that body mount bushing hardware for tightness. you may have to put an extra ugga ugga on it then see what happens.

 

[PeterTheBeater]

if you're feeling something near the foot rest, check that body mount bushing hardware for tightness. you may have to put an extra ugga ugga on it then see what happens.

Haven’t checked that, might be a good idea. Maybe the heat from the welding has loosened up a body mount.

Certainly doesn’t “look” right. Here are the forward ones.

 

[alia176]

Haven’t checked that, might be a good idea. Maybe the heat from the welding has loosened up a body mount.

Certainly doesn’t “look” right. Here are the forward ones.

View attachment 3960439

View attachment 3960438

Ok, that one is cockeyed looks no bueno. I did the same project and no heat makes it that far to impact the body bushing in that manner. Something ain't right!!!

 

[Old Nick]

I’ve got a 1997 fzj80 with about 255k miles.

35’s, fox shocks no bypass, dobinsons 3” - 3 1/2” heavies.

Recently, decided to splurge out and get delta control arms to fix the caster, got 3L’s which brought my caster back to +2.5*. As well as rear panhard bracket.

I’ve pressed the bushes in myself. (Rubber bushes, not Toyota ones, but look very close and they are pretty soft). Used all new Toyota bolt hardware, torqued at ride height to spec.

After install and drive, noticed my front panhard bar had a crack in it, so I’ve removed:

Steering stabilizer, front steering arm, steering box, loosened the brake lines bolted on the inside of the frame rail, also replaced the battery. Welded in a delta vs steering bracket reinforcement, torqued to 100lbft the steering box with new longer 1/2-20 bolts & nylocks.
Torqued all tie rods 67ftlb. Steering coupler bolts torqued as well.

At first, I was getting this loose suspension rattle (like something is bouncing around, binding) and grinding noise when braking. The grinding noise turned out to be the driveshaft, which I’ve removed and got a DC coming.

However, can still feel this “loose” part/noise, can almost feel it in the steering wheel & foot rest. I’ve triple quadruple checked all the bolts and everything is tight (I was surprised that the control arm bolts were loose in the bushings, even OEM arms).

I’ve also check all the brakes (like calipers and rotors), wheel bearing play, loose components in the engine bay. Knuckle steering arm bolts & studs. Kind of at my wits end (no pun) and not sure what to do or what else to check.

Help.

I had a similar rattle noise in my wife's 94 (very similar set-up to yours: 35's OME heavies and OME shocks... which will get updgraded to Dobinson's later). It came on after the lift, new tires, new panhards, control arms, caster correction plates, etc. The noise only came on when accelerating or slowing down... not when cruising at a consistent speed... and only when moving over 30mph... freaked me out.

It was the front ds. Ordered new front and rear from Tom Woods. Sorted out the noise completely. Just finished the build. When you install your new drive shafts, I'm guessing that the noise will go away.

Edit: after seeing that pic above... man, that is something.

 

[jpoole]

Another thing to check is the front springs. Depending on how much the axle has rotated the spring(s) can hit the bump stop perches / similar on the inside of the spring. If this is the source of the noise the the noise will typically happen during suspension travel, like when you hit a speed bump, and there should some visual evidence showing where contact is being made.

 

[alia176]

Another thing to check is the front springs. Depending on how much the axle has rotated the spring(s) can hit the bump stop perches / similar on the inside of the spring. If this is the source of the noise the the noise will typically happen during suspension travel, like when you hit a speed bump, and there should some visual evidence showing where contact is being made.

This is a good point too. I had to angle my internal bump stops so that they land squarely on the axle pads AND not scrape the inside of the Dobinson coil springs.

 

[PeterTheBeater]

Checked the bump stops, no witness marks on the springs.

Checked the body mounts, they’re all tight. I got maybe an extra turn or two on them. I thought the gap is not supposed to be there in the front, but that’s how they're appeared to designed.

Checked the rear panhard bracket, no witness marks on the spring from the bolt.

Other ideas? It sound like a caliper is falling off (bolts are tight, caliper are tight, pads are good. Took them apart to inspect)

 

[lumbee1]

Have you checked the front sway bar mounts on the axle?

 

[PeterTheBeater]

Have you checked the front sway bar mounts on the axle?

Yes to both. The welded upper is still welded together and lower appears to be fine.

 

[voodu3]

Check the upper front shock bolts if you haven’t already. I had a similar front clunk sound and there was a small gap between the shock and body. It wasn’t there at install but after the suspension settled I needed to tighten the shock bolts again and that solved it. YMMV.

 

[lumbee1]

Yes to both. The welded upper is still welded together and lower appears to be fine.

Are the bushings in good shape? The reason I ask is because I was chasing a front end noise. My bushing were original and in awful shape and caused clunking in the front.

 

[jpoole]

If you get desperate enough on this issue a few more ideas that could help:

• Chassis Ears - for around $50-$100 you can set yourself up to listen for sounds, 5 or 6 points at a time, beneath the 80 as you drive. You could clip the listeners/inputs onto different components until you find the source of the noise.
  • 6 Channel Chassis Ears Electronic Stethoscope Diagnostic Kit Engine Noise Finder | eBay - https://www.ebay.com/itm/236157347814
• Mount a camera (like a gopro) at different points beneath the 80, ideally with a mic. and then drive/replicate the sound. Visuals may or may not help here but if the camera had an active mic the noise seems loud enough for it to be picked up and a camera may help isolate the location of the sound (it will be louder when the camera is closer) and possibly connect the sound to specific movement in the drivetrain/suspension.

 

[alia176]

I've done the GoPro things to find suspension noises in the past.
Great idea!

 

[lumbee1]

I've also climbed under the truck and started hitting parts with a rubber mallet. I found a broken exhaust hanger with this method.

 

[alia176]

I've also climbed under the truck and started hitting parts with a rubber mallet. I found a broken exhaust hanger with this method.

i'd love to build me one of these shaker things that you put under each wheel. Saw one of those things in a FB reel one time. You do need a two post hoist first! If a local shop would offer that kind of service, that'd be so killer!