Vibration under acceleration (1 Viewer)

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Sorry to hear you're having issues tracking it down.
I can't really think what would cause it to happen only when loaded.
Obviously, its something to do with the extra weight... which could be suspension components... but which?
Could also be a tuning issue - spark plugs, injectors, etc... which is more noticeable under the increased power required to accelerate extra weight...

Does it only happen under acceleration, or only when at constant cruising speed, or just at a particular speed?
Possibly could also be a drive train related issue... again only noticeable when moving a load...but I'd guess if it was drive train related it would be most noticeable under acceleration...
Sorry, I'm not a mechanic, but going on my gut feeling.

Probably cheaper to take it anywhere but a dealer, unless its under warranty.

It could be worth paying the relatively small fee to take it to a suspension place for a test... they offer some limited testing for a flat rate...in Aus we have a company called Pedders that offer a suspension test for around $30 AU (Guessing $20+ USD) to test x amount of suspension components on their computerised system.
Never done it, but could be worth it if you've got someone nearby with similar offers...

Obviously, at the price, I'd take anything they reported with a grain of salt, as they no doubt make their real money from finding something to repair.... but if something stands out it could be a cheaper option.
Failing that, taking it to a dealer, and giving them a brief write up of the issue, when it happens, at what speed/s, etc and what you've tried already, and paying just for a diagnosis, if at first, probably won't be as expensive...
Let us know how you go.
 
Hey, that's life with an old truck. :)

I took it to local dealer yesterday. I explained the issue to them, how it only happens during acceleration, with passengers in the rear seats. If you throw a hill in, it's even more pronounced. He said they would try to diagnose it, and he'd have to get a few of the mechanics in the vehicle for weight during the diagnosis so they could replicate it. I dropped it off around 9AM, Tuesday.

The place looked super busy. Around one, he called to let me know they were waiting for one of their master techs to look at it, and likely they would not get to it. That was yesterday. Hopefully they can diagnose it today (Wednesday).

Once they hopefully do, I can decide how to proceed.

Sorry to hear you're having issues tracking it down.
I can't really think what would cause it to happen only when loaded.
Obviously, its something to do with the extra weight... which could be suspension components... but which?
Could also be a tuning issue - spark plugs, injectors, etc... which is more noticeable under the increased power required to accelerate extra weight...

Does it only happen under acceleration, or only when at constant cruising speed, or just at a particular speed?
Possibly could also be a drive train related issue... again only noticeable when moving a load...but I'd guess if it was drive train related it would be most noticeable under acceleration...
Sorry, I'm not a mechanic, but going on my gut feeling.

Probably cheaper to take it anywhere but a dealer, unless its under warranty.

It could be worth paying the relatively small fee to take it to a suspension place for a test... they offer some limited testing for a flat rate...in Aus we have a company called Pedders that offer a suspension test for around $30 AU (Guessing $20+ USD) to test x amount of suspension components on their computerised system.
Never done it, but could be worth it if you've got someone nearby with similar offers...

Obviously, at the price, I'd take anything they reported with a grain of salt, as they no doubt make their real money from finding something to repair.... but if something stands out it could be a cheaper option.
Failing that, taking it to a dealer, and giving them a brief write up of the issue, when it happens, at what speed/s, etc and what you've tried already, and paying just for a diagnosis, if at first, probably won't be as expensive...
Let us know how you go.
 
@joshAUST - and everyone else, so I got a call from the dealership. They informed me my truck needs about $8,000 worth of work.

I told them to give me the itemized list, and I do not approve their estimate. I will be picking it up tonight.

Once I have their itemized list, I will post a new thread asking for everyone's opinion.

Please note this is not the complete list, but what I remember from the phone conversation.

Their opinion on the vibration was that the:
  1. drive shaft u-joints need to be replaced. ($700)
  2. rear end tie rods and sway bars needs to be replaced ($210)
  3. the center pipe of the muffler is rotting and should be replaced
  4. the rear diff vent is clogged and needs to be cleaned out / replaced ($250)
Additional "findings":
  1. my front brake calipers are completely seized and stuck in the closed position (WHAT?!) And I need new calipers and rotors, because the rotors are warped.
  2. my rear brakes need to be completely replaced to fix my parking brake ($1900).
  3. The exhaust manifolds are completely rotten and need to be replaced ($3500)
  4. The front skid plate is completely rotten and needs to be replaced ($450)
  5. The frame is starting to show signs of rot.
  6. The truck is completely rotting everywhere and about to fall apart (Ok, this last one is a joke).
That's all I can remember right now.

Meanwhile, my personal mechanic has inspected the brakes and informed me I might need new rear pads in a few months, but that's it. The truck front end isn't dragging, I don't smell anything burning, and it brakes fine. At least that's how it was when I dropped it off...
 
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Wow...
I'd probably step back from that dealership.
However, given the price they charge for labour, that may not be far off.

Re the drive shaft u-joints, you should be able to replace them relatively easily, but I'm not sure if you'd need to get it balanced afterwards... not sure, never done one. Price sounds way too high.

Sway bar and tie rod costs sound reasonable.

The muffler - worth checking the main box post cats... if the pipes dodgy that wont be far behind.
I picked up one s/hand for $250 AUD - minimal surface rust - the entire part coming from the two cats to the end of the vehicle.

The rear dif vent blocked - search this forum - I'm sure I've read about someone fixing-cleaning this... shouldnt cost much.

My truck had a lot of rust, and all the callipers and rotors were bad...
I ended picking up two front and one rear calliper second-hand from a wreckers for $250 Aus. each. Came looking virtually new, with no rust.
I purchased new rotors from the front, but still using the existing ones on the back.
Think the rotors were under $100 each from repco.

If your callipers aren't in too bad condition, i.e. not rusting away, despite them being seized - which I find hard to believe, as they'd be smoking while driving if that was the case, you could take them to a brake service place, get the callipers disassembled, honed, new seals, slider thingies, etc, for a lot less than replacing them.

I had a calliper seize on my old Holden Torana... and yes it smoked when driving.
Took it to a brake specialist, he pulled it apart, honed it, new seals, cleaned it all up, and it looked good as new. Never had another problem with it.

The only calliper I didn't replace on my landcruiser gets a bit smokey only if I'm hard on the brakes for a while. :)

RE the handbrake... they don't ever really work in a landcruiser 100 series anyway do they? ;)

Mine didn't work, as the whole mechanism on the rear left wheel was stuffed, ended up replacing the whole rear axle/brake assembly, as that's the only way the wrecker would sell it. Think I paid around $75 AUD for it.
I had to fix it, as I was registering it, and therefore needed a roadworthy inspection.
That fixed it, although it doesn't really seem to do its job... either the cable stretches, or something, and anyway, I'd never trust it.

The exhaust manifolds - at a guess they've rusted - but I find it very hard to believe that they've rusted completely - they're pretty thick solid steel.
Probably just need exhaust gaskets, and possibly a bit of tig welding if there's a crack or two. If more serious, I'd just get a second hand set, or an aftermarket set.
For the price they've quoted you, you could get a full aftermarket kit with stainless steel, extractors, etc, the works, installed, for a lot less.

The skid plate - again, s/hand - picked up a virtually new set of main bash plate, sub plate, and some other plate for around $150 AUD.... inc shipping.

In regards to any rust, as my had lots, I invested in a needle scaler - an awesome tool. cleaned if right off everywhere, and easy to use in awkward places. Did that to everywhere under my truck, cleaned with a mild acid solution to remove grease and grime, then sprayed it all with a high pressure hot water sprayer for ages... Then hit everywhere with spray on rust converter.
No obvious further detioration in the last year anyway.

When I got my truck s/hand, I got it for less than 1/2 price... and after all the repairs it was still a cheap buy, and I've learnt a lot.
The main thing I learnt is replace with s/hand where you can - you'll save heaps...
Obviously, some things, spark plugs, ignition coils, filters, or internal engine components or parts in hard to reach places, always use new.

I reckon you should be able to fix most of that for under 1/2 that they've quoted you... and you can do bits at a time to break up the pain.
:)
 
Thank you for your thorough response. Tonight I recorded some video (just for the audio). I had my phone laying on the floor on the passenger side, second row.

After being at the dealership, it’s now back to making the noise even if I’m the only weight in the car, but only when I really step on the gas hard.

It seems more pronounced when accelerating and turning to me. Have a listen.



I reckon you should be able to fix most of that for under 1/2 that they've quoted you... and you can do bits at a time to break up the pain.
:)
 
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Any updates OP?
 
So, the closeness of the exhaust pipe to this sway link was pointed out in another thread (ignore the booger weld, that was done at a shop when the PO had part of the exhaust replaced).

View attachment 1699830

I feel like this is probably the source of the vibration, for my truck. I wanted to see if I could create some space between these two parts, so I took a two by four that was long enough to reach from just outside the wheel well, and a hammer, and started hammering. I couldn't get that exhaust pipe to budge. I think the hangers are absorbing most of the force from the impacts?

After hitting it a bunch...
40A2B6AC-CDDF-45CA-9D80-B4613DCE8EEB.jpeg


Whoever previously did the work routing the exhaust pipe failed to consider these parts making contact. It looks like it gets really close to the floor, too (the section after the bend up).

Now that I'm thinking about it, there are two separate rattles: one during acceleration, and another on pot holes (like bouncing metal on metal, could be the exhaust hitting the bottom of the cabin floor.)

Of course, there is always the chance this isn't even the source of the noises.

364C4C32-866B-4E68-AC33-09E627C5FCA1.jpeg
 
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I haven’t had time to investigate this noise further. Can someone with a a 100 series do me a favor and take a pic of this area under their truck? I’d like to compare how mine was routed.
 
Sorry I haven't got back in a while, I didn't realise they'd been other posts.
Its hard to make out in the video over the noise of the engine.
Does the exhaust wobble or move enough to touch the other metal parts, if you shake it?
Can you see any evidence of rubbing - polished metal, or the like, between the near components?
If they are rubbing, there should be a visible sign.
Is there any noise from the exhaust if you wobble it?
Could perhaps be caused by a crack, rust, where the exhaust pipes go into the muffler?
 
I checked the driveshafts for any play but they were solid. I ordered 4 u-joints anyway, but the current ones are fine.

I ended up taking it to a local auto shop recommended from other mud users.

As soon as I got there, we test drove it so he could hear the noises. He mentioned he thought it was definitely the muffler.

I left my truck with that shop. They called the same day. Turns out, as quite a few people suggested, whoever the PO had do the muffler work did a really terrible job.

The shop cut the pipe, added a section with the correct bend, re-routed it and properly secured it. The vibration under acceleration is now completely gone. That V8 engine sounds so good. :)

Sorry I haven't got back in a while, I didn't realise they'd been other posts.
Its hard to make out in the video over the noise of the engine.
Does the exhaust wobble or move enough to touch the other metal parts, if you shake it?
Can you see any evidence of rubbing - polished metal, or the like, between the near components?
If they are rubbing, there should be a visible sign.
Is there any noise from the exhaust if you wobble it?
Could perhaps be caused by a crack, rust, where the exhaust pipes go into the muffler?
 
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I wonder if you can sue the dealership if you had all that work done but the problem was still there because all of their fixes had nothing to do with the problem.
 
I wonder if you can sue the dealership if you had all that work done but the problem was still there because all of their fixes had nothing to do with the problem.

Who knows? I'm no legal expert. I did not have the dealership do any work. And technically, if you look at the estimate, one item was to replace the muffler from the center all the way back. They never said that was the cause of the vibration. The service manager insisted both front u-joints were bad and needed replacing. All u-joints are fine, though. To me this is an indication they knew it was the muffler, but were trying to get all this other work done to make money.
 

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