Another front end 'clunk' thread

[87warrior]

I have been chasing down what I believe is a front end clunk on my 100 since I bought it in January. The clunk occurs when hitting bumps or dips. Not only can I hear it, I can feel it in the floor.

My reaction was to crawl under the truck to see what has any play. I have done the following:
- Replaced steering rack (Toyota)
- Replaced ball joints (555)
- Repacked wheel bearings (got 10lbs on the fish scale but it took some torque)
- Replaced front sway bar end link assemblies (TRW)
- Rebuilt rear sway bar end links (Toyota)

I have pried on the front and rear bushings but cannot find any play. Based on the sound and feel of this clunk, I think it should be pretty obvious what is worn out. I am running out of ideas so I am asking for suggestions on what to inspect and how to inspect it.

Thanks!

 

[lead62]

Some people have reported a clunk associated with the front differential mounts. Others have it with engine and transmission mounts. Some have to replace the upper or lower control arm bushings/mounts.

 

[Trunk Monkey]

Lifted? Hitting the bump stops in travel?

 

[87warrior]

Some people have reported a clunk associated with the front differential mounts. Others have it with engine and transmission mounts. Some have to replace the upper or lower control arm bushings/mounts.

I was wondering about the control arm bushings. Is there any way to inspect them without removing them? I've pried on the mounts but haven't seen or felt movement. I'll double check the front diff as well.

Lifted? Hitting the bump stops in travel?

It is stock. I don't think it is hitting the bumpstops since large expansion joints in the road can produce said clunk.

 

[Lowbudgetlc100]

i have that same clunk once in a while. my truck lifted with ome tb. only sometimes not all the time still trying to find it

 

[Julian Stead]

Check cv joints, inner and outer. I Just done my front end @ 170,000. Movement was in ball joints, sway bar links, inner and outer cv joints, rotational movement on outer cv and lateral on inner cv and diff mounts. Suspension bushings where in a reasonable state on the front. Rear control arms had the most wear on bushings but this was causing a booming noise on bumps..

 

[abuck99]

Some people have reported a clunk associated with the front differential mounts. .

I would start here.

How many miles ?

 

[87warrior]

Thanks for the ideas. I'll crawl back under this evening with a bit more focus.

I would start here.

How many miles ?

250k miles. I realize everything should be replaced at this point, but I'm trying to get the big bugs worked out first.

 

[G-Cat]

Stock, so no rock sliders (I've read where others have issues with the sliders needing to have the front mount adjusted to avoid a clunk and only put it in here for when someone searches)

Super easy/obvious is a damaged/missing bushing in a shock. (I assume you checked these first and I only post for the person searching).

 

[RobRed]

Front diff - look at the mounts.

 

[Ali FJ80]

I second the front shock bushing. The lower bushings wear out and the shock hits the mount when you hit bumps etc. I had the same thing when I first got my truck and one day I grabbed the shock and moved it back and forth and sure enough there was the clunk.

 

[RobRed]

I second the front shock bushing. The lower bushings wear out and the shock hits the mount when you hit bumps etc. I had the same thing when I first got my truck and one day I grabbed the shock and moved it back and forth and sure enough there was the clunk.

This is another one to look at - I consider the shock bushing sound to be a "knock" more than a "clunk". Solid suggestion.

 

[ihadmail]

My clunk in my 2000 LX was the front diff carrier mount. The one that connects the tube on the driver side to the diff crossmember.

 

[04UZJ100]

Sway bar bushings themselves?

 

[oftpiste]

I have a similar clunk.... is yours particular to one side of the truck? Mine seems to be on the driver's side. Had it up on a lift, wiggled everything, made some repairs and it's still there. Drives me nuts. '03 with 153k miles. Just did front axles, wheel bearings etc.

 

[87warrior]

I think I found the culprit(s). The front shocks, lower bushing. Initially I did not find play in the shock bushings when looking over the components as I only looked for vertical play. The bushings are worn in such a way that when the suspension compresses, even just a little, the lower part of the shock twists sideways allowing the lower eyelet to make contact with the shock mount on the LCA. I pulled the shocks (black Toyota) and noticed they have zero rebound. Nothing, nada, zilch. They are probably the 250k mile originals. I have a new set inbound from beno.

I wasn't able to find any play in the front diff, but the middle bushing looks like it will need replaced soon due to the aged rubber cracking.

 

[Ali FJ80]

Nice, glad you got it. it took me a while to figure it out also. I think I was in despair when I just grabbed the shock and yanked the hell out of it as it there was nothing else to test and heard the clunk. Also nice that the shocks are only like $40 a piece. Your truck will ride so much better you will be shocked

 

[l3n0x]

I've just installed an IM FCP lift on my truck, and initially it was good, but after around 30miles the front passenger side has a knocking going on.

It happens on bad roads at low speeds (at least that's when I can hear it), and also if I'm coasting on a good surface and apply the brakes.

I've already replaced the diff mounts this week, and the steering rack and swaybar bushings and links earlier (~1 month).
Everything was marked by a paint pen, and nothing seems to have moved.

I've tried to wiggle the most obvious components, like the shock, TB, wheel, swaybar, control arms, steering link, CV shaft, but can't reproduce it in the garage...

 

[MongooseGA]

@87warrior did the shocks definitively solve your issue?

I have a similar knock or clunk in similar circumstances. I can feel it in the steering wheel and my brake pedal over harsh bumps or surfaces. I'd attributed it to my steering rack as I know there's a ton of play in the bushings. Shocks are all new so I'm going to assume they're good on mine.

Diff bushings are on my short list over winter but so was rack... Reading the suggestions here, I should definitely work on the diff before digging into the rack.

 

[87warrior]

@MongooseGA - You are testing my memory here My 100 was riddled with clunks when I bought it, but I definitely have them taken care of now. In this particular case, replacement shocks did cure the clunk since the lower bushings were shot. Since your shocks are new (and presumably the bushings as well) I'd look to your swaybar links. Rebuild them with Toyota parts. The aftermarket links I initially purchased were clunking again in just a few months.

My front diff bushing stopper was bad. Replaced that and most of the driveline clunk went away. I never noticed it when cruising down the road though.