Help with Front end Pop-Solved! Finally.

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Joined
Sep 23, 2013
Threads
24
Messages
1,364
Location
Louisiana
Symptom: When the weight of the vehicle shifts to the front while braking, I get a pop/thud that I can feel through the floorboard and can hear. When I let off the brake to accelerate and the weight shifts back, it pops again. I can get the same pop when turning sharply left or right. I've only noticed this the past couple of months.

Driving style: Predominately long commute 4 days a week, light city driving on the weekends, mild trails for 2-3 weeks a year.

Parts: All bearings, bushings, suspension arms/components, CV's, ball joints, drive shafts, steering components have been changed out in the past year and a half with new OEM. A couple of weeks ago, I loosened every suspension component bolt front and rear and re-torqued to spec at ride height. Vehicle was just aligned. No change in the pop/clunk. Front height is around 21.25", have diff drop installed.

Short of getting under the vehicle and having someone drive over me, I haven't been able to pinpoint exactly where it's coming from. From sound, it seems like it's on the drivers side.

Other things I've tried: Loosening, moving, and then re-torquing the U bolts that hold my sliders on. Didn't seem to make any difference.

Primary Concern: Going on a 2 week road trip, including overlanding in UT, AZ, and NM at the end of the month and don't want to experience a failure.

Options I'm considering:
1. Do nothing further / wait and see. (not sure what the failure would be in this case...) Re-pack wheel bearings, new lube in diffs / transfer case before trip and hope for the best. (Done, no change)
2. Throw new lower control arm ball joint at it, potentially other parts if someone thinks there is a smoking gun here. (Done, no change)
3. Drop it off at what I can only guess from google reviews to be a competent shop locally for a week or more and see what they can come up with. (Done, not helpful)
4. Find a toyota/ LC specialist on the way from Louisiana to UT and drop it off for the day during the trip and see what they come up with.

Any ideas or anything I'm missing here? I'm at a loss at the moment.


EDIT:

It was the 4 bolts on the cross member of my diff drop. I'm pretty sure I torqued them on initial install but they seem to have all come loose. I retorqued them to 80 ft-lbs and it completely eliminated my pop. Finally, this has been quite the saga and time sink. These are probably the only bolts that I didn't check, not sure why I skipped over them, I think bc they were small and relatively newly installed, I convinced myself there was no way they could be the problem. Thanks to another poster on the last page who had the same problem, I finally checked mine and sure enough.

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Check your U-joints and DS slip-joints.

See if it goes away if you grease the DS.

Mine does a similar sound and I only experience it at the end of a one-hour drive at a stop light.

Mine goes away if I grease it. Pretty sure it's worn out splines in the DS yoke on the rear.
 
Check your U-joints and DS slip-joints.

See if it goes away if you grease the DS.

Mine does a similar sound and I only experience it at the end of a one-hour drive at a stop light.

Mine goes away if I grease it. Pretty sure it's worn out splines in the DS yoke on the rear.

Thank you for the suggestion but those drive shafts are just over a year old and they get greased every 5-8k so I don't think it's those unfortunately.
 
Thank you for the suggestion but those drive shafts are just over a year old and they get greased every 5-8k so I don't think it's those unfortunately.
Maybe look for a broken body mount bolt or a crack in the frame.
 
ha! i'm going through almost the same thing. wish i had some words of wisdom, but i'm stuck in the same place. re torqued all the suspension, replaced diff bushings, checked body mounts, removed sliders...

at least you know someone is suffering with you. good luck! i'll check back if i figure it out.
 
ha! i'm going through almost the same thing. wish i had some words of wisdom, but i'm stuck in the same place. re torqued all the suspension, replaced diff bushings, checked body mounts, removed sliders...

at least you know someone is suffering with you. good luck! i'll check back if i figure it out.
New best friend, nice to meet you.
 
New best friend, nice to meet you.
If you think you may have a body or engine mount failure you can do an easy test. Put the vehicle in drive and put your foot firmly on the brake. Have someone stand out of the way for safety sake and look in the engine bay. Give a quick brappp of the throttle pedal and watch / listen for clunks

Otherwise, front end clunks could be cause by ball joints or various assortment failing bushings ( like in the control arms )

If you're getting more of a driveline clunk when shifting / letting off the gas and back on it, well good luck with properly diagnosing that. See the official clunk/thunk thread if you want to get depressed.

If you have a feeling like someone rear ended you at stop lights when slowing down / coming to a stop, then pump the slip joint grease fitting on your rear end until you see grease come out from around the seal.
 
ha! i'm going through almost the same thing. wish i had some words of wisdom, but i'm stuck in the same place. re torqued all the suspension, replaced diff bushings, checked body mounts, removed sliders...

at least you know someone is suffering with you. good luck! i'll check back if i figure it out.
Can I be friends with you guys as well? I have the same pop that happens under the same circumstances in my 98 LX. Please keep us posted if you find anything.
 
My LX has been having the same symptoms since a few months ago. The sound and feel to me were likes a brake caliper pulling the pad away from the rotor not in a smooth manner. I also notice my body tends to lean forward more once come to a full stop no matter how slow I press the brake pedal.
 
My LX has been having the same symptoms since a few months ago. The sound and feel to me were likes a brake caliper pulling the pad away from the rotor not in a smooth manner. I also notice my body tends to lean forward more once come to a full stop no matter how slow I press the brake pedal.

I sometimes think it's a caliper too, but mine are only a year old. They are re-man's from Napa though, so maybe thinking because they are "new", that can't be it, isn't the right thought process here.
 
Strange Pop: stopping, take off accelerating and turning. All suspension and mounts inspected or replace.. Hummmmmmm :hmm:

Spare tire perhaps or attach or mounted aftermarket component!
  • You'd not believe how often I find the spare has lost air pressure, and now flopping around in carrier.
  • Just had one come in with strange sound. Most prevalent in slow turn through dip in the road. Found aftermarket bumper install, without all recommend bolts into frame.
Otherwise, number one I find when "stopping, take off accelerating and turning" is ball joint(s) failing,
 
Alright..... mine is gone.... for now.

I re-torqued all the bolts in the front end again and it seems like the 4 bolts on the diff support were a little loose. buttoned everything back up, drove around and what do you know, like new!!

It makes sense if I think about it, lots of noise in fore aft and some popping when frame is twisting in a full lock turn.

Anyway, hope you guys are having the same issue. good luck and happy wheeling!
 
Strange Pop: stopping, take off accelerating and turning. All suspension and mounts inspected or replace.. Hummmmmmm :hmm:

Spare tire perhaps or attach or mounted aftermarket component!
  • You'd not believe how often I find the spare has lost air pressure, and now flopping around in carrier.
  • Just had one come in with strange sound. Most prevalent in slow turn through dip in the road. Found aftermarket bumper install, without all recommend bolts into frame.
Otherwise, number one I find when "stopping, take off accelerating and turning" is ball joint(s) failing,
I'm considering just throwing a new ball joint in there and seeing what happens.
 
I'd inspect ball joints, to determine if bad or not. Factory installed ball joints can last a very long time.

Depending on use, tires, build (lift & weight). Most importantly how well front end maintained (PM). Which PM start with proper wheel bearing services every 30K miles.

If wheel hubs wobble due to loose wheel bearing. This put excessive side to side force on ball joints, TRE and steering rack. Same holds true if steering rack or TRE loose/sloppy. They also, put excessive force on ball joints.

Other causes are ball joint boot going bad. Boot not sealing out contaminates. This is due to hole in boot or boot not sealing on knuckles seating surface due being curled/warped from blows. These blows are typically from beating off ball joint with BFH, to release them from knuckle. Another I see so very often, when BFH used to beat ball joints off knuckle. Ball takes a misguided blow, damaging boot and ball joints. For these reason, I always use a ball joint puller.

Uppers ball joints are difficult to diagnose, with knuckle on. But lowers are easy with a camera or helper.


Lowers are easy to diagnose, when this bad.

Any movement up into boot/lower control arm, they're bad. Even if only the tines almost undetectable movement into boot, they're bad.
 
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I'd inspect ball joints, to determine if bad or not. Factory installed ball joints can last a very long time.

Depending on use, tires, build (lift & weight). Most importantly how well front end maintained (PM). Which PM start with proper wheel bearing services every 30K miles.

If wheel hubs wobble due to loose wheel bearing. This put excessive side to side force on ball joints, TRE and steering rack. Same holds true if steering rack or TRE loose/sloppy. They also, put excessive force on ball joints.

Other causes are ball joint boot going bad. Boot not sealing out contaminates. This is due to hole in boot or boot not sealing on knuckles seating surface due being curled/warped from blows. These blows are typically from beating off ball joint with BFH, to release them from knuckle. Another I see so very often, when BFH used to beat ball joints off knuckle. Ball takes a misguided blow, damaging boot and ball joints. For these reason, I always use a ball joint puller.

Uppers ball joints are difficult to diagnose, with knuckle on. But lowers a easy with a camera or helper.


Lowers are easy to diagnose, when this bad.

Any movement up into boot/lower control arm, they're bad. Even if only the tines almost undetectable movement into boot, they're bad.

Super helpful videos, I'll check these and report back. Kinda hope one of the ball joints is bad, even though they aren't very old. Nice to just have a diagnoses and fix it, even if it seems unlikely and I don't want to believe it.
 
I threw in the towel and dropped it off at a local off-road shop. The tech immediately said it sounded like passenger side lower control arm after a few drives around the parking lot. Will keep you guys posted next week on the official diagnosis and the fix hopefully.
 
And this is why I don't take my vehicle to shops/mechanics. Things this guy told me...

"The torsion bars look maxed out" -Not even close, I have 1" of lift and proper droop, adjusting nut is only about half way up the threads.
"Torsion bar system has to be the worst system ever designed, you should think about getting rid of this" - Um, ok...yeah Landcruiser's are poorly engineered, noted.
"Did you hit something and knock the torsion bar out of alignment" - Is this even possible, wtf? It's literally captured on two ends with splines. Ok
"I think the torsion bars just need to be adjusted" -"....um, not even sure what that means but ok yeah, I'll...try that".
"Ironman uses some cheap metal for their parts (torsion bars), we normally see OME" ...cheap metal. Ok guy.

Needless to say, still no smoking gun here. I plan to separate the ball joints from the hubs and check them for play/noise/range of motion etc. Will report back.
 
Have you inspected the front sway bar links and mounting points/bushings at the frame? Especially passenger side, AC is known to leak down and rust out mounting point, could be shifting under hard braking.
 
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