Classic Front End Popping Rattle 98 Ls400

[rfworld]

120K on this LS400

Popping rattle coming from front suspension both sides on rough surface under 25mph.

Not a thud on speed bumps or 5 mph hard braking.

Okay old topic but need help so not to waste money replacing parts that are good.

So far,

replaced lower ball joints. This took care of the big bang sound on sharp bumps IE railroad tracks, big pot holes.

replace tie rod ends slightly smoother and firmer steering but pops still there

Inspected UC ARMS by disconecting their ball joints, checked rotational firmness and bushings for play. All seemed firm.

Strut arm bushings and LC Arms are firm without cracks no play.

Brand new MXV4 primacies all around really helped restore original ride but the pops still creeep in there and you know ruin what can be a perfect ride. Get rid of the pops and the car would be basically riding as well as whne it was new.

All bushing play checked by unloading and prying with long driver

Stut shocks tested okay using standard test, no visible leakage

Lexus tech says strut shocks can go bad and cause rattling as can upper strut mounts.

other posts descrinb strut shocks with dried out bump stops inside shock gator can cause ratle pops

Anyone out there go straight for the shock bump stops and nail the problem.

Can the strut rod bushings inspect okay but still send vibrations up thought the shocks???

Hate to spend money replacing parts and not nail it plus wasting time sucks as well.

rfworld

98 Ls400 black

08 Corvette coupe black

05 Accord EX silver V6 for sale

05 Highlander

[billydpowell]

This info is for a 1997 LS400, probably the same as yours, but check.

Hi, replace both strut rods, The strut rod part numbers are 48670-40011(LH) and 48660-40021(RH).

They come complete with bushings and 2 pressed-in bolts.

they run about 95 each.

http://photoshow.comcast.net/watch/Fj9WH6CM

this will show you how.

and that lowspeed clunk will be gone. cheers..

120K on this LS400

Popping rattle coming from front suspension both sides on rough surface under 25mph.

Not a thud on speed bumps or 5 mph hard braking.

Okay old topic but need help so not to waste money replacing parts that are good.

So far,

replaced lower ball joints. This took care of the big bang sound on sharp bumps IE railroad tracks, big pot holes.

replace tie rod ends slightly smoother and firmer steering but pops still there

Inspected UC ARMS by disconecting their ball joints, checked rotational firmness and bushings for play. All seemed firm.

Strut arm bushings and LC Arms are firm without cracks no play.

Brand new MXV4 primacies all around really helped restore original ride but the pops still creeep in there and you know ruin what can be a perfect ride. Get rid of the pops and the car would be basically riding as well as whne it was new.

All bushing play checked by unloading and prying with long driver

Stut shocks tested okay using standard test, no visible leakage

Lexus tech says strut shocks can go bad and cause rattling as can upper strut mounts.

other posts descrinb strut shocks with dried out bump stops inside shock gator can cause ratle pops

Anyone out there go straight for the shock bump stops and nail the problem.

Can the strut rod bushings inspect okay but still send vibrations up thought the shocks???

Hate to spend money replacing parts and not nail it plus wasting time sucks as well.

rfworld

98 Ls400 black

08 Corvette coupe black

05 Accord EX silver V6 for sale

05 Highlander

[killerFatty]

My dad's 98 camrey had that same sound and, after lots of wasted time, was cured by replacing the CV boots.

[Marklouis]

Good info on the replacements! i have a 95 LS400 having the same problems. will check into getting those replaced.

[McSwine]

Mine makes a pop/clunk over speed bumps. Strangely enough, it is dependent upon the ambient temp...it does not do it unless it's about 50 or below. Changing the strut bars did not fix it and I'm reluctant to throw money at it until I know what it is. <*BLEEP*ed>

[rfworld]

Mine makes a pop/clunk over speed bumps. Strangely enough, it is dependent upon the ambient temp...it does not do it unless it's about 50 or below. Changing the strut bars did not fix it and I'm reluctant to throw money at it until I know what it is. <*BLEEP*ed>

Thanks for responding,

My strut bar bushes are tight and do not have cracks. I don not get the speed bump clunk or the hit brakes hard at 5mph clunk that most LS owners associate with stut bars.

My next prob is going to diasseble the strut shocl assembly and inspect all including bump stops and strut tower mounts.

Since you are experience the same i will let you know how I make out and vice versa if you can

Dave

rfworld@aol.com

[McSwine]

Since you are experience the same i will let you know how I make out and vice versa if you can

you got it...thx

[landar]

Rf,

I know you dont want to throw money and time away. And neither would I.

However, I also own a 98 LS400 and lets face it, after 10 years, there are a lot of tired components up front.

I replaced my strut rods last year to get rid of a low speed clunk. But yours sounds to me to be somewhere in the shock/strut area.

Even though mine still rides very nice and no noises, I am going to replace the shocks all the way around. Maybe its wasted money/time but

after 10 years, I am inclined to believe that these parts are very worn. And they have lasted longer than I would have ever imagined

them to last. Every time I tear into my Lex, I am totally amazed at how well it is designed and built . That after owning and working on

many lesser cars.

If you do the work yourself, go ahead and start replacing the wear items such as the struts/shocks and related parts. Better for you to pick

the time and place of repair than to have the offending parts force you into a quick and sudden breakdown situation.

[billydpowell]

Hi, we just replaced my front struts on my 97 LS and the Clunk is now gone. thanks for all the help. took about 2 and a 1/2 hours to complete. It seems even tighter than ever. our mileage is 228K.

[nc211]

As the guy who replaced every single suspension component, ball joint, mounts, tie rods on his 95' LS400, let me chime in here, if I may. This one is right up my alley. I replaced all control arms, strut rods, struts, ball joints, outter tie rods, stabilizer bar bushings "might want to check those by the way, at those miles, I'm betting they're close to the end, and will cause clunks". BUT I forgot to replace one part, just one stinkin' flippin' part. When I sold my 95', at 132k miles, in 2007, it might of had a 12 year old vin #, but I promise you, it had a 24 month operating age. And yet, on those chilly mornings, going out of my neighborhood at speeds below 35 mph, and hit a bump...POP POP up front... Anyone care to guess what the part was?

No?

Ok, I'll tell you...

The strut MOUNTS! After I had nearly killed myself from exhaustion one weekend from replacing all the front end suspesion parts with new OEM parts, I realized I forgot to order the upper strut mounts, and was too damn lazy to go back in and do them, for the next two years.

If all bushings look ok "don't forget the stabilzer bar bushings", and you've still got the POP POP from blunt bumps on chilly mornings....check the uppper strut mounts.

Two cheap parts that make a difference in the smoothness of the car.... Stabilizer bushings, and new steering rack grommets. The rack gromments are rubber wraps that go around the rack. Over time, they get compressed, and eventually the rack will wiggle loose on it's seat and start to make faint clunk clunks. It won't wiggle loose to the point of being dangerous or anything.

The mother of mother parts for smooth operation though..the #1 part..... is Engine Mounts. New Engine mounts can transform the car like you wouldn't believe. Plus the transmission mount too.

Ahhhh...feels good to talk suspension parts again! It's been a long time!

[SKperformance]

LOL NC

I always hate the strut rod bushings they need to have tighter tolerances and a stiffer bushing , I am going to change my LS400 and GS430 over to Daizen as soon as i get a good price as if they go bad they take everything up front down with it.

[billydpowell]

Just for the records, I had already replaced the struts and mounts, and as a retired mechanic, I knew to replace the mounts with the struts. I did not know how sensitive the Lexus' was until I got on this club. Since I retired in 96, we didnt get many Lexus products in the shop, so I have used your knowledge to keep my self up, so thanks.. bp

As the guy who replaced every single suspension component, ball joint, mounts, tie rods on his 95' LS400, let me chime in here, if I may. This one is right up my alley. I replaced all control arms, strut rods, struts, ball joints, outter tie rods, stabilizer bar bushings "might want to check those by the way, at those miles, I'm betting they're close to the end, and will cause clunks". BUT I forgot to replace one part, just one stinkin' flippin' part. When I sold my 95', at 132k miles, in 2007, it might of had a 12 year old vin #, but I promise you, it had a 24 month operating age. And yet, on those chilly mornings, going out of my neighborhood at speeds below 35 mph, and hit a bump...POP POP up front... Anyone care to guess what the part was?

No?

Ok, I'll tell you...

The strut MOUNTS! After I had nearly killed myself from exhaustion one weekend from replacing all the front end suspesion parts with new OEM parts, I realized I forgot to order the upper strut mounts, and was too damn lazy to go back in and do them, for the next two years.

If all bushings look ok "don't forget the stabilzer bar bushings", and you've still got the POP POP from blunt bumps on chilly mornings....check the uppper strut mounts.

Two cheap parts that make a difference in the smoothness of the car.... Stabilizer bushings, and new steering rack grommets. The rack gromments are rubber wraps that go around the rack. Over time, they get compressed, and eventually the rack will wiggle loose on it's seat and start to make faint clunk clunks. It won't wiggle loose to the point of being dangerous or anything.

The mother of mother parts for smooth operation though..the #1 part..... is Engine Mounts. New Engine mounts can transform the car like you wouldn't believe. Plus the transmission mount too.

Ahhhh...feels good to talk suspension parts again! It's been a long time!

[amcdonal86]

Also, what are the more specific symptoms of bad strut/shock tower mounts? I replaced my strut rod bushings and front sway bar bushings and I'm still hearing a crunching noise up front. It only happens under about 50 mph (maybe I don't hear it when I'm going faster), but whenever I go over a large dip or some sudden large bumps (or even going over the transition between driveway and road), I hear this noise coming from the front somewhere.

It looks like an easy enough job to do, and it's not too expensive (maybe $60 for parts for both sides). Any ideas?

[McSwine]

The strut MOUNTS! After I had nearly killed myself from exhaustion one weekend from replacing all the front end suspesion parts with new OEM parts, I realized I forgot to order the upper strut mounts, and was too damn lazy to go back in and do them, for the next two years.

If all bushings look ok "don't forget the stabilzer bar bushings", and you've still got the POP POP from blunt bumps on chilly mornings....check the uppper strut mounts.

That is certainly good news. Did you put them in yourself? Are they expensive?

[90LS400Lexus]

Yeah, when I win the lotto, I am going to have the engine mounts changed on our LS. They are terrible. I can get it done (labor) for $150, but still have not have the gumption to shell out $190 for engine mounts and another $60 for the transmission mount, then the $150 labor. I have a pretty good amount in my savings, but thats my "nest egg" for something else I may need it for incase of emergency.

On another note... my old 1990 LS had a terrible clunking front suspension, but so far, the 1991 LS (with about as many miles now as my 1990 had when I bought it) does not have clunking yet, but I know its probably due for tie-rod ends and/or ball joints. I know it could use some new struts... the front suspension "gives" very little up and down movement.

The mother of mother parts for smooth operation though..the #1 part..... is Engine Mounts. New Engine mounts can transform the car like you wouldn't believe. Plus the transmission mount too.

[amcdonal86]

Yeah, when I win the lotto, I am going to have the engine mounts changed on our LS. They are terrible. I can get it done (labor) for $150, but still have not have the gumption to shell out $190 for engine mounts and another $60 for the transmission mount, then the $150 labor. I have a pretty good amount in my savings, but thats my "nest egg" for something else I may need it for incase of emergency.

On another note... my old 1990 LS had a terrible clunking front suspension, but so far, the 1991 LS (with about as many miles now as my 1990 had when I bought it) does not have clunking yet, but I know its probably due for tie-rod ends and/or ball joints. I know it could use some new struts... the front suspension "gives" very little up and down movement.

The mother of mother parts for smooth operation though..the #1 part..... is Engine Mounts. New Engine mounts can transform the car like you wouldn't believe. Plus the transmission mount too.

$500 isn't that bad for a repair if you know it's going to give you the result you want. I, on the other hand, spent $500 getting scammed by a dealership and replacing parts that did nothing to resolve the problem (although there were a few side benefits of replacing those parts).