Suspension Question: Shocks, Strut Rod Bushings..how Much?

[LS 0181158]

My 1998 LS 400 (non-air suspension) just passed through 180K recently, and I feel the ride has degraded since 115K when I bought it. I'm quite sure the suspension has never been altered/replaced since new. Obviously any wear-down has been extremely gradual over 65K worth of driving, but it would stand to reason that a 180K LS 400 cannot be expected to ride like a 0K LS 400. I think it's time for some $$$ (hopefully just $$) invested.

Symptoms: the car sits pretty level, but if I had to choose, the back is a bit lower than the front.

-The ride has become 'sharp' over pavement imperfections--frost heaves, expansion joints (these can actually elicit a 'crack' sound from the dash if they rise up enough relative to the road surface), manhole covers, unavoidable potholes, etc. Over milder bumps and in faster driving, body motions are still very well controlled. It seems like the sharp edges/kickback can be felt through the steering wheel as well.

-At steady speed on the highway (especially above 75 mph), there is a slight but steady 'jitter' coming through the structure. Not teeth-rattling or anything, but the ride isn't glass-smooth with the steering wheel resting dead in your hands as it should. Tires are less than a year old and I don't think the car is out of alignment or anything.

-I don't notice it now, but when the temperature was warm (started when it was hotter than 80 degrees only, but last fall occurring at slightly cooler temps as well), there is an incessant creaking sound (like a tired bedspring) accompanying front suspension motions. Most noticeable going over heaving bumps (speed bumps, etc.) at low speed. Kind of goes away at high speeds, but I think it's just because the ride motions are smaller and there's a higher volume of general wind/road noise. Again, the warmer the ambient temperature, the more noticeable the sound.

I'm not trying to alter the suspension from stock; I just want the OEM ride back. My thoughts are to begin with new shocks. Any thoughts on where to buy and what brand? What about springs; will they be necessary? In a reply to an older post of mine, SW03ES had mentioned (I think) strut rod bushings to quell steering wheel kickback. Now, I found some of those online for $65 each (should I be replacing two or four?). Anything else I didn't think of?

I would like the most dramatic increase in ride comfort (restored close to original) for the least amount of money. Has anyone replaced the suspension on their 1998-2000 LS (or 1995-1997 if it's the same design)? How many hours of labor should I expect to pay for?

Thanks in advance for any ideas.

[1990LS400]

If your strut rods haven't been replaced since you bought the car, I'd start there. My mechanic buys new strut rods with the bushings already pressed in -- they don't cost all that much more and buying the complete assemblies ensures that the bushings fit properly. Also, his labor to remove/press in new bushings in the old strut rods is more expensive than buying the entire new assemblies.

It's possible that the shocks could be worn but they can last far longer than 180K miles. I've never heard of standard springs on an LS wearing out.

My strut rod bushings were completely worn out when I had the strut rod assemblies replaced at 86,000 miles -- I had serious front end vibrations and some front end "clunks". At least on my 00 LS, replacing the strut rod assemblies made the car ride like new. I'll probably replace them again when they've got about 65,000 miles on them.

I don't know how long ball joints last on a 98-00 LS400 -- my 00 LS400 is at 120,000 miles. I think I had all the ball joints on my 90 LS400 replaced between 120,000 and 160,000 miles but I suspect the ones on my 00 LS will last longer.

[sgretchko]

I think (very amateur opinion) you have a few different things going on.

On the "clunking" over small bumps, etc. I believe this may be front strut mounts. I had this on my '97 around 120k. While I probably should have replaced struts at that time, I was advised not to so I didn't.

In terms of parts, aftermarket KYB struts can be found online for about $320 for all 4. Many on this forum have been pleased with them. OEM struts from parts.com or Lexus of Pembroke Pines are probably closer to $500 to $550 with shipping. They will be smoother and closer to the original ride. I have asked around about labor, a few small shops quote in the $85 to $100 range per strut. Afterwards, the car should be aligned.

I am curious about the bushings. I have a feeling my front left side bushing is going and will look into to replacing both sides. Symptoms are a bit of looseness and slight slippage on the left front. (Almost like 1 table leg is slightly loose). Also outside thread of tire has slightly more wear.

I have the same creaking noise, it comes and goes.

Keep us posted. Many others, like me, have similar issues and would like to see how they are resolved.

[blake918]

I think the best thing to do would be for you or your mechanic to inspect all rubber bushings and mounts under the car since vibrations, quivers, clunks, etc. can come from any of a bunch of different parts.

I'm not trying to alter the suspension from stock; I just want the OEM ride back. My thoughts are to begin with new shocks. Any thoughts on where to buy and what brand?

The KYB GR2 shocks seem to be the most common nonOEM choice since KYB makes the OE shocks. When I change my shocks, I'll get the KYB shocks since they are about 1/2 the cost of Lexus shocks. My '99 has pasted 200k miles, and I think I'm getting ready for some new shocks--it's getting a little floaty.

What about springs; will they be necessary?

At your low mileage, it's probably not necessary. I changed the springs on my former LS sometime around 285,000 miles. It made a huge difference in the way the car rode, but it did not make the car sit level which is why I bought the springs in the first place (leaned to the front left, which appears to be somewhat common.).

In a reply to an older post of mine, SW03ES had mentioned (I think) strut rod bushings to quell steering wheel kickback. Now, I found some of those online for $65 each (should I be replacing two or four?).

There are only 2 front strut rods. There are rear strut rods, but other than the axle carrier bushing and the shock, rear suspension usually doesn't need much attention.

[LS 0181158]

How I love to hear 180K referred to as "low mileage!" Only with a Lexus, I guess. It certainly FEELS low mileage, and the ride is really the biggest factor introducing sharpness and quivers that detract from this sensation.

Thanks to all for your advice and the experience you collectively related. Since my car is sitting level, I think it's safe to pass on the springs.

1990LS400, you're right--the complete strut rod assemblies are only like $65 each. Maybe I should just start there...but I'm so tempted to want the best ride possible and I KNOW four new shocks ought to improve the ride noticeably, even if it falls short of 0K mile perfection. However, doing everything (2x strut rods @ $65, 4x struts @ ~$100, $400 for labor (plus alignment) is looking like more than $1,000. I guess that's not unreasonable considering how infrequently these parts need to be replaced. How do I know if my ball joints are worn? Do you think this is something I should just get out of the way given the important safety role of these parts? I find they run about $90 each. How much was labor?

blake918, it may indeed make sense for the mechanic to look for the most worn suspension components to address--those most likely to make a significant difference when replaced. I guess that's better than blind speculation, although once again, any parts replaced at this mileage are bound to have a noticeable effect.

Thanks again to everyone for your help.

[blake918]

How I love to hear 180K referred to as "low mileage!"

Because it is! B)

How do I know if my ball joints are worn? Do you think this is something I should just get out of the way given the important safety role of these parts? I find they run about $90 each. How much was labor?

I think you can check them lifting the tire off the ground and try to lift up on the tire vertically. It takes no time to change lower ball joints; 30-45 minutes a side if memory serves. I changed mine around 170k (chasing after a mystery noise), and while they were worn, they weren't that loose and could have gone a while longer.

[RDM]

I've noticed a common issue on earlier models is the rear axle carrier bushings, ADUS sells a urethane replacement set (part #505) and a quick search of that will show you the one in question. Mine are completely torn apart allowing for the rear lower link to twist and rattle up/down, I've got the ADUS bushings but have yet to have a time to put them in. Those alone can allow for rear wheel wobble and increased tire wear.

[LS 0181158]

blake918, that sounds quite labor intensive! Lifting a tire off the ground--I'm going to need to recruit Swedish strongman Magnus Samuelsson or something to help with that one. I might as well get the ball joints done, though; sounds like less than $400 parts and labor, perhaps even less labor if I'm having other suspension components replaced at the same time.

RDM, I don't notice any kind of rattle, clunk or other noise coming from the car, especially not from the rear end. But I will keep that in mind--after all the parts seem to be only $35 each.

[FiatLex]

If your strut rods haven't been replaced since you bought the car, I'd start there. My mechanic buys new strut rods with the bushings already pressed in -- they don't cost all that much more and buying the complete assemblies ensures that the bushings fit properly. Also, his labor to remove/press in new bushings in the old strut rods is more expensive than buying the entire new assemblies.

1990LS400,

You are a deep well of information, and I see you regularly admonish people to search the forum so as not to waste your time. This reply to a long dormant thread is the product of significant searching.

I just bought a LS400, and I'm thinking about tightening up the ride. In reviewing the forum, I need to clarify some terms.

Strut rod bushings are what some here call "cushions?" This is the part that has to be pressed in and out of a long tube with a large circle on the end? These pieces are somewhat difficult to find.

Strut mount bushings are a different part containing a flange with three studs and a long rubber piece? These pieces get sold on Ebay.

Strut mounts are yet again a different part, also containing three studs and are commonly available on sites such as RockAuto?

Struts are obviously struts.

If I want to change the struts, what parts do I really need to change?

Thanks.

[sha4000]

It's actually called a shock. It's part# 48510/48520 On the right side of the diagram. You can reuse the top hats ( what you call strut mount bushings) if they are in good condition but I would just replace those also so you don't have to do the same work twice. They are part#48680 in the diagram. The diagram shows the front shock assembly for a different year so the part #s will be different for your year. It's just to give you an ideal of the parts you will need. By the way part #48674 are what's called the strut rod bushing.

http://www.lexussouthatlantaparts.com/showAssembly.aspx?ukey_assembly=789323&ukey_make=1082&ukey_model=15669&ukey_category=21754&ukey_driveLine=8081&ukey_trimLevel=19107

[landar]

Craig, I think you have posted a diagram from a 98-00. The 1994 is slightly different. For one, the strut rods have rubber cushions on the end instead of the 'hole' (ring) design of 98-00.

[sha4000]

Thanks landar I figured the first gen would be slightly different but I could not find a diagram with my quick search before I went out the door.

[FiatLex]

Thanks, Sha and Landar.

Now for the disputatious matter: Liking to toss my car into corners with some speed is about 70% important, and having a plush ride is about 30% important.

What shock do I choose?

[sha4000]

You would have to either buy stiffer shocks and pair then with some lowering springs or just buy a set of coilovers.

[billydpowell]

my 99 has 193+ and I recently replaced my lower ball joints, SRB's and tightened the top nut on the struts (under the rubber cover) about one turn. got 4 wheel alignment and it is so silent, it is like new... really...

I also have 2001 17 inch wheels with 235/55/17 Goodyear Eagles on it and it just floats on the interstate...

here is a current photo