rrgone

I'm not sure how to tell if I should replace the springs at the same time I replace front shocks. I have been meaning to replace shocks on wife's 98 LS400 for some time now. Ride seems jarring to me, especially cornering and on roads with expansion cracks. Yesterday I was riding with wife when she hurried to make a green light at a busy intersection. There's a slight dip at the crossroad and I felt the front end bottom slightly when she hit the dip. Is that a sign that I should replace the springs as well as the shocks?

Thanks!

steve2006

If I were you I would replace both at the same time or you could end up doing the job twice.
Check the springs for any broken coils at the top or bottom and check the shocks by pushing down on the top of the fender then releasing, the car should not bounce more than a couple of times before stopping, also check them for signs of leaking.

RA40

iTrader: (6)

Metallurgy these days is quite good that the OEM springs seldom need replacement. When you have them out, measure each side to compare and if they are obviously off, then it is a possibility.Otherwise, replace the struts and you'll be back on the road.

Other bushing wear will also give symptoms as the parts thump-clunk under the loose tolerances.

PureDrifter

iTrader: (10)

unless rusted or obviously damaged, the stock springs do tend to take age quite well. being that the OP is in arizona, I doubt rust is going to be an issue.

keep the springs, swap the shocks. if you've got sig. mileage on it, throw new top mounts in too.

now, if you're feeling clunking/thumping over bumps/dips, then that's a whole different matter (search: front strut rod bushings)

rrgone

Thanks for the info folks. The LS has about 110k miles and has been in AZ about last 5 years. Before that it was in Seattle and first owner was Cali Bay area. I believe shocks are original. Am I premature in thinking it's time for new shocks just based on age/miles?

I rarely drive this car or ride in it. It seems to me like handling is not what it should be for a LS 400. Steering feels strange to me, but wife says it is "normal". When I drive it I feel kind of "floaty" when taking curves at highway speed - like when you hit a patch of ice and are just beginning to feel like the rear end might be breaking loose. Of course it does not break loose, but it's that queezy pit-of-stomach feeling you get when that happens.

That plus the jarring you get on crappy roads in Tucson that are full of large expansion cracks, and the bottom out the other day hitting a dip at probably 35mph.

Oh yeah, there was a shimmy at hiway speed last year that I never experienced. I had wheels rotated/balanced and wife says it is okay again.

Any more thoughts? I was thinking shocks were a good place to start. Thanks again.

RA40

iTrader: (6)

Start with fresh struts then go from there. If the history shows not suspension maintenance, high probability then goes to:

1. Strut bar bushings
2. UCA or LCA bushings
3. Rear strut bushings
4. engine and tranny mounts
5. carrier bushing
6. Rack bushings

As you can imagine a whole shopping list of potential areas. The most obvious are the struts. The OEM in mine were dead before 70K miles as were the strut bar bushings.

rrgone

Thanks for the quick reply.

So, hard rubber parts huh? I will def look those over while I have wheels off and working on shocks. What about rubber parts in shock setups? I see there are insulators and bumpers on the fronts. Seems like it would be good to throw new ones in and maybe upper supports too like PureDrifter mentioned. I see KYB has supports for about half what OEM run. I'm thinking OEM shocks though as we're into our 60s and don't care much for stiff ride. I want the lux back.

PureDrifter

iTrader: (10)

add Lower Ball Joints in after Strut rod bushings.

sethjon

If the dip was big enough and you were going fast enough it wouldn't matter if you had new shocks. As far as the springs go, its doubtful they are bad.

RA40

iTrader: (6)

I have yet to wear a strut mount in any of my cars. While this is not common, it can happen through years of compression and harsh conditions. The most obvious symptom would be a slightly different length when the strut assembly is measured.

Yes, basically any hard rubber suspension part will contribute to suspension problems and noises. The LS's wear through them with regularity so watching the strut bushings are important. My mechanic says they can last a lifetime and others be gone in a few K miles, all depends on roads.

Unlike the 2-GS, the ball joints haven't been seen to fail catastrophically on the LS but having those changed before it becomes a problem is advised. I did mine at ~85K miles I recollect. I'll be due to inspect them probably end of the year. When ours will have about 170K miles. I did the ball joints and tie rods end at the same time.