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Hey all... Here's the promised follow-up from my original post last week that mentioned some strange vibrations I was experiencing with this newly purchased '99 LS. When I originally went to look at this particular car a few weeks ago, as I was doing a customary 'walk-around' inspection, one thing I did is rev the engine up a bit with the transmission in Park and noticed it wasn't exactly what you'd call 'Lexus-smooth'. Actually I think a 15 year-old Pontiac Grand Am with the Quad-4 engine might've been smoother. Hmmmm. From the initial feel of it, if you tried to balance 17 wine glasses on this engine I think all you'd end up with was a bunch of tiny shattered glass shards and an aluminum V-8 drenched in your favorite choice of vino. It had a particularly rough spot near the 2K-RPM range that varied in intensity above and below. Duly noted. I didn't bother mentioning anything I found to the owner of the car as my belief at this point was that his mechanical aptitude was limited to putting the key in the ignition and adding fuel every few hundred miles. Anyhow... my thought at the time was "probably not a deal breaker", but I was already seeing $$$ signs dancing in my head. With that said, unfortunately I bought the car somewhat spontaneously without the benefit of a high-speed drive either as I ended up viewing the car in the middle of a large, highly-populated city during rush hour. Retrospectively, I realize this action in and of itself wasn't too bright (I never claimed to be bright) and goes completely against my grain under normal circumstances. What can I say. I was antsy for an LS! In any event, to make a long story short after looking at a LOT of these cars over a period of months, I decided to take the plunge because this seller had an alternate buyer already waiting in the wings... so it was a case of "buy-now-on-the-spot"... or let it go and keep looking. Just couldn't let it go... it had the very desirable (to me) Nakamichi stereo, excellent overall cosmetic condition, was owned by the same family since new (that much I was able to confirm), had a decent level of maintenance for most of its life (apparently up until the last couple of years), and was painted in what my eyes view as a great color. Once I got it home and had a chance to really spend some time with the car I began to question whether I'd make a huge mistake. Classic case of buyers remorse when reality sets in and completely eclipses initial excitement. What a buzz kill. Kind of a sucky feeling, particularly when you've just dropped enough cash on a purchase to finance the government operations of a third-world country for at least an hour. In a nutshell, that earlier noted mid-RPM vibe translated out on the road into a fairly loud, low-pitched thrumming/humming sound right where you spend a lot of driving time... the 40 - 55mph band. I was really thrilled with myself at this point. Smell the sarcasm? The car also has notably warped rotors and some clunking & banging going on in the front end over certain types of bumps. Multiple issues. Ok, no need to freak out... I think. Like a late-night Poker hand gone wrong, I was kinda feeling 'pot-committed' at this point. With 161K on the clock, I do realize virtually ANY used automobile is going to need some type of work. The unknown question is how much work. On some cars I've owned it just seems to never end. Considering Lexus parts pricing, I was praying (and still am!) that this isn't one of them. In any event, I'm fairly mechanically savvy in my opinion and do the majority of my own work, so the first thing to do is get under the car and spend an afternoon getting dirty. I call it 'vehicular-bonding'. I could make a far more human analogy but I'll refrain for the benefit of any female forum readers who may be out there. Anyhow, first thing: Flush every fluid from stem to stern. Mobil-1 synthetic 75w90 gear oil in the differential (not much metal stuck to the factory magnet - a good sign), 6 quarts of correct Toyota T-IV trans fluid (drained the pan twice - fluid was pretty ugly), oil and filter change (OEM Toyota filter), power bleed the entire brake system with the specified DOT-3, etc. The good news is that the underside was completely dry and since the car was garaged the majority of its life and seemingly not driven much in foul weather, so it wasn't a rust bucket undernearth. What a treat. Slight attitude change at this point. Maybe this won't be so bad after all. Fingers crossed. After many late nights reading this and other Lexus-specific forums (which I have to say has been a HUGE help overall - thanks to ALL!), I decided to make the transmission mount a focal point since it was seemingly one of the least-costly, easiest-to-change components on these cars which had the potential to make a significant difference. I will say at this point that doing a simple visual inspection of the mount with the car up on a lift showed exactly nothing. The mount looked normal in the sense that it wasn't horribly deformed or visibly broken. No matter, it definitely looked original so out it came. Now, this is where the story gets interesting. This site has been such a valuable resource of information already, I feel the least I can do is try to give a little back and hopefully assist someone else in solving their own troubles with one of these cars. With that said, it was only when a brand new transmission mount is compared side-by-side directly with an old mount with some real miles on it that it becomes painfully clear what occurs. Not only was my old mount compressed roughly 1/4 inch in overall height, which changes the all-important driveshaft angle, but once the weight of the transmission itself had been removed, it was obvious the old hardened rubber had actually cracked and broken free of the mount on both sides! My optimism that this mount may solve at least one issue was definitely rising now. To keep this post from reaching Biblical length, I'll state that once this $45 dollar part was installed, the difference was literally 'Day & Night'! The driveline vibration... completely gone. Wow. 50mph was now glass smooth, along with all other tested speeds. Subsequent close analysis of the old mount shows clearly what causes the vibration. The engineers built-in sort of a 'fail-safe' to prevent the mount from completely collapsing with age. It's equipped with a snubber that when enough degradation occurs, the two pieces compress enough it defeats the design intentions of the mount by allowing the top and bottom halves to contact one another and literally pass driveline vibration straight through to the body of the car. This was the cause of the harmonic 'hum' which varied with engine speed. Sure the rotors are still warped and give the sensation you might lose a filling or two when applying the brakes, and the front end bangs in a decidedly un-Lexuslike manner entering certain driveways with a sound more akin to an '86 Yugo on it's last legs, but hey... one thing at a time here! Rome wasn't built in a day and I consider myself a realist, so let's face it - even a Lexus ages. So my advice at this point would be: anyone with a similar type of driveline vibration... if you're on the fence about it - go ahead and replace that aging transmission mount. It's a dozen bolts 'n nuts and about 45 minutes of your time. It sure can't hurt! I'm going to try and attach 2 photos to this post. Assuming it works, the first pic is the brand new mount. In the second photo, it may be tough to tell but look closely and you'll see that the rubber on the old mount has completely sheared from the metal base. The amount it has compressed over time may not be quite as obvious, but believe me, it's there. More posts to follow as I delve into the front-end shortly with wallet wide-open and new-found optimism...