Nomis

My search through previous posts has led me to believe that no one on the board has changed their own SC400 mounts. I'm writing this so the next guy will have a better idea of what he's getting himself into. The lower nuts are fairly easy. It's the upper nuts that are a pain. They are tucked up under the exhaust extractors (manifolds), and then angled towards the block. The lower is a 19mm nut, the uppers are 17mm. A deep socket won't fit, a box end won't fit - all that well either. The best way I found was to use either a 3/8 socket wrench with a short or "stubby" shank and a standard depth socket. The only problem with this is that you can't really get any leverage on it, because you have to contort your arm up and around the wishbone susp. Luckily, the drivers side came off after a couple heaves. The pass side has a few more lines in the way, although I found that I was able to come at it from the front - it still wouldn't budge, so I put some liquid wrench on it and will try again when I get home. Then I'll have to jack up the engine - place something under the pan to evenly distribute the weight. The preferred method would be to use an engine hoist from the top to pull up on the engine - which I might end up renting if this doesn't work or I deem it unsafe.

After this the trans mount should be a breeze. I took a look at it and it looks like I just have to remove the 4 trans cross member bolts and then the trans mount bolts (while supporting the trans).

So there you have it. I couldn't take pics of the process if I wanted to as everything is so cramped and obstructed. So the above description will have to suffice.

Incidentally, I called the dealer and was quoted @ 2 hours each for the engine mounts and 1 hour for the trans mount. This came out to a grand total of $450. No thanks; even if I smash my hand while putting in the new mounts, and have to visit the emergency room - I'll still come out on top.

Nomis

Sorry Mods - please move this to the engine section.

O. L. T.

iTrader: (17)

engine topic = engine forum.

Moved.

(good luck on the mounts, hope they hold up and everything works well.)

HotBoy

thanks a million man and you are correct there was no previous info on doing this yourself you are the first. I will be attempting this great feat in the next few months let us know how it feels when it is all done.

Nomis

Got the new mounts in, but not without some issues. When raising the engine with a floor jack and a piece of wood under the oil pan, I got it most of the way up when all of the sudden, fluid started pooring down - turns out it was a brittle hose on the p/s reservoir. I will attempt to pick one up from the dealer tomorrow, if they don't have one i'll just use some plain hose as its a low pressure line anyhow. Man that freaked me out with all this fluid raining down - oh well better now while its in my garage rather than on the road. The old mounts came out okay once I got the nuts off but the new ones were a pain to get in there. As one would expect, they sit higher than the old compressed mounts and the top bolt just did not want to line up with the top bracket hole. I tried to raise the engine to give me more room and ended up denting the pan ever so slightly - no oil leakage but I'll keep an eye on it. Oh one more thing, the stock mounts use a very thin heat shield on one side of the mount. With the increased width of the new mounts, there was no way I could this thing back on. The mount is about 3-4 inches from the manifold and I don't anticipate any heat related issues (although engineers don't usually add on parts for no good reason). Once the mounts compress a bit I may go back and install them - if I'm in a sadistic mood.

The good news is the tranny mount is simple to install - a 20 minute job.
- Support the trans with a small jack with block of wood to distribute the load.
- Remove the small trans mount bolts in the middle of the crossmember - 13mm?
- Remove the 4 trans crossmember bolts and remove crossmember - 14mm?
- 4 more bolts secure the mount to the tail housing and then you can remove the old mount.

Both my engine and trans mounts were showing wear but nothing horrible. Don't do the mounts unless you're sure they're bad. My SC400 has 107K on the clock so I figured it was time, but they probably could have lasted another 15-50K depending on wear and usage. I feel better now that they're new but what a pain. I haven't had a chance to test drive it as I'm waiting to replace the p/s hose.

I hope this helps you guys in the future.

HotBoy

Thanks man, very informative and I think it is def tinme for mine as I'm at 240K miles !! and the history says nothing about changing mounts. Damn it. You actually thinking it might be better just to pay the dealer to do it. But I'm pretty sure I will just suck it up and do it myself.
Thanks

Nomis

I think the price I was quoted was a bit on the high side @ $450.00. If you've got the cash go ahead and shop your local lexus dealers to get the best price and then have them take care of it. Do the trans mount yourself and save some cash as it's relatively easy. Oh, the cost of the p/s hose that broke is $26 - not too bad.

vredniykot

Another thing you might want to check out if replacing the engine mounts is your upper/lower control arm bushings - they are made out of same rubber compound (I think) and if mounts are bad than bushings are probably too or that's what I ran into anyways

john_sc400

I just purchased a 95 SC400 with 95k miles and found both front motor mounts were bad. An independent mechanic was testing the engine, brakes etc., by holding the brake and opening the throttle when in gear.

Due to torque, the engine lifted up so far that it disconnected the power brake vacuum hose and broke a plastic bracket that fastens the two fuel lines to the left inner fender well. I can even see the worn spot on the power brake vacuum hose where it had been rubbing against the hood liner when the engine lifted. Needless to say, suddenly losing braking power assist was a surprise. I'm lucky I didn't have to make an emergency stop.

FWIW, since I had just bought the car, the (independent) dealer replaced the mounts free of charge, I do not know, however, if they checked the trans mount. I'm going to have to do that myself. The bracket is on order from a Lex dealer right now ($4.00)

Moral: check your motor mounts, A broken mount can cause an accident.