Replacing Motor And Trans Mount

[95LS400Bob]

I thought I would post this while it is fresh in my mind on replacing the engine and trans mounts. Took about 3 hours. I could do it quicker next time. And these mounts are so soft..there will be a next time.

Car supported. jack stands, battery cable disconected etc.

Mounts are 17 mm nuts top and bottom. Remove the lower nuts.

Passenger side (easier side): First remove the power steering return hose or the holdown 10mm clamp to body. You will be raising the engine to replace mounts and can break or damage the hose if you don't remove the holdown. I didn't. I hurt the hose (old hose was hard as a rock anyway). Power steering fluild dripping on you isn't fun. Learn from my mistakes. Remove all the air cleaner stuff while you are at it and to get to the hose holdown anyway.

Now remove the top 17mm nut on the passenger side. Box end wrench. Shortest wrench you have. More feeling than seeing.

Driver side:

No access from the rear cause rack and pinion is in the way. No room..you gotta make some. 10mm wrench and remove the bolts holding the wiring loom that goes across the crossmember. With the same 10mm, remove the supports for the power steering hose. That lets the hose get out of the way. Now remove the oil filter. Unfasten the oil pressure sender wire clip. Now there is another wire loom in the way. Plastic clip carefully spread and free the loom. Then remove the bolt and bracket (12mm wrench).

Now you have just enough room. But you should remove one more little wire loom clip right at the back of the A/c compressor. 14mm bolt..use 3/8" extention to get it. Finally remove the top 17mm nut on the motor mount.

Now using a floor jack with a wide board across it..jack the motor up to get the mounts out. I found I could just barely get the mounts out...motor woulsn't go up any higher..never did see where was the holdup. But I got the old mounts out.

I took the passenger side out first. It was broken at the top. But the new mount was not sagged like the old one so I couldn't just slide it in. I could get the bottom started..but the motor needed to be higher to get the top in.

The mounts are indexed so they only go one way. Heat shield is important and must go back in place. Since the motor couldn't go up...that meant the crossmember had to come down...at least a little to give me room to get the mount in. So I loosened the crossmember (17MM deep socket) and let the crossmember lower enough to get the mount in.

Then I did the driver side...had to lower the crossmember a little more. Soon as I had both mounts in place...then I tightened the crossmember back up. Then I started the 17mm nuts on top of both mounts..tightened just enough to hold the heat shields in place. Then I lowered the motor some and started the bottom nuts. Then lowered the engine completely and tightened the top mount nuts both sides.

I left it like that and went to the tranny mount. Used the floor jack to support the transmission. removed the crossmember using 14 mm and 12 mm wrenches and replaced the broken mount. Moutn was so sagged and broken...I had to jack tranny up more to get the new mount in. Tightened everything and lowered the jack. Trans mount is a piece of cake.

Then went back and tightened all the front mounts and replaced the oil filter and brackets and what not I had removed.

Finally I went to the topside and replaced the power steering return hose I had damaged and refilled the power steering. But you won't have to do that because I typed these instruction.

Vibrations are now gone. Driveline angle has been restored with engine and trans at the right heights.

[99lsguy]

bob,

thanks for the report - job well done! Like you say, it pays to DIY. I'll cut n paste this to a MS word file for reference. Can I get some more info?

cost of mounts

length of time

In the procedure, would it be better to do tranny mount first? - or does it matter?

Anything else you'd do different?

Go buy yourself a nice big steak - you saved nice $$$

[95LS400Bob]

Best price I could find was Park Place Lexus. No tax and no shipping charges. But must be ordered over the internet for these prices:

Part number 12361-50100 Engine mounts $91.67 each

Part number 12371-50060 Trans mount $32.10

3 hours time but I bet I wasted an hour trying to figure out what was keeping the motor from going higher.

Since the tranny mount is rubbery fragile...I did it last. It's a flimsy little thing. Didn't want to strain it at all.

I did passenger side first because there was more room and it's always best when in unfamiliar territory to remove the item watching real close it's orientation. You have a heat shield to deal with that indexes on top the mount.

What would I do different?

#1. disconnect that power steering return hose.

#2. Jack the motor up till you feel resistance....then loosen the crossmember and let it give you some more room. Even with that, it's a tight fit. 2 hours next time easy.

#3. Do this with the motor cold. It takes a while for these things to cool down.

[95LS400Bob]

Here's what the old mounts looked like. One engine mount was barely hanging together and came right apart. I could twist the other one apart if I wanted to. The trans mount was fully seperated.

[VBdenny]

Great post and photos. Thanks. I save that one.

[99lsguy]

Well done bob..........

It's in the books for me too!!!

[ebridges]

Thanks a BIG BUNCH for the tips. I've been "laying" under my 91LS for over an hour total, trying to "figure out" just what to do and how. The tranny mount was really pretty easy, and mine wasn't separated.

Got the motor mounts from Iron Toad for about $88 each, plus shipping. Just haven't figured out just how to do it, til your post.

Big Thanks :-)

Earl B

[95LS400Bob]

I should have done pictures but I was just feeling my way through the job. Glad this is helping.

[Jacob]

95LS400Bob,

Some web sites list two different mounts for LS400, a front and a rear one. This is confusing because you said the mounts were right and left (it makes sence because it's a rear wheel drive). Am I missing something?

Jacob

[ebridges]

Finished mine (91 LS, 104,000 miles) yesterday. Alas, the mounts didn't appear all that bad, but did have slight "slits" all around them. Glad they're changed. Still have a vibration at 75-80.

Back to the balancing shop. Last job was nearly 8,000 miles ago, and although the weights remained on - the second time, air pressure was about 5 - 7 lbs low. Think I found a shop which does on car balancing as well as tire truing.

There are two motor mounts, left and right. There is also a transmission mount on a smaller crossbar just below the gear shift. It's easy.

BOB, Thanks again for the write up. Gave me the "courage" to "just do it".

eb

[95LS400Bob]

95LS400Bob,

Some web sites list two different mounts for LS400, a front and a rear one. This is confusing because you said the mounts were right and left (it makes sence because it's a rear wheel drive). Am I missing something?

Jacob

It is a little confusing. They call the transmission mount the rear motor mount. And they call the front motor mounts.....well, they bolts on the side of the engine so we would just call them motor mounts. On the 95 the motor mounts are the same left and right. Not sure on the earliers but I assume they are also.

[Jacob]

Bob,

Thank you for the explanation.

[azmalu]

guys the explanation helped but park place has higher pricing on the one they referece as the transmission mount...

"Thanks for your email. I have received your request for pricing on the mounts.

Your price is $92.60 for each motor mount and $57.00 for the transmission mount, plus shipping, if applicable."

These are what I ordered as referenced in the thread.....Did the price just go up or am I missing something

Part number 12361-50100 Engine mounts $91.67 each ( I ordered 2 of these)

Part number 12371-50060 Trans mount $32.10 (I ordered one this)

Is the price listed at 57 just list hat part they are referencing a differnt part. This is for a 91 ls ....325k miles btw....

[mobilyte]

are the motor mounts just solid rubber or filled with fluid?

[blake918]

I just changed my motor mounts last weekend. It was a gigantic pain in the !Removed!, but the results are amazing. I always thought that my old ones didn't seem that bad. But, I was way off. It feels like a new car now. It starts and sounds differently with the new mounts. No vibrations or anything. Now, I don't care when the damn thing idles down to 400rpms at stop lights since I can't feel it any more. My car also used to thump when I'd floor it. I thought it was something related to a rubber mount because for some reason it just didn't feel like the tranny. The thump is also gone.

We used this thread as our guideline. Really the only deviation from what Bob did was that we didn't remove the oil filter. The passenger's side is a cake walk, and the driver's side is the difficult side. Also, 98-00 (might apply to 95-97) people watch how high you lift the engine. While installing the driver's side mount, the engine got lifted too high and snapped the right side port off of the plastic heater control valve like it wasn't even there. It was a $100 mistake.:chairshot:

As far as I know the mounts on my car were never changed, and I'm at 202k miles now. The drivers side was broken in two pieces, and the right side was not quite as bad, but it was torn in the same spot as the driver's side. The trans mount was changed a year or so ago.