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Discussion Starter #1
I think it may be time to do my first motor mount R&R. DCM has 158k on it. Im getting a subtle jostling motion on the passenger side when I brake. Replaced pads rebuilt calipers rebuilt suspension including new upper control arms. I had this issue on my previous B-Body and threw all sorts of parts at it, come to find out motor mount was bad on the passenger side. I was told by the previous owner, the passenger side mount was replaced before, best way to confirm? I could find a good spot to perform a pry bar test.

I have replaced motor mounts on my Lexus IS300..........it was a PITA.

Im mentally preparing to start this, read many prior posts. Questions, for the replacement mounts, you are replacing the entire clam shell? I I have to get the motor high enough to slide out and slide in new? What is the bolt size for the bolt that goes through the motor mount? I know its 15mm for the mount bolts connected to the frame.

What are using to lift your motor?
What mounts are you using, I want to use rubber, not poly.
 

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I think it may be time to do my first motor mount R&R. DCM has 158k on it. Im getting a subtle jostling motion on the passenger side when I brake. Replaced pads rebuilt calipers rebuilt suspension including new upper control arms.

You might want to check and make sure the shims did not fall out that were used to align the front end. The control arm moves quite a bit if they do fall out.


Mike--94MSP9C1
 

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^^^, this and start car, put in gear with foot on brake (have a helper do this) and give it some gas...does the DS of engine lift up more than a 1/2" (like holly F it raises) than your MM are done

But check the A arm shims first as noted

If MM are being replaced the rivets of the clam shell need to be drilled out to separate. The new MM is the rubber or poly insert (I used ES black ones) that goes in-between the now 2 piece calm shell. Small bolts come with the new mounts to go where the rivets were. I did mine when engine was out and 2 people (one from above and one under the car) really helped. With motor in car you will need to jack the engine up some after removing the one long bolt (5/8" IIRC). It won't be a fun job
 

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I replaced MM's a while ago when the Engine was out and even then it was a PITA to get the Bolts off the Frame. The nuts they use inside the Frame aren't welded in place. I think I sacrificed an old wrench to get inside the frame as I needed for the job.

It's worth mentioning on the Upper Control Arms and the Shims....you ALWAYS want to replace the Nuts that secure the Upper CA Shaft to the Frame. These will lose their holding power after just 1 or 2 uses and should be replaced to prevent backing out and losing your shims.
 

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You might want to check and make sure the shims did not fall out that were used to align the front end. The control arm moves quite a bit if they do fall out.


Mike--94MSP9C1

This x100. BTDT. Our mounts just don't go bad like modern vertical fluid filled mounts.
 

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Discussion Starter #6
Thanks guys, I will check the A arm again, the jostling was happening before and after I R&R both A- Arms along with other suspension parts. The car is all original as the owner had mentioned to me and I see it as it had the original wires and plugs which I replaced a few weeks back.


I heard the task is easier if you remove the LCA. I may replace the LCA's and while Im at it R&R the mounts.
 

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Removing the lower control arms gives you access to the bolts/nuts on the backside of the frame. I replaced my bushings in the lower arms while I had them out. To be truthful, I did the uppers too, while I was at it. Be careful that you do not pinch anything between the engine, and cowl. Removing the lower arms, and replacing the mounts is easier than trying to just replace the mounts. Remember to spread the frame mounts before you try to reinstall the arms, or you will fight with them for hours. Two people will make it a lot easier. The nuts for the mounts are prevailing torque nuts, like the ones for the upper A arms (smaller). Use new ones every time you have to remove them.

I put urethane in my old clamshells. They gave me a couple of HD tiewraps, because the holes must be available for the bolts. I had to use a vice to get the urethane parts in. There is a right side up to the inserts. The instructions said I could cut the tiewraps off once they were installed...BS the car will rust away around them before I remove them. The urethane ones are a lot less compliant than the stock mounts. They are as close to solid without being solid that you can get. In my case the 454 makes the whole car shake a little, but it is like having a massage chair that can get you from point a to b instead of sitting, and watching TV.
 

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I work on these cars everyday for people and from experience, I would
never replace the motor mounts w/o pulling the motor first.
I also doubt your mounts need replacing however.

Nab
 

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Lol, I must be the only one who thinks motor mounts on these cars aren't that big of a deal. I know it seemed pretty daunting when I was first preparing for it, but it really wasn't all that bad. It's pretty basic nuts and bolts work, just requires prep, patience, the right tools and some time. You will need to raise the engine slightly, first to take the load off the mounts to get the crossbolts out (one goes in from the rear, the other from the front, I assume that's important, so pay attention to how they come out) and then raise it a little more to get access to the nuts on top.


You will absolutely need a well stocked socket set with a wide assortment of extensions, and probably a wobble adapter, but every bolt can be removed and reinstalled with the motor in the car. You will get dirty, you will cuss a lot, your hands will hurt when you're done, but it can be done. The biggest tip I can offer is to get yourself a flexible magnet, I got that tip from someone else on here, it makes reinstalling the bolts a lot easier. Still a pain in the butt though, but it does help a lot. Stick the bolt on the end of the magnet and fish it up into the hole. And when you inevitably knock the bolt off and it falls down into the crossmember, you can use the same magnet to retrieve the bolt.


I think this was the one I used, my local O'reilly's had one in stock. The light is useless though, that'll break or die in the first 5 minutes. And it is stiff enough to hold the shape that you need to get the bolt to where you need it, you'll probably have to keep pulling it out and adjust it to get the angles right, but it will work. I only wish the magnet was a little stronger. If someone knows of a version of this tool with a rare earth magnet in it, I'd be interested in getting one.



https://www.amazon.com/Performance-Tool-W25934-Mechanical-Retriever/dp/B01KHLKVSW


Other than that, just put it all back together the way it came apart. And there are a bunch of bolt holes on the front of the motor, but I had a bunch of stuff apart because I was doing other work at the same time, but I'm pretty sure I still had my throttle body and water pump on the car when I did it. I might have pictures somewhere, I'll have to check on that. If you're a regular mechanic you could probably do this in an afternoon, if you're more of a driveway mechanic it's probably a full day job if you've got everything lined up, but I'd probably allow a weekend to be safe if you need to drive it right away.
 

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Discussion Starter #10
I feel better. I will see if I want to take a stab at it. Maybe this week, I saw another vid where they recommended an extra long flex head wrench, along with using some rtv on the sockets to hold them in place as you fish the bolts back in.
 

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I know I took a picture when I did it, I'll see if I can find it, but I know there are unused threaded holes in the front of the motor. If I didn't upload it on one of my own threads, it'll be on my old phone which is at home, but I'll find it and post it here at some point.
 

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This isn't the pic I was thinking of, but looking at it I think I may have had the water pump off when I did it. I'm pretty sure I did it when I did the torqhead install. I'm positive I took a pic while I had the chain attached though, so I'll keep looking. I distinctly remember running a tap into some rusty, unused holes though before I put a chain on it.


Edit - Actually, looking at that again, I think I used a couple of the lower holes in the block. The chain came up alongside the timing cover and alongside the throttle body. Although I have the water pump off right now, I bet you could snake the chain up between the water pump and timing cover without hurting anything.
 

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I think I used these two holes.


Edit - But I will still find the pic of the chain attached to confirm that. Just won't be right this minute, probably later tonight. I don't remember the thread size though, I'm leaning towards standard but don't take my word for it, this was two years ago after all.


Edit - You'd also probably need to remove the tensioner to gain access to the hole on the passenger side, but that's easy. Pretty sure the driver side is easy to access, especially if you've already removed the air pump.
 

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where are your lift points that use have used to lift the engine?
I had a pic somewhere here but cant find it. Just use any of the Bolt holes on the front of the Block/heads. I think I just used 2 of the Water Pump holes, just slip the bolt thru the Chain of your hoist and thread it into the Block. Put a couple of washer on there if the chain too large and allows the bolt head to slide thru. But really any bolt holes will work...you got lots of places to use. 0:)
 

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Found the pics, those were the holes I used. I agree though, there are other options. And I still wouldn't be surprised if you could use mine with the water pump still on. There are some bolt holes on the ends of the heads, but I wasn't too keen on lifting by the heads. I'm not that familiar with this sort of thing and didn't know if it was kosher or not. Someone else could likely elaborate on that. It would simplify the lifting, and to be fair you're probably not exerting more than a 100lbs or so at each side, but like I said, I'm not an expert and I didn't want to break my motor. Not that it would have ultimately mattered, shortly after these photos and everything was back together, I blew a head gasket due to a weird electrical gremlin that caused the electric water pump I put in to not run. So, your mileage may vary.
 

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It just occurred to me that you might want to unbolt the trans mount at the trans crossmember too. I know I did, but that was because I was doing a lot of stuff at once. I also put a new mount in there, the same energy suspension black graphite that I used for the motor mounts. I don't know that they list anything specifically for our cars, but it's a pretty generic mount. Only thing you need to know is whether you need the 1 hole or 2 hole version, but I think the one I bought had provisions for both.


And as long as you're doing motor mounts, you may as well do that one too, it's inexpensive. I may have disconnected the exhaust at the ball and socket also, but that was because I was fixing and modifying a lot of stuff all at once. But I do remember that my limiting factor at that point was the firewall, I was able to lift the engine until it started running into that. Had plenty of room to work on the motor mounts at that point. It's just the bolts underneath that everyone dreads.


Edit - if you're interested, this is the correct one.


https://www.amazon.com/Energy-Suspension-3-1108G-Transmission-Mount/dp/B000CN956K
 

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When I was replacing the trans mount, the local parts stores referenced the wrong part, and it could not be installed, because it was too tall. It has the stud on it like the original. DO NOT buy it, it will not fit.

Make sure the installed height is the same as factory, even if you need to put shims under the trans.
 

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IMHO, if running poly motor mounts use a rubber (stock) tranny mount

Often there are 1-2 shims between tranny mount & trans, keep them and use with new tranny mount to maintain DL angle
 
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