The Lotus Cars Community banner
1 - 11 of 11 Posts

·
Registered
Joined
·
102 Posts
Discussion Starter · #1 ·
As I was looking around at things under the Elise today, I saw that my rear engine/transmission mount has a big tear in it on the upper side.

Automotive tire Tire Wheel Tread Motor vehicle


Looks like the tear isn't all the way through any of the major parts of the bushing, but how many miles could I drive with it like this before it gets serious? From a quick search, it sounds like this job takes quite a while.

I see the hole in the transmission bracket for this bolt is slotted. Is there any certain way to line things up to prevent this from happening in the future? Any certain orientation of this bushing?
 

·
Administrator
Joined
·
6,823 Posts
Replace now. It will affect your shifting. You might want to replace with stiffer aftermarket mounts for the front and back one. It will help shifting but you will feel more vibes.
 

·
Registered
Joined
·
81 Posts
Funny, I've just finished replacing mine ;)

My mount looked like yours, with a shear a the top. This is probably due to the acceleration movement. I've replaced it because I had trouble getting into the 2nd gear at high rpm, I need to test yet to see if it has improve something or not.

The rear mount was easy to replace, the front is more complicated. A also put the powerflex insert.

I was just disappointed to pay a lot of $$ for the OEM part, and get a part with scratches on it.... The scratches seems standard on the part, because we can see them on the part picture, lol. There is also aftermarket mounts.


but how many miles could I drive with it like this before it gets serious?
If you drive your lotus gently, it's ok but otherwise the engine mouvement will put stress on a lot of other parts.
 

·
Registered
Joined
·
111 Posts
Get the Innovative Black Shore 75A Mounts to stiffen up the Engine moment and increase the Shifting Feel.
For Normal Use only the front and back one, for a more sporty feel all 4.

When you drive with a damaged mount you risk to kill your intake and Exhaust system as they can not absorb that much movement and will crack.
Been there... done that .. ;)

DO NOT get the shore 85A ones as they will give you many vibrations to the Chassis. ( I have them)
They are far from normal unless you like the Racecar feel. but you loose a little of the Feel of the car movement and most passengers will find it annoying ;)

I can't even estimate who ever wants to drive with the Shore 95A mounts, that must feel like the engine is bolted to the frame directly without any damping.


Changing itself is an easy job that i did in my own garage, just switch only one mount at a time and support the engine (oilpan) so there is no pressure on the mounts.

The correct torque settings you can find here. And use some kind of loctite or vibratide:
 

·
Registered
2017 Evora 400
Joined
·
839 Posts
For a couple decades now, I have been pouring castable urethane that I buy at McMaster-Carr into motor mounts of my various high performance Toyotas. Not much work, much cheaper than replacing and very performance oriented. You take the old mounts off, seal one side well (plastic food wrap + duct tape,) set them in some sand sealed side down, pour in the urethane, come back tomorrow, put them back on. They will "wear in" within a few hundred miles and stop transmitting all the vibration that they do at first, yet still provide excellent support for the drivetrain.
 

·
He's on fire!
Joined
·
3,430 Posts
The rear being worn out is probably over-stressing the front mount. Is it 'do not drive until fixed urgent'? The answer is no. Engine mounts are rubber, and rubber wears out and/or degrades over time. Unless you're hitting a track I'd recommend replacing OEM, or something similar to OEM. Anything harder will put vibrations in the cabin that you'll definitely hear.

Harder mounts or inserts for the OEM ones do represent some shifting and performance improvements at the cost of increased cabin noise.
 

·
Registered
Joined
·
102 Posts
Discussion Starter · #7 ·
I was just disappointed to pay a lot of $$ for the OEM part, and get a part with scratches on it.... The scratches seems standard on the part, because we can see them on the part picture, lol. There is also aftermarket mounts.
Ah, you buy the whole thing with the bushings pressed in already. That answers some of my questions. It also makes the job much easier.

Unfortunately, I can't replace it now. I don't have the part, at the very least. I will minimize my driving (especially spirited) till I get it in. I think I'll stick with the OEM mounts. Shifting feel hasn't been an issue for me, and the fewer vibes I feel, the fewer everything else feels too.

I guess I was looking at an Evora thread regarding the difficulty of the job. Oops. This does look very simple. One of my initial questions still remains. That bracket on the transmission is slotted. Does it matter where in the slot the bolt sits? I'm gonna have a jack under the transmission, so I'll be able to move it up and down a bit.


The correct torque settings you can find here. And use some kind of loctite or vibratide:
Is there any reason to not use the torques specified by Lotus? Here's a page from the service manual that shows different torques than those listed in that forum post. The post seems outdated (he says there are no torque specs in the service manual).
White Font Parallel Auto part Art


Also, for anyone just curious & perusing, here are a couple images showing the mount position:

Automotive tire Motor vehicle Hood Automotive exhaust Automotive exterior


Automotive tire Motor vehicle Automotive design Rim Automotive fuel system
 

·
Registered
Joined
·
81 Posts
That bracket on the transmission is slotted. Does it matter where in the slot the bolt sits? I'm gonna have a jack under the transmission, so I'll be able to move it up and down a bit.
I didn't have to use a jack to lift the transmission, I've just put the bolt in his "natural" position. I've also read that somewhere in this forum:

I have just the rear mount from BOE. I talked to them about it and they recommended that I loosen all the bolts around the mount and start the engine, letting it idle for a little bit so that the mount can "settle". Also, they told me to rev the engine a few times and then fasten all the bolts.
Ah, you buy the whole thing with the bushings pressed in already.
Yes exactly.

Is there any reason to not use the torques specified by Lotus?
Euh, no. I didn't find it... nice.

For a couple decades now, I have been pouring castable urethane that I buy at McMaster-Carr into motor mounts of my various high performance Toyotas.
I will definitively try that!
 

·
Registered
Joined
·
111 Posts
Is there any reason to not use the torques specified by Lotus? Here's a page from the service manual that shows different torques than those listed in that forum post. The post seems outdated (he says there are no torque specs in the service manual).
Your Specs are NM mine are ft.-lb. should be nearly the same :)
 

·
Registered
Joined
·
102 Posts
Discussion Starter · #11 ·
My rear mount looked the same. I got these inserts from GRP to fill in the voids, haven't gotten the car buttoned up yet but hopeful for improvements. Powerflex Engine Mount Inserts for Elise & Exige
Oh nice! I might just get those to tide me over if I can't find a US vendor for the mount.


Your Specs are NM mine are ft.-lb. should be nearly the same :)
They're pretty different though. The big bolt through the center of the bushing is 80 Nm = 59 ft-lb, whereas that post says 69 ft-lb. If you're going to the hassle of torqueing something to a certain spec, it might as well be the right number. Otherwise just crank down on the thing and call it good. Will it really matter? Who knows.
 
1 - 11 of 11 Posts
Top