Kirk’s Urethane Motor Mounts

In reality this is not difficult, other than undoing bolts, and doing them back up again. The problem with undoing is rust, wear and stiffness, the problem with installing is getting everything back into line.

Jason (Muffdan), Russ (UKtotty) and I did two cars in a leisurely day. Mine took nearly 2 hours, Russ’ was done in 45 minutes! Jason and I then did his car the following week, and it took just about 90 minutes. We can also confirm no differences post or pre 03.

The basic tools for fitting the mounts are 14mm & 17mm sockets (preferably 6 sided) and a torque wrench, though it might help to have same sized (ratchet) spanners, extenders, medium size ratchet as well as a bigger one, all to make the job that little bit easier. You will also need to lift the back of the car up, ramps, jacks, axle stands, take your pick – BUT BE SAFE.

The mounts come in pairs, each very different. You will easily see which is for which once you get the mount off the car.

The two mounts in question can be reached down the middle line of the car, which definitely needs to be jacked to give working room. Make sure you put in axle stands because you may well be applying lots of force to the car. First task is to take off the two back “nappies”. 10mm socket and Phillips screwdriver should be sufficient.

We did the operation on one mount at a time to at least ensure one side of the engine / gearbox remained in its proper position. What would happen if you took both mounts off at the same time, not sure?

The first job on each mount is to take the centre bolt out with 17mm tools. This is done up tight so the torque wrench or a breaker bar could be very useful. With the nut off the bolt should slide out or unscrew fairly easily. Here is a picture of the mount nearest to the front of the car. The large 17mm nut is highlighted as are 2 of the 3 x 14mm bolts.

Please excuse the excess tubing which you might not have, oil feed for turbo and wires to the oil gauges!

You then have to take the mount off the chassis member. 3 bolts in the case of the front one, 4 in the case of the rear. Here is a view of the front one. The centre bolt is already out, and 1 of the 4 mounting bolts is partially undone..

Here is a different view. Note this is the mount that you can put a jack on to lift the car. Also please note from the photographs that there are other nuts and rubber thingies around. These DO NOT have to be undone.

Once your chosen mount is off you can come out from under the car and study the pattern of the existing rubber insert.

Firstly it’s a good idea to give the original rubbers a brush up to release any dirt that may have accumulated. All you then have to do is match the appropriate Kirkosaurus and push it on. Note that there is only one way they can all go, so look at the designs carefully. We noticed on Jason’s rear mount there was a little “nib” on one side of the OEM rubber mount which seemed to stop the Kirk’s mount going fully in. We took this off with a Stanley knife, and afterwards all OK.

Once both sides are in, it is a good idea to squash them together with a vice or “workmate”, so the rubbers were level with the centre bolt sleeve. We also added a smear of washing up liquid to the outer faces so movement within the holding bracket becomes easier when re-fitting.

As they say in all good manuals, installation is the reverse of dismantling. It makes sense to put the centre bolt in to keep everything square, but this can get in the way of the chassis mounting bolts installation.

Again on Jason’s we noticed that one of the chassis mounting bolts on the rear bracket was longer than the others, probably as a result of his engine “takeouts”. This proved very useful. Alignment of the bracket was being a bit difficult. With I a bit persuading we managed to align the bracket with one hole and screw in the longer bolt (the shorter ones would not have reached). We then did this one up and used it to pull the bracket towards the chassis member and align the other bolt holes.

Sorry, don’t know the bolt size (or length), but happy to add it here if somebody can oblige.

The chassis bolts seem to have no particular torque, but the centre bolt nuts are done to 93 NM. The bolts themselves are done to 78 NM on the front one and 89 NM on the rear. Why different – don’t know.

Be prepared for a much better gear change and take-off, but a glass vibrating resonance especially at a cold tick-over or a high gear pull away. We are told it gets better!

<ADDENDUM 2/2/2009 >

I’m afraid I couldn’t cope with the vibration. After much thought it was decided that most of the vibration was not because the mounts were too stiff, but because the new inserts were transmitting resonance back into the vehicle. If you look at the last photograph you will see the flat face of the mount is very close to, if not slightly proud of the centre tube / ring. Having taken the mounts off the car we actually saw the indentation of the metal arm of the mount in the inserts.

So we cut off about 2-3 mms off that face with a hacksaw. Putting the inserts back in they definitely fell back below the metal ring.

Did that on all 4 inserts, put them back on the car, and bingo!!!! Vibration, resonance, noise all gone. I suggest this is a mod to the insert you should thnk about before you even fit them.

There is a thought that the insert might now move a bit, and I suppose could start touching the arm again, with the resonance coming back. If it does the thought is to clamp them together with nut/bolt. I’ll post here if I ever have to go down that route.

This documentation in no way replaces the Toyota MR2 Repair Manuals. The purpose of this content is only to provide supplementary information to fellow MR2 enthusiasts. Midship Runabout and its contributing authors will not be held responsible for any injury or damages that may occur as the result of practicing any of the methods or procedures described within this website. Article and photo submissions are property of the contributing author.

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