Unbreakable Engine mounts - A step by step guide

As we all know, GQ and GU patrols have a habit of breaking engine mounts, especially the passenger side as it is the one subject to the lifting force from the engine torque when the loud pedal is pressed :) here is how to solve the problem once and for all!!

I have made a few sets of these now and i have changed the design a little each time until i finally ended up with one i'm happy with. So here's what to do.

WHAT YOU NEED
- 1 Rear lower control arm from a toyota surf / 4runner 1989 - 1996 (don't forget to get the two mounting bolts as well)
- 2 pieces of 6mm x 100mm steel plate cut to a length of 130mm
- 2 pieces of 6mm x 50mm steel plate cut to 400mm
- 1 can of black spray paint

I think the steel and can of paint cost me somewhere around $25 and i got the control arm from a mate but i would assume something like $20 or $30 from a wrecker so makes for a pretty cheap mod really

ok, lets get to it!

a quick shot of why we're doing this, broken is no good!!

Attachment 62067 Attachment 62068 Attachment 62069

Step 1

we start by taking the lower control arm and mark 15mm in from the lower part of the bush housing - do this at both ends

Attachment 62070 Attachment 62071

use a thin cutoff wheel in the grinder to cut the bush ends off, i sat it loosly in the top of the vice and rotated the arm while holding the grinder still which gave me a nice square edge
then you'll be left with this

Attachment 62072

Step 2

use a sharp blade to cut whats left of the rubber off the existing engine mounts as we need the plate that bolts to the chassis, i used a sharp kitchen knife but i thing a decent stanly knife is the go, you can throw away the top parts of the mount as the bottom plate is all we need

Attachment 62073 Attachment 62074 Attachment 62075

cut the top and bottom off level and clean any remaining rubber off the base plates, i used one of these paint stripping disc's which work well but fly apart fairly quickly

Attachment 62076 Attachment 62077 Attachment 62078

then you should be left with these

Attachment 62079

Step 3

clean up the cut on the bush housing and give it a bit of a "vee" to make it easier to weld, center it on one of the base plates making sure the holes in the bush line up straight with the bolt holes in the plate

Attachment 62081 Attachment 62080

tac it on one side and check that it's level, tac the other side and check, check and triple check everything is where you want it. Grab the welding gun again and zap it on

Attachment 62082 Attachment 62083 Attachment 62084

give i a hit with the wire brush and blast with some black paint, i prefer to paint it while it's hot as it seems to bake on there pretty good, hang it up to dry and hit it with a few more coats as needed

Attachment 62085 Attachment 62086 Attachment 62087

Step 4

now make another just like the other

Attachment 62092 Attachment 62093

i found that the heat didn't transfer enough to harm the bush and because these bushes were in pretty good nick i'm not even going to bother to change them

Step 5

Take the 6x100mm plate and mark out the holes, i just use the bracket off the engine

Attachment 62141 Attachment 62142 Attachment 62143

as the holes are the same for both the driver and passenger side i just lined them up in the vise and drilled them together, pre drilling with a 3mm bit and eventually getting the hole to 14mm as that's what size they are in the factory bracket. I used a step drill last because the drill bit set only went up to 13 and also with the step drill it leaves a nice chamfer on the edge of the hole, no burrs

Attachment 62144 Attachment 62147 Attachment 62148

now take one of these plates and mark out the cutout to allow access to the oil feed hole most guys use when they turbo the TD42
mark it out 17mm down form the top of the plate and 37mm to the left of the top rear hole
Pre drill with a 3mm bit then run through it with a 35mm hole saw - remember slow speed and cutting lubricant here

Attachment 62102 Attachment 62103 Attachment 62104

mark out the edges and cut them back with a cut off disc, round them all off on a bench grinder and give them a buzz back with a flapper disc

Attachment 62105

take the second plate and mark it out for clearance for the bracket for the injector pump. measure 10mm down from the top of the plate and 15mm in from both top hole centers, cut it out with the grinder, i used a 3 quarters worn cut off disc to make it easy, curve off the corners on the bench grinder and give them a buzz with the flapper disc to clean it all up

Attachment 62106 Attachment 62107 Attachment 62108

you should be left with two plates that look something like this..

Attachment 62109

The next step is to bolt the passenger side plate onto the engine, then bolt the pre mount bush onto the chassis

Attachment 62111 Attachment 62110

use some cardboard to make a template of the joining piece, i used the lid of the paint can to draw the curve at the end :)
line it up to the bottom of the plate on the engine to give as much clearance to the oil feed port

Attachment 62112 Attachment 62113

Transfer the template onto the 6x50mm steel and cut them out, drill the hole out to 16mm for the bolt, give it all a bit of a clean up with the flapper disc and vee in the ends for welding

Attachment 62114

bolt them into place and get them sitting where you want and tac them on

Attachment 62115 Attachment 62116 Attachment 62117

whip it back out and weld it up firm

Attachment 62118 Attachment 62119

a hit with the wire brush and a few coats of paint

Attachment 62121 Attachment 62120 Attachment 62122

when the paint is dry all that is needed is to bolt them in :)

Attachment 62124 Attachment 62123 Attachment 62125

For the other side, as they say, wash, rinse, repeat

bolt the plate and the bush on

Attachment 62127 Attachment 62126

cardboard templates, transfer it to the 6x50mm and cut them out

Attachment 62130 Attachment 62129 Attachment 62128

tac them, weld them up, add a bit of paint and bolt them in

Attachment 62132 Attachment 62133 Attachment 62131

Awesome write up!!!

And just like that there will be no more broken engine mounts, these suit a TD42 diesel engine but the same principle can be used for all the others, we used the same sort of thing to convert a RB30 GQ to a TD42 without having to cut or weld the chassis, the only difference is the plates on the engine were longer and took up all six holes in the block because the mounts on the chassis were further back.

i used the Toyota surf rear arms for a few different reasons, the first being they were available to me for free so...
the bush has a lot more rubber in it than the patrol rear arm so it absorbs the vibrations better using the patrol rear bush the engine vibrations can be felt through the car a lot more than the factory mount but using the toyota surf bush there is very little difference over the standard mounts

here's a photo of the difference between the patrol rear arm bush and toyota rear arm bush

Attachment 62134

i just did one side at a time that way i could jack up the engine with some wood and keep it at the right height to make the mounts

Quote:

---

Originally Posted by Rocket55

Awesome write up!!!

---

thanks mate
i thought it might be useful to some people to save a bit of hassle while planning them out

very in depth write up mate with loads of pics. just how I like it. thanks for the post

Very good write-up and good comparison re the vibration differences. I've read that the similar commercially available ones transmit quite a bit of vibration.

Tongue in cheek, but I'm a little surprised that a N/A 4.2 is breaking engine mounts just with the "loud pedal" :)

Quote:

---

Originally Posted by jff45

Very good write-up and good comparison re the vibration differences. I've read that the similar commercially available ones transmit quite a bit of vibration.

Tongue in cheek, but I'm a little surprised that a N/A 4.2 is breaking engine mounts just with the "loud pedal" :)

---

haha if the baby little RB30 can break them they don't stand a chance with the TD and it's 91 Kw of pure fury :)

Great write up.. and a great little project

Here is a couple of quick snaps of the one's we made to convert an RB30 to a TD42 without having to cut or weld to the chassis

Passenger side and Drivers side

Attachment 62164 Attachment 62165