GregHoon's Engine Mount thread

[GregHoon]

A while back i managed to shread the rear chassis where it joined the engine mount. This was due to corrosion in part and also all the abnormal stresses a mk2 engine places on a MK1 shell.

Key:
Black: Problem/Event to be dealt with
Blue: Solution
Red: Points to consider/Note
White: Johnny G is a batty boy
1) This managed to break my near side inner c.v. joint. This needed replacing completely of course.

These can be purchased from places such as 'parts in a box' new.

2) Where the rear engine mount attached to the chassis was welded in a stronger way by a welder local to stretford and trafford and i would definitely use him again. You get a quality job but it isn't cheap.

PM me if you need anyone for welding in this manchester area.

3) At JAE Ooohmatron and Podge (good guys the both of them) helped me with the noise coming from the engine. A definite knocking. They pointed out when driving (with engine lid removed) that there was excessive movement of the engine in the bay.

I purchased Polybushes to go in the mounts as that was what we expected required replacing.
Can be piurchased here: http://www.larkspeed.com/index.pl?c=...LEX&s=category

Note: Frong engine mount bushes for a mk2 mr2 turbo come in three sizes.
73mm diameter
79mm diameter
83.5mm diameter

This may well be in line with engine revisions, re1, rev2, rev3 However you should remove the engine mount and measure it. As for example my engine is rev 1 but i have a 79mm diameter, front engine bush.

I also believe Podge makes them but i bought mine before i knew that information.

4) Few weeks later, still BEFORE the polybushes were to be fitted.The gearstick was moving sideways when accelerating and deccelerating at normal road speeds. Suspected here: movement of the engine latteraly.

On closer inspection we (me and snowtigger) found that the front engine mount brackets were not held in with any bolts into the gearbox as they should have been. They has sheared out when the engine dropped taking the thread with them. The offside engine mount although still conected to the chassis, and bracket to the engine, have seperated as the bolts have sheared clean off.

The offside bolts need replacing completely. The front engine mount bolt holes need to be re-tapped (hopefully in-situ) and larger bolts fitted in to them.

Summary.

Just wanted to show a progression of knock-on effects that one event has had and point out how they were overcome step by step should anyone else have this happen. Will get pics up to show at the end of the weekend.

This thread by Paul Woods contains information about reinforcing the front engine mount where it meets the chassis:

http://forums.twobrutal.com/showthread.php?t=8000

[Jiff Lemon]

You may want to consider heli-coiling the gearbox bolts instead of re-tapping them.

[Gary Symons]

You may want to consider heli-coiling the gearbox bolts instead of re-tapping them.

Thats exactly what I had to do. Proper PITA doing it in situ, had to borrow an angle drive drill.

[snowtigger]

I think if we go down the helicoil route which is a threaded insert they will need drilling out then the helicoil putting in which with the space constraints between gearbox and bulkhead is not much, I think it's an idea to look into if it makes it stronger?

The other thing we may need is the drivers side engine alloy bush/bracket as we need to remove it to see the damage that's been done to it and find if we need some new studs and nuts?

The other thing is if we drop the engine slightly with my engine crane it may be an Easyer job.

[GregHoon]

Cheers guys. What did you end up doing Gary? Just in situ and work on it? Did you have to remove the clutch bracket?

[Gary Symons]

Cheers guys. What did you end up doing Gary? Just in situ and work on it? Did you have to remove the clutch bracket?

I had 1 thread that had tore out so I drilled it out and fitted a helicoil.

As for the bracket I cant honestly remember, but woud imagine that the bracket would get in the way.

[GregHoon]

Cheers Gary, i'd kiss you but you are so far away....... And a bloke

[BSM]

Get yourself some time serts they are much better than helicoils and will hold a lot more power than a thin bit of wire.

wurth site

[GregHoon]

Cheer Si! :)

[Jim-SR]

personally i think its worthwhile using steel inserts in all of the gearbox threads as soon as you do the swap. aluminium isnt supposed to have bolts threaded directly into it, its inherently weak.

and the torque mounts ripping away from the chassis isnt just a mk1.5 issue. it happens to stock AW11's as well, there have been quite a few reported cases on the US MR2OC forum. with either heavily worn stock side mounts, or stiffer poly engine side mounts it exaggerates the problems. its probably an area to reinforce on the chassis before even fitting the engine (front and rear mounts) to save from future problems.