Gearbox mounts

The gearbox mount on the Triton  five speed being used did not conveniently line up with the original Vogue mounting points in either of the factory places. It seems from the holes provided in the under body that the same mount bracket was used for the standard four speed manual  and the longer Overdrive or Automatic transmission. However Rootes very conveniently made the mounting points flat and parallel to the drive line centre. So after a little checking and measurement I created a drawing on a piece of old carton to see how the parts would fit together. Much easier than crawling under to check it every time I tried some other arrangement/

Some mental gymnastics was required as the right side is on the left and the left is on the right and the one in the middle got drafted :-)  Apologies to Peter, Paul and Mary for stealing a line from their song :-)

Dating myself there 

Also found that the measurements needed to be in the language used by the two vehicles. Rootes being imperial and the Mitsubishi being metric. It was to difficult to get it right with a translation each time. The holes in the Mitsubishi mount are 50mm apart but a measure makes you think it is 2" (Approximately 51mm)

The first mock up offered to the vehicle revealed an error in my first measurement that looked like the Mitsubishi mount holes line up with the rearmost Vogue ones when if fact I had to adjust the mount 15mm further forward to line it all up. Measure several times and cut once.

This picture shows the Vogue mount in the rearmost location which I have assumed suits the Overdrive or Automatic gearbox

This picture shows the Vogue mount in the position used for the four speed manual gearbox used in my car. The three front holes each side had clean threads while the two others used for the rear mount were a little clogged with underbody dirt and underseal. As the engine and gearbox had already been removed from the car when I purchased it.

Here we have the Triton mount attached to a coupe of test pieces to see how it all married up.

This was the point when I discovered that I needed it 15 mm further forward. Re-drilled the bits of lightweight Aussie shed bracket and tried again. The test brackets had holes drilled to attach to the car so I could see exactly what was going on while lying under the car thinking I am getting far to old for this. Also thinking I should invest in a hoist so I can just walk under. This also verified that I had the gearbox height correct with the Triton mount attached about 24 mm below the existing mount points

So next step was to translate all this knowledge into a couple of mounts that will hold it all in place and satisfy the vehicle certification people. 

They tried to reject the cross member under the Trimatic gearbox I put in an EH Holden I built a few years ago. That was until I politely pointed out that it came from the HQ model that donated the gearbox and Holden found it adequate for use on the same even when using a large V8  engine. 

Step one... actually a few after that. What we see here is a big bit that will bolt to the Vogue and a little bit that I will weld to the big bit to bolt the Triton gearbox cross member to. Simple enough even for a poor welder like myself. These parts were cut out of some  off cuts of 100 x 50 4 mm RHS, Looks very professional with the nicely curved shape

Some adjustment of the holes I drilled was required, I should have realised that the over sized slotted holes in the Vogue cross member suggested that the accuracy of the tapped inserts in the under body area was a little suspect. No problem I just filed the holes to suit, seeing as I am using five bolts each side to attach instead of the original three I am sure everything will be adequately strong.

A picture from under the car showing the clearance between the gearbox and the standard Vogue gearbox hump, tons of room here. The gearbox is mounted centrally to get the driveshaft in the centre of the tunnel, while the front of the engine is set about 40 mm to the left. In practice this is not noticeable but there was a fair bit of tension applied to the gearbox to get it to sit where I wanted it. I will adjust the front engine mounts to release this tension and prevent premature wear on the front engine mount rubbers. Getting the driveshaft central in the tailshaft tunnel was vital as there is very little space.

This was my final check that everything was correctly aligned before welding it all up

LHS in place, still need to ease the holes a little to have it sitting exactly where I want it

Triton piece attached to gearbox and mount holes tested for fit. 

Repeat of earlier picture rotated to see better how it fits together.

I have since made the RHS plate as well and some little 40 x 75 mm bottom pieces to bolt through and clamp up the Mitsubishi rubbers correctly on the crush tubes in the rubber mount.

The gearbox has a central rubber mount between the gearbox and the cross member as well as the rubbers on each end of the cross member so sound isolation from the drive train will probably be better than with  the Vogue's two rubbers under the gearbox.

Enjoy