Modifying bellhousings on FWD gearboxes?

[wagonist]

There's been a lot of effort put in by various people making different gearboxes fit onto an engine in RWD applications.

Make an adaptor plate & space out the flywheel, or thicker throwout bearing are the norm.
Rather easy when the tailshaft can be shortened to suit.

But I'm looking at a situation for a FWD/AWD box.
Space (ie width) is a premium (most FWD engine/box combos just fit between the chassis rails), and offseting the box will change the length of at least the front shafts (one needs to be lengthened, while the other is shortened. Plus if its an AWD box, the tailshaft position is now offset as well.

So are there any ideas on how this could be solved?
The only thing I can think of is to cut and shut the 2 bellhousings together, probably by welding. And this would need to be done well as often the engine mounts are on the boxes bellhousing.

eg, I was looking at how to fit a GT4 E series box onto an Aurion 2GR-FE V6 on the weekend.

[50RTD]

G'day Steve,

My thoughts would be mount the gearbox and shafts into the vehicle in their natural position and taking a few measurements of the remaining space between the gearbox and drivers side chassis rail to get an idea how close the 2GR will sit to the chassis rail and the furniture that lives around there like ABS, power steering etc.
This should give a reasonable indication how much extra space you will have to sandwich an adaptor plate between the E box and the 2GR, as an adaptor plate (no doubt a custom made one in this instance) will add around 10-12mm to the overall width of the engine/gearbox combo which could make all the difference in the clearances.


The idea would be to try and keep the GT4 box in as close as original position as possible otherwise, as you mentioned, it will introduce all sorts of headaches with tailshaft angles and modifying driveshafts, let alone the headaches of re-mounting the box.

Terry's readings on the Road & Track website suggest that only the passenger side short shaft can be shortened on the E-series boxes, otherwise a custom/hybrid shaft/s will be required, unless something from the Toyota catalogue may just work, thinks V6 Camry shafts, MR2 shafts etc etc.

As far as cutting and shutting the 2 bellhousings are involved, it would have to be some heavy duty welding as, like you say, the gearbox supports the engine weight as well as the box.

Good luck with it!

[wagonist]

I did just remember that the 1MZ is shorter than the 3S, so maybe it's the same for the 2GR.

The 2GR seems better to fit against the GT4 gearbox (ie seems less metal off the block to remove).

[50RTD]

Here are a few pics from a mate of mine's Mazda, mating an E58 GZE MR2 box to his Mazda BPT.

He made a template out of cardboard and had an engineering mob cut the adapter from 12mm plate.

With any luck the 2GR will be shorter (you'd almost expect so being a V config) and you can go about it with an adaptor, rather than cutting up and re-welding an alloy bellhousing.

Cheers

-Dan

[the_random_hero]

http://www.toymods.net/forums/showthread.php?t=43884

I'm assuming the GT4 boxes are pretty similar to just a FWD box.

[50RTD]

Yeah very similar, E153 FWD up the top, E151 GT4 down the bottom.

[TurboRA28]

When making these adapter plates how do you ensure that you have centered the box correctly and that you are not putting unnecessary stress on the input shaft?

[wagonist]

The other thing I'm concerned about is getting the angle between the box & the engine correct, which effects where the bolt holes go on a adaptor plate.

eg I've noticed that the 1MZ/3MZ has a lot more lean than a 2GR, which meant that the transfer case statted interfering with the bottom of the block on the 2GR vs part way up the block.
And this could cause issues for bonnet clearance etc on a FWD

[AL510]

When making these adapter plates how do you ensure that you have centered the box correctly and that you are not putting unnecessary stress on the input shaft?

once you have made your adapter you can bolt it and the bell housing to your engine.Then assuming the bellhousing has a round spiggot for the gearbox you can mount a dial indicator to the crank and turn the motor over by hand and this will tell you if it is centred or not.you can then use the dial on the back face and this will tell you if all is square.to correct any offset you can open up the bolt holes appropriatly then bolt down again till it is centred again then drill oversized dowles.this would be an easy way to allign a bellhousing that is having a new flange welded on. Just cut off the old flange fabricate a new one to suit the new engine, bolt it all up, centre it as described above then tack in place.You would then have to machine both faces flat.
I believe this dialling in of bellhousing is good practice any way as a line bored engine can move the main journals. The tremec website i read some where recomends no more than 0.005" runout for the tko 600.

Cheers, Al.

[jesiotrot]

Here's a few more pics from mating the same 4AGZE box as above to a 2 litre Mazda 626 FE3 engine. A friend of mine made this one, to get it centred perfectly, he machine up a thick tube of steel, that bolts into the mains of a stripped block, the other end has a machined out centre so it slides over the sleeve that the clutch release bearing sits on. He could then rotate the box to find the best place for it to sit, then made a rough template with a piece of board. It was then drawn up on Autocad, laser cut from 12mm plate, and the holes plotted and drilled on a jig borer.

[oldcorollas]

A friend of mine made this one, to get it centred perfectly, he machine up a thick tube of steel, that bolts into the mains of a stripped block, the other end has a machined out centre so it slides over the sleeve that the clutch release bearing sits on. He could then rotate the box to find the best place for it to sit, then made a rough template with a piece of board.

great idea (from your friend )

[Tim Waldock]

hi, new here from Perth and I am here to get the solution else will purchase new, I am following your idea but could you please explain more "sit to the chassis rail and the furniture that lives around there like ABS"???