Monaro Gearbox

[sheepdip]

Hi Folks

I have a Monaro gearbox that I have had as a spare just gathering dust in the workshop for years. It was from an 04 car with 30 to 40k miles only but does not have a bell housing. Are they sort after and if so what sort of value does it have. I would love to swap it for a box that has lower 5 and 6th ratios!

[SturdyHSV]

sheepdip said:

Hi Folks

I have a Monaro gearbox that I have had as a spare just gathering dust in the workshop for years. It was from an 04 car with 30 to 40k miles only but does not have a bell housing. Are they sort after and if so what sort of value does it have. I would love to swap it for a box that has lower 5 and 6th ratios!

A few weeks ago I'd have probably had that off you but picked one up from a friend!

They're easily worth £1,500, probably more to be honest, they are sought after.

[stevieturbo]

you could try

https://www.facebook.com/groups/1375847329333903

https://www.facebook.com/groups/840158013062664/

Or if you were keeping it, just buying and swapping 5/6 to whatever ratio set you want could be an option

Value is a difficult one. I can see where £1500 is reasonable for a good box.

But deeper in my mind, a Magnum whilst a bit over double the price, is a stronger and better box and would be brand new. But there are people who do search for used boxes ok.

[SturdyHSV]

stevieturbo said:

But deeper in my mind, a Magnum whilst a bit over double the price, is a stronger and better box and would be brand new. But there are people who do search for used boxes ok.

Do you have any first hand experience of the T56 magnums that allegedly fit the GTO (and thus Monaro), and whether they do in fact fit...?

I've heard various things about possibly needing a different yoke on the propshaft because of a different spline count, or possibly just a slightly different length that can be achieved by milling down the end of the yoke, it seems difficult to get a straight answer out of 'murca with their idea of 'bolt on' parts...

[bonesxu1]

I have a stage 4 T56 Magnum that I bought from Tick performance in the states and it came with a Strange yoke that was welded up to my prop when the box was fitted. They used the T56 Magnum and GTO rear end so that it would fit my Ute which will be the same as the Monaro. Tremec started making ready to go bolt in box which is the called the Magnum F

[stevieturbo]

SturdyHSV said:

Do you have any first hand experience of the T56 magnums that allegedly fit the GTO (and thus Monaro), and whether they do in fact fit...?

I've heard various things about possibly needing a different yoke on the propshaft because of a different spline count, or possibly just a slightly different length that can be achieved by milling down the end of the yoke, it seems difficult to get a straight answer out of 'murca with their idea of 'bolt on' parts...

Obviously the Magnum has a bigger output shaft, so yes will require a different yoke.

I have an early Magnum with the tail end swapped as that was all that was available because the OE Magnum F was not available at that time.

Front end is also a little different, but the OE bellhousing would be ok I'd think. I had a steel quicktime which required some grinding to suit the front plate.

[Lincsls1]

SturdyHSV said:

Do you have any first hand experience of the T56 magnums that allegedly fit the GTO (and thus Monaro), and whether they do in fact fit...?

I've heard various things about possibly needing a different yoke on the propshaft because of a different spline count, or possibly just a slightly different length that can be achieved by milling down the end of the yoke, it seems difficult to get a straight answer out of 'murca with their idea of 'bolt on' parts...

The answer I got when enquiring sometime ago from AmericanPowerTrain.

"Tremec designed the TUET16363 to bolt right into the F-body’s and GTO cars, but be stronger. They used the same tail housing that the OEM cars had in them to correct the shifter location. Because of this you should have zero issues installing it directly into your car unless you have a remote shifter. In the event that you do you would just need to unbolt it from your stock housing and bolt it onto the new transmission.

The only difference that we have seen is the rear output shaft is the stronger 31 spline versus the 27-28 spline your factory transmission has. Because of this difference you will need a new Tremec 1330 series 31 spline slip yoke and a 1330 x3R crossover u-joint to fasten it to your driveshaft."

[bonesxu1]

Standard bell housing does fit the T56 Magnum. My particular Tick performance box was rated at something like 900lb ft rear wheel torque, I can't remember now but more than I'll ever need.

[sheepdip]

stevieturbo said:

you could try

https://www.facebook.com/groups/1375847329333903

https://www.facebook.com/groups/840158013062664/

Or if you were keeping it, just buying and swapping 5/6 to whatever ratio set you want could be an option

Value is a difficult one. I can see where £1500 is reasonable for a good box.

But deeper in my mind, a Magnum whilst a bit over double the price, is a stronger and better box and would be brand new. But there are people who do search for used boxes ok.

Is it possible to change the 5 and 6 ratios if so what is involved, what ratios and what cost?

[SturdyHSV]

sheepdip said:

Is it possible to change the 5 and 6 ratios if so what is involved, what ratios and what cost?

5th gear from the Aston Vanquish is a slightly longer ratio, which maybe one or two people have swapped on to give a higher top speed (as 6th tends to be too long for top speed runs anywhere sensible) but otherwise I'm not aware of any gear options off the shelf.

It'd be fairly labour intensive which is where the cost will be, not a lot of people rebuild gearboxes :/

[stevieturbo]

sheepdip said:

Is it possible to change the 5 and 6 ratios if so what is involved, what ratios and what cost?

Pretty sure you can do it ok.

Would it really be cost effective ? probably not. Especially with the crap dollar rate at the minute. Plus parts are getting harder to come by for the old T56.
I looked at a couple of sites that sell parts and don't see an selling the main laygear for 5/6, although some of the other parts are available.

[vxr2010]

better just doing the diff then all gears become more useable , plus mpg does not appear much effected

[sheepdip]

vxr2010 said:

better just doing the diff then all gears become more useable , plus mpg does not appear much effected

I am actually using the Monaro engine and box in a Escort MK2 with a Supra Turbo plated diff. Unfortunately I can not find a ratio high enough to not use 5th on track, which feels like hitting a brick wall dropping from 1 to 1 to 1 to .75 hence the need to change to sensible 5 and 6th ratios not the stupid over driven ratios of the standard Monaro (UK) box.

[SturdyHSV]

sheepdip said:

I am actually using the Monaro engine and box in a Escort MK2 with a Supra Turbo plated diff. Unfortunately I can not find a ratio high enough to not use 5th on track, which feels like hitting a brick wall dropping from 1 to 1 to 1 to .75 hence the need to change to sensible 5 and 6th ratios not the stupid over driven ratios of the standard Monaro (UK) box.

The VXR Monaros (with the 6.0) had a 0.84 5th gear, so it's much less of a drop

This was the 'M12' gearbox, instead of the 'MM6'. There are the 'TUET' part numbers around somewhere. If you could pick up a later box you'd likely have better ratios. I believe first was also shorter with the LS2s, someone did post the ratios up but I can't find their post.

[Lincsls1]

MM6 - TUET2100 2.66 1.78 1.30 1.0 0.74 0.50

M12 - TUET2066 2.97 2.07 1.43 1.0 0.84 0.56

Get an M12 box from a 6.0 VXR breaker.

[stevieturbo]

sheepdip said:

I am actually using the Monaro engine and box in a Escort MK2 with a Supra Turbo plated diff. Unfortunately I can not find a ratio high enough to not use 5th on track, which feels like hitting a brick wall dropping from 1 to 1 to 1 to .75 hence the need to change to sensible 5 and 6th ratios not the stupid over driven ratios of the standard Monaro (UK) box.

Are you saying you want numerically higher, ie taller to prevent you using 5th ?

Or numerically lower, ie shorter to bring 5th into play ?

Often a solution is more power...more power solves everything

[sheepdip]

stevieturbo said:

Are you saying you want numerically higher, ie taller to prevent you using 5th ?

Or numerically lower, ie shorter to bring 5th into play ?

Often a solution is more power...more power solves everything

At the moment diff is something like 3.6 and 1st is redundant! 3.3 would allow the use of 1st off the line and a max speed for most circuits/hillclimbs in 4th hence not having to use 5th as it too big a jump from 4 to 5th. I cannot find this ratio as only built for special race spec supras. Hence the option of a closer ratio box to allow the use of 5th. Until I get this gearing right I have keep to standardish power approx 400bhp. The future should see a cam change at least.

[stevieturbo]

must be very small diameter tyres ?

I've switched between 3.27 and 3.55 on mine, and a variety of 16-18" tyres.

1st is generally taller than I would like, it'll do around 60 in first, but for sensible speeds in 4th and 5th I sort of need the 3.27, although it drives nicer with the shorter 3.55

I also have a 3.73, but as much as it'd make 1st nicer, it'd leave the top end useless.

I guess changing to a different rear end would be a major hassle ? as opposed to the box itself. If you picked the right one, it would give you a good range of ratio change options.

[sheepdip]

As its an escort I run 15 inch wheels with the widest tyres possible.
One option is to change the rear end to say a jag irs with plated diff or go back to a live axle using a ford 8.8 - note Atlas as not up to the job I believe. All extra fabrication work!
On a side note I did lower the ratio on my CV8 to the 3.7 and it made it a much better car.

[stevieturbo]

sheepdip said:

As its an escort I run 15 inch wheels with the widest tyres possible.
One option is to change the rear end to say a jag irs with plated diff or go back to a live axle using a ford 8.8 - note Atlas as not up to the job I believe. All extra fabrication work!
On a side note I did lower the ratio on my CV8 to the 3.7 and it made it a much better car.

Although I highly doubt it would need an 8.8 in such a light and moderate power car, the 8.8 IRS would be an option. Older Mustang Cobras and now I believe the more modern Mustangs use a version of it too.
The cobra was an alloy housing, the newer car iron I believe. I think they call the newer one a super 8.8 ? Not versed up on exactly what is different though.

Or there are quite a number of modern powerful BMW's that would be well supported in diff options that I think would offer low numerical ratios.

But a live axle 8.8 could be an option....I use one in mine. But all rose jointed etc etc...I do f'ing hate it. I wish I'd done an IRS of some sort, but options were much fewer back then. With so many very powerful standard cars these days, there are just lots more IRS setups about.