Nobility help!! - Standard 5 Speed Gearbox - Specs

[leadboot]

Blown diff has probably taken the gearbox with it on my GTO-3.

I will be getting a Quaife ATB LSD but would be very grateful to know if the original gearbox is modified in any way from the off the shelf Ford MTX-75 gearbox.

Thanks in advance to any expert's help.

[mgbond]

leadboot said:

Blown diff has probably taken the gearbox with it on my GTO-3.

I will be getting a Quaife ATB LSD but would be very grateful to know if the original gearbox is modified in any way from the off the shelf Ford MTX-75 gearbox.

Thanks in advance to any expert's help.

No its standard but if I were you I would get it shot peened by "the gearbox man". I wish plans had mentioned this to me as an option when I had to have a new box when my diff went.

Bondy

[leadboot]

Thanks Bondy

I run a standard power engine. A strengthened gearbox from Plans costs and extra £800. I know that the open diffs don't survive but I thought the gearbox was reliable enough?

Do the standard 5 speed gearboxes tend to break when the engine is left at standard 352 BHP?

[F.C.]

leadboot said:

Thanks Bondy

I run a standard power engine. A strengthened gearbox from Plans costs and extra £800. I know that the open diffs don't survive but I thought the gearbox was reliable enough?

Do the standard 5 speed gearboxes tend to break when the engine is left at standard 352 BHP?

Go to the gearboxman direct then, your only paying Plans a premium for handling, all the g/box work is done at CTS in Herts. should save you a fair amount.
Then your g/box would be bullet proof at standard power and would also survive any power upgrades you throw at it.
Some people are running 500 bhb + with a CTS modded g/box! and even if you do go mad you can always map the torque curve around the g/box via the ECU.
F.C.

[NobleGuy]

leadboot said:

Do the standard 5 speed gearboxes tend to break when the engine is left at standard 352 BHP?

No. If you don't plan to mod then I wouldn't bother to be honest.
Had a chat about the MTX-75 with a garage bod and he mentioned that they are pretty sound.
I've only heard about the 6-speed breaking.

[Biggriff]

My mods will take the car to over 500bhp and we are not intending to change the box at the moment. My race engineers seem happy with the current box and will either map around delivering too much torque in the lower gears or rely on my adjustable right foot for mechanical sympathy.

[alex s]

Biggriff said:

My mods will take the car to over 500bhp and we are not intending to change the box at the moment. My race engineers seem happy with the current box and will either map around delivering too much torque in the lower gears or rely on my adjustable right foot for mechanical sympathy.

On the six speed, 5th is the weak link....

[saucyboy]

Sorry for the late reply as I have just seen this one.

I had a 5 spd box with an open diff up until last year. I stripped 5th gear. I was only running a standard lump and to be honest it was very underpowered at the time due to a CAT failure. If I was you, I would get it strengthed or go for the 6 speed as I did.

James

[leadboot]

I've had to make a decision in the meantime so have gone for Quaife LSD and standard 5 speed. I believe it was the failure of the original open diff that damaged the gearbox.

The balance of opinion is that the 6 speed has its own weaknesses and its a major cost and faff to change the linkage. I was really happy with the change on my 5 speed (honda-like IMO) so hope it comes back the same.

Thanks to all for your advice

[NobleGuy]

saucyboy said:

I had a 5 spd box with an open diff up until last year. I stripped 5th gear.

Bugger. That's my theory gone .

[saucyboy]

Tell me about it mate. I didn't expect the box to blow either, especially at only 70 mph with a very slight throttle input. I always thought the diff would blow.

Oh well, every cloud has a silver lining. I managed to fall on my feet and made a very useful contact with Matt at BRUNTERS. I got a new 6 spd, LSD, new clutch and M400 linkage for a very very reasonable price. Top bloke and top job. The gear change is now fantastic and finding the correct gear in a rush is never a struggle!

James

[Mike Tuckwood]

I'm expecting my gearbox to give way at some point based on likely power (torque actually) that we'll see through it.
We've already discussed custom uprated gear sets with a our gearbox specialists.

As we get to that point (unless somebody gets there first and wants a solution earlier) we'll have some custom strengthened gearsets made. We will need to order a minimum quantity to get them made, but most likely there will be people needing them in the future anyway so we don't mind.


Mike