Strengthening ford ST220 gearbox

[andygtt]

I run a Noble which believe it or not run a mondeo box, due to running a mildly breathed on mondeo V6 as std

My car is quite heavily modified and running 530ftlb (575hp at the wheels) and its going to increase... all this is going through the Mondeo box albeit with gearbox cooling steel bearings shot peaned and polished and quaife lsd.

Trouble is whilst I havent yet broken my box, 5th gear is a weak point and does break eventually... I want to pre-empt this and resolve prior to failure... seems the splines that hold the gear to the shaft are too fine.

Looked into a complete replacement and cant find anything suitable for road,... there are around 5-10 of us running similar power looking to fix same potential issue.

so am wondering if anyone has any suggestions, will cryo freezing them help/solve and issue?

[one eyed mick]

Cannot Hewland supply or Quaife ?

[andygtt]

quaife dont do one strong enough and hewland is dog box I believe

Want something I can comfortably use on the road

[one eyed mick]

Porsche G 50 ?

[Podie]

I believe the 6 speed box is stronger.

Seem to recall the only difference on the Ford and Noble applications was the use of metal (rather than plastic) selector forks..?

IIRC, shot peening is believed to be an option.

[andygtt]

cheers for the responses

I have a couple of porsche G50 boxs (actually getrags from the GT2 and GT3 but they are G50 internals) but these are for my other project and cant be fit in the noble as engine is wrong way around
No i wont consider turning the engine lol

The ST220 box is a 6 speed, I used to have the 5 speeder and upgraded at great expense as the 6 speeder is stronger.

The box is shot peaned and polished.... Im getting worried there are no possible options to upgrade to take the power more reliably.

[stevieturbo]

andygtt said:

I run a Noble which believe it or not run a mondeo box, due to running a mildly breathed on mondeo V6 as std

My car is quite heavily modified and running 530ftlb (575hp at the wheels) and its going to increase... all this is going through the Mondeo box albeit with gearbox cooling steel bearings shot peaned and polished and quaife lsd.

Trouble is whilst I havent yet broken my box, 5th gear is a weak point and does break eventually... I want to pre-empt this and resolve prior to failure... seems the splines that hold the gear to the shaft are too fine.

Looked into a complete replacement and cant find anything suitable for road,... there are around 5-10 of us running similar power looking to fix same potential issue.

so am wondering if anyone has any suggestions, will cryo freezing them help/solve and issue?

the splines on the gear itself, or the actual shaft it fits onto ?

If this is the only known weak area, shouldnt be too hard to have a stronger single gear made and matching shaft. Or cry treating could help.

The fact nobody has broken one yet ? is surely a good sign.

[andygtt]

its the splines on the shaft itself that the gear then goes on... they have failed and its always 5th that goes, spins on the shaft due to torque strain over time.

its not common as it requires a lot of torque and not a huge number have the levels required... but it is failng on cars with 100ftlb less than mine and im going up so its a matter of time.

I have 2 spare box's but thats not the point, I want a box that copes not a box thats cheap to replace when it fails if that makes sense.

I thought remaking the shaft with beefed up splines would be easy... but it seems not to be the case and every avenue seems to be drawing a blank.

Might get a spare box cryo treated and see if that then lasts, i just know nothing about the process and its real world application.

[Podie]

What are Adrian and Phil running?

[stevieturbo]

What is the issue about getting a stronger shaft made ?

It isnt necessarily bigger splines you need, just a shaft made of stronger material with the same splines.

Is nowhere in the UK willing to make it or what ?

Try contact DJM Motorsport, they can do that sort of stuff.

[stevieturbo]

Is the box based on the MTX75 ?

[Podie]

stevieturbo said:

Is the box based on the MTX75 ?

MMT6

[HustleRussell]

Surely it'd be cheaper to just accept the 'box might fail every 40k miles and simply repair it with original parts as/when, and fit a new clutch kit at the same interval while you're in there? it seems that you will be spending a significant amount to fix a problem which might occur tomorrow or 50k miles down the line...

[chuntington101]

HustleRussell said:

Surely it'd be cheaper to just accept the 'box might fail every 40k miles and simply repair it with original parts as/when, and fit a new clutch kit at the same interval while you're in there? it seems that you will be spending a significant amount to fix a problem which might occur tomorrow or 50k miles down the line...

I think thats andy's point. He dosen't want the uncertinty of how long the box may or may not last. Also andy's current setup is massively limited by the gearbox and wanting to keep it in one piece.

[Podie]

Worth speaking to Mountune / Revolve?

[andygtt]

Adrian and Phil run the same box with same mods... whilst they run similar torque neither do anything like the mileage that I or some of my friends do and Like Adrian mine is used hard.

expected mileage before it fails seems to be between 2000-10000... at a min of 1k a rebuild Im not prepared to accept this.... also I dont want to be pampering the car, I use it hard, very hard and expect it to cope or re-engineer it till it does.

Im not sure why remaking the shaft is an issue, just everyone thats been asked has initially said maybe then looked into it and come back and said no.... its an ongoing search though.

[davepoth]

andygtt said:

The ST220 box is a 6 speed, I used to have the 5 speeder and upgraded at great expense as the 6 speeder is stronger.

Googling around a bit, and especially looking at Ford Contour (Mondeo) forums in the US, it looks like their preferred option is a beefed up MTX75.

[stevieturbo]

andygtt said:

Adrian and Phil run the same box with same mods... whilst they run similar torque neither do anything like the mileage that I or some of my friends do and Like Adrian mine is used hard.

expected mileage before it fails seems to be between 2000-10000... at a min of 1k a rebuild Im not prepared to accept this.... also I dont want to be pampering the car, I use it hard, very hard and expect it to cope or re-engineer it till it does.

Im not sure why remaking the shaft is an issue, just everyone thats been asked has initially said maybe then looked into it and come back and said no.... its an ongoing search though.

Have you tried DJM ?

http://www.djm-motorsport.co.uk/

Or maybe SQS in Czech

http://www.sqsracing.com/

[Kitchski]

What does the newer Focus RS run? I know it's a Volvo engine, but it might run a Ford gearbox with a adapted bellhousing which could be exchanged for a Ford-pattern one.

[Podie]

Kitchski said:

What does the newer Focus RS run? I know it's a Volvo engine, but it might run a Ford gearbox with a adapted bellhousing which could be exchanged for a Ford-pattern one.

Volvo based engine - they are quite different.