MJ_RST

We constantly get asked about our 5 speed MTX75 gearbox conversions on the ST170. This time we thought we would do a write up with various pictures highlighting the differences and issues faced.





The vehicle in question is a 2004 ST170. These come with a 6 Speed Getrag gearbox and Dual Mass Flywheel (DMF). Being a 2.0 Zetec there is no real reason to have a DMF, and we suspect this was Ford's way of capping performance to create a market for the 'ST' badge when compared to the 'RS'.

The regular 2.0 Zetec runs a much better ratio gearbox, the very strong MTX75. Along with a solid flywheel. So even from the Ford parts bin, you dont have to spend a fortune replacing the original ST170 DMF & Clutch.

First we removed the ST170 Gearbox, Clutch and Flywheel











Next we compared the 2.0 Solid Flywheel to the ST170 DMF. Showing the difference in depth. We also took note of the difference in flywheel bolt size, the bolt on the left is 2.0 zetec, the bolt on the right is ST170 DMF.

The 2.0 Solid Flywheel bolts straight to the ST170 engine with clearance to the crank sensor as expected. Use the original 2.0 zetec solid flywheel bolts. Again, the 2.0 zetec clutch must be used due to different input shaft size on the MTX75. The original 2.0 or ST170 clutch bolts can be used.

















Next we took the MTX75 and Getrag and sat them together to show the size difference and mount differences




















As you can see from the pictures, the MTX75 is actually much bigger despite being 5 Speed. The gearbox mounts are completely unique to the gearbox so you require the MTX75 mount when carrying out this conversion






The MTX75 will bolt up using the same bolts as removed from the Getrag. Using the MTX75 gearbox mount the gearbox will bolt back up the the vehicle as before. You will notice the powersteering pipes will be very tight around the back of the gearbox, due to the MTX75's additional depth. Routing the pipes diagonally over the back of the box gives enough clearance.














Next its on to the driveshafts. We compared the size difference between the ST170 shafts and 2.0 zetec. They are completely different both in length and spline size gearbox end. The hub end is the same, but as shown in the picture, the ST170 tripod bearing is larger than the 2.0 zetec so will not fit in the tripod housing. (Note: A 2.0 Zetec Tripod bearing will fit in an ST170 Tripod Housing)

So for this conversion the MTX75 driveshafts must be used. We also noted the centre bearing carrier is in a different position. So you also need to fit an MTX75 long driveshaft centre bearing carried in order to fit the o/s driveshaft.








Two final points you will find in this conversion is the difference in reverse light switches, both in location and length. The ST170 is longer and has a triangular plug. The MTX75 is shorter and this particular one doesnt have a triangular plug. We will be offering an adaptor kit for this shortly.


The 2nd point is the speedo pick up, again located in different places, but use the same sensor and plug, so its a direct plug and play. The only difference is the sensor location on the MTX75 is right next to the ST170 exhaust. Its down to your own discretion if you fit a small heatshield to it.

The Underdog

good post. what is the weight of a 2.0 etec flywheel do you know ,thanks.

MJ_RST

I havent weighed it. Will do next time its out. Will be getting an uprated clutch shortly

wombat76

thanks.. plus 1, what's your feeling on how it pulls now with the std 4.06 diff.. i think that conversion with 16'' wheels and 45 tyres would help my track days.. will

saph in dorset

other than cost, is there any other benefit of this conversion over just fitting a light weight single mass flywheel and clutch to the ST170 keeping the standard gearbox.

car will be used mainly as a track car, so would most likely get a lightened flywheel for the MTX75 conversion anyway (which would increase the cost).

also surely if the MTX75 is bigger it must be heavier. any idea on the extra weight?

PaulinhoT

Interesting post, thanks

Glenn_

iTrader: (1)

Surely the 6 speed bix is gonna be the better box.


I wonder how many mk1 focus rs have a 6 spped box now.

wombat76

In reply Getrag is a good gearbox company, they make many great boxes for exotics.. USA Ford used this box as a way of giving decent mpg on the freeways. it is semi close ratio and is lighter and smaller than the MTX75..NO ONE NEEDS A ROAD CAR WITH A RATIO THAT WILL DO 75 IN SECOND at max rpm.. the diff ratio is mad afaik ,its 3.28 and Changes depending on which gear you are selecting while the mtx is 4.06 . and no changes in any other gear.. the only other UK supplied cars that use the 285 are the Cooper S and Audi TT.. Personally i thought it would be strong but evidence to the contrary is all over the NET, Ford in the RS used mtx 75 with a Quaife slip diff, and it has way more torque than any ST, plus read all the bloggs etc on these pages about some high powered 300 brake modified fords using this box..whats often forgotten when diss is applied to st170's is that if you can steer and have the cars handling really sorted there are very few similar cars that will stay in touch on the bendy stuff and even less with a proper ratio'd gearbox.. just my view.. i have rallied, raced, hill climbed and built quite a few yokes in my 35 years of having a competition license , i have lightened my 2002 model by over 100 kg and totally rebuilt the brakes and suspension.. it makes me smile when i hit a good road & would go as far as saying its now one of the best handling FWD cars that i have ever driven..period..

red sport

hi see the conversion went well do you think its possible to use the flywheel to replace dmf

wombat76

THE std 16v 2.0 FLYWHEEL Will bolt up to the st motor using the 2.016v f/w bolts, however the splines in the getrag box are different to the ones that the mtx uses..if you could get someone to put the st centre clutch plate splines in a std 16v clutch[ENGINEERING JOB] or purchase a sprung clutch from one of the suppliers who make conversion smf flywheels for st 170's .. PERSONALLY i would do a bit of research with one of these st smf suppliers before i would go down this route unless you happen to be very skilled .. it has been done..i think the main issue is getting a suitable clutch plate. it must be sprung old school type .. and don't forget after 6/ 2002 the size of the clutch went to 240 from 230..

wombat76

mentioned here is the cable change which is necessary for either an IB5 OR MTX box change, as someone who is at present stripping a donor vehicle for this manoeuvre , getting gear cables out of a focus is no job for an innocent.. i found i had to remove the complete dash, then the steel crash bar strut that runs from A pillar to opposite side,one hidden bolt in the right os door jam.. then the heater and blower assembly ,disconnect all air con pipes at the inner bulkhead!! heater pipes, and a bolt on the bulkhead engine side which is almost hidden and that secures the heater at midpoint and that's after doing all the screws and nuts on the inside, just to access these cable bracket bolts with 10mm heads which are under the heater [now removed], that secure the cables to the floor.. before they exit to the engine bay, then to remove these cables you drop the exhaust, the heatshield and wiggle them through to inside the car.. access in my case helped with carpets and seats removed .. and then do the same on the st 170.. so not a job for anyone who's fainthearted and i would leave refitting the heater etc until you prove that the cables are correct and working perfectly..

Br1tishwarcry

I currently have a mk1 focus 1.6 zetec and am seriously contemplating an st170 conversion. ( car has an immaculate shell) i know one of the issues with the conversion is swapping over all the mechanisms for the 6 speed box, but in reality could i not just do this. st170 engine in a 1.6 zetec with a 2.0 gearbox? theoretically that would still work on the 5 speed manual mechanisms within my 1.6?

wombat76

NO that WON'T WORK, you could however i think keep your existing transmission and hook it up to the st motor.. the other issues you will have and afaik they are hard to solve is the ecu in your car won't work with the st requirements.. you could look at using a stand alone ECU which could be wired in and piggy back it to your ECU again complicated imv.. not for the faint hearted , even the experienced will pull hair out on that one, again just my view..

big_wasa

St won't bolt up to the late 1.6 as its a zetec SE.

wombat76

afaik the op said his was a mk1 focus which will have a IB5 BOX According to info widely available.. there are many instances of guys fitting this st 170 zetec unit in fiesta and escorts with this exact trans and all this knowledge again currently available on various forums..I don't claim to be Focus expert in any way,Golfs 1's and 2's . mk2 and mk1 Escorts yeah. these i know .but i run a st170 , have stripped it down and rebuilt it, as mentioned i am in the middle of a total tear down on an early 1.8.. with the purpose of trying to mate the st with an IB5.. so am i wrong guys..

big_wasa

The op said he had a 1.6. This is a zetec SE not a zetec e like your 1.8.
The St170 is a tuned zetec E that shares the bell housing pattern with most pre zetec ford engines like the xflow/endura/ cvh ect that had the Bc and Ib5 box, they bolt on with a little bit of work to the sump. The mk1 1.8 focus will be a zetec E with the lower duty ib5 so the St will bolt straight to the Ib5 you have n your car, you can use the sump, clutch flywheel, the whole lot.

The all alloy engines found in the focus and puma ect is the latter zetec SE.
This is a totally differant engine and does not share the bell housing pattern but they still had there own version of the Ib5 and mtx75 gearbox For the bigger engines like the duratec.

I've played with the odd zetec/ St / SE and have posted up the ecu pin outs for any one working on a conversion although my work is aimed more at the kitcar build than a transplant as it doesn't take into count the car side of the conversion.

big_wasa

I am half way through a Stripped out turbocharged st170 but the bloody thing is rusting away faster than I can pull it to bits

wombat76

Yo, last year I rebuilt the wheel boxes around rear wheels where they join the inner floor pan and right down to where the trailing arms locate so i know what you mean, thankfully i had a good friend who builds high dollar mk2 escorts ,he sorted it, the holes , then i finished her off.. had Ford spent a few quid more and sealed and rustproofed them and put decent arch protection not the sodding nylon based cloth yokes that were fitted none of the above would have happened.. don't give up as with many low production number fords 20 years down the road these will be worth dough.. and thx for the info, i think i'll go with an MTX... have you a link to your ecu pin outs?? please.. WILL

big_wasa

Most of them are a work in progress.

Focus rs is the current project and I've not posted the pin outs yet.

St170's are so cheap at the moment I will just buy another but I have been gazumped twice in the last 10 days.


St170

http://www.locostbuilders.co.uk/view...php?tid=190440

1.6 zetec SE

http://www.locostbuilders.co.uk/view...php?tid=199233

Silver/ Blacktop zetec E

http://www.locostbuilders.co.uk/view...php?tid=179921

mattxr3i

Excellent conversion. Always thought that the 6spd box was partly responsible for the poor performance. Gear ratios and the DMF blunting what should be a fairly good performance car. How does it feel after the conversion, much more keen to rev I bet

wombat76

Big WASA, Perhaps a silly question but one that came up just the other day, with the amount of knowledge you have amassed while sorting ecu's etc for 7 type installs is there a way to remove or disable the pats in a ST 170.. frankly i don't need or want it, i was going to try and sort out a button start system and for RAC type events the steering lock has to be removed or disabled from memory.. it would certainly make things easier if it can be gone..

big_wasa

No you won't disable the pats, well not with any software that I've come across. This is why most nicked cars are taken with the nicked keys. they also add a steel cage around the ecu plug and ignition barrel.


You could mount the rdif chip into somthing with the aerial around it then just use a toggle switch and start button.

pyle

Sorry to upload an old thread but I see the bolt pattern on the mounting point is different, does it require any cutting or welding? Any performance difference?

Rowe

No.......... if you're fitting the mtx box, then you need an mtx mount.

pyle

Can a mix and match be done with the gears and shafts?

Rowe

'Next its on to the driveshafts. We compared the size difference between the ST170 shafts and 2.0 zetec. They are completely different both in length and spline size gearbox end. The hub end is the same, but as shown in the picture, the ST170 tripod bearing is larger than the 2.0 zetec so will not fit in the tripod housing. (Note: A 2.0 Zetec Tripod bearing will fit in an ST170 Tripod Housing)

So for this conversion the MTX75 driveshafts must be used. We also noted the centre bearing carrier is in a different position. So you also need to fit an MTX75 long driveshaft centre bearing carried in order to fit the o/s driveshaft.'

^^^ i'm guessing from the part in red, that no they cannot.

pyle

No no, I mean the shafts inside the gearbox, so as to swap say 1-2 gears and so on.

Rowe

Doubtful. It's a completely different gearbox

pyle

Did you make the electrical bits work and what is the difference in performance?

McGoo 69

whats the way to fix the speedo issue?

I want to do this conversion as i know of a rs2000 gearbox with a quaife diff i can use.

what advantages does the escort rs2000 gearbox have over a stock zetec mtx75

thanks

mattxr3i

Escort box will be rod shift and cable clutch so if fitting into a Focus you will have to overcome these.

You could just take the diff out and put it into a Focus MTX box but I have a feeling that normal Focus boxes, the gear ratios are really long...

Mickyy31

I am currently carrying out this conversion but finding that no gears are engaging with the engine. there is no problem with the gearbox or the selector as far as i can tell, and im using a brand new clutch. I've taken it apart, checked over all parts and cant seem to work out what the problem is. Any help would be appreciated?

Rowe

assuming the cables are connected correctly, does the selector clung into place if you move it by hand?
the dowel may of sheared on the selection fork inside the box - it's a common issue.

Mickyy31

thanks for the reply. the cables are connected correctly, but i haven't removed the selector to check the fork. when the box is out and put into gear by hand the gears are selected as i can feel the resistance on the gearbox shaft when turning it by hand. would this not tell me that the selector is in good working order?

Rowe

if its selecting by hand then the issue must be either the cables or the shifter assembly inside the car.
Did you fit the MTX shifter assembly?

Mickyy31

yes, I have fitted the mtx75 selector cables and shifter assembly and they appear to be selecting gears without any issue. I have checked them multiple times and they seem to be okay so struggling to understand what is wrong.

Rowe

there must be an issue with the shifter mechanism inside the car or the cables.
There's no other thing it can be if it engages gear by moving the selector on the box by hand is there.

pyle

How did you manage to get the speedo sorted, what gear selection mechanism is required? The MTX one or just the stock Getrag one?