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Old 3rd August 2011, 23:28   #23
Robson Rover Repair
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ZT-T 190 / 75 Diesel x3 / 6 door limo / 216 Cabby / Rover 25 van

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Default CHAPTER 14 - Transmissions

TRANSMISSION VARIANTS

Transmissions on all front wheel drive models (all bar V8 models) were either the Getrag 283 5-speed manual, supplied from the company's new facility in Bari, Italy, or the JATCO 5-speed automatic unit - one of the first transverse engine deployments made with this feature.

Add clutch prices for range. Flywheel info

Automatic gear box notes

ECU's / Faulty fuse

Most gearbox ECU faults can be cleared by taking fuse 4 out of the engine fusebox, and leaving the gearbox disconnected for a few hours, then reinserting the fuse. This will revert the ECU back to default settings and often cures silly problems.

The ECU in the front passenger footwell, and sometimes this can die for age, wear or water damage if you are unfortunate. Easy to replace, but possibly expensive depending on your source.

Additionally there are numerous sensors, both outside and inside the gearbox itself, any of which can cause the ECU to malfunction. My experience of the Auto box was the ECU will default to 4th gear for drive in a limp home mode.

All faults are logged in the ECU, so a proper garage can download the fault codes and find what has gone wrong. Again this will cost you maybe £30 on computer diagnostics machine.

"Petrol smell" after test drive

This usually means very bad news. You check the car with no signs of a fuel leak then, I would suggest you will most likely find there was some gearbox fluid on top of the box which looks like it has been dripping onto the exhaust system.

What happens is the torque converter cracks and the fliuid leaks into the reverse gear so the car just sits there and refuses to move eventually.

A torque converter new is huge money (circa £1500) and because of this the auto boxes command good value in scrap yards and so on as if the torque converter dies completely it will usually scrap the box. Something to be very wary off when purchasing an automatic car.

This is not a "common fault" as such, but as the cars get older is becoming more and more frequent, especially on neglected cars with poor service history.

Gearbox selector failure

There is a cable link from the gear selector to the gearbox, should you be unable to select any gears this may be disturbed and is not a expensive fix.

Additionally, more common, the inhibitor switch on top of the gearbox, which tells the ECU what gear has been selcted. This is a muliti position switch, with contacts which may be dirty or broken. This is also fed from a fuse in the glovebox area which may have gone and should be checked first before any further investigations.

Jumping out of gear

Typicially suffers in 3rd changing to 4th gear and then pops back to 3rd gear. Low fluid level (needs checking when hot and with engine running) are again a common fault for this or if the car has been standing unused for a while.

EG, on a dealer's forecourt, and the valves get a bit sticky. Likely to be cured by some hard driving, up and down the box with good use of kickdown.

Servicing - very important

MGR service shedules indicate autobox transmission oils should be changed every 4yrs/60K miles. The box is a "sealed for life unit" and this can create its own unique costs. Should someone service the gearbox NEVER have the car idling whilst changing the gearbox oil.

The one and ONLY fluid for the Jatco box is Texaco N402/ATF402. Part No. VYK00040 from Xpart or LNR402 from Land Rover. Xpart price is £20.70 / 5 Litre (+VAT) and the change will require about 4.5 litres. It is impossible to drain all 6-6.5 litres due to the nature of the unit and design.

Manual gearbox notes

MG ZT 190 gearbox

It should be noted that final gearing (eg manual 5th gear) in the MG ZT 190 is different to the rest of the range to allow for a higher top speed, thus the gear box is unique to them and commands a premium in the second hand market compared to the other V6 gearboxes.

Topping up fluids

The clutch system is "sealed for life" a part of the BMW design the car, however its an an extremely awkward place, up behind the dash above the clutch pedal. The brake fluid reservoir is also there.

Often this has caused premature failure of clutches due to wear on the plate for it not being fully engaged or disengaged when changing gear.

You can actually bleed the system following this advice. http://www.the75andztclub.co.uk/foru...leeding+clutch

Clutch and Flywheel replacement

This is where it gets scary again (but nothing compared to the price of a ten year old VW golf diesel for example!) and often why the cars are scrapped. Should you be changing your clutch on a high mile car (90,000 miles and onwards is the average failure rate, but this depends on the cars life, I had 130kout of my first clutch on my first ZT V6), then changing your dual mass flywheel is advised to save you future costs.

The dual mass flywheel was fitted to our cars to prevent engine vibration (so say modern car designers) and there isnt a single mass conversion for our cars like other manufactures sadly which would reduce costs significantly.

A complete kit for the cars costs roughly below as a complete kit (including slave cylinder and master cylinder), plus six hours of labour from a decent mechanic.

1.8 Petrol / 1.8 Turbo Petrol / 2.0 v6 Petrol / 2.5 v6 Petrol / 2.0 Diesel- £250 ish for a complete clutch kit, and usually £300 ish for the flywheel.

Note there are three clutch types, one for the 1.8 none turbo, one for the 2.0 diesel, and another that covers the entire V6 range.

Last edited by Robson Rover Repair; 2nd September 2011 at 05:28..
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