Frequently Asked Questions

Should I drive it? You must always remember that the gearbox bearings hold the gears together, when they break up the gears break. If the transmission noise is getting worse as you drive it is time to call a breakdown service, it will save you money in the long run

Will you road test it and tell me what is wrong? 

No problem, just call in and we will give you a free road test and advise you. We can usually pinpoint the cause using our years of experience.

Obviously long distance fault diagnosis is difficult but we can often suggest common faults that can be causing the problem. 

My car crunches in to gear when it is cold. Suspect that the wrong grade of oil is fitted. If the oil is too thick it creates excessive drag stopping the syncros from working. This causes more problems with up shifts than downshifts especially 1st gear to 2nd gear.

My gear change is sloppy. This is usually a problem with the linkage or cables not inside the transmission.

If it has the correct oil fitted the syncromesh cones will be worn. It needs an overhaul.

I can only get gears with engine switched off. 

The problem is with your clutch not the gearbox. With the clutch pedal down the gearbox input shaft should stop turning, if it doesn’t the baulking action of the synchromesh will stop the gear stick moving

My automatic doesn’t change gear at all. 

Your transmission is controlled by a ‘brain’ this takes electrical signals from all over he car to decide what gear it should be in. If there is a permanent electrical fault it won’t change gear at all. It may stay in a low gear or a high gear depending on how it is programmed.

Sorry, it needs an overhaul. Changing the oil and filter can be expensive and is unlikely to cure it.

My automatic goes sluggish sometimes. This can mean that your engine is losing power (it will probably still change gear) or it’s ‘brain’ has detected a fault. It then puts your transmission in to ‘safe’ mode, stopping it from changing gear and boosting the pressure. This will also make it bang in to drive and reverse. The problem may not be within the gearbox. It needs a diagnostic test to see what fault codes are stored in the ECU so a diagnosis can be made.

Does my car need special oil? This depends on the age. In general for manual gearboxes we recommend that you use automatic transmission fluid not gear oil. Gear oil is generally too thick for the Scottish climate and causes both gear changing problems and doesn’t lubricate well from cold. This can cause the synchros not to work.

Automatics require as a minimum a good quality fluid such as Dextron 3. More sophisticated transmissions such as 6 or 7 speeds and CVT’s need special fluid to function correctly. If in doubt ask for advice.

My 4X4 seems to lock up especially going round tight corners. This is you transfer box ‘winding up’ It could be,

Being driven in diff lock

Have incorrect sized tyres

Have a faulty viscous coupling.

Should I drive in four wheel drive all the time? 

Some transmissions, such as the Landrover Discovery are indeed designed to do that, many aren’t. If your vehicle has the option of being driven in 4 wheel drive or 2 wheel drive choose the former. It will feel livelier and save both in fuel and tyres.

If your car is fitted with a viscous coupling in it’s transmission, yes!

The coupling is designed to allow one axle to turn faster than another when turning corners. If the tyres are different sizes the axles will constantly turn at different speeds due to the circumference of the wheels being different. Uneven wear makes the tyres different sizes. As a rule of thumb the tread depths should be within 2mm of each other and they should all be the same make. 

Fitting new tyres in twos rather than full sets puts strain on the viscous coupling, which will seize then destroy the differential and transfer box.

Do all of your parts come from the main dealer? No. We fit parts of equal or better quality sourced from specialist suppliers to keep prices down to our customers. Very often they are made in the same factory as the main dealer parts.

Sorry but no. We are often asked to fit a secondhand automatic gearbox that a customer has bought. We have no idea wether this will be any good so regrettably we do not want to be involved in this, we do not want to be in the position of charging someone to fit a gearbox that doesn’t work.

No. We only supply reconditioned units or repair your own.

Will you sell me parts? 

Certainly, for manuals, axles or automatics

Can you repair cases, gears and shafts? Not always! Cases can be welded or repaired with resin as long as the affected area isn’t structural, such as a bearing housing. Gear teeth are not usually repairable, although there are specialist companies who build up broken parts for plant equipment. Bearing surfaces on gears and shafts can sometimes be re-ground or bushed if replacement is very expensive.

Stripped threads can be helicoiled and broken bolts can be drilled out, please don’t try yourself first as it can make life difficult for us. 

Help, I’ve taken my gearbox apart and need advice! No problem, bring the bits in if you want advice, phone or email. We are happy to supply technical info.

Should I tow my Automatic or manual that isn’t working? 

You need to remember that the transmission is still turning when being towed so generally towing a car with a faulty transmission can cause further damage. Towing autos for short distances at low speeds is usually OK, manuals that are locking up or excessively noisy should go on a transporter. 

Four wheel drives will be destroyed on a suspended tow!

We only repair transmissions. We never do services or repairs to brakes, suspension etc.

This keeps our technicians and workshop free to repair your transmission related problem