Manual Gearbox Repair


While stick shifts are simpler in design and tend to be quite robust compared to automatic transmissions, manual gearbox trouble is by no means rare. Manual shifts require greater driver skill than auto transmissions and can pick up serious damage if the wrong gears are engaged by mistake.

Manual gearbox repairs often involve the clutch mechanism, as this can easily be damaged by drivers “riding the clutch”, i.e. not releasing it completely when driving. This can cause overheating and all the problems that result from too much heat.

Gearbox trouble mostly announces itself through crunching noises during gear shifts. In case of a serious fault, a manual shift vehicle may not go at all.

The gears in most modern manual vehicles are permanently meshed, with the gear selector or gear shift simply controlling which gear combinations to link to the drive shaft. Heavy machinery or specialised performance vehicles may use unsynchronised gearboxes.

A thorough repair job on a manual gearbox requires the complete dismantling of the gearbox. Every part is stripped down and inspected one by one, ensuring that it has not suffered damage. At 7th Gear, we replace all damaged parts, as well as soft components and consumables. As we have our own machine shop, we can do retooling as necessary. All parts that are still serviceable for the long run are cleaned thoroughly and re-installed.

Manual Gearbox Service

Is your manual transmission getting harder to shift?

Does it feel like it just doesn’t grab like it used to? Or maybe it’s starting to chatter or vibrate? A worn clutch may be the culprit here. Or it could be the result of something else, such as a transmission misalignment. One obvious sign that this is the problem would be rust residue on the disc and pressure plate.

Make Adjustments

Prior to putting the clutch back together, the flywheel should be re-surfaced and a new pilot bearing installed in the flywheel, which is always recommended. Other tips include using a drop of Loctite on the threads of the bolts prior to bolting the flywheel to the engine.
Also, clean the flywheel and pressure plate with acetone to ensure an oil-free surface of Manual Gearbox (this is one area where you don’t want any lubrication at all).

Make sure to use the correct alignment tool when placing the disc up to the flywheel. Once again, before bolting and torqueing the pressure plate to the flywheel, apply a drop of Loctite on the threads of the bolts.