The first call for any replacement part is the local motor factor, but when it comes to a part such as a clutch input shaft sleeve (guide/bush) and seal, most garages turn to dealerships. It must be a UK thing!
Essential in clutch changes for many German, Italian and French-built cars, dealerships hold a virtual monopoly on aftermarket sales throughout the UK, but the fact is they’re not an OE supply only item. Garages only think they are.
New direction
Until quite recently, for example, that’s precisely what they thought up at Almark Garage in Wirksworth, Derbyshire: “We always sourced them through the dealers. It just seemed like the place to get them because it was associated more with the OE gearbox than the clutch,” says Proprietor Mark Swift.
“Our problem was that once you’ve got the vehicle up on the ramp and the gearbox off, you couldn’t hang around all day. We’ve had up and down experiences with sourcing parts and service levels from dealers, so it has meant that we haven’t always replaced them, even though we know they can be a source of problems with the clutch.”
Because the availability has improved, Almark is now fitting more.
“It was only when the motor factor came along about three months ago and pointed out that they now had them in stock that we switched over. They are not expensive to buy, but even so, they are half the price that we purchased them from the dealer at. I have to say that the service they provide means we are now fitting more than we ever did,” he adds.
Guide/bush function
When not in operation, the clutch release bearing withdraws and comes to rest on the shaft sleeve. The shaft sleeve can become pitted through wear and tear and as a result a worn release bearing can catch on it, leading to misalignment problems that can cause the clutch to slip. This accelerates clutch wear.
Inside the shaft sleeve is a rubber seal. This is designed to protect the clutch from ingress by gearbox oil but if the seal fails there are problems ahead. Seal failure is often related to debris generated by clutch wear.
Contaminants
Clutch ‘dust’ accumulates in the gearbox. If the dust accumulates on the shaft and on the sealing lip, the seal can be compromised, which can damage the seal and reduce operational life. A worn or damaged seal allows the oil to leak into the clutch housing and if this contaminates the friction plate, premature failure of the clutch is inevitable.
This leads to excessive slippage. Any excessive slip between the clutch and flywheel causes overheating and soaring clutch temperatures increase the potential for failure.
Installation errors
After removing the clutch, the clutch input shaft sleeve (guide/bush) and seal is sometimes ignored or not considered for replacement.
Three alternative views are:
a) It is part of the gearbox, rather than the clutch;
b) It looks ok, so let’s save the customer money;
c) They are difficult to replace so are best left alone.
Each of these constitutes an error of judgement that can expose the garage to an expensive rectification procedure and damage its reputation.
Best practice
Corteco, one of the world’s largest manufacturer’s of clutch input shaft sleeves (guide/bush) and seals, says that although these components are highly reliable performers, they must be replaced when changing the clutch.
It adds that because so many garages have always sourced their replacement from dealerships, many motor factors are unaware of the demand. Given that labour is the major cost of the clutch change and that the clutch input shaft sleeve (guide/bush) and seal is not an expensive part, garages would be inclined to change more of them if the parts were available.
