AIBU to ask why my car vibrates in low gears since replacing clutch?

[SophiaLorenxoxo]

Replaced clutch on 4 year old Skoda Fabia. Ever since, the car vibrates when going up hills in third gear. Garage have had car back and checked new clutch but can't find anything wrong with new clutch.

Does anyone have any ideas?

@SophiaLorenxoxo

Replaced clutch on 4 year old Skoda Fabia. Ever since, the car vibrates when going up hills in third gear. Garage have had car back and checked new clutch but can't find anything wrong with new clutch.

Does anyone have any ideas?

I wonder if the flywheel wasn't put in correctly - it needs to be clean and prepped before installing, and if it isn't and the surface is impaired in any way, it can transmit vibration? So if it's a rush job done by someone who cut corners a bit that could be the case.

I used to be a mechanic.

My initial thought would be they've put the clutch in pissed.

It comes in 2 pieces, a friction plate and a pressure plate, well 3 if you include release bearing. If they're not aligned when bolted to the flywheel it can cause this problem.

Flywheel shouldn't need to be taken off to replace clutch, unless that's a particular quirk of certain models?

Thank you both. This information is very useful.

It comes in 2 pieces, a friction plate and a pressure plate, well 3 if you include release bearing. If they're not aligned when bolted to the flywheel it can cause this problem.

When the gearbox input shaft goes through the clutch then it’s aligned. If the gearbox is in the car it can’t be out of alignment.

Did it have a new flywheel when the clutch was replaced? It could be a dual mass flywheel failing, all modern diesels have them and many petrols. There’s normally a noise as well though. How many miles has the car done?

When the gearbox input shaft goes through the clutch then it’s aligned. If the gearbox is in the car it can’t be out of alignment.

It can if the spigot bearing is worn or missing.

Agree that it could be a dual mass flywheel fault.

@Shade17

It comes in 2 pieces, a friction plate and a pressure plate, well 3 if you include release bearing. If they're not aligned when bolted to the flywheel it can cause this problem.

When the gearbox input shaft goes through the clutch then it’s aligned. If the gearbox is in the car it can’t be out of alignment.

Did it have a new flywheel when the clutch was replaced? It could be a dual mass flywheel failing, all modern diesels have them and many petrols. There’s normally a noise as well though. How many miles has the car done?

I had a new clutch fitted to the Mondeo I used to have. A few weeks later, the DMF went.

My DP said this often happens.

Engine vibrating at idle usually means engine mounts, but vibration under load, especially in a 4 year old car does indeed sound like DMF. They're tricky to get to so are normally changed at the same time as the clutch.

@Shade17 Thank you for your advice. As far as I can tell from the invoice, there was no flywheel fitted when the clutch was replaced. The car has done 44000 miles.

@Hollowgast Thanks for your advice. Car only vibrates (not that badly though) in 3rd gear going up hills. There is no vibration when idling.

If it is DMF on the way out as several people have suggested, I assume that we may as well wait for it to fail before getting it fixed?

It can if the spigot bearing is worn or missing.

That’s true, the whole input shaft would be moving about.

Car has only done 44k miles which suggests maybe an element of driver error here, lots of clutch slip = lots of heat into the DMF. The usual recommendation is to replace the DMF at the same time.

When the gearbox input shaft goes through the clutch then it’s aligned. If the gearbox is in the car it can’t be out of alignment.

I know how they work.

And they can still be out of alignment with the gearbox in.
Not by a huge margin but enough to cause problems like this.
I know because I've seen and fixed it.

That's why the clutch alignment tool exists.

I know how they work.

And they can still be out of alignment with the gearbox in.
Not by a huge margin but enough to cause problems like this.
I know because I've seen and fixed it.

That's why the clutch alignment tool exists.

The alignment tool exists to allow you locate the input shaft through the friction plate. If slightly out of alignment this will be corrected by the input shaft. As the friction plate is a perfect fit on the splines it’s a physical impossibility for the clutch to be out of alignment as long as the input shaft is correctly seated in the spigot bearing.