1997 M90 Clutch decision
 

A new cheap clutch was fitted to my car prior to my ownership of the car in 2010 so it's now coming up for 10 years old and has covered 80,000 miles upwards since then!

I don't know if I have a dual mass flywheel. According to forum posts I should have but according to the last Volvo main dealers I used they said it wasn't fitted to the 1997 940 but they didn't actually look at the car.

I am not having any of the issues I've read of related to dual mass flywheel failure anyway but the clutch now feels very soft and I am wondering whether I bite the bullet and replace it now and avoid a breakdown or just wait and see how long it goes on, maybe it will go another year? I'm not having any gear changing issues or anything. It's so soft now that it's hard to determine where the biting point is to be honest.

Edited to say my garage would be quite happy to replace just the clutch and not the dmf even if I do have one.

From your description Ellie it sounds as if it's a normal clutch and the pressure plate is getting weak.

If my theory is correct, it will get softer and then you'll have difficulty engaging gears. No way of knowing how long that will take but 80k is a good life for an average clutch (pattern) although OEM clutches frequently last a lot longer. This diagram may help explain it better :

http://angelworldzone.com/clutch.jpg

As you press the clutch pedal down, the release lever/slave cylinder acts on the thrust bearing (called "throw-out bearing" in the diagram - USA terminology) moving it towards the flywheel.

This pushes the centre of the diaphragm spring towards the flywheel too. Remember those biscuits tins that if you pressed in then out again, they'd pop out or in with a bit of pressure afterwards? The same idea works on the diaphragm spring which pulls the pressure plate away from the flywheel releasing the driven plate aka clutch plate.

When the pressure plate as i called it (the pressure plate and diaphragm spring are one complete assembly) gets weak, that spring action is reduced making it firstly easier to press the clutch down and secondly, harder to release the clutch plate.

Eventually as you press the clutch down, the diaphragm spring just bends without releasing the clutch plate.

If you're not getting the usual symptoms related to DMF failure then it would be reasonable to assume Volvo are correct in saying you have a normal clutch in which case, i'd suggest getting it done ASAP but without panicking too much meanwhile.

If you can minimise gear changes, perhaps by "block-changing" or if you can teach yourself how to drive "clutchless" both will prolong the life of the existing clutch but it's only delaying the inevitable.

As the gearbox has to come out to change the clutch (you'll need a 3-piece clutch kit - driven plate, pressure plate and thrust bearing) expect 2-3 hours labour plus the cost of the clutch kit.

This is one possibility of the clutch for yours but is dependent on VIN number :

https://www.eurocarparts.com/p/luk-clutch-kit-641660410

There are others, i picked that one as it was more or less the average price but subject to ECPs discount of (i think) 37% with the code "WEEKEND37" at the moment. That would make it around £200 instead. Not sure how much Volvo would charge but might be worth checking on their prices for the clutch kit, they should supply the correct one as well and (in theory at least) it should last longer than a pattern one. :thumbs_up:

Hi Dave, thanks for that, I'll start preparations!

The clutch receipt came with the car's service history and it is a very el cheapo one, two hundred odd quid supplied and fitted and has managed between 80-100 thou so I wonder what mileage I would get out of a Volvo one?! I have been very kind to it! I'll find the receipt and scan it in later. I seem to recall they are in the West Country, too far for me to drive to!

Back then volvo clutches were designed to last the life of the car and did ! 250000 miles who knows ..... even the 340 was the same quality , we have a 1980 model with 250000 miles still on original everything ...( except Battery and front brake pads and one exhaust kit )

That assumes they are used properly, no riding the clutch, towing of heavy caravans and so on.

All of that will reduce the life of any clutch so it's entirely possible the previous owner had a huge caravan, rode the clutch and holidayed in Devon/Cornwall where the hills are more like cliff faces and go on forever!

Could explain why the clutch was fitted in the West Country..................

That was the norm back then , Volvos were used under all conditions , harder than todays cars are used with no problems . When you have a caravan on the back you don't even notice it so not a problem . except for the odd moron i guess on a long hill in a traffic jam :-) yes i have come across that , but the clutch recoves after some normal use ... i have friends with caravans who had 940's and 240's who did more mileage towing than without anything on the back , 6 or more breaks to France a year for example for one of them ,the guy with the 245 was getting worried at 200,000 miles of towing and wanted me to look at the clutch .. It was perfect a total waste of time for me .... .
The clutch only takes engine torque remember the weight of the caravan makes no difference once it is engaged . People who Tow know exactly what they are doing ..

I’m not 100% certain so someone may correct me, but is it possible that there is air in the line leading to the clutch slave cylinder? If there is air in the line could it cause a spongy feeling clutch, similar to having air in the brake lines?

I have read that the best way to bleed the clutch system is to reverse bleed it by pumping in the fluid from the bleed nipple on the clutch slave cylinder.

Back then clutches were made using asbestos too! :eek:

Good for heat though and also softer than the newer materials it has been replaced with as it doesn't chew the driven and driving plates (and in the case of brakes, discs and hubs) the way the newer stuff does - being soft it has higher friction coefficients as well. :thumbs_up:

There is a problem about not noticing a huge caravan on the back - you forget it's there! Suddenly you find yourself in the outside lane at 90 with blue lights flashing in every direction and an instant ban for being 30mph over the speed limit. :rolleyes: :nah:

The clutch itself is the essential weak link in the transmission - it is designed to fail before anything else. An explding clutch disc isn't nice, makes a hell of a row as it bounces round the inside of the bellhousing but nowhere near as much row as you and/or your passengers would make if the propshaft disintegrated and made a bid for the comfort of the cabin! :speechless-smiley-5:shocked::speechless-smiley-5

Assuming the clutch is in good condition and has been used properly, what you say is true, that once engaged there is no slip. However, with a large weight dragging the car backwards, especially up a steep hill where the forces of gravity will work against it, the limits of the friction in the clutch assembly will be approached. Once reached and it starts slipping, it will continue to slip. This just gets worse and worse until it's virtually impossible to drive anywhere.

As for "people who tow know exactly what they're doing" - a sweeping generalisation, have a look at a few of these "caravan fails on dashcam" :

https://www.youtube.com/results?sear...ils+on+dashcam

Plenty to choose from! :tounge_smile: :thumbs_up:

Crikey, some of those crashes! The Aussie pronouned expletives are hilarious!

I can see why you suggest that and to be honest, was one of my first thoughts too. However, that would cause the driven plate to not release because the air would get compressed before any movement on the release lever.

This would cause "clutch drag" making it difficult to engage gears, especially from a standstill.

As for reverse bleeding, horrible idea! Any dirt, contamination or grit present in the hydraulic line would then be pushed up into the master cylinder to destroy the master cylinder seals. Far better to bleed the correct way and expel any contaminants out through the bleed nipple.

This is also true for braking systems and in the case of ABS-equipped cars, particularly so as dirt can damage the ABS modulator leaving you with no brakes at all and a huge bill for a replacement modulator.
Even squeezing the piston back into the caliper to enable new pads to be fitted counts as reverse bleeding. As such, it is best practice to open the bleed nipple 1/4 turn with a one-way bleeder on while the pistons are pushed into the caliper. It's easier on the seals as well so they're less likely to suffer damage from being pushed back the wrong way with pressure behind them.

Once the pistons are back in the caliper, new pads fitted and everything secure, bleeding the effected legs of the system is all that's needed.

Anybody who says they've done it without opening the bleed nipple on an ABS car and has got away with it has been lucky. They have however potentially stored up trouble for themselves and could find the master cylinder fails when they need it most! :speechless-smiley-5
Even on non-ABS cars, it's not recommened to simply push the caliper pistons back in without opening the bleed nipples for the same reason.

It might save you a couple of minutes on a pad change but a working brake system will save your life. :thumbs_up: