Clutch despair

I have heard some BMW's suffered from tight splines on the input shaft. The disk hub would not slide freely when disengaging.

For 1000 quid I assumed the shop doing the work on the stag would have replaced the clutch disk, pressure plate and the throw out bearing as well as check and grease the input shaft splines.

snip

Draging clutches if not down to the release hydraulics/cable are usually down to warped driven plates -- can happen when the gearbox and engine are mate up

I'm not sure about this one, as lining dust will stick to the grease. I'd say there'd be enough oil mist inside the bell housing to prevent rust.

I usually just wire brush the splines then if they are sticky clean lap them using the old driven plate and Brasso/T Cut

Since this is a '73 Stag it probably spent some time sitting without being driven. Hard to say for sure what the condition is. If there was oil in the bell housing the garage would have replaced the rear seal and pilot bushing.

The symptoms only seem to occur when the clutch is spinning. We need to know more about what was replaced within the bell housing,

Very common for mechanics to forget to fit the spigot bearing if a full engine overhaul has been carried out and the crank reground --

Or to forget to lubricate it.

Out of topic : Dave, where do you get your signatures ... always a pleasure to read them

Anywhere and everywhere, really. Try doing a search on 'tags'.

Thanks for all your replies - really has helped me a lot. The garage have not replaced any of the internal clutch mechanism - just the hydraulics. Basically they replaced the clutch master and slave cylinders as they said they were leaking. In fairness it has fixed another problem, i.e clutch biting point was right on the floor and sometimes was crunching badly getting into 1st or reverse. For my £1000 I also got a service, replaced oil, coolant, filters etc, recon brake master cylinder, recon calipers, brake cylinders, new pads/shoes, new brake pipes. New throttle cable. Total 13 hours labour - sorry should have mentioned all this earlier. Still feel a bit miffed that the clutch was not fixed when I told them it only happened when it was hot. I'm taking it back to them this week for diagnosis of the remaining clutch problem but I expect they will just say - sorry cant tell you what it is unless we take the clutch/gearbox out - which sounds like it is fair enough from the replies I have had. They have quoted a day and a half labour over the phone if clutch needs replacing - about £500 in total - am I being ripped off ? Anyway - can't afford that, and they might get the thing apart and find something worse. I guess I am going to have to start learning DIY mechanics in the deep end. Am I foolish to attempt taking the gearbox/clutch out as my first major DIY job ?

Think it's the wrong way to approach DIY - as a way of saving money. The jobs you had done - well most of them - would have been much better as starter jobs.

If you do intend removing the gearbox, get the genuine factory workshop manual. It's over twice the price of a Haynes one, but worth 50 times that.

You'll also need a fair number of tools. The car will have to be raised securely which means ramps and axle stands. The exhaust (or bits of it) will have to be removed, and this can be a pain on any car let alone an old one.

Have you got an experienced friend you could bribe into 'helping' ?

On a stag I would say you need a bit of help and a very good hoist. The typical hire shop 1 ton ones arent really up to a stag lump which is one of the heaviest engines in a UK car, being a cast iron V8. If you have a good 2 ton crane then its not too dreadful. I would take engine and box out together. The worst bit is the exhaust downpipe flanges closely followed by the power steering pump. You'll need a good set of wobble bars and a good quality surface drive socket set for the downpipes. A trolley jack to support gearbox as it all comes forward is a must too. The box does come off the back but it is heavy and I'd only do it nowadays with a pit or hoist. You can do it lying on your back if you are young and fit abd can press two hundred pounds...:-) If you arent too far away I'm available to help on your sight at a reasonable daily rate. Jonners

Not in my opinion, though I'm not sure if Stags have any quirks that make them especially difficult. You'll need to get the car as high off the ground as possible and support it properly, so will need four decent axle stands. Also a trolley jack to get it up there and to lower the gearbox on. It might be an idea to line up a nearby volunteer (from one of these groups or the owners club?) who you can call on should you get out of depth. 'Fraid I'm too far away...

Two points, here :

- When a manufacturer guarantees a part for 100k miles, they dont always mean what you want them to mean. In fact, as you pointed out, certain styles of driving ( the E type guy ) would get 50 clutches. They almost certainly do not cover wear and tear. For instance Ford used to boast of a "lifetime peace of mind guarantee" on dealer fitted parts :-)

- The clutch in question is physically small, the car has 170 bhp and is extremely heavy ( over 3000 pounds, iirc ). Although I will make this last for ages, I have to admit that I think fast getaways coupled with the sort of downshifts that dont match engine rpm ( absence of heal/toe etc ) would see this clutch off quickly. . My evidence is the fact that the last owner of my car had done so in 20k miles and when I replaced the clutch I was able to have a good look : Small friction surface, definite signs of pressure plate/flywheel overheating. The only thing I cant comment on is whether changing the hideous double-flywheel would have been a better job - this wasnt an option on cost grounds. I have subsequently driven a new car ( while mine was dealer serviced ) - I think my clutch is as good. I've fitted a few clutches over nearly 25 years of motoring and the new ( bmw orig ) clutch is adequate but does not feel "strong".

Lastly, underspecced is an interesting issue - my take is that bmw's market is really the guy who likes a new one every year - they are not so interested in older cars like mine. If you do less than 15000 miles a year, and change once per year, you wont even see a service.

Steve

I dont think this is correct, what is your evidence ? I have found it tends to happen when the clutch has a few miles on it, say about 50k miles on the fords I used to have. I've never come across an obviously warped plate.

Steve

I can remember the first time I pulled at a large lump of cast iron of unknown weight, while flat on my back........and the utter surprise as it suddenly came free and came crashing down on my chest :-) And I can definitely press 100 Kg - well I could last time I tried....:-)

Steve

You'll have to be keen and I agree with the others about trolley jacks and an engine hoist. For gods sake do be careful about fully supporting the car :-) It is a hard job to start on, but possible.

Good luck,

Steve

In the US it does as it covers maintenance as well - even brake pads and discs.

I've not got a 3 series, but read and if early clutch failure was common it would be moaned about there - regardless of whether they have to pay for it or not. ;-)

Come to this ng back when actually you know something about cars, clutch disc warping only needs to be a few thousanths of an inch to cause problems not something you can see with the naked eye.