hi all
I have a 1977 datsun 810 4 door with engine L18 at some point i think a mecanic changed the clutch to the small size by mistake now i have to change a clutch kit and i want to be sure what size to use anyhelp how to be sure about that.
best regards
Ahmed Radwan
Egypt

Well, you either have the 4 Cly clutch or the 6 cly clutch without looking at the clutch it's going to be hard for anyone to know which one is fitted.

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RIP Photobucket

If you can remove the clutch that is currently in there and take a photo of the flywheel and some measurements of the clutch face on the flywheel, we can identify which size clutch you will need.

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green200b - aka Alistair

The fleet:

Australia:
'80 200B GX - the green200b - hibernating
'81 RX-7 - 12A extend port - daily
'74 RX-2 - 13B bridgeport - cruiser

Europe:
'93 200SX - CA18DET - tourer

thanks for your kind reply
i have a pictur for old clutch pressure plate i removed from the engine years a go i didint take the engine out yet and some one on ebay asked if it have a 5 or 6 bolt crank. (is ther is away to konw with out taking the engine out)
i can see in the picture that the clutch disc dosnt cover all of clutch pressure plate.
thanks for your time
Ahmed Radwan

this is the VIN : plj810014680
and some photo of the engine
engine number : L18 25267 W

it is 4cyl 1770cc

....and because it is an L18 4 cylinder it will have the 5 bolt crank / flywheel.

hi thanks for your time
so is it big clutch disk or small
best regards

It is evident from your photograph that the car had a small friction disc and a large pressure plate. At the moment, we don't know (but can only assume) that is has another small friction disc (as you mention in your original post). However, if I am not mistaken, to use a large diameter pressure plate assembly, the flywheel must be drilled to accept the bolts pitch circle diameter of the large pressure plate....ie. a large pressure plate won't fit a flywheel with small pressure plate without being redrilled and resurfaced for the large pressure plate. Therefore, my logic would tell me that the larger diameter friction disc will be required....I would measure the outside diameter of the pressure plate that you removed (and is in your picture) - it will probably be around 225mm or similar.....

However, my approach would be to purchase BOTH large and small size clutch assemblies (ie. pressure plate and friction disc) with an agreement with the supplier to be able to return the version that is NOT used....when your mechanic removes the transmission to replace the clutch they will be able to determine which version to use based on what's in there already...I would always be replacing the friction disc and pressure plate as an assembly and have the flywheel removed and resurfaced...so you will not be mixing disc and pressure plates. I'm not sure how easy it is arrange this with suppliers in Egypt...hopefully you have a good range of component suppliers who can work with you or your mechanic to supply the correct parts?

All the best!

hi thanks for your time is it ok just to use a big clutch disk with the new pressure plate just like the one in the pictur i think it still have some room for the big clutch
best regards
Ahmed Radwan

Yes, you could use the bigger diameter friction disc with the pressure plate you already have however you need to make sure:
a) it will match the contact surface on the pressure plate
b) it will match the friction surface machined in the flywheel, and
c) the pressure plate can bolt to the flywheel.
There are a number of factors that may or may not work by simply buying a friction disc to use with another pressure plate....it's not always so simple to take one part from one source and match it with another part...you may still have issues with the throw out bearing heights, etc depending on the combination already in the car, etc so I would still STRONGLY recommend that you find out what is already installed and replace it with that same size and type....best of luck.

hi
thanks for your time thats helps
best regards