Clutch Plate & CRB - Replace or Not?

[revilla]

I'll be swapping engines on Saturday, one in one out. Splitting engine and gearbox and leaving the gearbox in place.

 

While it's apart, should I replace the CRB as a matter of course? I have no indication that it has problems, car has done approx. 18k miles. Just wondering if it would make more sense to change it for a new one as changing it if it failed later with be PITA.

 

Similar question for the clutch friction plate. I need to move the clutch plate and cover over from the old engine to the new. My suspicion with this one is that there's no point in replacing it unless it is well worn or damaged. Anything obvious to look out for? Are there any specs for lining thickness when new and when replacement is needed?

 

Thanks,

 

Andrew.

[Mankee]

You can just about replace the CRB with the engine in-situ apparently, but for the sake of £20 or so, I'd be changing it.

 

Myles has a couple of useful paragraphs on the AP clutch wear measurement if that's what clutch you have:

 

http://www.alcester-racing-sevens.com/components.htm

 

http://www.alcester-racing-sevens.com/engine_upgrade.htm

 

PS: Are you going to bang in a lightweight flywheel while you are at it? I think you should.

 

Edited by - Mankee on 13 Jul 2014 19:55:07

[revilla]

Mankee,

 

Thanks. I think I'll order a CRB just for peace of mind. To be honest I don't know what clutch I've got as I've never had it out to look at before. All will become clear when I get the engine out, but I guess that's probably what I'll find. Thanks for the measurement links, I'll see how it looks. If, as Myles says in the linked article a 200+ bhp SLR has only taken 1/3 of the clutch material in 20K miles, I suspect that my 160+ bhp VVC won't have eaten it all away in 18K miles so I'll not order one for now and just hope I find good news when I open it up. If not ... well it just won't be done in a day.

 

As for the lightened flywheel, it would be lovely but I think the little ones have eaten all my salary for this month, so for now I'll stick with what I've got. I only use it on the road so a little bit of inertia probably smooths it out a bit anyway. Maybe one day ... 😬

[Roadru77er]

There was an article in Low Flying by Michael Calvert I believe where he modified a metal CRB carrier available from Burton Power.His was on a crossflow. I've just done a similar mod on my Kseries

[Jonathan Kay]

Here's what I gleaned from the archives:

1. Always change the CRB.
2. Changing the clutch plate depends on the thickness left, but there are lots of different types with different thicknesses. Which is just where you started.
3. Inspect the clutch fork.

Jonathan

[ECR]

This was from AP racing for one of my old VX clutches. It might or might not be relevant 🤔

 

Friction plate fitted August 1999 is an AP Racing product (NB new part number is CP6444-5)

CP3431-2 DP228RIGCER-1 00X23-7,37

DP = Driven Plate

228 mm diameter

RIdgid CERamettalic

1.00mm x 23 tooth spline

7.37mm thick

 

Allow 1 to 2mm of wear dependant on engine torque and cover plate springing . Slight marking (5 to 10 thou ) of the rivet heads is acceptable

 

[Bob L]

If going this far, I would consider replacing the spigot bearing. It was nowhere near as difficult removing the old one as some had advised. Use a Dremel to grind the lip of the bearing, then ease out with a screw driver. Lots of very detailed threads on this in archive.

[revilla]

Thanks everyone.

 

@Jonathan - Yes, good point, clutch fork inspection added to list.

 

@Bob L - The new engine that is going in is one that I built up over last winter. I converted an MG ZR engine. As part of the conversion I did already fit the spigot bearing. Unfortunately first time around I realised afterwards I had fitted it back to front (with the grease seal on the inside!) so had to remove it again. I must say it was every bit as difficult as people had warned me. None of the grease/hammer/screwdriver tricks shifted it one little bit. In the end I needed a sharp chisel and hammer to cut the bearing race apart until it collapsed and came out as shrapnel. I then dressed the hole in the crank lightly with a Dremel sanding drum before fitting a new one - right way around this time!

 

I must remember to grease it up with LM grease before assembly though.

 

Edited by - revilla on 14 Jul 2014 14:36:21