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Finally got around to shimming up the idler gear today, using a Minispares gasket of 30 thou (uncompressed). This is a 1071 engine that I still have the original gasket from as I was the first to pull it apart. I have even kept the original BMC crank bearings as a memento It had done about 30k miles when swapped for a 1275, so not too bad at all

Thing is the old BMC gasket is ever so slightly thicker by a thou or two, so when I torque up with the smallest shims I only have a clearance of just under 3 thou. So to give me more wriggle room, I have heard of thicker gaskets on Mini Mania etc., but don't know who does them?

Can anyone advise on such a gasket please? Or maybe the Minispares 'special' one (https://www.minispares.com/product/Clas ... 563GM.aspx) will just make that difference??

Hi Andy
What thickness are the thrusts? Ideally with helical gears 3thou is the minimum clearance to allow for thermal expansion. Have you tried the feeler gauge between the thrust and idler. Surfaces are equally flat and give a truer reading

If you let me know the size of each thrust I will see if I have any slimmer ones in my collection.

Regards Jason

I have a black gasket that I’m measuring up at 32 thou.
Happy to post it out if you think it would be a solution?

We always find the the old orange/red Payen gaskets are the thickest.

I'll see if the vernier is working tomorrow and let you know the thickness.

Jason wrote: ↑Fri Aug 11, 2023 7:13 pm Hi Andy
What thickness are the thrusts? Ideally with helical gears 3thou is the minimum clearance to allow for thermal expansion. Have you tried the feeler gauge between the thrust and idler. Surfaces are equally flat and give a truer reading

If you let me know the size of each thrust I will see if I have any slimmer ones in my collection.

Regards Jason

Hi Jason, thanks for answering - the ones I have taken off the car are both the smallest, but as we know they vary slightly. One measures at 130 and the other at 131. I have collected loads of spares over the years but 131 seems to be my smallest. Happy to swap a few btw

GraemeC wrote: ↑Fri Aug 11, 2023 7:32 pm I have a black gasket that I’m measuring up at 32 thou.
Happy to post it out if you think it would be a solution?

That's really kind, and happy to give you something for it? That's pretty much what my old one measures too (after decompressing a little I guess).

I'll pm you

Andrew1967 wrote: ↑Fri Aug 11, 2023 8:30 pm We always find the the old orange/red Payen gaskets are the thickest.

I'll see if the vernier is working tomorrow and let you know the thickness.

Thanks Andrew - be handy to know

Slightly off topic but out of interest, is the transfer gear casing 22G108 or 22G208?

Thanks,

Peter

Peter1071 wrote: ↑Sat Aug 12, 2023 7:10 am Slightly off topic but out of interest, is the transfer gear casing 22G108 or 22G208?

Thanks,

Peter

Hi Peter, just checked my engines and they both have the 22G208 on them. Pic enclosed - hope it helps?

I have a 22A1545 measuring 0.1285”. This will bring the clearance nicely in spec. If you can use it, message me your address and I will post it out to you.
Rgds Jason

That sounds perfect

With all the help I’ve had on here I’m sure it will get sorted pm coming your way

Over the years I have collected and saved as many drop gear housing gaskets as possible. They have thickness difference. I also collect idler thrusts. It's getting to the point where my thick thrust are in short supply and thicker gaskets are running out. I suspect like others I have a few drop gear housings with damaged idler gear thrust faces. I even have a couple that were faced with a milling machine to accept added thrust. I have access to a Rottler surface machine. I'm thinking about taking a skim cut off a housing to adjust idler thrust. I'll start with a damaged housing and see how it turns out. Steve (CTR)

Engine to Gearbox gaskets also come in a variety of thicknesses. Makes a big difference in straight cut drop gear noise.

OzOAP wrote: ↑Mon Aug 14, 2023 12:25 pm Engine to Gearbox gaskets also come in a variety of thicknesses. Makes a big difference in straight cut drop gear noise.

Thanks for the heads up - appreciated. I am reinstalling the old and nearly standard 1071 back into the car as the 1275 unit isn't original, but that's got straight cut gears and I wasn't thinking that far ahead

I had always thought of machining the alloy flywheel housing the readdress the wear in the thrust faces whilst getting better gasket face after 50years of engine splits.

I have yet to set up and machine one, I do have a pile of engines/trannys and housings to do. I also have a Turbo housing and two new outer support bearing for it. They are not cheap. Steve (CTR)

Huge thank you to Jason and Graeme - Still have some fiddling to do but a quick check today got me 5 thou clearance, so a single shim change and I should be on the 3 thou I want