Clutch linings

Al Coutts · Posted: Sun Feb 05, 2017 8:17 pm Post subject: Clutch linings

As my gearbox is out and the clutchplate looks tired, I feel I should de-rivet the existing friction surfaces and renew.

This looks like a fairly straightforward job to someone who regularly rivets brake pads to backing plates for disc brakes.

Are there any gotchas? I'm assuming the rivets are softish copper based alloy.

Thanks again!

Al

Christopher Carnley · Posted: Mon Feb 06, 2017 9:07 am Post subject:

The original rivets were brass, but you get hollow copper ones now.
I would send it to Terry Hanson at ACS in Dewsbury,look up "Tractor Clutches", his service is excellent.

The cast iron friction plates would benefit from a skimming to get below the hard spots.

Tell me what the "Hallmarks" are on the top rear of the gearbox, starting with BB****. then read off the lightly engraved part number on the flat rear end of the main shaft where the large nut secures the drive flange. RG *** something

Even with a good one, the original 3rd speed thrust washer breaks up then drops out with destructive consequences.

When you have read this I will tell you what I use to lace the gaiters, which should be done before you replace the springs. You will also need a large curved sail maker/mailbag stitchers needle.

Al Coutts · Posted: Mon Feb 06, 2017 9:13 pm Post subject:

Thank you again Chris. I've just dropped Trevor H an email.

I'll revert tomorrow with the serial numbers.

Al

Al Coutts · Posted: Tue Feb 07, 2017 10:54 am Post subject: Hallmarks

Top rear of g/box just has 3 digits hand stamped into it - 464

Top right hand side has embossed casting number RG3117 Patt B (or 3 or 7 or Cool

The hand engraved shaft-end reads:

RG193 RR X65 MOT96

There is another hand stamp front right of gearbox D29N RFA618Y

That's all I can see top-side.

Thanks,

Al

Christopher Carnley · Posted: Tue Feb 07, 2017 1:38 pm Post subject:

That is a very early gearbox from 1947. The Part No RG193 refers to the early weakened mainshaft, altered in 1949 and always replaced at overhaul by RG5469.

Read all about this in Section G of the Workshop Manual.
This gearbox will let you down.
Moreover it has the incorrect round shouldered main bearings replaced by square edged ones almost at the same time as the modifications in the DZ series.
The main bearings are held in place by thin snap rings and the back one has a bad habit of snapping under the chunking of the bearing movement.

Christopher Carnley · Posted: Tue Feb 07, 2017 3:58 pm Post subject:

This is an example of the typically broken RG193 main shaft, I took this one out last month.
The faulty design made for the milling out of a solid spline leaving 1/6" thick cheeks for the synchro cone lugs to break off.
The RG5469 has solid splines and bridge key selectors,so look at the parts list and compare them.