T595 Oil Pump And Drive Gear Advice

I noticed the drive gear/cog behind the clutch basket had a small amount of play/wobble on the splines. I had to drill and use an extractor to remove the retaining screw so, two things:

1) is the play/wobble acceptable? I can’t see any damage or wear to the splines.

2) does anyone know the inner-workings of the oil pump itself? When drilling out the screw, my cog ‘lock’ slipped and allowed the cog to spin with the drill for a second or so, which I think is in reverse for the oil pump...what are the chances that’s knackered the pump? As long as the oil pressure light goes out can I assume all is well?

https://youtube.com/shorts/noiuEGoijHU

 

What’s your thoughts on putting in a shim/washer as a solution? Would I put it all at a greater risk of coming undone if I say ended up with a micro gap between the ‘dished’ washer and the end of the shaft? Or would the transferred torque through the added washer to the cog suffice to keep it together?
I guess the risk is if the cog ever moves/wears back further onto the spline/shaft then both washers would be left flapping in the wind, with only the bolt screwed into the shaft end without any torque keeping it there?

 

Thanks, TD,
Late getting back because of a long day fitting the head back into the frame...leaving the clutch as the last job, knowing the oil drive is behind it!
That cog has been going round and round inside my head! It occurred to me the dished washer may not even be flush against the shaft due to previous excessive thread lock or gunk (it’s been removed before, the Torx was knackered), I never looked for this! 0.05mm of burr/gunk/thread-lock would definitely prevent the washer from sitting flat against the end of the shaft.
Will be taking the clutch basket out again tomorrow, so will check this possibly/hopefully overlooked issue!
TBC
Cheers,
Stuart

 

@Tricky-Dicky I didn’t get round to the clutch today, so will check back in tomorrow. In the meantime, if I should require a washer, did you mean something like this (below), and then drill a hole in either the cog or the dished washer to locate the lug in?

 

So, as a bit of an update, I wondered whether the back of the dished washer was actually flat, so rubbed it over a bit of Emery paper to find it was concave. When sanded flat the washer took up much more of the cog slack, but still a feeler gauge gap of 0.1mm is present behind the washer after tightening.
So I’m going to make a 12mm x 22mm x 0.1mm washer from stainless shim sheet and fit it behind, UNLESS anyone has any insights into this being a bad idea?

 

I’ve been calling it a dished washer, but I realise the term might be confusing as it’s really a countersunk washer. I’m wondering now whether the back (the sanded bit, which has now been completely flattened) should actually have had that profile? Will buy a replacement and find out.
The bolt/screw was drilled and extracted, so definitely mullered!

 

That’s extraordinarily generous of you, YM...I think, because the gap is greater than 0.1mm (somewhere between 0.1 and 0.15) that the washer would simply ‘dangle,’ not being crushed by anything. I was taking a look at a few preformed shims online and could only find 12 x 18 and 16 x 22, plus the 15mm variant you have there.
Truly appreciate you coming forward with that though. Best, Stuart

 

Not sure what happened with the quote then - see below

 

@Tricky-Dicky Re interference fit, this has also been suggested: ‘if the designer wanted the gear to be held axially tight with the screw and washer, they would have put a shoulder on the shaft for the gear to butt against.’
There clearly isn’t a shoulder on the splines (see drawing and grainy manual picture of the actual splines the cog goes onto), so I’m even wondering if it needed to be tight in the first place? There is a YouTube link at the start of the thread that shows the amount of movement on the splines, let me know what you think?
AND finally WOW, such generosity on here. The lathe job would be the best of all solutions if I end up needing to crush that cog into the back of those splines. That’s so kind of you to offer, and for me to have that in the back of my mind is amazing.

 

It runs the oil pump as pictured here (the arrow points to the splines the offending cog fits on).
There doesn’t appear to be any bearings at all, looks like the case has been machined, a bit like the camshaft journals?
I can take some photos of the actual shoulder of the splines, and the back of the cog too if that would help to shed any light?

 

So, even another thought...the splines themselves are specifically oiled by the cut out seen in the picture I’ve just taken of the actual spline itself.
Seeing that the actual shaft itself is equally oiled from behind inside the gearbox by a similar cut out, would it be a correct supposition to think that, given the splines dedicated oil supply and the internal star-shaped of the cog itself, that it was actually designed to be oiled and move? Maybe the oil compression takes up the slack?

 

You’ve been a great help...many thanks!
Have a great day!
Stuart