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Drive side axle and oil pump 1956 G80S

Posted: Wed Dec 30, 2020 8:49 pm
by 56G80S
Photos no resized from better definition ones thanks to Spriddler. I put the remarks below into another thread and realised I was hijacking so here it is:

"Engine now out of frame as well as the AMC gearbox.

I'll speak with Alpha Bearings w/c 04 January about getting work done as they did the bottom end last time, back in the 1970's.I'm confident that the barrel / piston is too badly damaged to be managed by a rebore and new piston. T&L relined the barrel only a couple of years ago and there were a couple of hiccups. I'm tempted to save carriage and send all to Alpha.

I now find that the drive side axle splines are worn and when the weather picks up I'll post a photo or two for an opinion on what's what. Setting aside the pandemic, when all's back together (but with the Burman box back in as there's some work to do on the AMC) I anticipate covering plenty of miles. I don't want to change things for the sake of it but wold feel a fool to have the pin and timing side done and then find the drive side lets me down. On the other hand, new parts may not be of the same quality as the old parts.

Looking forward to a better 2021 for us all."

Welcome comments on the axle spline wear and the oil pump plunger. Will follow up with pump bore in the case in another post. I've only used the thumbnails from the 'phone to eliminate re-sizing, so quality not the best.
Drive side axle (640x277).jpg
Drive side axle. Ruler (640x418).jpg
Oil plunger. Splines close. (402x560).jpg
Johnny B

Re: Drive side axle and oil pump 1056 G80S

Posted: Wed Dec 30, 2020 8:53 pm
by 56G80S
And some other photos:
Oil plunger. Splines fuzzy (640x468).jpg

Re: Drive side axle and oil pump 1056 G80S

Posted: Thu Dec 31, 2020 9:49 pm
by SPRIDDLER
John. The parts look as they may be reusable but the pics (esp the axle ones) are too small and the resolution isn't good enough to offer any worthwhile opinion.
I've PM'd you my email address so if you take some larger (higher resolution) photos I'll resize them and send them back for you to post them.

Re: Drive side axle and oil pump 1056 G80S

Posted: Fri Jan 01, 2021 1:16 pm
by 56G80S
Hi Sprid thanks and got your PM and will send pics later.

Happy NewYear.

Johnny B

Re: Drive side axle and oil pump 1056 G80S

Posted: Fri Jan 01, 2021 9:25 pm
by 56G80S
Now changed the first set of photos, thanks to Spriddler resizing for me.

Johnny B

Re: Drive side axle and oil pump 1056 G80S

Posted: Sat Jan 02, 2021 9:01 am
by alanjennings
The drive side splines remind me of my old gran`s mangle, circ. 1850!

Re: Drive side axle and oil pump 1056 G80S

Posted: Sat Jan 02, 2021 9:18 am
by clive
I estimate that wear on the drive spline to be 2/3. There will be similar wear on the cam resulting in knocking on acceleration and a tendency to faster wear. If you can get the spline it makes sense to replace it. I broke one which was worn to about the same point but it was pulling a loaded double adult sidecar at the time. You will need to replace the cam too if you replace the spline.
Wear on the oil pump does not look too bad and this is not under stress so I would be happy to reuse it but what is the wear like on the drive spline? If you are replacing that I would try to get the best pump you can and not start with a worn one.

Re: Drive side axle and oil pump 1056 G80S

Posted: Sat Jan 02, 2021 2:18 pm
by 56G80S
HI Clive

Thanks for the advice and information.

When I split the cases I'll get a look at the timing side shaft and the worm gear. Probably more worried about the bore for the pump.

It's snowing heavily here and not going to the lock up!

HNY

JohnnyB

Re: Drive side axle and oil pump 1956 G80S

Posted: Fri Jan 22, 2021 5:24 pm
by 56G80S
G80S_t_side_ca;lcs.jpg
timing_axle measure 220121.jpg
Update. Have now split the crankcases, feet kept warm by running the genny with fan heater pinched from daughter's bedroom.

I took photos of the timing side axle but not very enlightening. There are clear signs of scuffing round the bearing surfaces but the worm gear looks immaculate. Sod's law that Mum's micrometers are a size too small and a size too large but the vernier seems to be working better.

The photos are my chalk notes and a spreadsheet. I tried to measure twice, at 90 degree angle and do the inner part and the outer part. This was very difficult inside the crankcase as the vernier didn't fit! Hence the odd results but I think it's clear shaft and bush are s--gg-d.

More positively, I re-examined the cylinder and after cleaning up the scoring looks like it might be remedied by a re-bore. Such a short time with a standard bore after re-lining.

I can feel no play at all in the drive side bearings which have been in since I acquired the Matchless in the mid 1970's. Same for the conrod on the big end. The latter will rock, by which I mean pivot with the pin as the fulcrum. There is absolutely no up and down though. I'll give them a rinse in paraffin and try them again before making any decision as the SAE oil is pretty thick and could easily mask any play. It's a tough call.

Does look like off to Alpha for bush and two axles at the very least.

Johnny B

Re: Drive side axle and oil pump 1956 G80S

Posted: Wed Jan 27, 2021 2:55 pm
by 56G80S
Response from Alpha:

"John We only work on crankshafts , not cases
Sounds like you had damn good value out of your 40 yr old Alpha big-end.
We can sort the shafts / big-end out if you wish. We have o/size , un-ground
pins if needed.
Need to have a look , can discuss the job prior to starting.
Any queries , give us a buzz T : 01384 253030 - left this in as it's in the public arena anyway -
Yours, CW"

My concern is that the oil pump bore in the crankcase could be damaged.

Johnny B