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Thoughts on this? Is it worth replacing with this amount of wear? If so, is the MiniSpares C-BTA166 any good? It’s being run with a standard 850. Im trying to avoid replacing everything in sight if what’s already there will go again for the relatively small number of miles I’ll eventually do in the car. There’s already a million and one other things that do need replacement outside the gearbox so trying to be pragmatic about reuse where possible.

If there is any discernible wear then, if you're that far in, I'd replace.
Once it wears through any hardening it will quickly get worse.

Agree whole heartedly with Graham. wipe clean with methylated spirit then measure with a micrometer and ALWAYS follow that up with the Mk1 eye-ball and an eye glass. The micrometer and slip gauges etc etc don't see what the eyeball does

Peter Laidler wrote: ↑Fri Mar 19, 2021 12:48 pm Agree whole heartedly with Graham. wipe clean with methylated spirit then measure with a micrometer and ALWAYS follow that up with the Mk1 eye-ball and an eye glass. The micrometer and slip gauges etc etc don't see what the eyeball does

What am I looking for with a mic measurement? How much wear from the unworn part?

If you can't feel any significant wear with a fingernail, stick it back in. This stuff was made to last, and it has.

34 bhp/clean oil/no wheel spinning = fine.

Quite by accident I ordered a new one - had one in the basket from Somerfords, so it'll be here along with a bunch of new lock tabs, a layshaft and bearings and a few other odds and ends. I presume a standard Rover one will be OK.

In the top pic, you can see a pretty significant lip, looks like about 3-5 thou.......

But, the wear seems very smooth and polished, not all scratched and galled....

In your situation, with the intended use, I would use it, but, then again, I am the king of building stuff with my best least worn used bits.....

Just assembling a diff for my own use that has parts out of 4 different diffs, will be used in a similar situation to yours.....

I decided to change mine as it looked a bit worn!

I dunno, I think you're being a little premature, that thing has at least another week or so in it.......

olddave wrote: ↑Fri Mar 19, 2021 5:55 pm I decided to change mine as it looked a bit worn!

gearbox 3.jpg

Gerit welded up olddave , then grind/rasp it to size or near enough , it'll go again

gs.davies wrote: ↑Fri Mar 19, 2021 4:22 pm ,,,,, I presume a standard Rover one will be OK.

The Pins that had the Cross Hatch Pattern on them were very good, but the later and current types with the flats on them aren't even suitable for a child's pedalcart. One of the uprated types are better. The Wear in the pins really doesn't have a whole lot to do with how much power the car makes, but more so how many bends you drive through.

If replacing the Pin, the Gears too should be replaced, as they'll be worn too.

It's also worth fitting the latest Thrusts for the Planet Gears, though you'll need to mill / file / grind a could of slots in the Diff Cage for the Ears on the Thrusts. I think by the look of your old Centre Pin, you would have Brass Thrusts for the Output Shafts - keep those. The later Fibre Types fall in the same category as the Pins with Flats.

Spider wrote: ↑Fri Mar 19, 2021 6:59 pm

gs.davies wrote: ↑Fri Mar 19, 2021 4:22 pm ,,,,, I presume a standard Rover one will be OK.

If replacing the Pin, the Gears too should be replaced, as they'll be worn too.

Where do you buy decent gears or even crown wheel and pinion these days?

olddave wrote: ↑Fri Mar 19, 2021 5:55 pm I decided to change mine as it looked a bit worn!

gearbox 3.jpg

Maybe I’ve been a bit hasty in retiring mine

Exminiman wrote: ↑Fri Mar 19, 2021 7:10 pm

Spider wrote: ↑Fri Mar 19, 2021 6:59 pm

gs.davies wrote: ↑Fri Mar 19, 2021 4:22 pm ,,,,, I presume a standard Rover one will be OK.

If replacing the Pin, the Gears too should be replaced, as they'll be worn too.

Where do you buy decent gears or even crown wheel and pinion these days?

Not sure which particular gears you're referring to here Marc ? If its Planet Gears, when I did buy them, I was on good terms with my suppliers, so I'd go through just about all they had and select the best from their batches. I no longer run open diffs, so I may only but 1 or 2 sets a year now for the rare times I do 'outside' jobs.-

I gave on on Crown Wheel & Pinions years ago. I designed my own, which I have made;



In the taller ratios, for a Mini, generally the factory items are OK, but in a Big Wheel Moke of any configuration, they are junk.

If the pins feels "undridged" I'd check the planet gears. If there's any scoring, replace. I don't know how many diff pins I've bought the last few years (RICH?) but it1s quite a few, and no problems laters. However, I ALWAYS fit the lipped gear washers. That makes a massive difference to longevity. Yes, this requires a modification, but thats's five minutes with a file.