Pinion Nut Removal

[850man]

So using an impact driver is OK?

From the damage I've seen, no.

Thing is, it won't damage the Pinion, but the larger problem with using an Impact Driver here is the Gearbox internals are quite dry of oil, and many parts have case hardening - Bearings, Shafts and the Gear Teeth. The action from the Impact Driver on these can fracture these Cases and if not picked up, later in use flakes off. The Bearings may not be a big deal, as they would usually get replaced, but I think items like the Gears, the Mainshaft, the First Motion Shaft and Laygear are a different story. The tighter the nut is, the worse it will be on all these parts.

Imack's Ball Joint Spanner I feel is a good idea. I have an Open Ended Ring Spanner that I have used from time to time. When using the Socket, if I have troubles keeping the Socket square on to the Nut, I've just put a packing piece under the Ratchet Head, though Bob's solution is nicer.

hahahahahaha, sometimes I wonder about the mental state of some people.
Not once ever have I damaged a gear by using a rattle gun to undo a pinion nut.
Maybe if you were silly enough to lock it into gear and let the thing rattle itself to death while attempting to undo the nut it might chip a tooth, so as I said in my last post, hold the socket to prevent it spinning and DO NOT have any gears locked together.
Hell, 30 years ago I was doing this as a young kid working after school in Australia's biggest and best Mini business, stripping hundreds of gearboxes so the good parts could be sorted & put on the shelf for later use.
If you chip a tooth, you are clearly doing it wrong. Go and buy a decent rattle gun, and an impact socket. That's how the qualified, experienced people do it.

[imack]

[/quote]



hahahahahaha, sometimes I wonder about the mental state of some people.
Not once ever have I damaged a gear by using a rattle gun to undo a pinion nut.
Maybe if you were silly enough to lock it into gear and let the thing rattle itself to death while attempting to undo the nut it might chip a tooth, so as I said in my last post, hold the socket to prevent it spinning and DO NOT have any gears locked together.
Hell, 30 years ago I was doing this as a young kid working after school in Australia's biggest and best Mini business, stripping hundreds of gearboxes so the good parts could be sorted & put on the shelf for later use.
If you chip a tooth, you are clearly doing it wrong. Go and buy a decent rattle gun, and an impact socket. That's how the qualified, experienced people do it.
[/quote]

Never used a rattle gun on a mini box myself but as you say if the box isn't locked there's nothing to damage but as you also mention, you probably need a decent rattle gun, most of the budget ones are absolutely useless.
How are you tightening the pinion nut again? Rattle gun or lock it and torque wrench?

[850man]

Never used a rattle gun on a mini box myself but as you say if the box isn't locked there's nothing to damage but as you also mention, you probably need a decent rattle gun, most of the budget ones are absolutely useless.
How are you tightening the pinion nut again? Rattle gun or lock it and torque wrench?
[/quote]

I made a tool that I use to lock the mainshaft and then do the nut up with a torque wrench. Never used locktite, only ever used a new locktab. On all types, from an std 850 to a 200hp twin cam. Even the ultra performance 13in wheel Mokes that are well known for smashing pinions and destroying centre webs still just get 150ftlb and a locktab.

[Oneball]

Thanks 850man will try that route next time.

[Gary Schulz]

Well if you actually can do it without locking the gears, then you are certainly correct that there is nothing to break!

I would need to buy a pretty serious impact wrench then. All I have is a 3/8" drive Milwaukee. Don't suppose that would do it...

I am quite sure I would also need to go back and reinstall the diff ring gear. The only way this works is if it has the inertia of all the gears (especially the large ring gear) to work against.

[Andrew1967]

Next time I have one to take apart that I'm not bothered about, I'll try the works £500+ battery Snap on impact gun in the way you suggest 850man.

[MiNiKiN]

To prevent gears from spinning during impact gun application, I put a piece of annealed copper sheet between the gears. Copper is very soft and doesn't harm the hardened teeth of gears.

[850man]

To prevent the gears spinning while using a rattle gun, as I have already said, hold the socket with your hand. Its that simple.

[Gary Schulz]

To prevent the gears spinning while using a rattle gun, as I have already said, hold the socket with your hand. Its that simple.

Well I can absolutely confirm this is correct. Instead of locking up all the gears and risk breaking teeth, I bought myself a decent impact gun and put it on the pinion nut while holding the socket to prevent it spinning and within about 4 seconds the nut was off and in my hand. I highly recommend this method for removing the stubborn first motion shaft nut and pinion nut.

Thanks 850man!

[floormanager]

What gun did you buy?

[Gary Schulz]

From Amazon-

20201124_133107.jpg

[winabbey]

To prevent the gears spinning while using a rattle gun, as I have already said, hold the socket with your hand. Its that simple.

I recently watched 850man use this method during a rebuild of my own Cooper S gearbox and confirm it works exactly as he says.

[floormanager]

From Amazon-

20201124_133107.jpg

Excellent, thanks! Amazes me that the amount of effort I put into trying to undo the pinion nut, by locking the gears and standing a mini on the box while I stood on the bar and failed to move it, could be undone by using an impact gun and not even locking the gears. Weird stuff

[970s]

Not fancy special tool but my handy angle bar made the job straight easy!
I use the good old IR impact gun to un done the nut and a spare gear put between the gears to lock is preferred instead of engage 1st and 4th gear.

Al

[woodypup59]

Have you guys ever broken teeth by locking up the gears internally? This seems to be crazy tight

Yes I have. Effectively writing off the whole gear cluster.

[Gary Schulz]

The beauty of 850man's approach is no gears are engaged so nothing is overly stressed. In this case I just reinstalled my diff so the pinion had some inertial load to work against but this is a really great method and quite painless with no need to fixture the gearbox to prevent it from moving.

I will be fixturing it to assemble things but in that case you are working with known amounts of torque that you control so the dangers are a bit more manageable.

In this case I would say whoever assembled mine might have used an impact gun to assemble it so it made disassembly by locking the gears a sketchy proposition.

[rogerotto66s]

I have an 1 1/2 deep impact socket, 1/2 inch drive. And a CP rattle gun. I grip the socket with one hand and squeeze the trigger of the gun with the other. I have never, ever not been able to undo a nut, and I have stripped 1000s of gearboxes. EDIT - No need to ever lock the mainshaft.

Just used this method. Both large nuts removed very easily. First time using an impact wrench (rattle gun). Much easier than alternative. One nut required 1 1/8” socket and other required 1 1/2” socket. Thanks!