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Just reassembling the gearbox for my pick up and on close inspection of 2nd gear I am concerned that there might be terminal wear on the small teeth.

The teeth are not symmetrical like on the other gears and I am thinking that this is wear and not really acceptable. Hopefully you'll see what I mean in the picture.

Its from a '79, pre A plus (but with larger idler and three step type laygear) gearbox which is still 22G1094 I think.

Anyone able to comment and maybe supply a gear (good used is OK) if necessary ?

Thanks in advance

Andrew

I always build my own gearboxes , have done for years , and I would personally change it . 2nd gear is the important one for me . I wouldn't want to risk building it all up to find that there is then a problem . ... Ken

the lead ins on the small teeth are meant be different, if you look at any gear they are different in batches, so you will get (say) five, then a change, then five, then a change.

its to help the syncroniser hub engage with the teeth and stops the gear 'grabbing' in as they go together.

its one of those things that people never really spot with gears!, thought sometimes its not that obvious

I think the ones in your photo look worse as they look a bit chewed up

Thanks Ken and Rich,

That's my thinking too Ken, its too much to take out if it is a problem.

Having known the animal who drove the car that this unit came out of, I think it had a hard life and would not be surprised at all if the gearbox took a hammering.

I have found another 2nd gear and the teeth seem much less chewed or worn and are more symmetrical in appearance. However, the main teeth are a little rusty

Anyone got a good (or possibly new) 2nd gear ?

Cheers

Andrew

Have you tried geussworks . Very helpfull on gearboxes and always quick delivery ... Ken

swifty wrote:Have you tried geussworks . Very helpfull on gearboxes and always quick delivery ... Ken

According to his website the 22G1094 is currently out of stock Ken, could drop him a line though just in case.

Bin it.

If there's any wear on the dog teeth, they are binned at mine.

As far as I'm aware no one is making new ones of these for the pre a+ mainshaft. It is a little thoughtless to simply say bin it, especially with a not so great photo of half the gear.

If you're worried on either counts take both your gears into a specialist and get them to check them out. The dogs are very important but by their nature they will wear and chip depending on driving style, so it is very common to see a few chipped dogs, and a bit of rounding. It may still have life in it.

If the rounding is too severe or too much chipping has occurred then you need to seek a replacement. Also the dogs on the gear are only half the story, you need to take in your hub as well, I believe you can get replacement hubs.

Usually 2nd is the worst, this is why it's so hard to get good second hand units.

Thanks for your reply 69k1100.

The picture of the gear does show how all of the dog teeth are cut/worn (?). There not a huge amount of rounding or chipping, its just the non-symmetrical way they have either been cut or worn that concerns me.

It does seem that the 22G1094 is currently not easy to find although Rich says that MS will be getting some new ones in in a couple of months.

I have got a NOS 1st/2nd hub so that'll be OK on that side.

Also found an old 4 sync mainshaft with some gears on so will have a look at 2nd to see if its any better but would be nice to fit a NOS gear if possible as most of the other gears are going to be new.

Thanks

Andrew

I agree with V, that gears fooked………
from what i've seen there are better secondhand ones available.

If they're not chipped or rounded then I can't see an issue, they can be cut asymmetrically from the factory, some are shocking.

The other thing to Check is how much the moly coating on the cone has worn, you can check this with a baulk ring and a feeler gauge. If the gap between the baulk ring and the feeler gauge is less than 1mm then you either need new baulk rings or a new gear.

Generally the more worn the cone the better the dogs as the driver waits for the gear to fully match the hub speed before engaging it.

So either a Nanna wears out the cone, or a chav bang shifts it. You can't win really.

Edit

To visualise what's happening get two sharp lead pencils, try to put them point to point. They should slip past each other easily, this represents the pointed dogs. The profile doesn't matter much, they just have to have some sharpness to them. Now blunt both pencils, it should now be far easier to rest the points together, in this situation the dogs and the hub will tend to skate past each other. The difference is a box with a positive shift that you don't have to wrestle with and a box that will need more pressure on the stick to get the gears to engage.

69k1100 wrote:
To visualise what's happening get two sharp lead pencils, try to put them point to point. They should slip past each other easily, this represents the pointed dogs. The profile doesn't matter much, they just have to have some sharpness to them. Now blunt both pencils, it should now be far easier to rest the points together, in this situation the dogs and the hub will tend to skate past each other. The difference is a box with a positive shift that you don't have to wrestle with and a box that will need more pressure on the stick to get the gears to engage.

this is a good indication as to why the dog teeth are cut in an asymmetric pattern, it means that no matter where the dog teeth on the synconiser are, they will always be a position on the dog teeth on the gear where they will 'lead in', if all the teeth where in the same position it would be possible to go 'dog to dog' and the gear would 'snatch' its self into mesh, which will wear the teeth faster than normal (which is what happens when people 'ram' them into gear and beat the syncro)

I'll take some more photos and post them up as I'm not sure now if they are worn or just cut assume asymmetrically to quite an extreme.

There doesn't appear to be any chipping or rounding to the dogs so ambitious worrying over nothing

From the photo of your gear, it does appear OK to me.

Here's a couple of gears, both used, but the one on the right has had the biscuit, you can see the dog teeth are rounded, were as that on the left are still nice and square;-



The one on the right was jumping out of gear.

From my experience, the chipping is usually from slamming them through the gears, however the rounded teeth are from worn selector forks. When they are worn, it doesn't fully engaging the hub to the detents, and then with the small amount of play in the shafts and bearings etc, they don't hold and slip out. Once they have done this more than about 4 - 5 times, they teeth will have rounded as it usually happens (particularly with 2nd and top) under power.

Here's a couple more pics of the gear with hopefully a clearer view of the cut and wear of the dog teeth.

All the dog teeth are much the same as those on view.

Any views or opinions ?

Andrew1967 wrote:Any views or opinions ?

Just an opinion...

The moly on the cone is good, the teeth do not appear to be worn, just not centered very well with the angular cuts. This will slow the engagement down a little.
The speed synchronisation will as normal if you use a new baulk ring.

If it was me and I had a choice of the one with the worn moly and mashed teeth, I would use this one and just be careful with it for a few hundred miles.

You will very quickly get the 'feel' of it once it is used.

Thanks for your thoughts Smithy,

The more I look at the gear, the more I think its just piss poor machining rather than wear.

Although the previous driver this car was an animal I did drive the car a lot before that and it always had a good gearbox.

Anyone else with any views before I bite the bullet and stick it back in ?

Cheers

Andrew