Dog gear fit on 915 gearset - too loose

[mikedsilva]

This gearbox is kicking my a$$.

I went to mount the gearsets for selector fork alignment and noticed a tiny gap between the dog gear and third gear.

During assembly of the shaft last week, I stupidly put the 4 point bearing and retainer plate on backwards, so had to remove the parts to refit. I did the old, "drop it on a block of wood" method..
I think this is what caused the gap but I have NEVER seen this happen before (only done a handful of these boxes).
The gear is the origninal porsche 3rd, and the dog gear is a brand new Albins.

So I went to remove the lot again and when I put the gear in my press to slide the dog down, it went on far too easily.

Trying to figure out if I
- have a bad dog gear ? (new Albins shouldnt be an issue)
- have worn splines on the gear itself?
- or something else?

A friend pointed me towards an old thread which didn't have any real answers for me.
Loctite or bearing retaining fluid sounds like a no go.
If attempting to peen the gear, what would be the right method?
How tight should the dog gear actually be on the gearset?

Open to any suggestions.

https://forums.pelicanparts.com/porsche-911-technical-forum/260070-welding-dog-teeth.html#post2342375

[Jonny042]

Seems odd. Did you press the dog gear on and do you recall how it went? Same question about removing the original one, any trouble? For the price of a dog ring it might be worth getting another one, I'm sure since you're in Australia, Albins would be more than able to dispense some advice and send a replacement asap.

[gled49]

Most of the time replacing shift hubs goes ok. But have had lots of loose hubs that can’t be repaired, glue doesn’t work, welding doesn’t work and there is really no way to stake the splines. I read people say, I had my gearbox rebuild and replaced all the shift hubs/dog teeth. Factory attachment can’t be duplicated, I never replace a shift hub unless absolutely necessary. When the gear is critical I replace it. Low 3rd gear ratios are particularly venerable to problems.

[shoooo32]

I read somewhere that you should grind a slot in the dog gear to release tension before pressing them off (maybe Pete's Wiki?) so that's what I've always done.

[john walker's workshop]

We used to do a couple of tig spots on vw dog teeth for racing purposes.
I dress the swages a bit before pressing on the dog teeth. The inner bore can be distorted if you don't and can cause binding on the needle bearing, potentially causing issues with the bearing and the bore. Never had any come loose, that I know of.