Cracked Gearbox Case

The thin area between the main and layshaft seals. Worth repairing, or just 'glue' the new bearings in place?

Quite common and mostly ignored.

They all do that. Assume you mean between BEARING pockets, not seals? Pics.... Mine's been ok for 25,000 miles since I discovered it.

concours said:

They all do that. Assume you mean between BEARING pockets, not seals? Pics.... Mine's been ok for 25,000 miles since I discovered it.

Click to expand...

Yes, the pockets for the bearings. Sorry.

Where arrow points:

Is there a chance the bearings could start to spin since there is less friction? If so, what about using some Loctite around the bearing on install?

rockitdoc said:

concours said:

They all do that. Assume you mean between BEARING pockets, not seals? Pics.... Mine's been ok for 25,000 miles since I discovered it.

Click to expand...

Yes, the pockets for the bearings. Sorry.

Where arrow points:

Is there a chance the bearings could start to spin since there is less friction? If so, what about using some Loctite around the bearing on install?

Click to expand...

It is possible the bearings could spin, but that happens with the sleeve gear bearing fairly often even if the case isn't cracked. Might only be after high mileage or hard use, or maybe running the primary chain too tight, but I've run across several that were loose enough to slide back and forth in the housing. I haven't had that happen with the layshaft bearing, but I would imagine that's possible too. I don't use Loctite on the layshaft bearing because it makes it much more difficult to remove. I've used Loctite 620 successfully on the sleeve gear bearing, but you can also use one of the other bearing mount compounds, as well as the regular thread locking compounds. Loctite has a good user's guide on which compounds to use here

http://www.loctite.sg/sea/content_data/LT4680.pdf

Be forewarned that not all the forum members are fans of Loctite for such applications, so you may get some varying opinions. I'm just passing on my own personal experience.

Ken

According to Loctite, the 609 green medium strength would be the appropriate 'glue' for a press fit bearing. That's what I'll use unless I get convincing arguments against it. I don't want those bearings moving in the pockets.

rockitdoc said:

According to Loctite, the 609 green medium strength would be the appropriate 'glue' for a press fit bearing. That's what I'll use unless I get convincing arguments against it. I don't want those bearings moving in the pockets.

Click to expand...

While I am a Loctite fan, I would advise against the use of a green retaining compound as you'll find it almost impossible to replace the bearing when it becomes necessary. A pink or purple grade would be much better.

I tried various types of loctite there. None held.

Fitted a clutch bearing with green loctite compound, heated to remove it with little fuss...