B2 90Q rear gearbox seal

[David42U856]

Originally Posted by Groundhog

Cap head bolts are usually harder than standard bolts so make sure you have a keen drill and bit. If you have one a number 8 multi splined sockets ( used on drive shaft bolts) it can be hammered into the cap head....has always worked for me 99% of the time.

Unfortunately, the multi-splined sockets didn't work. I tried three or four times with the 8mm version but was unsuccessful. The next size I have is 10mm, so a big step up - I guess I should try it though. I'll soak it with release oil for a while. I got the loosened screw out and have ordered new ones. I think I'll try installing two new screws with loctite and see if that solves the issue. I've got a bad feeling about drilling the top off the damaged screw as I'll end up with a dowel holding the damper/counter weight in place and a flange that stops me removing it. If that happens I'm screwed.
Incidentally, the screw I removed has a vertical crack in the side of the cap head. Not a failure mode I've seen before. Have you ever seen a cracked bearing support housing as a result of loose/missing screws? If the screw can crack I guess the bearing housing can too.

[David42U856]

Image of cracked screw (90Q rear output shaft bearing housing)

[mikes2]

I take it there's no room for a grip socket in the space available ?

These have saved my bacon a few times on rounded cap bolts

[Groundhog]

Sorry to hear it wasn’t successful. It would seem someone has been there before you and failed. The split bolt, I suspect, is as a result of a previous removal, I’m guessing someone hammered something to big in there, it had the desired effect in that I would imagine they removed it but then failed on the last bolt which is why the splined socket trick won’t work. I would do as you said replace the two and keep your fingers crossed.
I have never known a housing to split.

[tractor Dave]

Have you got a mig welder?
Weld a small bolt in there.
Don't forget to remove you ecu's first.

[David42U856]

Originally Posted by mikes2

I take it there's no room for a grip socket in the space available ?

These have saved my bacon a few times on rounded cap bolts

Unfortunately, it's about 10mm down inside a counter-bore - so pretty inaccessible. Thanks for the suggestion though. I've never used a grip socket - sounds like it worth having in the tool kit.

[David42U856]

Originally Posted by tractor Dave

Have you got a mig welder?
Weld a small bolt in there.
Don't forget to remove you ecu's first.

I don't have a mig welder. The head is down inside a deep counter-bore though so there's no access. Thanks for the suggestion though!

[David42U856]

Originally Posted by Groundhog

Sorry to hear it wasn’t successful. It would seem someone has been there before you and failed. The split bolt, I suspect, is as a result of a previous removal, I’m guessing someone hammered something to big in there, it had the desired effect in that I would imagine they removed it but then failed on the last bolt which is why the splined socket trick won’t work. I would do as you said replace the two and keep your fingers crossed.
I have never known a housing to split.

Waiting for the bolts and CV joint grease to be delivered. Hopefully they arrive in time to put it back together on the weekend. The grease in the prop-shaft CV joints was pretty dried out so I plan to clean and re-grease.

[John.]

Originally Posted by David42U856

Unfortunately, it's about 10mm down inside a counter-bore - so pretty inaccessible. Thanks for the suggestion though. I've never used a grip socket - sounds like it worth having in the tool kit.

This is the type, https://www.ebay.co.uk/itm/221924576...IAAOSwXWZgtjkC , very handy things to have but sounds like your bolts might just be un-accessible for them ?

[David42U856]

Thanks for the link John. Much appreciated.