4 replies to this topic

[Ozzy109]

Just writing a new post about a previous oil leak post (http://www.theminifo...a-big-oil-leak/)

Found a missing bolt (only have 3 out of 4 bolts) on the right hand side of the crank case and wondered what bolt I needed to fill it? Its 11mm head but not sure what the thread is like.

Anyone know what its going into (possible crankcase)? And could you tell me what I exactly need as the replacement?

Look on the original post for more info

A photo is here to show you what I mean:

Thanks

 IMG_1348.JPG   61.17K   24 downloads

[matty...]

Thats the speedo housing, thats bolted to the side of the gearbox, and im fairly certain that ,missing bolt is actually a locting dowl.

most of the bolts on the gearbox are 5/16 UNC.

That oil leak looks like it could be coming from higher up, something like the timing cover gasket or half moon seal.

[coopdog]

yeah thats meant to be missing :)

[tiger99]

The bolts are UNC, not metric, and if the head seems to be 11mm, it is actually 7/16". Please use the correct spanners always. This particular size has the best match of any between imperial and metric sizes, but it it is not perfect and forcing a metric spanner on will damage it, and possibly ruin the next metric bolt that you use it on.The aggro of extracting a chewed bolt greatly exceeds the difficulty of obtaining the correct tools. Oh, and even though the difference seems to be tiny, a 7/16" spanner will invariably strip the head of a tight 11mm bolt.

Actually, as I remember these bolts, they are not 11mm or 7/16", but have a 1/2" head, which does NOT match 13mm closely enough for the metric spanner to be in any way useful. The thread should be 5/16" UNC.

There are also two smaller bolts, which should be 7/16", holding a small cover plate on to the main casting.

What may be more useful than that info is that the gearbox very rarely leaks in that area unless it has been disturbed, so your oil leak is probably coming from elsewhere. Clean it carefully, run the engine for a bit, or if necessary drive a short distance, and see where you find the oil. You can also take these bits off, i.e. complete speedo drive gear housing, to fit a new gasket, should it turn out that yours is really leaking. Just jack up the gerabox at that end, remove teh engine mount, and the rest is obvious. Drain the oil first!

Edited by tiger99, 21 August 2012 - 08:36 PM.

[Cooperman]

As 'tiger' says.
Oil running down from that area usually comes from the bottom of the timing cover where the 1/4" UNF screws at the bottom have been over-tightened and the gasket has split. Very common problem.