Sump bolt tightening

[skippyc]

Attached is a diagram of the sump bolts with numbers. What is the best pattern for best results?

[georgesgiralt]

Hello,
I've done that in order to close a leak.
I did it in a criss-cross pattern : 1-8, 12-5  and so on. First pass was to put bolts into contact with the sump. Then another pass at middle of the prescribed torque and a final pass at the correct torque.
Remember that these bots are small and the thread in the housing is fragile. So having to put an Helicoil with your back on the garage concrete will be no fun...

[nhmaf]

+1 with George - Side-side or criss-cross is OK, but the main thing is to do it in 2 or 3 stages of tightness to the proper torque (with dry threads).  The alloy block is fairly soft so you really want to avoid stripping the threads.

[Barry]

I don't recall ever seeing a sequence pattern for the sump so if I had to come up with one I'd do it like this:

3 -10
14 - 6
13 - 7
1- 8
12 -5
2 - 9
11 - 4

I suspect doing it in multiple stages is more important than the pattern

[mrclubike]

If mine ever  needs to be taken off I will try to reinstall it  with studs
Small threads in aluminum are very fragile 

[Matt Chapter]

I'm pretty sure I replaced this gasket recently and also did some sort of criss cross pattern with multiple tightening stages.  Definitely do not over tighten!  And while you have the oil pan off, make sure the gasket surface is clean and level and so forth.

[skippyc]

I like the stud idea and am going to look into it. thanks for the ideas.

[Justin B.]

I agree with Barry.  When there is no torque pattern listed in a shop manual they refer to this as a "logical torque sequence."   The three stage tightening is also a good idea.

[marcmax]

I'm waiting on delivery of a silicone sump gasket from realgaskets.com and I am sure I will be very light on my torque specs when I install it due to the sealability and compressability of the silicone gaskets. I know when I replaced my valve cover gaskets with silicone gaskets I used a lot lower setting with no leaks.

[nhmaf]

Be careful with that squishy sump gasket, marcmax - I got the squishy silicone valve cover gaskets for my R100 as it seems to have slightly non-flat head surfaces (and it works good there) so I got the same silicone oil pan gasket to try to stem a leak on the bottom that didn't seem to go away with a good surface cleaning and new OEM gasket.   It is pretty tricky estimating the torque on those bolts with that squishy pan gasket - it just seems to keep on squishing.   I've still got a slight leak in one spot cause I think the gasket has deformed and bulged out of position.  I don't dare tighten it anymore so I'll soon be dropping the pan again and trying it over... might end up going back to OEM gasket and putting a bit of form-a-gasket under the heads of the bolts... I think some of the sump pan bolt holes on some of the airhead model engine cases actually aren't blind and go into oily areas.   Does anyone know for sure?

[Barry]

I recall the original gasket has adhesive on one side presumably to face upwards so that the gasket is retained when the sump is removed.

Somewhere I have a spare one that came with the bike but as I see no evidence of a leak I've never had to use it.