What to do with crankcases apart?

[pete]

Hi guys,

I'm sure I've seen this around somewhere on the forums before, but buggered if I can find it again! My searches have revealed nothing that I can see, but probably just me doing a bad search :-)

Anyway, I'm hoping soon to get my crankcases apart now that I've discovered my impact driver has a socket driver on the end (never knew this for 8 years!).

So, apart from the obvious visual inspection and clean up of everything and my need to look at the gearbox components, what else is good to be done while it's apart?

It's taken me years to get to this point, so I want to do it properly so it lasts quite some time once I get it back together.

It's an '81 450 by the way.

[NICK!]

Cases. Scrape, scrape, scrape, clean, clean, clean. Chase any troubled threads and Helicoil stripped ones. Makes sure your studs are tight and threads OK. Blow everything out with compressed air.

Trans inpection. Looks for damaged slots and dogs, bent forks worn shift drum and stickey or rough feeling bearings.

Crank. This is a plain bearing engine so look for scored journals and worn bearings. Plastigage the bearings if you suspect large clearances. Look for bent rods or scored small ends.

Great time to mask and paint, it really pays off in appearance if you paint everything while its apart. After reassembly with new gaskets it looks like a brand new engine.

I'm sure I've forgotten something, been years since I've been inside a bottom end.

[Larry D]

been years since I've been inside a bottom end.

Sorry to hear that Nick!....

[NICK!]

LOL!!! Yeah, that too. :P

[pete]

Thanks Nick, I will definitely be painting while it's apart.

The rest of the tips I'll do to the best of my ability also :-)

Had some minor issues with changing into 5th and 6th where it would drop back to 4th and 5th under hard acceleration unless I really shoved the gear change hard, which is why I'm splitting the crankcases.

[NICK!]

Hmmm, thats unusual. If anything its second gear that slips out. Take a good look at the shift shaft and drum ratchet (pawl, whatever they call it) also. Let us know what you find.

[pete]

I actually have a feeling it's worn splines on the shaft where the gear change lever sits. Was rather loose on them when I was pulling it apart, even though the screw clamping it on was done up as tight as could be.

[journerr]

Take pictures of before & after & keep us informed how it all goes ?????

[pete]

Actually I do already have some pic's somewhere of before... will have to find them on photobucket, not that it really shows how loose the splines are, but at least it's a pic :-)

[NICK!]

Pete, heres an old trick to tighten up the gear change lever on the splines. Clamp the lever in a vise so that it closes up the split that the bolt tightens up. Take a hack saw and saw through that split, this makes the split wider and then the bolt can draw it up tighter.

[pete]

Thanks Nick, that could be a real simple fix that never even crossed my mind... no wonder I come to these forums!

[pete]

Found my before pic's of the gear lever... sorry they're so crap, photography is not one of my talents.

Unfortunately I've also cut these pic's down for my old web page and I don't have the large originals anymore.

[NICK!]

Pete, check those hiem joints. Thats the rotating pieces at each end of the adjusting rod. They have a habit of going bad. Sometimes the mounting stud gets loose, not hard to fix. Sometimes the hiem joints themselves get REAL sloppy and can cause problems. If your joints are still good, look up and say "Thank You" and get some grease in them somehow. If they are bad I'm afraid that is expensive.

[pete]

Thanks again Nick. Somehow I don't think I'll be saying thank you, I think some four letter words may be uttered instead as I recall them being rather loose and not good at all...

I'm not too worried at this point though as I was thinking of buying or making some rear sets anyway.

[pete]

Well I managed to get one of the two allen bolts holding me up removed today. Yeehaa!

Unfortunately, I then managed to snap my last remaining allen bit on the other bolt, so gotta wait until I can get some more.

Hopefully my mate will be picking another couple up tomorrow and I may get a chance to have another go next weekend.

Looks like a combination of lots of WDF, lots of blows with the impact driver, and a bit of leverage on a socket driver will do the trick. Just gotta be careful with the socket driver as that's how I've busted all the allen bits so far.