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1971 cb750 countershaft bearing holder

rswilkin

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I am currently in the process of tearing my 1971 engine apart and have run into a quandary. I am having an extremely hard time trying to remove the 5 screws holding the counter shaft bearing holder. I have not stripped the screws, but that is probably going to happen if I continue trying to remove them. Any suggestions? Also can I remove the crank and primary chain without removing the counter shaft bearing holder? If I can work leaving the bearing holder in-place, I would prefer to do so. Thanks.
 
You mean the 4 phillips head bolts on the left side?? If so then you need a hand impact driver, they will come right out. If the heads strip then you will need a dremel with small cutting wheel and make one slot for a straight blade but you still need the hand impact driver... it is the only thing I have found that works the best. You have to remove that holder to split the cases.
 
You mean the 4 phillips head bolts on the left side?? If so then you need a hand impact driver, they will come right out. If the heads strip then you will need a dremel with small cutting wheel and make one slot for a straight blade but you still need the hand impact driver... it is the only thing I have found that works the best. You have to remove that holder to split the cases.

I have a hand impact screwdriver and yes the phillips head bolts. Do you know if back in the day, if Honda used any type of lock-tight. These screws have been the bain of my day. Thank you for your reply.
 
Shouldn't be a problem with an impact driver, those screws all over the engines tend to strip not using one. Shouldn't be any loctite that early used but if a PO has been in motor? Even so, the impact driver should move loctited parts too unless the superstrong stud and bearing type used. The loctite will melt if screw heated but touchy as too long with torch and other things get damaged. Any seals or o-rings there local will go first.

Make sure the impact driver is switched the correct way, common to have them TIGHTENING rather than loosening. Mine is actually marked backwards from the maker, it tries to go tight with it on loosen.

One can often take a sharp flat blade chisel & hammer and dig into screw head on the outside edge to angle sideways in direction to get it loose. You'd best be good though, if not done exactly right then you actually stake the screw in place harder rather than loosening it. The chisel must be super sharp to dig in very easy with as little peening done as possible, if you peen the OD of screw down, it locks harder in place. I start not at the very edge of screw but in a bit, do the very edge and it locks in place worse. You want enough thickness on screw there to hold any deformation to the screw rather than transferring it to the material underneath. Don't punch straight in, try to start sideways in direction to loosen.

Screws are not that hard and a pilot dent is pre-made made by stripping them out, drilling may be necessary-of course the mess.

That type of screw tends to really lock down well with zero loctite and why they are used there. Don't want them coming loose. Look close, they may even be peened in place like staking, a small round sharp punch sometimes used to punch a small mark to lock them even harder.
 
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Make sure you put some preload to the impact driver before you hit it with a hammer, if you dont most of the impact goes toward taking up the slack inside the driver instead of going to the bolt. sharp hit with the hammer needed to make them work the best, normally 3 sharp hits with a decent hammer and the screws come loose for me. Have seen people peck at the drivers with a little hammer and all they do is round the heads off.
 
Make sure you put some preload to the impact driver before you hit it with a hammer, if you dont most of the impact goes toward taking up the slack inside the driver instead of going to the bolt.

Make sure you put some preload to the impact driver before you hit it with a hammer, if you dont most of the impact goes toward taking up the slack inside the driver instead of going to the bolt.

:thumbsup: Very important!
 
Make sure you put some preload to the impact driver before you hit it with a hammer, if you dont most of the impact goes toward taking up the slack inside the driver instead of going to the bolt. sharp hit with the hammer needed to make them work the best, normally 3 sharp hits with a decent hammer and the screws come loose for me. Have seen people peck at the drivers with a little hammer and all they do is round the heads off.

Thanks for the advice. I had an easier time removing the cylinder head studs. I think I am going to split the case with the bearing head in place by removing the top of the case instead of the bottom half. I just am not sure if I can replace the main drive chain once I am in side the case without removing the bearing holder. The reason I am going into the case is to replace the primary drive chain, cam chain and have the crank lightened & balanced and replace all the seals with new ones.
 
you cant split the case with bearing holder in place, it has to come out. part of that holder goes into the upper trans shaft and supplies oil. Wont say cant be done, with a big enough pry bar you can pry anything apart but the holder needs to come out one way or another. If you have a good new bit for the driver and hit it good a couple times they will come out and if they strip out do as I said earlier and grind a straight slot in the head of the screws...they need to come out. You wont get the thing back together with it on there...to much stuff to line up as you put the cases together. Maybe post some pictures of what you got and a picture of the hammer...alot of people use too light of a hammer with the driver and it just doesnt work.
 
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