Topic: Remove Oil Pan. Easy job? "73 CB750"

[sm8]

I noticed an oil leak from the oil pan drain bolt. Looks like the crush washer is missing and the bolt got over torqued and split the oil pan at the bolt thread. I guess the PO didn't bother to replace the washer.
I ordered a good condition pan off eBay. Got a NOS gasket and a new bolt with washer.

It seems like an easy job to remove the old pan and replace it. Besides the obvious of draining oil, is there anything i should be aware of with removal? I see all the bolts that hold the pan in place, I'm assuming I remove the bolts and the pan drops down.

I'm new to old motorcycles, so I wanted to check in with you guys before I start removing stuff. Nothing is going to fall out right?

I'm hoping this is something I can accomplish myself in an hour or so while the bike is up on the center stand. Any advice is much appreciated. Thanks!
-Steve

[Bankerdanny]

It should be very straight forward. My 550 is wet sump, so a bit different, but the pan just unbolted and dropped right out the bottom of the frame.

[Jerry Rxman Griffin aka MuthaF'er]

As easy as it looks. See what surprises await you in the pan. Clean the screen too. I just checked the torque settings for 6mm flange bolts before I reinstalled my pan. 7 to 10 ft lbs. A 1/4 inch torque wrench would be best. 84 to 120 inch lbs. Got one for $10 at Harbor Freight.

[70CB750]

It depends what exhaust you have, for mac headers - and maybe others too - it is necessary to remove them to get all the bolts out and pan off.

[MCRider]

Yeah, depends on the exhaust.

AS to torque, beauty in the eye of...

http://www.salocal.com/sohc/tech/torquetable.htm

I would take a 6mm (are these flange bolts? Mine are allens) only to the bottom of the range:  See if it leaks. If not leave it. If yes, tighten a skosh more.

This chart has the drain bolt at 25ft lbs! Wow. I'd go till its snug, then an 8th more to crush the washer and give it the drip test. If it dripd, tighten a skosh more.  MAybe 10ft lbs max.

To each their own.

[flybox1]

My kerker needs to be removed to get to all the pan bolts.  Allen heads made this easier, though.

On installing your replacementpan and gasket, be sure to wipe your gasket in oil, and apply some thread sealer to all the 6mm pan bolts and 90inch lbs torque is all you need.

[sm8]

Great advice everyone! Looks like i need to drop the exhaust to reach all the pan bolts. Its a Mac 4-1.

Hoping I don't find anything too bad in the bottom of the old pan 

I'll repost here when its all done.

Thank you!

[MCRider]

Great advice everyone! Looks like i need to drop the exhaust to reach all the pan bolts. Its a Mac 4-1.

Hoping I don't find anything too bad in the bottom of the old pan 

I'll repost here when its all done.

Thank you!

While the pan may have deposits, as already mentioned, look up into the beyond you'll see the wire mesh screen on the bottom of the oil pump. You'll want to inspect that too, which can be done without removing anything more.

But if you have time to kill, or later this fall, you may want to freshen up the oil pressure by removing the pump and replacing the ORings. Many threads on doing this.

[Stev-o]

I did mine recently, piece of cake [exhaust was off].

A couple of the bolts were more easily removed using a 1/4" ratchet extension [as opposed to 3/8"].

Be sure to remove all of the old gasket from the bottom case and do not over tighten - see Rons post above for torque info.

[70CB750]

+1 on 1/4". Short and long extension and you are good to go.

[Jerry Rxman Griffin aka MuthaF'er]

Just a FYI, my torque figures came from the Honda Service Manual AFTER I snapped one using the 3/8" torque wrench.

[MCRider]

Just a FYI, my torque figures came from the Honda Service Manual AFTER I snapped one using the 3/8" torque wrench.

Jerry: I thought it may sound like I (we) were picking on you. Not the case. I didn't doubt you had a good source.

That chart I posted had your same figures for 6mm Flange bolts. I looked up on a microfish at motogrid.com and they say flangebolts in the list, but the picture is a std bolt with a washer, which carries a lower torque value.   So some contradistion there.

My comments are my personal experience and what I like, which is a lower still torque as those bolts can strip the cases or break as yours did.

[Jerry Rxman Griffin aka MuthaF'er]

Understand. When I went to buy 3 new 6 X 35's for my oil pump at the local Honda shop couple weeks back the kid goes for the drawer. I told him if they aren't in Honda bags I don't want them  And that's precisely why, there is no telling what the quality of generic fasteners are and I don't wish to snap another. Plus the flange bolts vs standard bolts have different torgue figures I think (without looking them up). That's why I dug out the Honda torque figures from my manual. You and I both know how expensive these things can get!    Probably more than anyone else here. 

[MCRider]

Understand. When I went to buy 3 new 6 X 35's for my oil pump at the local Honda shop couple weeks back the kid goes for the drawer. I told him if they aren't in Honda bags I don't want them  And that's precisely why, there is no telling what the quality of generic fasteners are and I don't wish to snap another. Plus the flange bolts vs standard bolts have different torgue figures I think (without looking them up). That's why I dug out the Honda torque figures from my manual. You and I both know how expensive these things can get!    Probably more than anyone else here.

Yes, the flange bolts are higher than the non-flange bolts.

I'm not up to a million dollar MRieck baby, but close. 

[sm8]

Got it all done last night. Everything went smoothly. Thank you all for walking me through it. Didn't find anything in the bottom of the pan or in the wire mesh of the pump. I ended up adding some 1/4" crush washers to the pan bolts just to add a little more leakage protection.

Now i'd like to replace the front sprocket from 18T to 17T. How complex is that job? Any Advice on that project?

Thanks!

Steve

[MCRider]

Got it all done last night. Everything went smoothly. Thank you all for walking me through it. Didn't find anything in the bottom of the pan or in the wire mesh of the pump. I ended up adding some 1/4" crush washers to the pan bolts just to add a little more leakage protection.

Now i'd like to replace the front sprocket from 18T to 17T. How complex is that job? Any Advice on that project?

Thanks!

Steve

Slightly higher difficulty than the pan. Remove the sprocket cover. Loosen rear wheel axle, then the adjusters so the wheel can move forwrd a bit. Assuming your chain is in decent shape? Shame to put a new sprocket on old chain, but what the heck?

Remove oiler in center for drive shaft. May need to put it in gear to hold drive shaft still. Remove 2 clipi bolts, twist the clip to align with splines and slide off. Fiddle with the chain to get it off. Fiddle some more to get old chain on new sprocket, then offer it to splined shaft. Offer clip to shaft and tighten 2 bolts a lot. Reinsert oiler, tighten and afix with clip in splines.

Adjust chain (whole other procedure). Tighten rear axle A LOT (60+ftlbs.)

[sm8]

Thanks MCRider!

I'll tackle that after I get the fork seals replaced. Started leaking this past week.

Another question for you guys. I warmed up the bike to check the oil today. Put her on the center stand and the oil tank was empty. Nothing on the dip stick. No leaks anywhere. I used 3 Qrts of Royal Purple 20w50 Synthetic oil when i changed the pan. Wondering if the 20w50 viscosity being thicker is holding the majority of the oil in the motor? I've also noticed its harder to start in the morning. Also because of the thicker oil?

Should I add another quart? Or maybe just go back to 10w40?

Thanks guys

[Jerry Rxman Griffin aka MuthaF'er]

Infamous leak stopper valve in the oil pump. Want to take the pan off again? Check with Elan, he has kits. Cheap. Just a little tougher than the pan, 3 more 6 X 36 flange bolts hold the pump in place. 2 screws hold the spring and stopper valve in place.

Check your oil level right after running it. If you only added 3 quarts you're probably 1/2 qt low but don't add until you check it this way.

Sprocket is easy. Take the cover off and there it is. Loosen the chain and take it off the old sprocket. Remove the sprocket. install the chain over the new sprocket and install the sprocket. Re-adjust your chain. Bingo. The worst part is stuffing the 2 large wire harnesses back in place so pay attention to the placement of those when you remove the cover.

The 1/4" crush washers aren't necessary, just on the drain bolt. Just be sure you have enough thread on the flange bolts to seat them good if you keep them.   

[sm8]

I decided to check the oil once more before replacing the leak stopper valve. I took the bike on a little ride, came back, put her on the center stand and checked the oil. The tank was full again! I'm thinking because I warmed the bike in neutral on the center stand, then checked the oil, something slowed the pump from returning oil back to the tank. Once i rode it around a bit, it pumped oil back in. Glad that was the only problem. Now i know how to properly check the oil on these bikes. Thanks for all the replies. This forum rocks.