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Author Topic: CB350F Cracked oil pan  (Read 823 times)

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Offline daniel.cb350f

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CB350F Cracked oil pan
« on: August 02, 2015, 05:57:59 pm »
Hi all, new guy here.

Like folks in a few old posts, I've overtightened the oil drainage bolt on my CB350F's oil pan, causing a hairline crack of around an inch long.

I've read the options on it, and the consensus seems to be that you should either weld it shut or replace it. JB Weld also seems like an option, but not something that is especially reliable.

So, I have a couple questions. First of all, I've had trouble removing the oil pan from my bike. I've removed the 11 main bolts on the pan, while the drain bolt as well as the oil filter are also removed. However, I can't get the thing loose despite pounding on it with a rubber mallet. Am I missing a bolt or two, or are there any tricks to loosening these pans?

Secondly, if anyone has any in-tact oil pans sitting around I may be interested in purchasing one for a reasonable price. Let me know if you're interested in that.

Lastly, I'm not a welder, but am considering blowing a little more money to buy a cheap welding kit instead of a new pan. It's probably over my head, but are there any tips out there on how to repair a hairline crack correctly?

Offline MoMo

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Re: CB350F Cracked oil pan
« Reply #1 on: August 02, 2015, 09:05:53 pm »
Fairly certain I have a good one somewhere in my storage...Larry

Offline flybox1

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Re: CB350F Cracked oil pan
« Reply #2 on: August 03, 2015, 07:19:46 am »
heat it along the gasket seam.  it'll eventually loosen
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Offline skidooextreme

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Re: CB350F Cracked oil pan
« Reply #3 on: August 03, 2015, 07:32:08 am »
block of wood with a BFH

Offline calj737

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Re: CB350F Cracked oil pan
« Reply #4 on: August 03, 2015, 07:39:17 am »
A cheap welding kit won't weld that pan, it's aluminum and requires AC voltage. You might find a cheap MIG rig that does weld alloy, but a TIG would be preferred, and that's not cheap.

If you plan to have it welded, take it to someone who welds for a living. It will cost less than a cheap welding rig, and it will be right.

Your drain plug should have a rubber o-ring on it to prevent over tightening. If not, install one. It's not a torque-fit, it's a compression squeeze  ;)
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Offline MoMo

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Re: CB350F Cracked oil pan
« Reply #5 on: August 03, 2015, 12:10:05 pm »
A cheap welding kit won't weld that pan, it's aluminum and requires AC voltage. You might find a cheap MIG rig that does weld alloy, but a TIG would be preferred, and that's not cheap.

If you plan to have it welded, take it to someone who welds for a living. It will cost less than a cheap welding rig, and it will be right.

Your drain plug should have a rubber o-ring on it to prevent over tightening. If not, install one. It's not a torque-fit, it's a compression squeeze  ;)




rubber cal??   never seen rubber, only fiber washers on the olde bikes..Larry

Offline daniel.cb350f

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Re: CB350F Cracked oil pan
« Reply #6 on: August 03, 2015, 01:24:20 pm »
Thanks all... I'm looking for a new pan locally. Will definitely use a drain plug gasket this time around :)

Offline calj737

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Re: CB350F Cracked oil pan
« Reply #7 on: August 03, 2015, 02:30:25 pm »
Mine have been squishy, presumed rubber, sorry. It sure wouldn't hurt if it were rubber versus non-existent
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Offline MoMo

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Re: CB350F Cracked oil pan
« Reply #8 on: August 03, 2015, 05:23:10 pm »
Mine have been squishy, presumed rubber, sorry. It sure wouldn't hurt if it were rubber versus non-existent



92800-12000  is the part number and is available, some were fiber-some were metal.  A good quality O-ring should work...Larry

Offline daniel.cb350f

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Re: CB350F Cracked oil pan
« Reply #9 on: August 03, 2015, 05:33:24 pm »
I found a pan here locally, which I cleaned up with mineral spirits and am hoping to get installed this weekend. The gasket on this oil pan is brittle, but seems well intact... if the gasket is still smooth, would one just use a sealer like Loctite on it?

Thanks for all the help... this bike has served me well the past 7 years, but now my limited mechanical skills are being tested  ;D

Offline MoMo

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Re: CB350F Cracked oil pan
« Reply #10 on: August 03, 2015, 05:36:14 pm »
I found a pan here locally, which I cleaned up with mineral spirits and am hoping to get installed this weekend. The gasket on this oil pan is brittle, but seems well intact... if the gasket is still smooth, would one just use a sealer like Loctite on it?

Thanks for all the help... this bike has served me well the past 7 years, but now my limited mechanical skills are being tested  ;D



If you go that route use a non-hardening sealant..   New gasket recommended though...Larry

Offline daniel.cb350f

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Re: CB350F Cracked oil pan
« Reply #11 on: August 03, 2015, 08:20:07 pm »
Thanks MoMo. With a new gasket, would one still need a sealant?

Offline MoMo

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Re: CB350F Cracked oil pan
« Reply #12 on: August 04, 2015, 02:31:26 am »
Thanks MoMo. With a new gasket, would one still need a sealant?

I do not use sealant  on anything other than case halves...Larry

Offline DaveBarbier

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Re: CB350F Cracked oil pan
« Reply #13 on: August 04, 2015, 02:56:33 am »

Thanks MoMo. With a new gasket, would one still need a sealant?

I do not use sealant  on anything other than case halves...Larry

I'd say with an OEM gasket you shouldn't need sealant.

Just replaced the Vesrah gasket on my 550 after 6 months because it was leaking. I got an OEM one and used a non-hardening sealant just because I didn't want to deal with it again. Not a lot, a thin bead. You don't want it to come oozing out much when it's tightened down.

Offline Lou

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Re: CB350F Cracked oil pan
« Reply #14 on: February 09, 2019, 05:32:30 pm »
I'm in the same situation with the cracked oil pan. Previous owner tightened the oil drain plug too tight so I had to crank hard on it to remove for oil change. This caused a small crack.

Question - to replace the oil pan on a CB350F, can you do it from underneath simply by unbolting old pan and bolting in new one? Or does it require removing the engine or other parts?

Thanks!

Offline robvangulik

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Re: CB350F Cracked oil pan
« Reply #15 on: February 10, 2019, 08:02:48 am »
The engine can stay in, depending on what kind of exhaust you have yo may have to remove that.

Offline Lou

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Re: CB350F Cracked oil pan
« Reply #16 on: February 10, 2019, 08:49:56 pm »
Thanks! Good to know I can do it on my own then. Whew!

Question - is the oil pan for the 350F the same part as the 400F? I found someone who has a used 400F pan.

 

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