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#76056 04/08/2007 1:09 AM | Joined: Nov 2003 Posts: 236 Shop Shark | | Shop Shark Joined: Nov 2003 Posts: 236 | The main bearings on my 60, 235 need replacing. Does anyone know how to decipher the codes on the back of the bearing? I of coarse need to know what size to put in. I thought it would state std, -20, etc on the back but it doesn't. well, maybe it does. There is a 7-30 mixed with all the rest of the numbers. Thx.
Glenn, | | |
#76057 04/08/2007 6:15 AM | Joined: Jul 2004 Posts: 5,708 'Bolter | | 'Bolter Joined: Jul 2004 Posts: 5,708 | Glenn,
In order to put new mains in your truck, aren't you going to have to pull the crank? This would be the time to 'mic' it and compare the reading to a stock journal size. A visit to the local automotive machine shop for some first hand knowledge wouldn't hurt either.
Stuart | | |
#76058 04/08/2007 3:08 PM | Joined: Feb 2007 Posts: 13 Junior Member | | Junior Member Joined: Feb 2007 Posts: 13 | you will have to use a ball micrometer to check thickness | | |
#76059 04/08/2007 6:33 PM | Joined: Feb 2004 Posts: 29,771 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,771 | Just use a the pointed part of a dial caliper to measure the crankshaft diameter after you get the first bearing out. You'll be able to get a close enough estimate of the diameter to figure out if it's undersize or not. There are .001" and .002" undersize bearings available to compensate for minor crankshaft wear without regrinding, IF the crank isn't worn egg-shaped. Be sure you don't create a tight spot if you use the 1 or 2 under bearings, however. I always check for proper clearance with Plastigage when I'm replacing bearings without a full teardown and regrind.
Jerry
PS: If the bearings are factory original to the engine, they probably won't have an undersize stamped on them, just a part number. That would probably mean they're standard size, but don't guess, measure!
Jerry
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#76060 04/09/2007 2:12 AM | Joined: Nov 2003 Posts: 236 Shop Shark | | Shop Shark Joined: Nov 2003 Posts: 236 | Thx guys, I'll will measure the crank. I have two engines, a 51 and a 60. The bearings on the 51 looked brand new. The 60 bearings are shot.Lots of copper. Neither set gives a size. I know the 60 was rebuilt and I can't believe the 51 wasn't. The 51 plastigage to .002. I don't need to replace them but I do on the 60.
Glenn, | | |
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