rod bearing question

[Fudog]

When i change the pan gasket i was thinking about doing the rod bearings. When i looked up the parts they are listed as +.25mm, +.50mm, or +.75mm.
What the difference and how do i know which to get?

Thx guys
and gals

 

[Off Road SHO]

It depends on whether you have .25, .50, .75 or standard bearings in there now. How many miles are on your motor and how often was the oil changed?

The initials "STD" will be on the back side of the bearings if they are standard size.


Tom

 

[Fudog]

It's got 168k on it. I got it at an auction. So i dont know how often the oil was changed. So what your saying is that i nd to take the old ones out to find out which part is needed? Is there anyway to tell other wise?

 

[Ishodu]

99% chance you just need the Std size. Just get them and if you find different ones in there you know that the crank has been ground at one time and you will need the ones that are in there.

 

[SHOblime]

This may be ignorant, but shouldn't you *measure* the crank and determine the size you need? What if they are slightly out of spec and need machined?

 

[Slo-Sho]

Yes, you can certainly plasti-gauge the journals to check clearances. I chose not to, and promptly installed 6x CB1435 (std.) Clevite 77 Rod bearings from NAPA. Motor runs excellent and install was a breeze.

 

[Rockledge]

This may be ignorant, but shouldn't you *measure* the crank and determine the size you need? What if they are slightly out of spec and need machined?

Here's the other relevent questions: What will you do if things are a little out of spec? You can't just drop in a different size bearing without doing some crank work, right? Of course things just don't add up that nicely. So what are your options at that point?

 

[Ishodu]

Here's the other relevent questions: What will you do if things are a little out of spec? You can't just drop in a different size bearing without doing some crank work, right? Of course things just don't add up that nicely. So what are your options at that point?

Yeah your right if things are out of spec the crank will have to be ground to use thicker bearings. But if there is no damage the crank shouldn't be worn much because the bearings are softer then the crank.

 

[stevetatro]

Very, very few people would go to the expense/trouble of removing the crank to get it machined. Most just put the standard sized bearings in.

If there's minimal crank damage from a spun bearing, maybe check the bearing again in 20k miles. If the crank looks good (no previous spun bearing) the standard size bearings should do the trick for 100k miles.