New Clevite rod bearings @ 114K

[roswell998]

Just installed new Clevite std rod bearings and none were spun! On the 93 atx dropping the pan was a breeze. Straight down (and back up again) with nothing to interfere. Of course, the starter and y-pipe were removed first.

Only about 100 miles but so far so good! Runs and sounds smooth as silk. Gonna go easy for a few hundred miles just to be safe.

Also, just for good measure installed a new set of Autolite APP3924 plugs.

 

[GoofSHO]

B

 

[SASHO91]

its a good practice to change the oil at around 500 or so miles....

feels good to know that you have many more miles to beat on her, atleast until something else breaks... but hey, atleast you dont have to worry about the bottom end for a awhile.

 

[roswell998]

its a good practice to change the oil at around 500 or so miles....

feels good to know that you have many more miles to beat on her, atleast until something else breaks... but hey, atleast you dont have to worry about the bottom end for a awhile.

Do you get many wear particles with only a bearing change? Piston rings yes since the honing is designed to wear the rings to seat them but I wouldn't expect significant particles with new bearings on a crank that looked factory fresh.

That said, I was planning on changing the oil at a few hundred miles since I'm over cautious if anything.

 

[SASHO91]

That said, I was planning on changing the oil at a few hundred miles since I'm over cautious if anything.

so am I..... which is why I stated that... but its not a bad idea...

 

[Hank F.]

Why change the rod bearings, but not the mains? And, I never hear anyone say anything about plastigauge, either. Don't you need to check the clearance for good measure? I'm probably showing my age by asking these questions, but I've got to know.

 

[TYSHO]

Why change the rod bearings, but not the mains? And, I never hear anyone say anything about plastigauge, either. Don't you need to check the clearance for good measure? I'm probably showing my age by asking these questions, but I've got to know.

The SHO rod bearings receive more wear than the mains.

Some plastigauge, some don't. There's nothing you can do without removing the engine if it is out of spec anyway. It's only a precaution for those wanting to know if they have a turned down crank or not.

 

[Rockledge]

Do you get many wear particles with only a bearing change? Piston rings yes since the honing is designed to wear the rings to seat them but I wouldn't expect significant particles with new bearings on a crank that looked factory fresh.

That said, I was planning on changing the oil at a few hundred miles since I'm over cautious if anything.

IMO, it's not so much about wear particles as it is about removing any dust, dirt, moisture, or other potential contaminates that may have found there way into the bottom end while it was open and being worked on. For instance, I think one of the hardest things for me when I changed out my SHO's rod bearings was keeping my hands clean when I was fiddling around with the bearings.

 

[SASHO91]

my thoughts exactly...

 

[93rev2sev]

hoooray for new rod bearings!!!...probably one of the best things you can do for the longevity of your engine.

Changing your rod bearings changes the way the engine sounds and feels. It also increases oil pressure.

Increased pressure means increased "rinsing". I would bet that the increased pressure helps clean the engine of deposits and grime. Those deposits and grime will be knocked off the ring lands, block, rods, etc.. so changing your oil shortly after your rod bearing job is a really good idea...not just to be on the safe side. IMHO

 

[SASHO91]

whoa... hold on a sec.....
it will not increase oil pressure.... let me rephrase that... it wont increase oil pressure past stock spec. and even then, the oil pump would have to be a low mileage unit(even though our pumps are fairly strong, even with high mileage). But if your RB's were in bad shape (and i mean BAD) then you would see some increase in oil pressure(but again, only up to factory spec)

 

[93rev2sev]

I'll give ya that, SASHO.
Perhaps I should have used the term "restore" as opposed to "increase".

I'll even go one further by saying that new rod bearings will not restore 100% of your oil pressure. But I do think that the increased (restored) pressure will dislodged otherwise stationary 'gunk'.

 

[sdpatt]

Why change the rod bearings, but not the mains? And, I never hear anyone say anything about plastigauge, either. Don't you need to check the clearance for good measure? I'm probably showing my age by asking these questions, but I've got to know.

I debated the issue of the main bearings before I replaced the connecting rod bearings on my own engine at 268,000 miles (for the first time). After a bit of research, I found no history of problems with the mains in the SHO engines so I decided to swap only the rod bearings. Replacing the mains also required much more than just removing the Y-pipe, starter and oil pan.

I Plastigaged the first rod bearing I installed and found it to be well within the range. I then considered the extra stress that was being applied to the rod nuts and bolts after going through a second off/on/2-stage torque sequnce. Add that to the question of "what could I do if they were out of spec?" and the reassurance of the gap measurement was outweighed by the other factors.

 

[93rev2sev]

Another well put response from SDPatt

 

[1993MTXSHO]

yeah changing rod bearings is good...

Mine at 99k miles (yeah my engine and heads are toast everything all scratched up, crank included and i didn't have any spun bearings either just the 1 chewed up one):

 

[93rev2sev]

Those look about as bad as the ones I pulled out of the 3.8 windstar...only those ones came out in pieces.

 

[Hank F.]

I sure appreciate the quality of thought and debate on this site. Where else can I get informed info from an engineer, as well as 1000's of personal experience notes and pictures. I was looking for a project, and got a wealth of common sense and fun all in the same package. I cannot thank all of you out there in the ether enough for all the help this past year, even though some of my ?'s were pretty stupid, in retrospect. Happy New Year to you all.

 

[roswell998]

Photo of original rod bearings

FYI, I am original owner and this car has always had Mobil 1 oil changes every 4000 miles and is not driven hard.

 

[doclees]

So if I have no problem doing the 60k or the heater core should I feel ok about doing the rod bearings? For some reason this makes me very nervous. I have the parts. Just want to know I do it right the first time because I assume there is no second time. Right? Good to hear about the plastigage issue. So if the crank is original there is no reason I should need over sized bearings and no real reason to do all that extra torquing.
What time does it take after the starter and y pipe are out of the way?

 

[sdpatt]

You should have no surprises with the rod bearing replacement. Follow the procedures you can find in the Forum through a search and watch out for the problem areas that have bitten SHOwners like the oil pickup tube nut torque. Don't put yourself in a position to be in a hurry and follow the adapted carpenter's rule: set the torque wrench twice, torque once. That is, for each of the two stages in the rod nut tightenting sequence.

The picture posted by roswell998 still causes me to caution SHOwners about the use of synthetics, Mobil 1 specifically, in the SHO engine (I know some synthetic users have had good fortune with their choice). Those bearings look at least as worn as mine did when I replaced them for the first (and only) time at 268,000 miles. All of those miles were protected with Castrol GTX 10W-30 or the High Mileage version of the same oil. If you hear the sound of an unoiled engine during startup, you are wearing it out at an accelerated rate. Please be aware.