Crankshaft Bearings

[Billyboy34]

I have dissembled the entire engine (250sx) with exception to removing the crankshaft from the left crankcase. The manual states “Always replace the left bearing with a new one whenever the crankshaft is removed from the left crankcase.” Then later in the manual it states the bearings should be replaced in pairs. From what I found on Honda Parts Line your talking $90. Is this necessary if the bearings are still in good shape? Will using the old bearings cause the crankshaft to wobble?

[200xranger]

may not be necessary but why not replace them after all the time and work taking the motor apart. cheap insurance if you ask me!!!!

[Dirtcrasher]

Here's the deal, once you press out that crank, your placing a sideload on the bearing and damaging it (whether you know it or not). If the crank just taps out with a rubber mallet and the main bearing is as smooth as glass, I'd reuse it. If it takes any force, it's junk.

Thumper bearings are always bathed in oil, they are very often reused.

Then again, you may say "I've spent this much time and money what is another 100$?" I know how many pieces are in an SX, trust me.........

Just follow the manual; The way people install bearings in itself can shorten there lifespan dramatically. If it slips over the crank, you press only the OD into the case. If it slips in the case, you only press on the ID and any side force on the 2 crank halves during installation can again, ruin them.

Thats why freezing (shrinking) the crank is often done and the mains heated, sometimes they fall on or can be tapped on with a sleeve and only that half of the crank in your hand. Thats also why heating the crankcases is done when a main already on a crank wont slip in the crankcase.

Any improper procedure in this department can damage parts and it's not a 2 stroke where the mains often stay on the crank............ Every situation is different.

[Billyboy34]

I was able to knock the crankshaft through, leaving the bearing in the case. Bearings look good!

[tri again]

not necessarily recommended but I used to spin bearings with an air nozzle to see if they are noisy.

Also had a few come apart not unlike a load of undirected buckshot.

There must be a real way to check them.

I have also discovered that bearings can almost always be found cheaper
if you can match up numbers, cross reference or take them to a bearing
supplier.

Pretty sure most vehicle mfgs don't make their own bearings.

I think the sx swing bearings crossed out to ford falcon front wheel bearings,
for instance, and were 5 bucks each instead of 50.

[bcredneck]

when i need berrings my dad gets them from work for free and there way higher quality the axle berrings im using in my freinds 250R are abec 12

[Dirtcrasher]

SFK, NACHI, INA; NAME some redneck!