Installing crankshaft and crank bearings without specialty tools?

[T.Bird]

For those who have been kind enough to help me with my STIHL MS 362C rebuild (or pretty much just disassembly) thus far, I have some more questions now that I am about to put in new crank bearings and reinstall the crankshaft into the case.

I got the old bearings to drop out by heating them with a heat gun, but I am a little nervous about the reassembly process. I like the concept of the "oven and freezer" method of heating and chilling the parts in oder to get them together. Following that logic, I think I would:
1) Heat both halves of the case and chill the bearings and then drop the bearings into the case.
2) Heat the ignition half of the case with it's bearing and chill the crank shaft and then install it into the case/bearing
3) Chill the ignition half of the case, bearing, and crankshaft, and heat the clutch side of the case with it's bearing, then (and this is the part that I am skeptical about) scramble to get the gasket in place, slam the two case halves together, and somehow quickly and evenly pull the halves together with the crankcase bolts before temperatures equalize to the point of things becoming immovable.

Does this seem like it might work? I imagine it going poorly. Is there a better way for us mere mortals to accomplish this task?

 

[frank_]

i always heat the bearings (boiling water) then fit them on the crank
then tap the ends of the crank with an alloy hammer to nudge the cases together

 

[T.Bird]

Oh... and also, I ended up melting the plastic retainers in the old bearings before I managed to get them hot enough with the heat gun for them to drop out of the case. Is this going to be a problem when heating the new bearings? I guess I'm hoping that heating in the oven will be a little more controlled and avoid overheating.

 

[T.Bird]

i always heat the bearings (boiling water) then fit them on the crank
then tap the ends of the crank with an alloy hammer to nudge the cases together

Yeah. It does seem like many install the bearing onto the shaft before putting it into the case halves. The STIHL service manual that I have been leaning heavily on suggests otherwise, but what does that matter?

 

[T.Bird]

Well that was a big no go! I just tried getting the new bearings into the case thinking that that would be the easy part. Nope! I heated the case in a 300 degree oven and had the bearings chilling in the freezer for about an hour. I'd seen a few videos with bearings dropping right into heated cases no problem even if the bearings were left at room temp. That's not how it went for me! Mine seized up rock solid the moment they entered the heated case even a fraction on an inch. I mean... maybe I could have bashed them in with a mallet, but I didn't think that was how this was supposed to go!

 

[motorhead99999]

Iv always put the crank in the freezer bearings in oven or boiling water and put the bearings on the crank. Then crank assembly in the freezer and case half’s in the oven put it together then center the crank with a rubber mAllet or a press

 

[ZeroJunk]

I press the bearing in to the case half with a shop press using a deep socket. And, I'll pull them together with a shop press to the point that the screws will catch.
You can tap them in with a hammer, but you have to have the case against something SOLID .

 

[Bob Hedgecutter]

Well that was a big no go! I just tried getting the new bearings into the case thinking that that would be the easy part. Nope! I heated the case in a 300 degree oven and had the bearings chilling in the freezer for about an hour. I'd seen a few videos with bearings dropping right into heated cases no problem even if the bearings were left at room temp. That's not how it went for me! Mine seized up rock solid the moment they entered the heated case even a fraction on an inch. I mean... maybe I could have bashed them in with a mallet, but I didn't think that was how this was supposed to go!

Where did your bearings originate from?

One of those cheap wee digital readout "gun" IR thermometers can be your friend in this instance- could be your oven says 300, but the internal temp is closer to 200 and maybe you did not attain enough heat transfer into the case halves, or too long between removal of case halves and bearing dropping in to place.