Stihl 036 rebuild

[flh69]

Not sure if this will be of any real help but it should at least let you see what you’re getting into.

http://opeforum.com/threads/036-gets-a-rebuild.16469/

this video shows what you don’t wanna find with regards to the big end rod bearing.

After looking at this video it appears to be the big end bearing. My connecting rod really wobbles on the crank & what I can see it looks as though the bearing cage is in several pieces. This may be a stupid question but how is the crank & rod put together. Is the crank in two pieces? There is no bearing cap so something would have to be pressed or welded together.

 

[flh69]

I assume the pin that holds the connecting rod on to the crank is a press fit?

 

[Canadian farm boy]

After looking at this video it appears to be the big end bearing. My connecting rod really wobbles on the crank & what I can see it looks as though the bearing cage is in several pieces. This may be a stupid question but how is the crank & rod put together. Is the crank in two pieces? There is no bearing cap so something would have to be pressed or welded together.

Press fit. You’d need a skilled shop to be able to replace the rod bearing. Would be pretty costly too.
IMO it isn’t worth the expense when you can source a good used crank shaft for a fraction of the cost.

 

[fossil]

I assume the pin that holds the connecting rod on to the crank is a press fit?

Do you have a shop manual for the 036? I can PM you one if you like.

 

[flh69]

Do you have a shop manual for the 036? I can PM you one if you like.

I found my manual. Thank you for the offer.

 

[Stump Shot]

I found my manual. Thank you for the offer.

Running yet?

 

[Al Smith]

Specifically it would be a heat shrink fit .Much tighter than a shrink fit .Done by the use of an induction heater which often leaves a discoloration of a portion of the crankshaft half causing people to assume same was caused from a bad bearing which it is not .

 

[flh69]

Just a thought,, is the top ring pin still in place,, I can see the lower ring pin in the pic

Pin is still in place. From what I can see it looks as though the big end rod bearing cage is in several pieces. I'm guessing it should be all one piece to hold the rollers? The rod has tremendous slop in it at the crank end. When I get time I will remove the crank.

Running yet?

Not quite yet. Getting close though

 

[flh69]

Well further inspection revealed the big end rod bearing had come apart. What would have caused this?

 

[cuinrearview]

Well further inspection revealed the big end rod bearing had come apart. What would have caused this?

Heat and/or inadequate lubrication.

Or it could just be a faulty part

 

[huskyboy]

I’ve learned after a while that if the rod is blued or the clutch is blued... someone abused the saw at some point in its life... and it’s pretty obvious to me as the ones I’ve seen it on were rental or higher hour units. Poor tune, limbing while holding the saw at max rpm too long (short blips are the proper way to limb), poor mix oil/gas, stalling saw in cut repeatedly and poor chain are some of the things that can contribute to this. Common sense stuff really.

 

[drf256]

Well further inspection revealed the big end rod bearing had come apart. What would have caused this?

Everything has a lifespan.

Inadequate lubrication would be my guess.

Many used oem parts around for that model. I’d steer clear of anything am.

 

[cuinrearview]

I’d steer clear of anything am.

Best answer

 

[Al Smith]

[QUOTE="drf256, post: 967055, member: 319"

Inadequate lubrication would be my guess.

.[/QUOTE] Goes right back to the oil again .That would be my guess too for the 2 cents it's worth .
Once again and this is not to cause a fuss but when you use an induction heater for the purpose of a heat shrink fit,induction hardener etc it will "run the colors "of the steel or nodular iron .I've seen this from over 30-35 years of working in or around the auto industry building engines . The process is used for example to case harden the crankshaft mains and pins, on older cast iron cylinder heads to harden the valve seats ,iron cam shafts . On a tear down you'd never see the colors because it's masked by oil reside .On a new part you will .
On carbon bearing steel, nodular iron to change the properties you have to get the area to be hardened up to around 1400 degrees F ,which is orange like a pumpkin . Although it might be possible to have a part of a chainsaw crankshaft to get that hot but I would think it a really rare thing to happen .

 

[Michael Rupley]

Al did you think about trading in all those trophy points for a new saw?

 

[Al Smith]

I bought two new ones but that was years ago .It's just info Mike ,nothing more .

 

[Michael Rupley]

Oh you have 200 more points than me. I'm qualified for a 130 Husky or 170 Stihl but want to wait until I can get a 395 Husky or 500 Stihl.

 

[Al Smith]

I don't think you can cash them in like trading stamps from 50 years ago . I don't even pay attention to them .Wonder what they mean ? The only trophies I have are a couple from well over 50 years ago from running my lead sled '59 Pontiac at the drag strip .Although I did have a trophy wife once and don't want another .High maintenance .