455 Rancher clutch issue

[Cciesinski01]

Last night I put a 455 Rancher back together after having the bottom of the cylinder surface cut 0.010", no other changes. Crank bearings, seals, piston, etc. were reused as they appeared like they were in great shape.

After it was back together sprocket spins freely by hand with oiler drive gear, sleeve and sprocket installed but as soon as the clutch gets installed there is a considerable amount of resistance. Seems like the plastic rim of the oiler drive gear is pinched too hard between the sprocket and side plate?

I have pulled it back apart twice and reinstalled everything with the same issue. The sprocket can still be spun by hand when the clutch is on but it is noticeably more difficult. I can't seem to figure out what the underlying issue is.

What am I missing here...?

Thanks

 

[Michael Rupley]

Put the plastic worm on first then the bearing. Now put the clutch DRUM on the bearing and spin it a little until it drops into the drive tangs. If it is mis-aligned the drum will mash into the plastic and make it tight and maybe ruin the worm. Check it.

 

[Cciesinski01]

Thanks for the reply!

The plastic gear went on after the side plate, then the needle bearing, sprocket seated to oiler gear "ears" prior to install of clutch. Still feel resistance.

 

[Michael Rupley]

Ah ha. I think the worm on some of these goes under the plate. If it is to wide at the top it will hit and rub on the plate. Try under.

 

[Nutball]

Why cut .010" off the cylinder?

 

[Ronie]

Why cut .010" off the cylinder?

I was wondering the same thing, aren't they a clam shell?

 

[Cciesinski01]

Brought squish from 0.039" to 0.029".
Is that something thats bad on these saws?

 

[Ronie]

Brought squish from 0.039" to 0.029".
Is that something thats bad on these saws?

I guess as long as it doesn't cut into the seals and everything seals up it would be ok, but I don't know that for sure.

 

[Ronie]

Brought squish from 0.039" to 0.029".
Is that something thats bad on these saws?

Did you vacuum/pressure test it?

 

[old guy]

When I did a clamshell, I took the same amount out of the bearing pocket as well,

 

[Nutball]

or it won't improve the squish, just leave a larger gap to seal between the engine halves.

 

[Cciesinski01]

No vacuum leaks. I did not pressure test but held vacuum at -4psi for 5 minutes through plug hole with impulse line, intake and exhaust flanges blocked and then I took the mitivac off. I did rotate the crank while vac was on. I did not have any material removed from the bearing pockets. Train of thought was that I wouldnt need to at 0.010" but please correct me if im wrong.

 

[Ronie]

Looks like it worked. I'm surprised that you could pull it down .010 because of the bearing. Wish I could help you with the clutch problem.

 

[Nutball]

Just to clarify, you did remeasure and confirm a 0.010" decrease in squishband clearance right? It looks like the 455 uses gasket inserts, so maybe they were able to squish farther and were originally holding the block off the bearings, or maybe you used a gasket making paste instead allowing it to clamp together more?

 

[Cciesinski01]

I used a light coat of motoseal on the existing rubber inserts/seals. I just re-checked squish and it was reduced by 0.009" started at 0.039" now fully assembled at 0.030" Started it up for giggles after tearing it down and reassembling again to prove to myself I didnt miss anything.... Im at a loss.

 

[Nutball]

You cut the base of the cylinder and not the bottom half of the crank case right? Maybe the bearings were not well supported, and the cylinder half is now pushing the crank via play in the seals down just enough to make the clutch parts rub on something? Or if the oil pump attaches to the part moved (cylinder) the pump could be out of alignment. You always have to consider what will move when decking a clamshell. Sometimes the cylinder moves, &/or bottom half, ignition, oil pump, ect. I haven't done this mod to a 355t because it is just too complicated to make it work with what all moves.

 

[Cciesinski01]

Good points.

I did have the bottom half of the cylinder cut not the case portion where the rubber "gasket halves" are.

Oil pump is bolted to case below the crank shaft so shouldnt have changed anything there. I did try the oil pump gear inside the plate to make sure I wasnt wrong but that was worse.

I never really thought about the seal/bearing portion of the cylinder not being cut as well being it was only ten thou. In my brain it seems like if that was the issue, it would present itself way before I got the clutch on.

I really appreciate all the replies.

 

[Stevetheboatguy]

Good points.

I did have the bottom half of the cylinder cut not the case portion where the rubber "gasket halves" are.

Oil pump is bolted to case below the crank shaft so shouldnt have changed anything there. I did try the oil pump gear inside the plate to make sure I wasnt wrong but that was worse.

I never really thought about the seal/bearing portion of the cylinder not being cut as well being it was only ten thou. In my brain it seems like if that was the issue, it would present itself way before I got the clutch on.

I really appreciate all the replies.

Could the extra pressure on the seal from having the .010 taken off. Be distorting/squishing the seal out enough to make contact with the oil pump drive?


Steven

 

[Cciesinski01]

Hmm. You may be onto something there. It very well could be squeezing them out a bit. If it is maybe ill shave a touch off the oiler drive?