Crankcase Pinion Bearing Walked

[SP33DY]

The first photo is of a case that came in yesterday.

The second photo is of a preventative repair that was done on a different case to prevent this sort of disaster.

This is why it's important to have some sort of retention on the crank case pinion main bearing. The bearing walked out, the crank dropped and broke the oil scraper in both case halves, and ultimately broke the sprocket shaft.

When an engine comes to me with no pinion main bearing retention, I cut two grooves into the case and install snap rings. HD PN 35114-02

According to my parts software, from 2003 to 2010, the pinion main bearing had no retainers. Starting in 2011, HD started using two button head screws to keep the bearing from walking towards the oil pump.

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[Ohio HD]

That did some damage. I wonder if you buy replacement MOCO cases will they have incorporated the later years retention screws?
 

[SP33DY]

I don't know the answer to that question for sure, Ohio HD, but I think they may come with button head screws.

The last set of cases I bought from Harley were for a 2010 CVO110 B Softail. It came with upgraded balancers and two buttonhead screws for the pinion main bearing. Took four months to get them.

My plan for this damaged case is to put the scrapers back where they belong and weld them up and recut them. It'll be more cost effective than new cases.

[FSG]

...... I think they may come with button head screws.

the -06A cases will

your repair .......will be way more cost effective than new cases

[MBrown]

Did something else cause the bearing to walk? Maybe rod bearings going bad or excessive crank shaft run out, before the pinion broke?

I like your dual groove for prevention of bearing movement.

[xlfan]

I wonder why the factory ditched the pinion bearing retainers, retaining rings for the TC-A and buttonhead screws and retainer for the TC-B om 2002.

[Hossamania]

I wonder why the factory ditched the pinion bearing retainers, retaining rings for the TC-A and buttonhead screws and retainer for the TC-B om 2002.

All decisions are economic.

[SP33DY]

Did something else cause the bearing to walk? Maybe rod bearings going bad or excessive crank shaft run out, before the pinion broke?

I like your dual groove for prevention of bearing movement.

The crank had excessive run-out, and pushed the bearing out. Dual snap rings were used by the MOCO from 1999 to 2002. I think they had the right idea back then.

[OldBogie]

My knee jerk is as so many already pointed out the root cause is the pinion shaft out of alignment. This happens because the flywheels are rotating about the crank pin which unlike the pre twin cam engine is simply a press fit without positive alignment with keys, key ways and gland nuts to hold the crank assembly together. The twin cam and M8 depend on a friction fit. Especially if you like to twist your wrist and that combined with high mileage or from either alone.

While positive bearing retainment is nice whether done with clips or screws these are really fixes against the root problem, kind of like wearing gloves because your pen leaks ink.

Bogie

[SP33DY]

My knee jerk is as so many already pointed out the root cause is the pinion shaft out of alignment. This happens because the flywheels are rotating about the crank pin which unlike the pre twin cam engine is simply a press fit without positive alignment with keys, key ways and gland nuts to hold the crank assembly together. The twin cam and M8 depend on a friction fit. Especially if you like to twist your wrist and that combined with high mileage or from either alone.

While positive bearing retainment is nice whether done with clips or screws these are really fixes against the root problem, kind of like wearing gloves because your pen leaks ink.

Bogie

The various bearing retention methods are intended to allow the engine to make it home without a catastrophic failure if the crank starts to fail. If the job is being done here the engine will not be reassembled without a properly repaired, trued, plugged and welded crank. 

[les]

I did a 120R crate engine for a friend and ended up buying his 2010 take out engine and built a 124" out of it, which went into my 2011 Road King.  I sure wish I could cut snap ring grooves, but I can't so this is what I did.  I had a machinist make me the blank to my specifications and I took it from there.

[les]

A couple more pictures.  The one picture shows after using lapping compound (real thumb buster) to get a nice flat surface. 

[SP33DY]

Les, I like that! it's a simple and effective solution!

[les]

Here it is.  I call it the LF8-07-10.