Replacement Top Gear Bushing

[cannondale27]

What kind of lube are you guys running in these chaincases?

Just doing some pre season maintenance now, over 11000 kms, stock top gear with no oil holes and the bushing is still mint, No gold worn off the bushing, tight on the shaft still. I run my chain tighter than spec, and use mercruiser outdrive lube in my chaincase.

Just so you know. The bushing ID is supposed to be grey. If it’s gold it’s worn already.

 

[Big_Phil]

Just so you know. The bushing ID is supposed to be grey. If it’s gold it’s worn already.

Interesting, it looks even in colour, no slop on the shaft, I cant rock the gear at all. Looks and feels the same as it has since the sled was new. Never had an issues shifting into reverse or anything either.

 

[cannondale27]

Interesting, it looks even in colour, no slop on the shaft, I cant rock the gear at all. Looks and feels the same as it has since the sled was new. Never had an issues shifting into reverse or anything either.

Never saw a gold one stock but maybe out there. Would feel some slop otherwise. Wear is usually not even and is measurable taper. Have said all along maybe we are replacing them too early and worried about nothing . Is still the Babbit or copper coating left Everytime I replaced mine. Usually even half the grey ptfe coating. But Definitly sloppy compared to a new one and I have seen what happens when gear doesn't fully engage or that copper coating wears off the steel sleeve of the bushing. Not willing to risk it myself but I admit I could be premature in replacing every season.

 

[Turboflash]

Here's a 22 tooth w about 2700 miles on it. Still grey in color.

 

[cannondale27]

Here's a 22 tooth w about 2700 miles on it. Still grey in color.

Keep on doing what your doing!

 

[Turboflash]

Amsoil chain case lube. Tension at 1.75 turns out. Lube up to top of window.
Was 280 HP tune for last year. For this winter, gonna be 320HP so I hope gearing holds up (ditto track and belts)!

 

[ROCKERDAN]

Amsoil chain case lube. Tension at 1.75 turns out. Lube up to top of window.
Was 280 HP tune for last year. For this winter, gonna be 320HP so I hope gearing holds up (ditto track and belts)!

I went with 16 oz on buds sled.....this gets just above sight window on a FRESHLY cleaned out case with Cat 24/50 gears, so likely higher then 16 oz on a 21/41 set of gears.

Dan

 

[STAIN]

Well after some thinking, measuring, pressing, fitting and more thinking I am going with the oil impregnated bronze sleeve in my upper gear. It fits the tightest without binding and is different than the stock configuration. Drilled the oil holes.
I have spent FAR to much time on this bushing......

 

[Turboflash]

Stain, can you be specific about part number for the bushing? Was it the right length or did you have to modify? Where did you get it?
Tks!!

 

[PowderFalcon]

I just replaced both my 21 and 22 gears with the bushing from McMaster - Carr that clutchmaster recommended. See how they do.

“Multipurpose SAE 660 Leaded Bronze Sleeve Bearing for 1" Shaft Diameter”

 

[SumpBuster]

I made an oilite bushing for the primitive primary on my 73 skiroule rtx 447 and it lasted as long as I had it...over 6000 miles. So we put the oilite in the sw, with Polaris branded full synthetic (from Excell), just above the sight glass sitting level. Big Iron ordered these for us I think from Mcmaster Carr. My old one and the abrasive disc is in the bag too. Different material types in there but I used the oilite.

 

[STAIN]

These are the bushings I ordered from bronzebushings.com
AA-1110-1 | Oil Impregnated Bronze Sleeve | 1 ID x 1-1/8 OD x 1 OAL
101493 $3.39
Ordered: 1
Shipped: 1
$3.39
16BU16 Sleeve, BU (PTFE Composite), 1 " ID x 1 1/8 " OD x 1 " OAL
16BU16 $3.36
Ordered: 2
Shipped: 2
$6.72
EXEP161816 | Oil & PTFE Impregnated Sleeve | 1 ID x 1-1/8 OD x 1 OAL
EXEP161816 $2.27
Ordered: 1
Shipped: 1
$2.27
BBEP161824 | BB-16 Sintered Iron/Copper Sleeve | 1 ID x 1-1/8 OD x 1-1/2 OAL
BBEP161824

I ended up using the first one.

 

[Turboflash]

Thanks! Great to have all these experts and engineers trying this stuff and letting us know how it goes. TY is great for this!

 

[twyztid]

Cast bronze would have a higher load rating than oil impregnated bronze (sintered bronze). Being oil impregnated is really not needed as well since it is in a oil bath.

Although expensive at around $40/ea, this one may be one of the best if it isn't too hard and wears the shaft. It is made of ToughMet 3 Alloy (copper-nickel-tin). The "P Value" is 5X what the cast bronze (McMaster-Carr) bushing is (20,000 vs 4000). P Value represents static load.
https://catalog.buntingbearings.com...ze-c96900-toughmet3-alloy-bearings/tmcb161808

As I have said before, I do not believe the wear is rotational wear that is being seen. I believe it is from shock load since the bushing does not spin on the shaft while moving forward.

 

[Turboflash]

Cast bronze would have a higher load rating than oil impregnated bronze (sintered bronze). Being oil impregnated is really not needed as well since it is in a oil bath.

Although expensive at around $40/ea, this one may be one of the best if it isn't too hard and wears the shaft. It is made of ToughMet 3 Alloy (copper-nickel-tin). The "P Value" is 5X what the cast bronze (McMaster-Carr) bushing is (20,000 vs 4000). P Value represents static load.
https://catalog.buntingbearings.com...ze-c96900-toughmet3-alloy-bearings/tmcb161808

As I have said before, I do not believe the wear is rotational wear that is being seen. I believe it is from shock load since the bushing does not spin on the shaft while moving forward.

Hard to believe it would be from rotating as gear only turns when in reverse. I can't prove it but I have a theory that harmonics/resonance plays a part. I've seen cases before where ultrasonics/resonance/harmonics destroyed stuff for which there was no other explanation. Just my theory.