2023 Top Gear is Powdered Metal Junk

[KnappAttack]

DMC……any response to this? My DMC gear is perfect for 4 years now.

As long as he uses the billet gears from Yamaha and not the sintered......

 

[hibshman25]

I've been in contact with Dave at DMC and he is no longer using the new Yamaha gear. Cat still sells the original machined gears and he is only using them moving forward.

As Steve said the easiest way to tell the difference is by the depth of splines. The original good gears do not have full depth splines. These gears show machine marks and also do not have the gold color.

 

[Turboflash]

I installed the Scott Taylor top and bottom gears on my SW from new...both gears are now 15 wide hyvo rather then the top being 15 wide and the bottom being 13 wide as the sled came stock.
I have aligned the gears with a straight edge with shims so the chain runs true on both gears just like I have always done on all my other sleds.
Works good

Bottom gear has contact with inner bearing race on inside and then the outer gear presses against the inner gear with an outer snap ring to hold it.
So you had to have shimmed the top gear out? I assume there was no issue with the outer reverse gear not being able to slide in? And, I assume the reverse servo had no problem re-zeroing to the new location of the gear?

 

[sideshowBob]

Bottom gear has contact with inner bearing race on inside and then the outer gear presses against the inner gear with an outer snap ring to hold it.
So you had to have shimmed the top gear out? I assume there was no issue with the outer reverse gear not being able to slide in? And, I assume the reverse servo had no problem re-zeroing to the new location of the gear?

My SW is the only sled I have ever worked on that had two different width gears operating with the drive chain and I was quite surprised when I first disassembled it.
The 15 top gear and the 13 bottom gear were close to be aligned with the wider 15 width chain overlap on each side of the 13 width bottom gear pretty even.
With the stock setup my thinking is that the chain can still walk back and forth on the bottom gear especially when it is not under load and slack creating wear and contributing to oil contamination that would exasperate the top gear bushing issues.
The 15 wide bottom gear secures the chain from side to side movement and allows the chain to run true as long as the gears are aligned.
The gear alignment was accomplished by slightly shimming but mainly securing the top gear. It had no effect on reverse mechanism.

 

[NYTurbo]

Scott Taylor gears are over priced and the bushing in the top gear is slightly better than stock but not much.

 

[NYTurbo]

So it sounds like DMC has used the crappy gears so anyone that has bought from him lately better check it out. Also it’s not just yamahas that have the shitty gears in them .

 

[sideshowBob]

Scott Taylor gears are over priced and the bushing in the top gear is slightly better than stock but not much.

Many seasons on my SW with 15 wide top and bottom Scott Taylor gears...no obvious wear on top gear bushing and relatively clean chain case oil when serviced. I have the DMC bushing but didn't install it as so far no need to.
Worked for me.

 

[joe243]

This may be why the top gears dropped in price this year. I bought a few the other day they where only 29.99

 

[sideshowBob]

I tend to be out of sync with the norm...I float my secondary, run an 8DN belt, and lock down my chain case gears and chain with matching 15 wide gears...LOL...I never have been a conformist.

But it works for me!

 

[KnappAttack]

I tend to be out of sync with the norm...I float my secondary, run an 8DN belt, and lock down my chain case gears and chain with matching 15 wide gears...LOL...I never have been a conformist.

But it works for me!

But Bob, just because you float them, doesn't mean they float. Thats the problem, if they float out and don't float back in under WFO, the belts out of alignment.

I run a XS825, (now with 1500 miles on it, record for me) locked secondary, and narrow bottom gear with Cat factory billet 22 top gear and stock 41 bottom gear and that works for me. There's more than one way to skin a cat. I could also run the 8DN if I wanted or put a wider gear on the bottom. Wouldn't make a bit of difference, but I wont float the secondary anymore.

 

[sideshowBob]

But Bob, just because you float them, doesn't mean they float. Thats the problem, if they float out and don't float back in under WFO, the belts out of alignment.

I run a XS825, (now with 1500 miles on it, record for me) locked secondary, and narrow bottom gear with Cat factory billet 22 top gear and stock 41 bottom gear and that works for me. There's more than one way to skin a cat. I could also run the 8DN if I wanted or put a wider gear on the bottom. Wouldn't make a bit of difference, but I wont float the secondary anymore.

Awesome...we both have found our comfort zone after decades of experience...more then one way to skin a cat as we are proving
2500 miles on one 8DN on a tuned SW...never lost a belt since I picked up the sled!...Its all good.

 

[NYTurbo]

But Bob, just because you float them, doesn't mean they float. Thats the problem, if they float out and don't float back in under WFO, the belts out of alignment.

I run a XS825, (now with 1500 miles on it, record for me) locked secondary, and narrow bottom gear with Cat factory billet 22 top gear and stock 41 bottom gear and that works for me. There's more than one way to skin a cat. I could also run the 8DN if I wanted or put a wider gear on the bottom. Wouldn't make a bit of difference, but I wont float the secondary anymore.

I agree .

 

[Dave385]

Hello All,

As there are concerns related to the durability of the new style Yamaha top gear (the gold colored gear).
If you have one of our DMC designed bushing that is in the new style Yamaha gear and you would like to have the old style Cat gear instead.
Simply return the gear to DMC, we will remove your bushing and install it into a old style Cat gear (1702-490).

We only buy OEM gears, as we always intend to provide the best quality to our customers and utilizing the R&D, Historical experience, Engineering, Warranty Dept data and quality systems of a large OEM typically provide the best best results.

A few facts about our DMC Top Gear Bushing.
We have more than more than 4900 of our DMC top gear / bushings sold and in service for the past 5 years in in 8 different country's and currently have 5 bushing failures.

1 gear, the customer knocked a hole in his chain case and ran it with no oil till it locked up. (The gear was blue and the bushing came loose in the gear) we sent him a new gear. (2020)

2 gear, the bushing came loose in the gear. We sent him a new gear. (2018)

2 gears, some of the early 2019 gears were made with out drilling the oil holes and had a very tight tolerance to the jack shaft. Two of these had a build up of chain shavings logged between the bushing and the jack shaft. this stuck the bushing to the jack shaft, not allowing the machine to move when put into reverse. We increased the clearance between the jack shaft and the bushing, and began drilling the oil holes.

Thank you everyone that has and is using our products.

 

[RAMSOMAIR]

Your bushing is working great in my SRX Dave, thank you. Who knew that Cat would go to a sintered gear, so silly.

 

[SideHogger]

Hello All,

As there are concerns related to the durability of the new style Yamaha top gear (the gold colored gear).
If you have one of our DMC designed bushing that is in the new style Yamaha gear and you would like to have the old style Cat gear instead.
Simply return the gear to DMC, we will remove your bushing and install it into a old style Cat gear (1702-490).

We only buy OEM gears, as we always intend to provide the best quality to our customers and utilizing the R&D, Historical experience, Engineering, Warranty Dept data and quality systems of a large OEM typically provide the best best results.

A few facts about our DMC Top Gear Bushing.
We have more than more than 9400 of our DMC top gear / bushings sold and in service for the past 5 years in in 8 different country's and currently have 5 bushing failures.

1 gear, the customer knocked a hole in his chain case and ran it with no oil till it locked up. (The gear was blue and the bushing came loose in the gear) we sent him a new gear. (2020)

2 gear, the bushing came loose in the gear. We sent him a new gear. (2018)

2 gears, some of the early 2019 gears were made with out drilling the oil holes and had a very tight tolerance to the jack shaft. Two of these had a build up of chain shavings logged between the bushing and the jack shaft. this stuck the bushing to the jack shaft, not allowing the machine to move when put into reverse. We increased the clearance between the jack shaft and the bushing, and began drilling the oil holes.

Thank you everyone that has and is using our products.

Of course, I was one of the 2 with the 2019 problem but called Dave and he fixed me up with no more problems.