Hi Guys,

Does anyone have the following information as far as what the XR gears are made of and how the are manufacturered?

· Alloy of gear

· Forming operation (i.e. cold hot or forged)

· Method of hardening (i.e. induction or case hardened)

Thanks for your help.

Mark

Sh!tty
P!ss poor
Not very

Hope that helps.
PM "Smitty" he has that info I think.

What are you up to now, Mark?

Yes, why?

stuff

I had an upper gear set fail after ten hours of use (All work was perfromed by certified Merc Racing Tech who has worked on my stuff before with zero issues.) and where the gear broke it was obvious the casting was bad. Straight line crack all black on one side and bright silver on the other.

I have a friend who is a metalurgist looking at the failure and he asked for the information.

The term "near net forged" comes to mind.

I have a rather nice collection of these.

This collection includes a specimen of each type
of failure that's commonly known to man.

I don't know what you're up to, but you're more than welcome to borrow a sample

if the x and xz gears are the material any ideas why they seem less susceptible to this type of failure?

The XR has only one tooth in contact at any giving moment where as the x and xz have 2 1/2 teeth in contact.

1st - It is possible to get bad gear sets, send it in to Merc and get it warrantied if it only has 10 hrs on it.

2nd - Most of the time if the housing has had a gear set go bad it is most likely stretched and pinion bore is out of position, or the towers are bent. Very few people even think about this let alone have the tools to check the housing and towers after a failure.

3rd - Think about most people you know that have had a drive blow a gear set and have it rebuilt and just like you have it blow again in a short time, all because there is more to rebuilding a drive than putting in a new gear set. We junk a lot of housings do to stretch. XR housings seem to be worse off do to the size of the broken teeth that are going through the pinion and driven gears. Most of the time it has enough pressure to break the top cap bolts.