Taking a survey as to what you have personally had happen to your XR drive if it broke.

I need to know what failed first, not the other parts it took out in the process.

I am working on an improved upper gear set and also think the lowers are an issue for some as well.

Thx

The lowers seem to last longer then the uppers by a pretty good margin, you'll twist a prop shaft off before you loose the gears. I think in the upper the case is the problem though, not so much the gear set. Once you get any kind of HP and the case starts to deflect it game over for any gear set.

In mine i scrubbed teeth off the upper gear set on the left hand drive. Also noticed the top cap bolts were finger tight leading me to believe they had stretched and lost tolerance. Didne really take anything else out but the gear.

Broke a tooth off the upper gear set and you know the rest of the story .

On the boats I deal with,,,,, I would say about 3 to 1 uppers to lowers

Your poll is wrong.


Should be:
Broke XR Upper gears 1 time
Broke XR Upper gears 5 times
Broke XR Upper gears more than 10 times

I dont know about you guys, but Merc never should have done away with the TRS drives........ Of course they would have never made millions selling replacement equipment for the bravo drives------ like hooking up twigs to a tractor motor and expecting them to last....




Jim

imo,3 problems with xr uppers,1 the cases flex,gear contact pattern changes and then the teeth break.2,due to the physical size of the gears,it can only handel app 500 hp.3,the quality of material used in the gearsets is horable,no wonder they fail.

when products are driven by marketing rather the engineering thats what ya get . . . . .


I agree would have loved to see a second generation TRS type drive. Simple robust drive with a solid trans for six to eight hundred hp range . . . . or in other words Konrad

and this is the issue everyone wants to gloss over. the Bravo was engineered to handle less than 400 hp in a light runabout. its was created so they could put big blocks in runabouts because the Alpha could not handle it. Unfortunatly all the manufacturers wanted them because they dont have a transmission and they could move the back seat back and have a bigger cockpit. because they did that they kept telling Merc to make it handle more power because they already built molds and did not have room for a trans for a TRS or Speedmaster. as a result there is now no step from a crappy Bravo to a #6. it does not matter what you do with gears, the next weak link (and there are a lot at the power everyone wants to run) will show up (gimble, shafts, housing, etc). as Jim said "twigs hooked to a tractor motor".

Only have had 1 of my lower sets go and 1 lower set
on a friends boat...have a pile of uppers tho.