p4-33

Well, actually the same one for the third time this season. RH rotation, taking out 6-8 teeth on the pinion gear on the lower end of the of the vertical shaft. Had the exact same failure a week ago. FYI, running HP500's.

This is getting ugly, last time around it took out my BW tranny. That's a whole other story...

My drive guy is setting them up in the mid range on backlash, in the .008 to .010 range. Merc spec calls for a range of .002 to .015 backlash. He is being told from parts suppliers that I might have a lower unit case that is out of whack, but I'm not yet convinced this is the case. Nothing looks askew in there, bearing races all look clean. New case would require a nosecone job, and I've got a race in Cinci this weekend.

Each time he builds it, he changes races, bearings, and gears in the lower.

What gives? Any TRS gurus out there?

Thanks,
Brian

jpclear

You've probably heard all this before but I had similar problems until I cryo-treated everything. No frailer in last 51/2 yrs. (knock on wood) --- jp

p4-33

Hi JP, I don't disagree... where can I find a set already done? I think if I had the main lower gear and it's pinion cryo-treated, I'd be in good shape. Who offers them?

Have a race in cinci this weekend, and don't have time to get the gears, ship them somewhere, and wait for them to be treated. Any ideas? How about lending me your lower for the weekend?

Thanks,
Brian

Love Machine

Here's one solution...

http://www.offshoreonly.com/forums/s...ad.php?t=79783

mrv8outboard

what does the oil look and smell like? what oil are you using? i can't remember off the top of my head but the bravo's have gone to .030 on the backlash. if the gear pattern is OK than that extra clearance gives you more cooling and lubrication of the gear set. also at the speeds for P4 class you really don't need the nose cones as these tend to heat up the drives do to the loss of cooling water along the outside of the housing. just a little thinking out load. FYI.

throttleup

p433,

I know it won't help for this weekend but we have a local company we use for our cryo needs. If you would like more info let me know. It's very reasonable, price-wise.

Matt

Biggus

Pick up a pair of Konrads and be done with drive problems.

I've got 50+ hrs on my new Konrad 540's so far this season and I've been treating it like it was an ANVIL!!!

Kurt

p4-33

Thanks everyone, been thrashing on the boat to determine whether the tranny lived this time. I think I lucked out, looks like I just spun the dampener. I'm having the tranny looked at just for a sanity check.

mrv8, the oil is burnt. I hear you on looser tolerances. I will suggest to drive guy, but he's stuck on something is out of whack with my lower case. I still don't think so. I have a used complete lower lined up for this weekend as a last resort. I just need this to live for one more race.

Matt, if I had the time, I'd do cryo-treat. I'm sure it's helpful, but it's too late in the game.

Mr. Love, and Biggus, the Konrad 540 PRS program IS the long-term solution.

Thanks again,
Brian