3rd lower unit gear failure

[jlhyatt]

Can anyone suggest what might be causing my gear failures? I have a 1997 150 hp Evinrude mod. E150 ELEUE. First failure, my fault, hit some rocks. Insurance covered and forced me to a repair shop that I have heard bad reviews about. Anyway, gears went out again for no reason with fewer than 15 hours run time. Since it was longer than a year, they would not stand behind their work so I had to pay for the entire cost. Then the same thing happened again. I decided to attempt a repair myself. I am a good mechanical engineer, so I purchased a shop manual and the required tools and parts to rebuild. All new shafts, bearings and seals plus some other miscl. items. I checked the gear set up on the fixture from the last professional repair. It appeared correct. I continued my rebuild and set everything up per the manual. Did the recommended break in proceedure, and it failed again. Does anyone know what could be going wrong?

 

[DHPMARINE]

Re: 3rd lower unit gear failure

Sounds like your exhaust housing (outer) was 'bent' in the initial impact with the rocks.This puts excessive pressure on the driveshft/pinion.Off hand I don't remember how to check.I've had 2 similar motors,but replaced the housing due to cracks.

DHP

 

[Dhadley]

Re: 3rd lower unit gear failure

Who's gears are you using?

Describe what the damaged gears look like or better yet, a pic will help.

What oil are you using?

 

[jlhyatt]

Re: 3rd lower unit gear failure

Gears were purchased from Basic Power Industries (GLM). The oil I used is OMC Ultra-HPF Gearcase Lube. Can't say what the the repair shop used.
These pictures are the gears that were put in by a local boat dealer and repair shop that my insurance company sent me to. I didn't attach pictures of the GLM gears I installed. They have more damage to the forward and reverse gear and a little less on the pinion.

Hears my concern. When I put the forward gear in and the drive shaft set up with the shim fixture (from Basic Power also), I can pull the pinion gear and shaft upward away from the forward gear approx. .050. When it is down against the forward gear, they appear to be perfectly match. Is this to much play? Looks to me like this would be a better way to set up by using backlash or clearance measurments instead of the fixture since all the components that effect proper gear mesh have manufacuring tolerances and wear if reinstalling used components. Is there a backlash spec. anywhere?

 

[Dhadley]

Re: 3rd lower unit gear failure

OK, the pics didn't come out but if you'll send them to me at dhadley50@aol.com I'll see if I can get them up for everybody to see.

 

[Dhadley]

Re: 3rd lower unit gear failure

 

[kalla man]

Re: 3rd lower unit gear failure

3 times!! thats painful..
those are some great pics....maybe you should give up you mechanic hobby for photography... ha
.~~~~~~~~~~~~~~~~~
THE PROJECT.......
s99.photobucket.com/albums/l309/kallaman/

 

[ezeke]

Re: 3rd lower unit gear failure

I just saw a set of ATV gears that looked like that. The damage was caused by going from forward to reverse with no hesitation.

My prop weighs 16 pounds. If I shifted like that coming into the dock, I would expect my gears to look that way in a hurry.

 

[jlhyatt]

Re: 3rd lower unit gear failure

Okay, I finaly got to talk to a mechanic on the phone, however, I have no idea of his qualifications. He suggests shimming the drive/pinion shaft to obtain .020 of up and down travel of shaft when assembled. Can anyone verify this? There is no publication of this spec that I could find. If this is the proper way to set up gear clearance/backlash, then why did I buy and expensive set up fixture?

 

[Dhadley]

Re: 3rd lower unit gear failure

The spec is in the OE manual. I wouldn't deviate from that but I can't remember off the top of my head what it is. I certianly wouldn't shim it any more than what the manufacturer calls for.

What spec was it shimmed to before?

 

[jlhyatt]

Re: 3rd lower unit gear failure

I used the set up fixture before to determine shim amount. The fixture told me I needed .005 shim. And this is how it was assembled last time. But now that it has failed again, I started trying to determine why this thing keeps failing. This when I noticed that when the shaft is shimmed according to the fixture, there is .050 movement up and down in the drive shaft after assembled. This seems to me like this would allow way to much backlash in the pin and forward gears.

As I mentioned before, I check the set up of a previous repair performed by a supposedly certified repair shop, and it appeared to correct to my set up fixture.

The only manual I have access to is my Seloc manual. It only refers to the set up fixture and no reference to backlash or drive shaft end play clearance. I would really appreciate it if someone who has the OE manual could look this up for me.

 

[marinemech1]

Re: 3rd lower unit gear failure

hi: I think your problem is possibly that the housing itself is distorted
there is atool avaiable from brp to check housing alignment but its expensive.
we had a v-4 fail gears similar to your experence hit rock and repaired gears failed twice after that brp said housing likely bent so we put on new housing