Treated Gears Results.
 

Here are some pics of a set of lower gears that were Cryo treated. This is the same process that Articfriends and I have been doing for the past season.
This set of gears had 77hrs on them before being treated and had wavy lines on the teeth. (More pics forth coming to show that) and 55hrs on the treated gears. You can see a slight scuffing, but look almost as good as when they were installed.
This was 725hp and ocean running. Very interesting to see the results, I was very impressed.
I am also looking at a variation of this process and another coating process. In the process of adding power to my boat to test these gear treating processes myself.

You and Smitty (Wilbur) send me a couple of those fancy drives with that treatment, I'll test them on my boat for you...FREE! :D

Thanks for the offer Pantera.. I have had that one before!! :) :)

Dick,the gears I "retired" from my lower this year had about 60 hours on them which was 4 times longer then I ever had them live before,looked almost new still even after running 1000 plus hp. I have done over a hundred sets of gears for outdrives with good results 99% of the time. GPM had a set still fail under 5 hours BUT he is running over 1400 hp, I did not personally set up his drive and he was trying a un-proven lubricant. I have done a full regimen of testing this fall on new gear coatings/further processes,with mixed results at the 1050 hp level in my own boat,I will be modifying my treatment program and will continue testing next year,Smitty

Do you also treat the Upper gears?

Yes, I do treat the upper gears as well! The inner bearing has to be removed, but I can do it without damaging the bearing. There is almost always a paste of metal particals hidden below the bearing cage. I remove and clean this area when ever I rebuild a drive.
Still looking to see results from upper gears with hard hours on them. The only ones that have come back were damaged due to other reasons than just wear..

D*ck

Smitty treated 2 sets of Xr uppers for me this spring,
and it finally made it through a year without a
failure:D

D*ck,
what do you use to get the bearings out with ?

Those gears pictured in the first post are mine. I can vouche for the fact that I had 77 hours of untreated use last year and 55 hours of treated use ( on the same gears ) this season. I run the ocean alot. While I maintain my equipment well, I use my 725 hp everytime out. The process definetly works well. Ofcourse, the process is only as good as the set up. A few years ago, Dick took the time to help me learn how to set up drives. If they are not set up correctly, there is no magic process that will help. Attached is a picture of the gears after the first season of use ( 77 hours ) . Hey, I typed in Dick's name and it didnt get censored!!

One more picture..

That is very interesting stuff. We go through gear sets every 2-3 races. I would love to get 6.

Vinny,
Thanks for chiming in!! :) :)
I like the new handle!!

Dick ( We'll see if my name has been approved?)

Dick,

After I saw this thread you started, I remembered I was supposed to send you the pictures. I just figured I would post them here instead. If you want them sent to you before I optimized them, let me know.

Vinny,
That's ok.. I can get them from here, I believe. My email is down at this time anyway..

Thanks
Dick

PS. Thanks OSO for unblocking my name!!

I have treated about 20 sets of upper gears,most in twin engine applications,the feedback I got was very positive (like yours) with the exception of one race team that chose to just treat the upper pinion gear,not the complete upper set. I Have been replacing the stock mercruiser bearings in the upper gears with the max machine worx caged bearings,they run on the inside of the gear cup instead of a outer race. The max worx bearings seem to hold the gears truer on the tower and cap anyways,Smitty

Smitty,

The results you have achieved with the uppers is equally as impressive. The uppers in my drive are several seaons old. When I replace them, I will definetely be treating them as well. However, at my moderate power level, I think that the uppers will last a while. The weak link is the lower gear set. For guys like yourself , who is running big power, well that another story.

Maybe that was me.
Except, I had a small pit in the upper pinion on the COMPLETE treated set.
The other contributing factor is I changed oil, told by a major drive supplier that it was what they used on there 'house' drives.
That was OK, told Smitty about the pit, there is no problem.

The 2 x upper pinions (for customer boats) that I had done (not the set) both had failures within 15/20 minutes.
I lent them my treated XR and built up an X to use myself.
The first one had prop failure at about 10 minutes, received the new Mercury XR top and installed, my XR went under the bench.
The second one broke and I lent them my XR, run up on the boat and a weird noise (slight), pulled the top box and 1 x tooth was ******,hmmmm. Put in a spare gear, ran a different oil to what they were running and next race no problem.
Pulled the 'new' Merc XR on the other boat and a pit in the gear (after 10 minutes run in), hmmmm, changed its oil as well.....It won its next event.
Both these drives were running a highly recommended oil ,, customer supplied and not Mercury or Sierra.
My X drive runs at more horsepower than the other Two failed ones.
All upper gears used the Max Machine bearings except the new XR.
So oil selection is critical, I am not running the Merc oil, and have had no failures on Merc or Sierra.... Think twice before changing your oil spec...

I DO NOT WANT TO GET INTO AN OIL BRAND SLINGING MATCH,
this is only a report on what happened, they are race only boats running Bravo derivatives.

And I WILL get more treated gears from Smitty/Articfriends

duplicated

I have run the Royal Purple for years. This next year I will be bumping up the power to test, like Smitty has been. I am in the process of setting up my next drive. Havent worn out the old one yet, close to 300hrs on it, but with only 750-800hp (guessing) and no gear treatment. I was able to get 87.7mph out of my 283 Convincer this past summer..
Next year I will have the Procharger on it to be in the same leaque as Smitty for test purposes... :) :)

I have installed treated gears in several customer setups, all with good results so far. I dont recall the numbers, not as many as Smitty, but I think at last count around 40 gears, uppers and lowers.

Dick

Dick,

I have a question regarding Mercury's manufacturing of the lower gears.

What kind of tolerance variances have you been seeing between gearsets (new/old). Meaning, how much shimming have you had to do on the lowers when installing a new gearset, or have they been pretty much the same??

Panther, as far as depth goes, they seem to be pretty close. But I do see a variation in lash from set to set. Even with the uppers, they can vary an extreme amount..

Dick

Wow, that's make or break!

So basically your pinion depths are staying pretty consitent but you're having to continually shim the race on the driven gear in the lower?

Sorry to change the subject guys, but is there a way to mic or measure the wear on the gear teeth to determine if the upper or lower gear sets are useable or not? Besides looking at them. Thanks for the great imfo guys. Always a pleasure to read and learn from your threads.
Thanks Gary

I see more variation in the bearing races which causes the gears to move around some. Generally I dont measure the lower gear pinion height, if when tearing the drive down I see bearing wear. I think about it about 10mins after it is too late.. So I generally build from scratch and things get shimmed accordingly. I just did a drive that had a lot of hours on it.. and the tapered bearings look like new. It needed a new set of lower gears and without changing the shimming the gear lash fell into place.
The variation of lash is due to the net forging and what ever surface that the gears have on them. Be it nitriding or what ever. Not much you can do about it. I was hoping that the cryo treatment and polishing would help that, but it doesnt seem to. Although it doesnt seem to matter unless you get to serious power, from what I have experienced. I had a run of upper gears that were all over the place on lash, and they are holding up fine, even in high stress setups.
Gary, there isnt a way to measure the gear wear. It is more of a visual thing. Which gears are we talking about.. uppers, lowers, XR, helical?? The near net forged will start to show a line in the middle of the tooth and then give up metal as they are run.. If you can catch it before the tooth breaks off.. you got all the milage you can out of that set of gears.. The helical will shine up and wear till they break teeth.. usually a long run when behind mild power..
Hope this helps..
Dick

Thanks Dick, that's what I've seen as well! Just wanting to see if I was missing something. :cool-smiley-011:

Garry, when your gears look like the first picture just throw them out because they're near the end of their lifespan. The second picture is earlier on in its life and the shotpeen is wearing away and the teeth are getting shiny.

Hey Guys, many thanks for the imfo. I have worked my way up thru exploding, all the bravo styles since 1987 currently running XR with sportmaster lowers. Around here nobody rebuilds bravos, at least none that I trust, the dealers only want to sell you a new one when a drive breaks. So I have been learning by trial and error, plus the merc manuals to build my own drives along with a friend of mine. Now that I have high speed internet, much has been learned in the last 5 mo. from all of the imfo you guys share. By the way I too would like to know how do you get the middle bearing out of the upper XR gears without destroying it? Again many thanks for the imfo.
Gary

I believe it's part number; 91-31229A7

Thanks for the tool # Frank I will order that from Merc.

im in the middle of putting my drive back together it seems to me ( and this is my opion im a auto refinisher not a mechanic) that the only thing you are shimming is the case so if you are using the same case you should be ok. Am I close to being right?

I will need some of those cryo lower gears sets very soon....
Will be rebuilding this winter.

Besides the small lines you may also start to get tiny pits that sorta look like cavities,once you get them they start opening right up and the gear really starts to give off a ton of metal,when you start seeing a higher amount of metal in your oil when changing it and feelng a little gravelly feeling when spinning the prop its time to tear the drive down before you really destroy it,Smitty

You shim your pinion depth the same usually as what is was then check it with your pinion checker,it usually doesn't change much. You then mock the whole thing up and check your backlash,if it is off you leave your pinion depth shim alone but change your shim under the front big bearing race (or in my case I use a automotive pinion shim and remove the bearing from big gear vs removing the race from the case),Smitty

Thanks very much for the info. It is helpful, berfore I got into this thing everbody said that I would not be able to do it because of th shimming no one ever really explained how to shim it. (If that makes sense) once again THANKS!

Hey Smitty,

I like your idea of adding the auto shims behind the gear so you dont remove the race.But if you need more lash then you would have to remove some shim behind the race correct?Also what is that blue tool in your photo?I am just starting to rebuild my own drives,after setting up a ton of rears in my classic cars I figured it shouldnt be to hard.So I purchased all the tools and now Im looking for any pointers.Sorry for the hi jack od the tread.

Nordic95

The easiest way I have found to set the lash on the lower gears is to have a test race for the driven gear. I cut down the outside of the race a bit so it slids into the housing without having to be pressed in and hammered back out. After setting the lash up with the test race, I hammer in a new race and recheck the lash. I have not found the lash to change any between the 2 races.

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I also have done this with the pinion bearing on rears for the same reason.I also tried it on the lower bearing for the pinion height in my drive and it worked also.But im just getting into drives and dont have much of a learning curve yet.

Nordic95

The blue tool is a bearing puller that can pull a pinion bearing off the big gear on a bravo or most automotive rear end carriers or pinions without damaging the bearing,its a life saver when setting things up. Anthony,you are correct if your backlash was too tight the race has to come out of the housing in most instances. But what I started doing is if you were going to shim the race with lets say .025 to start I would put .015 under the big bearing race and install it in the housing new with press fit assist loctite,put the other .010 under the big gear bearing, then add or subtract or subtract shims as needed from the gear. I do this for several reasons,I have seen some lower housings that were slightly loose(race had spun) on the big bearing race and had to have the surface raised with a ***** punch bent 90 degrees and then put the race in with press fit asssist loctite and I really didn't want to pull the race back out unless absolutely neccesary. The automotive shims are cheaper too and it takes me just a few seconds to pull the bearing off the gear/press it back on compared to finagyling the race back into the housing,re-cleaning any aluminum,loctite,etc out,Smitty

Do you locktite all the press in races into your cases?How hard to get the races out later when you have to rebuild?Also do you find the blue tool easier then a bearing seperator plate and a press?Where can I get "THE BLUE TOOL" from:D?Which auto pinion shims did you find fit the best,12 bolt chevy etc.?

Thanks Anthony

i would like a blue tool also, wht is that thing called? I jus paid $152.00 for those cage bearings on the pinion shaft I didnt think I could save them to get the pinion gear off.

You can pull any of the bearings off the gears with a press and seperator plate. At least I do it without hurting any of the bearings. I dont loctite any of the races in unless they are loose. I use a knurling tool to raise the metal on loose cases. It is a home made tool but it works ok and then I use 620 loctite to hold the race.
I like your idea of using shims on the propshaft gear.. Where do you get them from Smitty??

Nordic, got your pm, the video is still in the works. Been too busy to finish it. But I may work on it this winter.

Fountain Fever, are you refering to the tapered bearings on the pinion gear for the upper? They also can be removed with a press and separator plate.

Dick

Randies ring and pinion sells the bearing puller tool, Dick is correct,on most outdrive gears you can just use a press plate and a 50 ton hyd press to knock bearings off but the puller allows you to also pull side bearings off most automotive differential carriers (using a impact gun) which are difficult to impossible to set up in the hyd press . I have heard someone other than Randies ring and pinion had copies of the bearing puller on E-bay but anyone interested in getting one can call them at 1-800-347-1188 ext 5539 brian anderson,tell him Steve at Smittys engine and transmission in Mi refered you to them,Smitty