Pitted gears in XR @ 75 hrs??
 

Just got off the phone with mechanic. Upper gears are pitted. He said this is common wear before catastrophic failer.

Drive was abused before I bought it. At one point it had a procharged 500 efi, around 750 HP. Long WOT runs, drive oil never changed. When it was changed it was black.

I brought it in to be looked at because of hesitation when shifting into reverse.

Superboat 30 Y2k, single, 5000lbs+

Any comments/expalanations??? Or just from abuse?

Re: Pitted gears in XR @ 75 hrs??
 

Hey PE,
Smart move going through your drive before running it with that new blower motor of yours... :eek:
I would guess you are right on; abuse and lack of maintenance... :(
From what I have read, the upper gears are the weak link.
The only comparison I have for you would be my buddy's Fountain. 1997 29' Fountain, single 525sc, standard Bravo drive. Gregg's boat and drive has over 600 hours. The drive has never been touched other than u-joint grease and oil changes every 50hours. The oil has always come out as clean as it has gone in...

Re: Pitted gears in XR @ 75 hrs??
 

I'm suprised it made 75hrs. If the gears start to have teeth marks pressed into them, your on borrowed time. Replace and be done with it, unless you plan to run under 500HP.

Re: Pitted gears in XR @ 75 hrs??
 

The clock is ticking fast on that one :D :D

Re: Pitted gears in XR @ 75 hrs??
 

That is normal wear on the upper XR gears. Depending on power applied, I have seen 70hrs on one set and two teeth on the driven gear were cracked. Not sure how it got on the trailer that day!! But that was 950hp and run very hard!! A lot of drag race time.. But we caught it before it was catastrophic.. Usual time on XR gears is about 250hrs as I have been told. All depends on driving habits, maintenace and setup... and good lube. You did a wise thing, having it checked.

Hope this helps
Dick

Re: Pitted gears in XR @ 75 hrs??
 

If you want more advice, post a picture of the gears.

Re: Pitted gears in XR @ 75 hrs??
 

Hey Pat!! Hope all is well!! I have not seen them yet but he described it as "small craters" in the gears. Hopefully I can make this drive live, I am very easy on my equipment, but there are times when.......well you know :D

Or thinking of B-Max or other drive may be the way to go. It's all an expensive crap shoot!!

Re: Pitted gears in XR @ 75 hrs??
 

I am very easy on my equipment

Yea, when it's tied up at Claudios...I've seen you run it easy :rolleyes:

Re: Pitted gears in XR @ 75 hrs??
 

It seems like the early xr gears were not as good as the newer ones. I had one of the early sets (around 2001-2002) that started wiping out the upper pinion gear after 90 hours with (then)750 hp. Replaced them and its been the LOWER gears that won't last for me. My uppers are going on almost 200 hours with 750 hp then 950 hp,my lowers are trashed at 50 hours or so. I change oil every 10 hours or so,there is ALWAYS metal in it,Smitty

Re: Pitted gears in XR @ 75 hrs??
 

Yea, mine is either 01 or 02. My mechanic said it is usually the lowers that go.

Re: Pitted gears in XR @ 75 hrs??
 

The 1 mile sprint to my house from Claudio's does not fall under the catagory of abuse!!!! :drink:

Re: Pitted gears in XR @ 75 hrs??
 

How about the blast from Claudios out towards Orient point, when that knucklehead almost ran you over :eek:

Re: Pitted gears in XR @ 75 hrs??
 

Allright, that counts :D

Re: Pitted gears in XR @ 75 hrs??
 

Mercury had a bad run of upper XR gears around 2000 - 2002 that would only last about 50 hours. There are a couple of threads talking about them.

Both my sets of original XR uppers lasted 50 hours before the bad pitting appeared and my current sets have 250 hours and no problems.

Re: Pitted gears in XR @ 75 hrs??
 

biggest reason for pitting is not changing drive lube enough also biggest reason for drive failure.....then launching the boat

Re: Pitted gears in XR @ 75 hrs??
 

If you are going to try and run it as is I'd use the Redline Heavy Shockproof gear oil. Nothing better out there IMO, probably a little more drag than say M-1 75-90. Make sure your drive passes a vacuum/pressure test before going with this oil as it is not marine, but definitely one of the best gear oils.

Re: Pitted gears in XR @ 75 hrs??
 

You guys might want to look into having XR gear set nitirided for added wear resistence. a lot of the big truck transmission building companies are now using this process with great results.

Ray @ Raylar

Re: Pitted gears in XR @ 75 hrs??
 

never heard of it, is there anymore info ????

Thanks

Re: Pitted gears in XR @ 75 hrs??
 

I just spoke to Dean at the Bravo Shop. They are using a new coating on the lower gears. It brings the surface hardness to 91 Rockwell. He offered to swap my lower gears out, so I'll give it a try.

Re: Pitted gears in XR @ 75 hrs??
 

Re: Pitted gears in XR @ 75 hrs??
 

PM JC Perf on it, from what I have heard the teague shaft is the way to go, to make it even that much better.

Re: Pitted gears in XR @ 75 hrs??
 

This is pretty technical and boring reading , however if you read between the boring chit you will see the benefit of this type of surface treating on gears and such. This is the process we treat the EV8H stainless valves with in our heads and the wear resistence, strength, corrosion protection and the benefits are incredible and very inexpensive @about .50 cents per valve. I sometimes take a extreme duty (HA)stainless valve and one of our nitrided valves at a show and try to scratch the surfaces of each valve with each valve, current score extreme duty valve +100 scratches and some deep gouges, the nitrided valve 0 scratches. Ladys and Gentlemen we have a winner!! When people in the gear industry start using this process on gear sets exposed to high wear and loads, the days of the past will be no more. Just some real science that works!

www.finishing.com/kolene/qpq

Ray @ Raylar

Re: Pitted gears in XR @ 75 hrs??
 

Very interesting. I been using automatic transmission components (steel plates) that been thru this process for years. They rarely warp or get hot spots. I wonder what the average guy or even a small shop could do to get a set or a few sets of xr gears done,Smitty

Re: Pitted gears in XR @ 75 hrs??
 

Raylar,
So where do you get this done? Any contacts in the midwest??

Thanks
Dick

Re: Pitted gears in XR @ 75 hrs??
 

Dean has my drives now . I am buying his new cresant lowers with the new lower gears and I am trading in my uppers for the new HT's. I should be good and have a new 950hp 950TQ warrenty also :drink:

On the bad run of2000-2001 XR gears I thought it was a bad run of pinion gears ??? Heard they were bad about loosing teeth :eek:


Rob :drink:

Re: Pitted gears in XR @ 75 hrs??
 

Contacts for QPQ nitriding

Kolene Corp 1-800 521-4182 ask for heat treater in your area with their process.

Bodycote @ (708) 344-4080

MMi @ (870) 236-6920

Hope this helps

Ray @ Raylar

Re: Pitted gears in XR @ 75 hrs??
 

Teague Platinum Shaft, wouldn't be my first choice.

Re: Pitted gears in XR @ 75 hrs??
 

Are you getting strait cut lower gears or helical?
And are you trading to the BMAX HT with intergrated streering?

Re: Pitted gears in XR @ 75 hrs??
 

That nitriting process is also used on the iron plates of rotary engines. If the nitriting is removed from the plates by machining "to true up the plate", they loose about 80% of their longevity!

Re: Pitted gears in XR @ 75 hrs??
 

I'd say you got the platinum shaft from Bob!!!!

Re: Pitted gears in XR @ 75 hrs??
 

It only hurts when I sit.

Re: Pitted gears in XR @ 75 hrs??
 

Dont put too much faith in Imco shafts either. This came out of my SC Lower. Hopefully their newer updated shaft without the oiling hole will be better.

Re: Pitted gears in XR @ 75 hrs??
 

Raylar,
Thanks for the info.. I will check into it. Very interested in this process..

Thanks
Dick

Vinny,
I think the new shafts are doing better than the old ones. I still have the old one like you have! I will be tearing down the 109mph Baja drive shortly.. So far 1150hp hasnt broken the vertical shaft.. And this guy runs it HARD!! Time will tell...

Dick

Re: Pitted gears in XR @ 75 hrs??
 

Should of gave me your drive ;)

Re: Pitted gears in XR @ 75 hrs??
 

Strip, you are right, the problem a few years back were the pinion gears.

Re: Pitted gears in XR @ 75 hrs??
 

I am trading in my BMax drive and getting the New HT 950HP 950TQ drives with the crescent lowers . No integrated ...He said it will be awhile for the heli gears . He said it should have the new style prop shafts though. Problem is he doesn't have everything to put it together now and I have a poker run march 18 weekend . He said he might have it ready . I am hoping!!

rob :drink:





rbtnt back when my buddy Mac worked at Imco He said they had the same problems with the pinion gears. It would crack/chip off a tooth on them. I went thru 3 Imco's on my Scarab. Like he said it was a maintenance item ya replaced it every year or so many hours.

They way I look at it is :D its like my race car if I break a rear end gear thats just part of racing, Everybody freaks out when the little gears or shaft break :rolleyes: . The shet happens .

Re: Pitted gears in XR @ 75 hrs??
 

Rob,

I thought the helical cut gears were still just an idea. I'm glad we are still getting the same info. What parts doesn’t he have for your drives?

I'm sending out my lower today. He’s going to put the new coated gears in.

Other than warrantee, why change to the HT uppers? I didn't think there was much difference. My upper is the closest thing to bullet proof I've seen.

Dave

Re: Pitted gears in XR @ 75 hrs??
 

zt260, Do you have the BMax upper?

Re: Pitted gears in XR @ 75 hrs??
 

I have the original style BMAX Upper.

Re: Pitted gears in XR @ 75 hrs??
 

he sia dthe gears are in the works . He didnt have a date But , he said there in the works ?The new HT has a differant prosses heat treating/cyro/that he does to the upper parts that gives it a higher rating , He said they have a bout 15 HT's allredy out there.I been out of town dynoing my new motors and havent talked to him about when.He said he's changing to the satinless prop shafts was one thing.

Rob :D