Drive swapping for even wear
 

Anyone swap drives from side to side to promote even wear on the gears?

i thought about it when I first got my boat but decided against it - I figured once the gears were "set" that I'd just let them continue that wear pattern as opposed to creating new wear patterns every season.

Pluss I was going to have to change around the top caps/etc for the tie bar and ext. steering.

I agree that swapping drives, or just the lowers, would help the gears last longer. This is in addition to running good fluid and changing it often. The best way would be to wait to swap till the fluid shows small flakes, swap, run about the same amount of hours or untill flakes, then rebuild before they explode!

Mr. Gadgets advised me to do this when I had my drives he had done. Never any problems.

just swap the whole drive out,, side to side,,,since one drive is using the upper gear and the other drive using the lower gear,, in the drive shaft housing,,going forward,,,you would get even wear on each side of the upper gear set,,

When you switch your drives you are running on the opposite side of the teeth in the lower and in the upper it now would use the reverse gear for forward, so you could double your drive life. The problem with waiting till there are metal fines on your magnets is all that same metal has gone through you entire drive, bearing and gears. There is no good rule of thumb as far as hours on a drive to switch them because it of the different way folks use their boats and maintain them. I have customers with 500 hrs on a drive with no problems and some with 100-150hrs and there shot. So to answer your question yes a lot of people swap their drives and get more life from them.

Swapping gears is never good. You are reversing the loads on the gear teeth. Thus causing reverse stress. This will result in much sooner failure of the gears, than if you just left them alone. Also you never want to change the gear pattern. There is no gear sets that I cannot get at least 200 hours on, under normal running. I've been setting gears in drives for over 40 years now. I've had tremendious success with every type of gear. From #6's all the way down, to include Bravo's and Alpha's. I've worked in gearing all my life.

I agree 100% I have a freind who blew the gears out almost the first time out after reversing his drives on his bravo with blower motors. Even the shafts can let go when you unwind them, so to speak.

Sorta makes sense but does that mean we can't run our boats in reverse any more since we might put opposite stress on the gears??! J/K

People better get 200 hours under normal conditions with any gears!! I have 1700hrs in 70,000 miles on my dodge towing 25000+lbs 99% of the time (way more then normal conditions) and the gears are fine. My dads 1977 checkmate 351 ford I/O has at least 3000 hours of water skiing with original gears.

My guess would be how to make a overpowered and over driven drive last longer? Not a stock bayliner taking the family tubing.

The best statement about drives ever "different folks use their boats and maintain them". Yes every situation is so different its almost pointless to talk about it.

If someone was going to swap drives it would make the most sense to ME to only do it once. So somehow if you could figure out the longest way to run on one side so you only have to swap out once. I change my drive fluid every 20 hours or sooner and can tell when theres more metal, I am not talking chunks, just tiny tiny slivers, compared to just metal dust. Obviously taking them apart and looking would be the best but to much work for most and once apart might as well just rebuild!

Bergers at LOTO recommends doing this as well.

The running in reverse. If you mean reverse as reverse that is not ever a problem, you are putting no load as to speak.
But if you are referring to Bravo's reversing the drives from one side as Port to Starboard. You would more than likely not be doing this after several hours are on the drives. That would shorten the life of the gears. If doing it in very earily stage, such as to test the boat for better operation. Than it more than likely would not have to much effect on the gears.
Because you haven't put enough load on the gears as of yet. But you wouldn't want to do this after a few hours, you would lessen the life of the gears greatly. I hope this helps.

This brings up some good points. Another thing to think about is switching prop rotations from turning out to in or vise versa. I guess the correct way to do that would be to also switch the drives from side to side once you decide which way to run?

Thanks everyone ! I guess it's better not to swap if John is correct.

Yeah, I guess I'm confused as to yes or no, different opinions.... Seems like a good idea......
Dean

First of all what are we talking about a stock application or a 700hp and up? I have been swapping drives for years and have never had one come apart.
When you buy a reman unit how do you know what side of the boat the used shafts were on before? Be careful how you answer that because you may start a up roar with a lot of re-builders. I do agree that if you are swapping drives on a boat that has twisted splines already you will soon be paddling back to the dock. There are a lot of variables that go with this conversion and each owner and their boating habits and power have a big roll in this.
We have all broken Merc vert shafts, they are like a chicken wish bone some times they stretch and sometimes they snap.

I like fried chicken....:party-smiley-004:

I agree with Waconda and about everyone else on this thread. Way too many variables. In a perfect situation, I personallt think swapping drive is acceptable.

John, my spare does have new shafts doesn't it???? :lolhit:

I just used JB weld and put the old one back together, it was original merc so I thought we needed to keep it. How is it holding up? :party-smiley-004:

Running good im my garage so far..... :lolhit:

Other ones are livng fine with that blue oil of yours in it.... :lolhit: Got any guages laying around there you would swap for a full BT cover? :party-smiley-004: :lolhit:

Well I have swapped upper helical gears and lower gears. So long as the net forged ones havent started to pit, it seems to last. But when they are pited, or just started, then the life expectancy may not be equal to the time running in the opposite direction. Now the helical uppers, if not over taxed, seem to like being flipped.
The XR uppers, it seems to be the pinion gear that starts to pit, so fipping them doesnt help. Of course if you are unlucky and have a driven gear with a weak tooth, that might break before you get a chance to flip them, or it may happen soon after you flip them. By fliping, I mean either change the position of the gears, or swaping props or drives, etc.

In the upper, the pinion drives both gears. The cone will engage either the upper or lower for forward or reverse, depending on what rotation of prop you have on the drive. RH prop = bottom upper gear, and so on.
In the lower the pinion gear will put pressure on the opposite side of the gears when rotation is switched.

Hope this helps explain to those that are not familar with how the bravo works before it breaks. :)

Dick

Good point, if you twisted a shaft again and again and it springs back, like the max machine worx torsional memory shafts, if you started twisting it the other way I can't see any good coming from it, Smitty

Remember all parts in a reman unit are not used. Only the housings are. The working parts are all new.

Maybe in a Merc reman, I have had cpo's units have used parts in them, but if you call around to rebuilders and ask what is new in their units most of them say only the parts that are bad.

That's what I'm referring to Merc. units. I would never use any other reman unit under no circumstances. You are asking for trouble.

John CPO's are merc units.

I do agree that there are some reman's units out there to stay away from but there are some very good ones also.

Ok, I am installing a "gone through" Imco xtream sc and don't know if it is left or right. It's on the bench in neutral. If it is a left what harm would running a left prop be in a 25' eliminator daytona? Or can I just swap forward/reverse in controller and run in reverse for forward? From what I have just read it sounds like a crap shoot for the ladder. Is running a left prop so bad?

jmo bergers need to close thier doors:stooges:

Wasn't endorsing it one way or the other. Just passing along what Mike Berger told me once in a conversation about Bravo Drives. I know plenty of folks that are glad their doors are open.

I tried swapping drives on my boat and promptly broke both of them within 2 days of each other. After talking to a LOT of people about it I found that swapping the drives is OK if you do it on a regular basis. Like almost every time you go out, otherwise you are asking for trouble.

I run amsoil in my drives changed every 20-25 hours with 600 SCI's and have to change the gearsets, bearings, etc. every 100 hours. Gears start to pit and then they are ready to break at any time.