Aluminum Driveline?

[2112]

Anyone out there swap out the heavy steel Merc driveline for an aftermarket aluminum or even carbon fiber driveline?

Seems that they have been race proven in many other arenas and in my boat, it is a straight line application, no angle at all. Could probably even eliminate one of the u-joints.

Any opinions out there?
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[Sean H]

yes. carbon will survive moderate power/not to rough/not to big of boat.

nothin beats a steel one in big power/big water conditions.

[2112]

Is there a reason to have a slip joint in the driveline if the distance is fixed length?

How about a u-joint on each end if there is zero angle? Both Needed?
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[phragle]

the probability of actually having a dead nuts zero angle is slim multiplied by any flex... you may get it close enough to live but it will fatigue and crack eventually unless you are running a rubber coupler. I have seen video of a boat running hard without the engine hatch... the motors move.

[2112]

I do have rubber couplers...Bravos.

Not perfectly zero. There is approximately .005" of "pivot" of each u-joint in a complete rotation. I am just wondering if 1 u-joint is enough.

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[phragle]

are you attempting to gain something by eliminating it? the actual mass given the diameter is fairly small....

[MikeyFIN]

Anyone out there swap out the heavy steel Merc driveline for an aftermarket aluminum or even carbon fiber driveline?

Seems that they have been race proven in many other arenas and in my boat, it is a straight line application, no angle at all. Could probably even eliminate one of the u-joints.

Any opinions out there?
.

Yes.
I don´t see the gain there..except bling factor if you polish one.

[Ratickle]

Weight is weight.

I don't know for sure what they ended up doing, but if you get ahold of Keith with the Cat Can Do team they use aluminum in their Super Cat/PX Cat. It broke at St Clair this year, but they had it repaired and they ran fine. The new blower motors they run have a lot more power than the old SuperCat engines use to have, so their opinion should be a good one. CK Motorsports in Spring Lake, MI. Keith Holmes. Plus he's a certified Mercury Mechanic on the big drives.

[DAREDEVIL]

Is there a reason to have a slip joint in the driveline if the distance is fixed length?

How about a u-joint on each end if there is zero angle? Both Needed?
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U don't whant 0 angle.

best for a drive shaft is 2-3 * !!!!!! And a slip joint is a must due to vibration !

[imco offshore]

U don't whant 0 angle.

best for a drive shaft is 2-3 * !!!!!! And a slip joint is a must due to vibration !

god knows i hate to say this,,, dd is right,,,damn it,,,, you need at least 2 o of angle in a u-joint so the needle bearings inside the cups will rotate , otherwise they stay fixed and pound flat and vibrate and blow out, those little needle bearings spin in the cup and reduce friction.(hp) and i did see carbon fiber driveshafts yesterday on 700 hp and a 39' boat ,,,:USA: god please save me.....lol

[Sean H]

Yes.
I don´t see the gain there..except bling factor if you polish one.

there are big gains in race setups with long driveshafts (cats, full staggered vee's). You take a 48" steel driveshaft and replace it with a carbon one, you will feel and see the difference.

[2112]

are you attempting to gain something by eliminating it? the actual mass given the diameter is fairly small....

Yes, I am thinking weight. My small driveline is probably 50 lbs and it is only on the one side. I have seen drag race drivelines in aluminum and CF advertized "good to 1200 horses" which is much more than I have, so I was thinking......

On the angle....my bad. I am not going to move the engine now so I will just have to replace the u-joints on a regular basis.
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[MOBILEMERCMAN]

The aluminum may work just fine but, it will need to be inspected much more often for cracks. I personally don't think it is worth the risk in a pleasure boat. I have seen an aluminum one fail. It sure does make a mess. It let go with out any warning or vibration.

I to agree a small variation in cross bearing angle is preferred. The slip spline coupler makes service easier and allows for boat movement. Any end load transferred in to the engine will cause crank failures.

[Sean H]

The guys who have run all 3 prefer either the steel or carbon, the alum not so much.

If built to the right spec, carbons work flawlessly. Just don't repower your boat with nearly twice the torque and leave the orginal carbons in there (ask Miccosukee).

[DAREDEVIL]

Yes, I am thinking weight. My small driveline is probably 50 lbs and it is only on the one side. I have seen drag race drivelines in aluminum and CF advertized "good to 1200 horses" which is much more than I have, so I was thinking......

On the angle....my bad. I am not going to move the engine now so I will just have to replace the u-joints on a regular basis.
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Put your batt, on the other side and u be fine. 50# aint nothing in a plessure boat !!!!!
Plus if its staggered u won't feel the difrents at all !!!

[Chris]

The likelihood that you got the engines in perfect alighnment is pretty slim. A degree or so isn't much. You should be OK.

On the aluminum shaft, the reason they have issues is that aluminum work hardens. On something like a roadrace car, you're not going to get dramatic shock loading like you will in a boat that's loading, unloading and sometimes reverse-loading the propeller. The first thing is to have it constructed from the proper grade of aluminum. Then after welding is should be re-heat-treated. 6061 is probably the best material if you need aluminum.

On the slip yoke, you absolutely need it. There's no way you can get the spacing to a thousandth or two and the engine mounts will flex, not to mention the hull/stringer/transom.

[2112]

The merc input shaft assembly has a .250" back and forth ability. I assume the additional 2 inches in the driveline slip yoke is also needed?
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[Chris]

There's a fixed flange on the back of the engine and a fixed flange on the transom plate carrier.

[2112]

There's a fixed flange on the back of the engine and a fixed flange on the transom plate carrier.

My Engine flange is not fixed. It is part of a pinion shaft that engages the bravo coupler. That it the piece that moves .250"
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[DAREDEVIL]

My Engine flange is not fixed. It is part of a pinion shaft that engages the bravo coupler. That it the piece that moves .250"
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Got any pictures.

[2112]

Got any pictures.

Yup, When I get home tonight I will get them up. I am left coast so it may be past your bedtime. :sifone:

[DAREDEVIL]

Yup, When I get home tonight I will get them up. I am left coast so it may be past your bedtime. :sifone:

MAYBE,,,but there is always tomorrow !!!:seeya:

[MOBILEMERCMAN]

Got any pictures.

http://www.mercruiserparts.com/Show_pictures3.asp?dnbr=879168&ivar=IMAGES/COMMON/20359.png&inbr=13369&bnbr=220&bdesc=Driveshaft+Extension+Components(Bravo)

The back of the bravo engine has a a carrier to hold the driveline and coupler like a regular bravo.

SSM are flange to trannie flange.

You still need the slide in the driveline. Engines, transoms, bottoms move more than a 1/4 inch underway.

[Chris]

My Engine flange is not fixed. It is part of a pinion shaft that engages the bravo coupler. That it the piece that moves .250"
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I would look at converting it. I'm not what you'd call a Bravo guy but I'm guessing this may be a conversion of some sort that allows the use of a plug-in transom assy. If you order a new Merc driveline it has the tailstock bolt-on flange.

[DAREDEVIL]

http://www.mercruiserparts.com/Show_pictures3.asp?dnbr=879168&ivar=IMAGES/COMMON/20359.png&inbr=13369&bnbr=220&bdesc=Driveshaft+Extension+Components(Bravo)

The back of the engine has a a carrier and coupler like plug ins.

SSM are flange to flange.

You still need the slide in the driveline. Engines, transoms, bottoms move more than a 1/4 inch underway.

THANKS JIM ,,,,,,LOL,,,got one sitting here just like that. + an older style Stelling box for a Bravo.
Anybody need one ?? LOL

[MOBILEMERCMAN]

There are in fact two spline joints in a bravo drive line. The bravo needs a conventional coupler. It has a carrier that supports the driveline. I am not sure how the input is located but if you say it has 1/4 that is not enough by itself.

Where as the trannie has a flange and the trannie contains a bearing with in to support the driveline.

[MOBILEMERCMAN]

I would look at converting it. I'm not what you'd call a Bravo guy but I'm guessing this may be a conversion of some sort that allows the use of a plug-in transom assy. If you order a new Merc driveline it has the tailstock bolt-on flange.

The drive line itself is or looks the same. The way it is supported is different.

[2112]

The first pic is the "adapter" that bolts to the bellhousing and engages the bravo coupler with its input shaft. It is a Merc part that came on the boat bolted to the 525efi that was in the boat. This is the shaft that has .250" movement fore and aft.

The third pic is the back carrier bearing that the input shaft from the ITS unit engages from behind and has a flange in front.
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[2112]

Here is the MERC bellhousing adapter unconnected, (sitting on the floor) showing the flange that bolts to the driveline flange. This is all stock Merc;
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[DAREDEVIL]

The first pic is the "adapter" that bolts to the bellhousing and engages the bravo coupler with its input shaft. It is a Merc part that came on the boat bolted to the 525efi that was in the boat. This is the shaft that has .250" movement fore and aft.

The third pic is the back carrier bearing that the input shaft from the ITS unit engages from behind and has a flange in front.
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I really think the driveshaft is TOO straight !!!!!
I would move the engine a little up in the back .
And other then that leave it !!!!!
Nice set up by the way.

[MOBILEMERCMAN]

I just read thru both 525 and #6 installation manuals looking for specs. Drive line flange variation is recommended to be between 1 and 3 degrees. Surprisingly I could not find a spec for drive spline clearance or any mention of it. I understood the spline should be extended about an 1". not closed. I would measure and make sure it had about 75% engagement. Maybe an older manual has a spec. I will look tomorrow. Maybe Stelling offers a spec.

I have heard horror stories of engine failures when shafts put a end load on the engine.

[DAREDEVIL]

I just read thru both 525 and #6 installation manuals looking for specs. Drive line flange variation is recommended to be between 1 and 3 degrees. Surprisingly I could not find a spec for drive spline clearance or any mention of it. I understood the spline should be extended about an 1". not closed. I would measure and make sure it had about 75% engagement. Maybe an older manual has a spec. I will look tomorrow. Maybe Stelling offers a spec.

I have heard horror stories of engine failures when shafts put a end load on the engine.

Thats what i know it is 1 inch out on the driveshaft.
Also def. an angle ,,i was told safest is 2.5-3 * angle.???

[2112]

I had the driveshaft shortened after that picture was taken (pic is old). It is approximately 1.25" out of the slip yoke which is about half of the total movement.

I took the driveline down to the driveline shop today and had it checked after nearly 60 hours of use. Everything is in perfect shape, including the u-joints.

I did this because I could hear a faint knocking in the driveline. Disconnected it to make sure it was not the motor (wasn't). Well, I found the problem tonight. The big ball (.250" balls) bearing carrier that is the first bearing the outdrive input shaft rests in after it passes through the bellows let go. It punched a hole in the bellows as well and let in salt water although none made it past that and into the bilge. the ball bearings are resting in the bellows now.

Now I need to replace that bearing and the bellows. :ack2: This will be my first after 19 years boating. I am happy to have caught it before something really let go like the input shaft or the u-joints on the outdrive itself.

Jim, can you give me a lesson on bellows and bearing replacement? Helmet off first and then it is good access? This is an ITS transom assembly BTW

[DAREDEVIL]

U can get the bearing out with a slide hammer and the bellow u can replace also from the outside .

just pull the drive and lift the bell,,u see how the belloww is in there and should be able to replace it just like that.

after u pulled the bearing,,use a bearing tool and just punch it in place.

should not take u longer then couple hours if its the first time.
Atleast thats on a Bravo,,but ITS should be the same.

[MOBILEMERCMAN]

Michael, Nice find on the noise. You can use a slide to pull the gimble bearing but, I prefer and have had more success with a puller. You can buy a bar and threaded rod type from Merc or Pro Marine. http://www.promarineusa.com . I have had the flat bar merc for years but often need to support it with pry bars. The new style uses a piece of box tubing and is offered as a kit instead of pieces. I suggest that one. You will also need the drivers to install the bearing and bellows sleeve.

Pretty easy job. Just be patient and have a stool to sit at the right height. The bearing gets changed while the bellhousing is still in place. Either before or after bellows job.

The bellows part is best done by removing the shift cable although it is not nec. Might as well change the shift bellows too. The water hose that connects the bell housing to the inside is something I suggest you change whether it needs it on not. Mostly because of the potential problem of salt pinching it and restricting flow. You will be right there and it will never be easier. There is a special tool for the retainer you will need..The point of the hose change is to clean the salt out of the housings around the outside diameter or the hose. Clean and repaint surfaces.

Back to bellows. Note clamp locations. Clean glued side with emery and solvent. The shift cable bellows fwd surface needs cleaning too. Clean aft side and repaint as needed. Install fwd first with top as marked on bellows. Use bellows adhesive or super weather strip adhesive as directed and clamp { fwd side only}. Secure not do not over tighten either bellows clamp. Especially the shift one. It will try to walk off. Both have a distinct slot to position clamps. I suggest a long @18" 1/4 long extension with swivel.

Install the bellhousing. The second groove in from the end of the bellows rides on the protruding ring of the seal surface. install dry. Use driver to install sleeve also dry. It says a drop of soap , I use spit if nec. Complete shift cable and water hose assembly.
I always find the clean and prep time matches the actual work time. Take the time to get all the salt off. If bearing got wet cross bearings should be changed too. Clean and grease yoke at seal surface.

Best of luck. I would by a merc service manual. If I were you. It may not be needed now but, it is worth every penny.

[Chris]

Auto Zone will loan you a bearing slide hammer- no charge.

[Geronimo36]

Best of luck. I would by a merc service manual. If I were you. It may not be needed now but, it is worth every penny.

I'm with Jimmy!!! Even if they're old out-dated manuals it's good to have them laying around for reference.

I get a lot of my manuals from the marina when they throw out the old ones when the new editions are released! :driving:

Also, if you know someone, try to get the CD's!!!!!! You wont be able to get access to MercNet unless the people you know are silly enough to give you the passcode but you'll have all the parts break-downs for quick reference when you need to order stuff!!!! ;)

Believe it or not, I still have a microfische set!!:willy_nilly:

[Geronimo36]

As for the slide hammer....this is one of those cases where I found the bigger the slide hammer the better for the job!

I made an instalation tool out of an old TRS bearing race, u-bolt flange, long azz bolt and a seal assembly from an Alpha drive!!! It ain't pretty but it was free and it works!!!

Also, if you haven't done so already, make yourself one of these shift cable snakes!!! It's made by using the "inner" from an old shift cable and cutting off the threads of the adjustment rod.... To use it you disconnect the shift cable as you normally would to pull it out....(Don't forget the plastic heat/vibration spiral crap) Then pull the inner out of the old shift cable, go inside the boat, thread this tool into the old shift cable "outter", then go outside the boat and pull the shift cable thru.... Disconnect your snake, install it on the new shift-cable, thread it thru the shift bellows then go inside the boat and pull the cable the rest of the way thru with your snake! Works like a charm! ;)

[2112]

Wow guys; DD, Chris, Geronimo, Thanks for the help, Jim great blow by blow tutorial. Thank you. :sifone:

I have a mail into Rick at CP for all the merc parts, Sounds like I should be able to handle it. I will have one (or several) more tool(s) in my tool box :USA:

Which bearings are the cross bearings?

[2112]

Rick @ CPPerformance just mailed me, everything on it's way. I guess I know what I am doing Friday. :driving:
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[MOBILEMERCMAN]

Cross bearings = u-joints

[MOBILEMERCMAN]

I

Believe it or not, I still have a microfische set!!:willy_nilly:

I still have original books. Both merc and cruiser.


http://www.mercruiserparts.com/partsByNumber.asp Bams site has pix too.

I have CD in both computers and look at Bam for latest pricing. Its easier than looking in a book.

[2112]

Cross bearings = u-joints

Ah, That needs to go to the driveline shop to be pressed. Someone once mentioned that there are better u-joints than Merc's, do you know which ones?

Can you teach me (us) how to pull that unit off the out drive now? :sifone:
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[MOBILEMERCMAN]

I don't know which are best.. There are many that have been used. I have noticed flaws in new ones before. Just need to pay attention when changing them.

I would suggest using Merc and order by serial number.

[2112]

On the driveline that instigated this thread, When I took it down to be shortened and balanced they upgraded the u-joint to some beefy spicer units. They are much more stout that what was in there but they have no zert fittings (non-serviceable)

Shop swore they were stronger and longer lasting than the stock units.
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[MOBILEMERCMAN]

Most newer ones you cant grease.. But I believe since you cant' they need to be replaced once they are submerged like from a leaking bellows.

[DAREDEVIL]

Good luck and happy drinking,,,,,i ment wrenching.:sifone::USA:

[2112]

Good luck and happy drinking,,,,,i ment wrenching.:sifone::USA:

Are you trying to tell me I have barked knuckles in my future :willy_nilly:
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[MOBILEMERCMAN]

It is not hard or fun. Just work.

[Geronimo36]

Are you trying to tell me I have barked knuckles in my future :willy_nilly:
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I feel for ya!!!!

Last Saturday I had a couple free hours in the AM so I thought I'd go out to the boat and get started on unplugging the engine... I got the blower off and into the shop and started unhooking the water lines to the exhaust manifolds and one was kinda stuck on the barb fitting so I put a little more azz behind it and pop goes the weasle....my hand swung away and in the process ripped across the oil dipstick tube gashing my pinky finger open.....instant blood everywhere.... I flipped over the flap of skin to see if I could see bone....no bone so I ran into the house to tend to it....Said to my wife; "hurt my finger bad, we might need to get me some stitches.".... she turned white as a ghost! :ack2:

So I get it under the faucet and start cleaning it and applying pressure... 5 minutes later it stops bleeding.... I make the decision to no go to the ER for stitches because I have a wedding to go to at 3 pm....:ack2:

So the bleeding stops and a few hours later I'm getting ready for the wedding, tying my tie....I bang my hand...cut splits open again and blood everywhere.....:ack2:

Apply pressure for 5 min. and get it to stop bleeding and get a bandaid on it and go to the wedding!!! :ack2:

Luckilly nothing happened at the wedding although my fingers is still a bit banged up but I should be ready to go this weekend!:willy_nilly:

[MOBILEMERCMAN]

Frank, I knew I was not the only one to bleed in boats... Grab a paper towel and electric tape and carry on.

[Geronimo36]

Electrical tape, classic!!!! Super glue works good too!!!! :)

[Ratickle]

Speaking of blood in boats. Where do you get the little rubber caps for the ends of hose clamps???? Friggin finger/arm slashing little bastages....:boxing_smiley:

[DAREDEVIL]

Speaking of blood in boats. Where do you get the little rubber caps for the ends of hose clamps???? Friggin finger/arm slashing little bastages....:boxing_smiley:

Buy some real hose clamps and that will not happen .
ABA out of holland i think ,,,expensive but 99% never fail ,they cut the hose if u tighten them not rip apart.

[2112]

Speaking of blood in boats. Where do you get the little rubber caps for the ends of hose clamps???? Friggin finger/arm slashing little bastages....:boxing_smiley:

I am not sure about Daredevils hose clamps but the rubber end pieces are Merc part # 19-807992 3 in bags of 20. May be the most affordable Merc part there is.
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[phragle]

Electrical tape, classic!!!! Super glue works good too!!!! :)

Superglue was first invented in an attempt to make a surgical glue.....

[DAREDEVIL]

Superglue was first invented in an attempt to make a surgical glue.....

THE MORE U DRINK THE MORE U KNOW !!!!! :rofl:

[Geronimo36]

Speaking of blood in boats. Where do you get the little rubber caps for the ends of hose clamps???? Friggin finger/arm slashing little bastages....:boxing_smiley:

Please add the ends of cut-off zip ties to the list of finger/arm slashing little bastages!!!:03::cuss::willy_nilly:

When I was doing this chit full-time my knuckles were so banged up I developed calluses from banging them almost every day at work.... Got to a point I was knawing on them when I was bored! lol

[Ratickle]

Please add the ends of cut-off zip ties to the list of finger/arm slashing little bastages!!!:03::cuss::willy_nilly:

If they are in a bad spot, sand the end a little and no issues. It's just those dang hose ends that slice and dice and vegimatic me too a bloody pulp.....:boxing_smiley:

[Geronimo36]

Superglue was first invented in an attempt to make a surgical glue.....

Was it for the military?

[Geronimo36]

If they are in a bad spot, sand the end a little and no issues. It's just those dang hose ends that slice and dice and vegimatic me too a bloody pulp.....:boxing_smiley:

I hear ya and they hurt quite bad, especially the ones people cut off to make them short!!!:cuss:

I have a really good pair of dikes that cut the zip ties all the way down!! Unfortunately other boats/customers don't have them and I always find them the hard way! Usually when I'm changing spark plugs or something at arms reach and they gash up my forearms!!!:ack2::cuss::cuss:

[2112]

Zip ties are bad. I use heavy stainless toenail nippers to get them flush. They're 10 bucks at the drug store. They look like baby orthodontic wire cutters.
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