IMCO SC - 50 hour drive update

[SVO 540]

I took my IMCO SC drive into IMCO yesterday so they could go through it and advise me if I needed to replace any gears or berrings. Everything looks great. Nothing needs to be replaced.
I have approx 50 hours on it and I am putting 1100 HP to this drive. Gear ratio is 1.25 The boat is a DCB Mach 26.
I have followed three golden rules and I think this is why my drive has lived while others have failed.
1. Don't cruise in the RPM range where your motor is making peak torque. This range is usually between 3,800 and 4,300 RPM. In this range you have maximum torque to the drive and the boat has alot of wetted surface. It is best to drive below or above this RPM range.
2. Don't let the prop get out of the water during high or low speed driving.
3. Apply power smoothly. Both out of the hole and while cruising.
I hope this advise can help keep some outdrives from failing. Good Luck.
SVO 540 - OUT

[Trash]

SVO
Sounds like good advice, but I have one question regarding the cruising around at peak torque. If I'm not mistaken, the engine is not making peak torque at its specified rpm unless you've got it "floored" and at the peak torque rpm. If you were to push the motor to WOT, then load up the output and bring it to say, 3800 rpm in your case, then the shaft would see peak torque (like a dyno pull). For simple cruising at part throttle I'm pretty sure you aren't seeing peak torque. Anybody else want to shed some light or am I on crack again?
Now, hows the motor doing? :p
BTW, boat looks killer.

[mbrown2]

SVO,
Thnx for the advice...so what if you have one of these big 600+ci plus motors that can put out the torque and hp numbers at those RPM's you listed and still being cruising 75-80? Depending on the cat, it might should already be getting packed with air at those speeds (not wetted). I guess what I am trying to figure out is it better to have a motor that makes more torque and hp at lower rpm's (less maintenance) or a smaller motor blown that makes more HP at a the higher RPM's where torque numbers would be lower, but engine life at those higher rpm's lessens..

[SVO 540]

Trash,
I agree with your comments on peak torque. Peak torque is achieved at full throttle. I do believe that cruising in the RPM range where a motor makes maximum torque (on a dyno at WOT) is harder on an outdrive than running above or below this RPM range.
mbrown2,
Clearly if a cat is running 75 to 80 MPH the boat will be packing some air and getting light. This will certainly take some of the load off of the drive. As for your question about a big cubic inch motor vs. a smaller blown motor, I am not sure. If I were to guess at it I would say that the motor with more torque (large cubic inch motor) would be harder on the outdrive.

[riverliver]

And the moral of this story is be nice to your outdrive ! or get ready to put out the big http://www.skaggmo.addr.com/wavybill.gif

[Charley]

riverliver:
And the moral of this story is be nice to your outdrive ! or get ready to put out the big http://www.skaggmo.addr.com/wavybill.gif shit the only reason my boat was at DCB the day it got stolen was cause I blew my XR drive so thats a fockin understatement!!

[LevoeDCB22]

Charley
[/IMG] [/qb]shit the only reason my boat was at DCB the day it got stolen was cause I blew my XR drive so thats a fockin understatement!! [/QB][/QUOTE]
and the day charley's boat was stolen, I was at havasu with a broken drive... another thumbs up to dave... while dealing with charleys unfortunate incident, he flew one of the boys out to havasu with a demo drive, getting me back on the water the next day

[HavasuDreamin']

LevoeDCB22
another thumbs up to dave... while dealing with charleys unfortunate incident, he flew one of the boys out to havasu with a demo drive, getting me back on the water the next dayHoly smokes..........I have never heard of customer service going that far.........but then again, I guess I shouldn't be suprised at anything DCB does. It seems as though they will bend over backwards for their customers. :cool:

[Craig]

Hey Charlie, did you break the upper gear?

[Charley]

I think it was actually the lower... I actually don't remember... It was the gear they didn't expect it to be....does that help? :confused:
[ March 06, 2003, 12:06 AM: Message edited by: Charley ]

[Craig]

Yeah, then it was probably the lower, you very rarly hear about those breaking becuase there isn't the shifting mechanics to deal with.

[Charley]

Craig:
Yeah, then it was probably the lower, you very rarly hear about those breaking becuase there isn't the shifting mechanics to deal with. There was a new prototype drive in the DCB booth at the LA boat show.... 5" upper gears, no more cone clutch/ same alloy and tolerences they are using in formula 1 cars.... looks awesome called "Fortin" .... no cone clutch apparently means they eayt Very little horse power and the guy at the show said 1000-1200 HP rating hmmmmmm
It is just an upper for now with a bravo lower but they are working on the lower..... rumour has it they may go on dafreezes Mach 34.... coupled to new quad rotor 565 Teagues that spin up around 7k and make around 1200hp wink Looks like Predator might have a fight on his hands
:D wink

[SVO 540]

The Fortin drive at the DCB booth during the LA boat show looked awesome. I think they are really on to something there. If they deliver on what they said they can do then there is a good chance one of those drives will be on the back of my boat next season. I was told that by next season, the drive will have two foward gears and reverse. You can choose the gear ratio for each gear. That means you can have a slow reverse for example. You could pick how low you want first gear to be. This gear would be good in the no wake zones. It would keep a high HP cat from going too fast in the no wake zones. All this and no transmission. This is the best of all worlds. You don't need to move your rear bench seat (make room for a transmission) and you don't carry around the extra weight of a transmission.
Let's all hope that this drive can deliver.

[Blown Lavey]

Fortin has been building off road racing trans for years, and they really know how to put a strong gear set together. I think they were stating that it would be in the price range of 11-12k.

[Craig]

Well, seems like that price will make it competitive with the Advantage SC and the B-Max.

[hulshot]

svo along time ago I took your advice on the sc drive. I broke the first one with under 3 hours and the second oneonly has 1 outting on it so I will let you know later this year. As for the new drive I missed it at the DCB booth, but am very interested in this as well as the new merc 5 blade. Is there any more info on this set up.

[Craig]

hulshot,what kind of boat and power are you using to do this?
Craig

[beach gomer]

svo540
when is your first trip to the river,and also, the wife and i would like to thank you and mama for the dress for sophia.

[blown23vee]

Charley:
I think it was actually the lower... I actually don't remember... It was the gear they didn't expect it to be....does that help? :confused: Hey Charlie, you broke somethin' already?? Sorry to hear that...what happened/what were you doing??

[Craig]

Rick, Charlie ain't broke dick yet except his wallet :D The drive he broke was on his 26. Did you pick up Tony's heads at Larrys?
Craig

[blown23vee]

Hey bud! Tried to call you about 12 times on the
road back...boring fricken drive!! I'm going back down monday to bring him my bell housing & motor mount hardware (knew I'd forget something)& I'm going grab the heads then. Those I didn't
forget, I was just way pressed for time 'cause I
left late (trailer wiring issue) & had to be back
for my appointment to do my taxes at 3:00.
Glad to hear nothing broke bud the bank!!
Rick

[Charley]

blown23vee:
Hey bud! Tried to call you about 12 times on the
road back...He sounds like a stalker Craig....... I would be very careful!! put yer pet rabbit somewhere safe whenever you leave the house
:D wink
JK rick :p

[hulshot]

Craig its well over 1000 but I am not going to dyno it this time due to time and the money I have dumped into this winters makeover.

[SVO 540]

IMCO SC 100 HOUR DRIVE UPDATE
This past weekend I broke something. I will be sure to post all that I learn on the failure.
What I know so far:
Pulled the top cap (drive shower area) off. Everything looked good, no metal, broken teeth, etc. When I spun the prop you could see the vertical shaft spinning. I don't know much about outdrives, but everything looked to be okay in this area.
When I pulled the drive off last night after I got home(late, tired and needing to rest from the weekend) the U-joint that connects the drive line to the front of the drive was broken. It was in several pieces and had caused some minor damage to the surrounding area.
The drive shaft doesn't want to slide out of the donut/cuppler. I will try to force this tonight.
I think the lower unit of the drive is okay because the prop shaft and vertical shaft spin freely.
Tonight I will see if the upper unit spins freely. I want to check the gear that is between the U-joint and the vertical shaft, in the clutch cone area. If this area is frozen, then the upper locked up and caused the U-joint failure.
Any thoughts?????
More to come.....
Hot Diggity Dog, Let's see the picture you took of us getting a tow home. There has got to be some humor in the ordeal.
SVO 540 - OUT

[mbrown2]

SVO, Hope its not too bad, but 100 hours for the HP you are pushing says pretty good things about the Imco Extreme drive...Good luck

[BoatFloating]

Is the coupler ok? I wonder if that went out. They said you wern't on it hard when it let go.
I did see you being towed as for humor it's only funny when it's not you, trust me we've all had our share of non-funny days. One thing is you boat sure looks awesome towed or not towed
[ September 15, 2003, 12:00 PM: Message edited by: BoatFloating ]

[SVO 540]

When it let go, I was traveling in a straight line, 2500ish RPM at about 35ish MPH. Not running hard at all. My drive oil temp gauge was reading normal. Go figure?????

[Party Cat]

SVO 540:
Hot Diggity Dog, Let's see the picture you took of us getting a tow home. There has got to be some humor in the ordeal.
SVO 540 - OUT I dunno if HDD got any pics.....but I did get one that has your boat with a full moon in it jawdrop I forgot the camera at home so I'll post the pics tomorrow.....

[hot_diggity_dog]

Hot Diggity Dog, Let's see the picture you took of us getting a tow home. There has got to be some humor in the ordeal.
Phil I didn't take a picture of the tow due to the KARMA factor, I'm pushing it with the 650 HP's on a stock bravo I. eek!
I need an excuse to get the new 2" shorter Imco Extreme lower unit this winter. :D
Hey I guess I could have dopped off a few taco's for you on the way in, next time I will! wink
HDD :cool:

[riverliver]

http://www.vesselassist.com/photos/VAdanapt.jpg
May be a late B-day gift ????? jawdrop

[Charley]

Phil, sorry about the bad luck my man....I guess we saw you in tow...Jen told me after we went by "hey there's Phil" .... we were with another boat and she said you already had the hookup for a tow so we had to keep goin...Believe it or not I have 96 hours on my boat too... Imco Extreme SC's and still ok(knock on wood) are your's SC extereme?>

[roln 20s]

Believe it or not I have 96 hours on my boat too... Imco Extreme SC's and still ok Hey Charley- how are those Peto motors doing? You still impressed? They sure do seem to perform well in that boat of yours! And 96 hours, thats not too shabby for season.
Roln 20s

[Charley]

roln 20s:
Believe it or not I have 96 hours on my boat too... Imco Extreme SC's and still ok Hey Charley- how are those Peto motors doing? You still impressed? They sure do seem to perform well in that boat of yours! And 96 hours, thats not too shabby for season.
Roln 20s STILL HAPPY wink .....still got a front seal leak on port motor but Larry and I are trying to work out the details on getting it fixed.... :D

[DBM]

Carlito, a little oil leak in that area will keep the belt's from squeaking.
BTW Where's my S.Pellegrino.

[WetWillie]

SVO,
Sorry to hear your bad luck.
You guys hear any update on the fortin drive setup??
WW

[Charley]

DBM:
Carlito, a little oil leak in that area will keep the belt's from squeaking.
BTW Where's my S.Pellegrino. I should be in Havasu weekend after next....will you be out there? :D

[DBM]

This weekend I'll be in havasu and on the river.
Can't make it next weekend, both my boy's play football.It takes up all my weekends for next eight weeks.

[Charley]

sorry dude... i got the Inland Invasion show this weekend... so..I'll be half way to the river but it just aint close enough for me .....should I Fed Ex em? wink

[SVO 540]

DRIVE UPDATE #2
I was able to spin by hand the imput of the drive. I could put it in gear and get the prop shaft to spin. However, sometimes it would lock up and not sound right. I took the drive to IMCO. They tore it down and found that a tooth had broken off the forward gear. The gear was in perfect condition, however somehow a tooth had come loose. This caused the drive to lock up and my U-joint to break. The u-joint breaking saved the drive from total destruction. I will need to replace the forward gear and the pinion gear. The reverse gear, shafts, lower unit, and other parts are okay. Imco said on a scale of 1 to 10 my damage is a 2. This sounds good, but it will still be expensive to fix. I don't have a price yet but I think my bill from Imco will be around $1,500. One other problem I still need to address is the collateral damage. I will need a new bellows. I didn't know what a bellows was until this ordeal. It is the rubber tube that runs through your gimble and keeps water out. The drive shaft runs through the bellows. I also still need to get the drive line out of the cuppler/donut. This weekend, I plan to attach a chain to it and tie the chain to a fixed object and yank it out with the power of my truck. It is that stuck. If the spline on the drive shaft is jacked up, then I will need a new drive line and will also need to check to see if the cuppler needs replacing. To get to the cuppler, you need to pull the motor. So as you can see, this could get more expensive.
More to come.....
SVO 540 - OUT

[hot_diggity_dog]

posted September 19, 2003 11:08AM
--------------------------------------------------------------------------------
DRIVE UPDATE #2
I was able to spin by hand the imput of the drive. I could put it in gear and get the prop shaft to spin. However, sometimes it would lock up and not sound right. I took the drive to IMCO. They tore it down and found that a tooth had broken off the forward gear. The gear was in perfect condition, however somehow a tooth had come loose. This caused the drive to lock up and my U-joint to break. The u-joint breaking saved the drive from total destruction. I will need to replace the forward gear and the pinion gear. The reverse gear, shafts, lower unit, and other parts are okay. Imco said on a scale of 1 to 10 my damage is a 2. This sounds good, but it will still be expensive to fix. I don't have a price yet but I think my bill from Imco will be around $1,500. One other problem I still need to address is the collateral damage. I will need a new bellows. I didn't know what a bellows was until this ordeal. It is the rubber tube that runs through your gimble and keeps water out. The drive shaft runs through the bellows. I also still need to get the drive line out of the cuppler/donut. This weekend, I plan to attach a chain to it and tie the chain to a fixed object and yank it out with the power of my truck. It is that stuck. If the spline on the drive shaft is jacked up, then I will need a new drive line and will also need to check to see if the cuppler needs replacing. To get to the cuppler, you need to pull the motor. So as you can see, this could get more expensive.
More to come.....
SVO 540 - OUT
Phil it sounds like you got lucky that tooth failed at a low speed and the U joint breaking prevented futher damage. wink
Still sucks when things break. :mad: :mad:
idea Put the tooth under your pillow this weekend, wink and see if the Boat Tooth Fairy puts about $2,000.00 dollars under your pillow. :D
HDD :cool:

[BoatFloating]

SVO 540:
DRIVE UPDATE #2
If the spline on the drive shaft is jacked up, then I will need a new drive line and will also need to check to see if the cuppler needs replacing. To get to the cuppler, you need to pull the motor. So as you can see, this could get more expensive.
More to come.....
SVO 540 - OUT SVO, the drive line is harder than the spline so hopefully it's only the spline, but then the motor will have to come out. I spun a spline one time and they said it was aluminum, is it a Merc or a Imco spline?

[SVO 540]

I don't know if the spline is Merc or Imco.
I will report back if and when I get that damn drive line out. Normally it would pull right out. Something has got to be wrong.

[fasteddie51]

SVO 540
It will be a merc part and it also is the light weight one used on a standard bravo unlike the HD one used on the XR IMCO is nothen short of a pile of crap and I think this is why they use the light weight parts to keep you guys comming back and spending money. One would think with a name like EXTREME it would atleast have the bigger u joints...What a friggen rip!!!!!!

[Craig]

I can see your line of thinking. I was talking to a local shop here who used to race for years and seems pretty knowledgable. He didn't understand why they went to the bigger u-joints when there really has not been much history of the u-joints failing :confused:

[SVO 540]

DRIVE UPDATE #3
Yesterday with the help of a chain and the power of my truck, I pulled the drive line out. It took quite a bit of throttle in the truck to get it to pop free. When the drive line came out it had a large berring attached to the drive line next to the u-joint. I don't recall this berring being on the drive line when I installed the drive last. I think this berring is from the gimble and somhow got locked onto the driveline. Can anybody confirm this????
The good news is that the spline on the drive line is in good contition. It will slip right into the cuppler and without any play. The cuppler also looks fine. I feel strongly now that I will not need to pull the motor. The reason the drive line would not come out was because of the berring mentioned above and was not stuck in the spline/cuppler area.
I decided that I would pull the gimble off so that I would not need to take the entire boat in to get my repairs made. I need some help here guys.
How do you disconnect the shifter cable from the gimble?
How do you disconnect the hydraulic lines for the drive trim from the gimble?
How do you disconnect the black and orange wires (I don't know the purpose of these wires)that mount under the gimble near the hydraulic lines mentioned above?
This week I will drop off the drive line at Imco. They told me they could convert the u-joints to the larger size that Merc uses on the XR drive. The u-joint I broke was the size of the standard bravo and not the XR. I was supprised to learn that the IMCO SC uses the smaller of the merc bravo u-joints. The new IMCO 4X4 uses the larger bravo XR u-joint but the SC does not. I think I will have the drive converted to use the larger u-joints. I hope the drive line checks out okay by Imco standards.
More to come....
SVO 540 - OUT

[Dave C]

Its probably the gimble bearing. (I just replaced mine.) Look into the gimble housing inside the big boot and there should be a bearing in the gimble housing where the drive shaft comes out. If it ain't there, yell bingo!
BTW, while you have it out, check the height & position of the motor, using the "special alignment tool". If the motor "squats" you will have to pick it up to get it to line up correctly. Motor mounts should have an adjustment. I noticed mine started to squat so I must realign it. If its not lined-up correctly the special alignment tool won't slide in & out easily. (some innuendo there!)
On the B1, the cable has a nut on the end where it enters the housing. Then take off the clip on the rubber boot and loosen the hose clamp on the rubber boot. Then it should pull into the boat. (BTW, loosening that damn hose clamp requires knowledge of yoga and/or small hands and tools.)
I think those wires attached to the rams are probably for the neutral kill switch. Just loosen them and keep the screws in place so you don't forget.
The hydraulics just unscrew but jam something into the hole so the fluid doesn't drain onto your driveway. Instead, can you just unbolt the rams and "hang" them to the side, rather than undoing the hydraulics? I use a coathanger.
Good luck.
[ September 21, 2003, 11:47 AM: Message edited by: Dave C ]

[Dave C]

BTW, just a thought.
I know the gimble bearing is a press fit. It usually requires a bearing extraction tool to get out.(like a slide hammer)
Due to damage maybe the drive line was held in by the bearing, which then must be extracted?
I dunno, is it possible?

[SVO 540]

Dave C.....Bingo!!!!
Thanks for the info. You confirmed what I thought. The drive line was stuck in the gimble bearing. The gimble bearing is still stuck on the drive line. The gimble bearing came out of the gimble housing when I pulled the drive line out. But at least the prop shaft is out. It confirms that the log jam was there and not further up the line in the donut/cuppler area.
I am clear on your suggestions about the hydraulic lines and also the black and orange wires, but not totally clear on the shifter cable. It would be helpful if you could further explain where this nut is and why the rubber boot that the cable runs through needs to be removed or did you just say loosened.
My best guess is that I will need a new gimble bearing and a new bellows. I hope this is not to expensive.

[Craig]

You should be able to pick up a gimble bearing for about 80 bucks if I recall.
Craig

[Dave C]

Bingo. cool,
Re: that damn cable. It’s kind of hard to describe and I have a B1, so I don’t know if yours is different.
Actually the cable slides to the outside. If you need to take it off, loosen it from the shifter housing also, under the hatch. Probably a small nut & clip. Its routed under the motor in the center, bottom of the boat.
Actually if you take the whole damn gimble housing off, just loosen the cable from the shifter and not the outside and see if it comes out with the housing.
The cable is held in the gimble housing in the part that swivels, side-to-side. The cable end is held into that portion of the gimble housing with a jam nut.
First, get a wrench & socket on both sides of the cable end, and loosen that jam nut. The cable end will slide out of the swivel portion of the cable.
Second, you must loosen both clamps on the rubber boot on the end of the cable. The cable will slide outside of the boat.
Don't forget to check the alignment before you reinstall all this stuff. With your monster motor you'll have difficulties if its wrong.

[Dave C]

When you reinstall, put some sealer around the ends of the rubber boots (bellows) and make sure they are sealed. Put the boat in some water and make sure its not leaking.

[fasteddie51]

No need to pull any thing off your boat just replace the bearing and bellows if needed from behind your boat!! Bearing 56.00 at bam marine, you can look them up on line! You should need tollance ring, seal and bellows "if you have a hole it it"....If you broke anything in your transom assembly then you need to remove the whole mess and buy a new one for 1,400.00!! It will be complete with everything, trim cylinders and hoses all the way to trim pump,shift cable, mercathoid and inner plate and all hardware to install, even the nuts and washers that hold the drive on...........You would have to email me for this coz bam would be a lot more........