Drive discussion: trs. 3's. And 5's
01-04-2015 | 12:46 AM
#61
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Joined: Jun 2009
Posts: 9,967
Likes: 6,456
From: Chicago
Original poster RMPRam
Lil red is correct. All the #4's have a "polygon shape" front driveshaft, while some of the early #5's did also. In my opinion, the polygon shaft is just as "good" as the splined version that Mercury switched to in the later #5's. None, again from my sources, of the #4's had the near net forged, straight cut upper gear sets. They were a later "up-grade" in the #5's. The lower gear sets, RH and LH internal splines, on the #4's and the #5's are different with the #4's having fewer splines on the pinion gears, than the later #5's. A #4 can be upgraded to be, again in my opinion, as strong as a #5 with the addition of a set of the net forged, straight cut polygon'd upper gears and also the 1.75" dia. propshaft. I have both of these pieces, new, available for the #4. Check my classified ad for more information. If I can be of any help, please don't hesitate to give me a call.
Gary
612-247-7081
Lil red is correct. All the #4's have a "polygon shape" front driveshaft, while some of the early #5's did also. In my opinion, the polygon shaft is just as "good" as the splined version that Mercury switched to in the later #5's. None, again from my sources, of the #4's had the near net forged, straight cut upper gear sets. They were a later "up-grade" in the #5's. The lower gear sets, RH and LH internal splines, on the #4's and the #5's are different with the #4's having fewer splines on the pinion gears, than the later #5's. A #4 can be upgraded to be, again in my opinion, as strong as a #5 with the addition of a set of the net forged, straight cut polygon'd upper gears and also the 1.75" dia. propshaft. I have both of these pieces, new, available for the #4. Check my classified ad for more information. If I can be of any help, please don't hesitate to give me a call.
Gary
612-247-7081
See this should help Dave understand the differences.
01-04-2015 | 07:21 AM
#62
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Joined: Jul 2004
Posts: 11,332
Likes: 73
From: chicago
Merc developed the SSM III drive for racing. It was a stronger drive than the TRS for that. After a while, the surface drive (arneson boats) showed up. Merc's rebuttle was the #4 drive. The #4 drive, was much shorter than a #3. It did not have a cavitation plate (prop clearance), and had a much larger skeg for surfacing stability. After a while, an upgraded version was needed, as the racing engines were getting more powerful, boats going faster, etc. Merc then upgraded the #3, to the #3A. The #4, to the #5. Most upgrades were done internally. Straight cut gears, thicker spur gears, larger propshafts etc. The #3, and #4, had 19 spline shafts. While substantially larger and stronger than a TRS, bravo, or XR propshaft, they still went bigger, to the 1.750 shaft like the #6, 26 spline style. Plenty of used 3 and 4 blade props out there for relatively easy money. Last couple sets of SSM 4 blade props, I've paid less than 2g per pair.
As far as the #5 being stronger than the 3A, I dont believe that is true. They both share the same style internals, just the 5 is the shorty version. These drives share nothing in common with a TRS, SSM 2, or Konrad. Design wise, they are more similar to a #6 than they are a TRS.
The #5 lower case, is also beefed up over the #4 lower case. Hard to tell by looking, but its a bit beefed up in thickness. I think this was due to some of the old race cats, cracking the lowers on #4's at high speeds in big water. Probably an issue most pleasure boats wont see.
The #4, and #5 series of drives, allow you to keep engine mounting height, reasonable. For example, if you were to install #3/3a drives on a 33 fountain, or 33 powerplay, youd have to mount the engines very high, to get the best propshaft height. Clearance would be an issue. Cutting into the rubrail, extreme blower hatches, etc. The #4, and #5, are about 5.5" shorter than a #3/3A, but can be spaced up to 3'' down. This is a very nice feature, esp if your running tall roots style blowers. Right off the bat you're getting almost 6'' of hatch clearance.
As stated, many many #4 drives, are called #5's, when in reality they are 4's that have big shafts. My 4's have 240 hours on them since they were installed on my boat. Prior to that, I am not sure if they were gone thru at that point, or not. But, for 240 hours, they have had blower motors in front of them. Knock on wood, I havent had a lick of trouble with them, other than a propshaft seal leak. I wouldnt say I am easy on them, lots of 3000RPM to full throttle accelerating, rough water, etc.
After owning a couple TRS boats, a couple bravo boats, I've decided the 3,4,5 drives are for me. Not only do they simply hold up well to a beating, I love the way the SSM boats handle big water. #6 boats are out of my budget, but plenty of SSM 3,4,5 boats I can afford.
I've seen guys claim 700HP will live with a TRS, bravo, etc. While that may be true, you're not gonna be getting any life out of it, unless you go easy. Bolt a #5 on it with 700's, and go drive it like an offshore cowboy, and it will still outlast that TRS.
As far as the #5 being stronger than the 3A, I dont believe that is true. They both share the same style internals, just the 5 is the shorty version. These drives share nothing in common with a TRS, SSM 2, or Konrad. Design wise, they are more similar to a #6 than they are a TRS.
The #5 lower case, is also beefed up over the #4 lower case. Hard to tell by looking, but its a bit beefed up in thickness. I think this was due to some of the old race cats, cracking the lowers on #4's at high speeds in big water. Probably an issue most pleasure boats wont see.
The #4, and #5 series of drives, allow you to keep engine mounting height, reasonable. For example, if you were to install #3/3a drives on a 33 fountain, or 33 powerplay, youd have to mount the engines very high, to get the best propshaft height. Clearance would be an issue. Cutting into the rubrail, extreme blower hatches, etc. The #4, and #5, are about 5.5" shorter than a #3/3A, but can be spaced up to 3'' down. This is a very nice feature, esp if your running tall roots style blowers. Right off the bat you're getting almost 6'' of hatch clearance.
As stated, many many #4 drives, are called #5's, when in reality they are 4's that have big shafts. My 4's have 240 hours on them since they were installed on my boat. Prior to that, I am not sure if they were gone thru at that point, or not. But, for 240 hours, they have had blower motors in front of them. Knock on wood, I havent had a lick of trouble with them, other than a propshaft seal leak. I wouldnt say I am easy on them, lots of 3000RPM to full throttle accelerating, rough water, etc.
After owning a couple TRS boats, a couple bravo boats, I've decided the 3,4,5 drives are for me. Not only do they simply hold up well to a beating, I love the way the SSM boats handle big water. #6 boats are out of my budget, but plenty of SSM 3,4,5 boats I can afford.
I've seen guys claim 700HP will live with a TRS, bravo, etc. While that may be true, you're not gonna be getting any life out of it, unless you go easy. Bolt a #5 on it with 700's, and go drive it like an offshore cowboy, and it will still outlast that TRS.
01-04-2015 | 07:32 AM
#63
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Joined: Jul 2004
Posts: 11,332
Likes: 73
From: chicago
#1 Arneson
#2 M8
#3 SSM 6 dry sump
#4 SSM 6 wet sump
#5 SSM 3A/5
#6 SSM 4
#7 SSM 3
#8 Konrad
#9 Kaama
#10 Bravo XR Sportmaster
#11 TRS/SSM II
#12 Standard Bravo
#13 Alpha
Just my opinion!
01-04-2015 | 09:50 AM
#70
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Joined: May 2011
Posts: 576
Likes: 1
From: Varna, IL
For the 4 vs 5 confusion, the easiest way to tell is the size of the pin that goes through the trim cylinders. 4s are 7/8" and 5s are 1". All the parts will fit in either case though. I was so confused when I bought mine
