Gimbal Ring Wear - How Bad?

[MERPerformance]

Why don't you just pull both engines ,remove the gimbal assy,rebuild with HP style kits from Merc cost $1175.00 retail $1600.00, sounds like you have a problem thats going to return over time. I perform this all the time

[MOBILEMERCMAN]

There were some complete new assemblies offered out around $2300 not too long ago.

[ROGUE]

Oh boy, this sounds all too familiar. The fact is, merc screwed up by not making the torque requirement a standard maintenance item, my 11 manual (1989) says 45 lb/ft. The merc shops all claim ignorance.

[ROGUE]

And, wanting to sell you lots of new parts at high dollars. There are good people around who sell gimbal repairs, good shafts and good u-bolts because of this Merc ignored problem.

[Knot 4 Me]

There are two ways to attend to it. You can service it with out pulling motors.

Correct, but it is not my boat and the owner prefers the motors be pulled to perform the work if necessary. To be honest, if it was my boat I would pull the motors too. I'm not a fan of cutting access holes that could eventually leak.

[Knot 4 Me]

Why don't you just pull both engines ,remove the gimbal assy,rebuild with HP style kits from Merc cost $1175.00 retail $1600.00, sounds like you have a problem thats going to return over time. I perform this all the time

I will recommend the HP kits to the owner. I agree, beef it up now and hopefully be done with it for a long time. At the end of the day, it will be his decision on what he wants to spend. He is not cheap so my guess is he will throw the best at it if a repair is indeed needed. Thanks!

[Revd Up]

Dave,
I know what the manual says. You are quoting it correctly. I have been round and round with this before. At some point you will break one.

I usually torque my u-bolt to 53lbs about once a year. Should I loosen it up a little? Going to have to make that correction in my manual.
Glad to see this post before I broke it.
Thanks

[MERPerformance]

I keep hearing you guys talk about the U-bolts, if you have to keep them tight, I would guess to say; maybe you have a problem with the steering you are using such as stock and the conditions you are running or power you have. The pin and arm have such a load on them that they are over stressed. To solve this problem, I would at least add and external ram, meaning a 1/2 system instead of a full hyd.

[MOBILEMERCMAN]

The gimble ring settles on the upper swivel even with hydraulic steering. Tightening the u bolt has no effect on that after the pieces are worn or corroded in my experience.

The u bolt needs to be tight when assembled and as part of maintenance. But they are not intended to be used to tighten worn parts. IMO

[Revd Up]

I have full hydraulic steering. I only torqued mine because I saw it in the manual. Usually check it when I pull my drive to check alignment and doing yearly maintenance. Think I might loosen mine a little now that I know its too tight.

[Ryan8886]

I will recommend the HP kits to the owner. I agree, beef it up now and hopefully be done with it for a long time. At the end of the day, it will be his decision on what he wants to spend. He is not cheap so my guess is he will throw the best at it if a repair is indeed needed. Thanks!

Hey Knot! I don't beleive in going cheap either....but HP rings seem to be a lot of overkill for 7.4L's. Unless he likes spending cash for the fun of it, why not just replace with standard Merc rings? Unless he's planning to yank those motors and replace with big horsepower, they should last another dozen years just like the first set and cost less. Even tweaked, you can't pull much more than 400 hp out of the old 330's.

[txriverrat2001]

The gimble ring settles on the upper swivel even with hydraulic steering. Tightening the u bolt has no effect on that after the pieces are worn or corroded in my experience.

The u bolt needs to be tight when assembled and as part of maintenance. But they are not intended to be used to tighten worn parts. IMO

I agree - I've never seen an improvement by tightening the U-bolt.

Check with Victory and see if they have some non current assemblies laying around. You'll probably just need to update the fitting for the oil resevoir as the new one just clip on vs. clamp on.

It's a much safer and easier option if the funds are right.

[Knot 4 Me]

Hey Knot! I don't beleive in going cheap either....but HP rings seem to be a lot of overkill for 7.4L's. Unless he likes spending cash for the fun of it, why not just replace with standard Merc rings? Unless he's planning to yank those motors and replace with big horsepower, they should last another dozen years just like the first set and cost less. Even tweaked, you can't pull much more than 400 hp out of the old 330's.

The stock 7.4L's were re-worked by Baker and dyno'd at 465 HP. Brodix II aluminum heads, a healthy Crane roller cam, Merlin single plan intake, Nickerson modified 850 Holley's, CMI E-Tops, MSD ignition, etc. Eventually all those top end goodies will be placed on a 502 or 540 short block. So, I don't believe the HP rings are overkill.

[Ryan8886]

The stock 7.4L's were re-worked by Baker and dyno'd at 465 HP. Brodix II aluminum heads, a healthy Crane roller cam, Merlin single plan intake, Nickerson modified 850 Holley's, CMI E-Tops, MSD ignition, etc. Eventually all those top end goodies will be placed on a 502 or 540 short block. So, I don't believe the HP rings are overkill.

Ahhhhhh....in that case, I'd have to agree. That's interesting too....all anyone has ever told me was that the 7.4's aren't worth hopping up. Glad he's had some fun with them!!

[Knot 4 Me]

Ahhhhhh....in that case, I'd have to agree. That's interesting too....all anyone has ever told me was that the 7.4's aren't worth hopping up. Glad he's had some fun with them!!

I personally wouldn't have put all those goodies on the stock 7.4 cast internal short blocks but he has put 80 trouble free hours on them to date. Boat is propped to top out at 5,000 - 5,100 RPM and he doesn't stay in the throttles for long periods of time. He knows the bottom ends won't last forever and is planning to upgrade the short blocks in a year or so. The cam and heads will make more power if he has them on a motor he can spin to 5,400 RPM. He is leaving HP on the table only turning 5,000 RPM but knows the 7.4's would be short for this world at 5,400 RPM.

[MERPerformance]

About 6yrs ago, we upgraded two 7.4 MPI 28 or 29 Baja. The owner was a true Merc owner no H.P. stuff for him! Well about 1 1/2 yrs of new ownership he started to have a piston rapping noise, tore them down and found the pistons pins getting tight, the pins were tappered wall and not round. Also found the cam was just a stock 330 hp cam not the 385hp he paid for. Called the area Merc rep. found out that sometimes the engines going down the line don't always get the up-graded cam if they run short, thats what I was told. Passed that one to the customer, along with out-a-warrenty. Well those engines were built back with Eagle rods, CP pistons, Canfield heads, different cam, new lifters, ECMs re-mapped, they made right at 490hp haven't touched them in 6yrs except for drive repair. The owner is an X US Air pilot, so he keeps up on maint. He likes H.P. now. The foundation of the block and crank, and MPI worked fine with some change of major parts.

[Thunderstruck]

The gimbals can be rebuilt for a fraction of the cost of even used stuff and a heck of a lot less work than pulling the motors and transom assemblies. Look at www.jrmarine.com and call Ron Bender. He can weld up and CNC the upper swivel area and the side pins. He has a stainless upper swivel shaft that is top notch and all the parts needed.

He has a kit that gives you a template to drill out the back of the transom assbly with special cut down wrenches to gain access to and remove the swivel shaft nut and the steering lever bolt. Much easier than the Merc kit and has a nice stainless plate to cover the hole. Ron is great to work with and is available by cell phone for questions/problems.

I refurbished both gimbal rings, new swivel shafts, gimbal and shift bellows, new shift cables, new steering levers all for <$2,000 for both sides.

PM me and we can discuss if desired.

Before the JR Marine rebuild:

http://www.youtube.com/watch?v=yEC9jtJ3KFg

[Thunderstruck]

Pic of the hole in the transom assembly:

[Thunderstruck]

Stainless plate to cover the hole with repaired gimbal ring.

[MOBILEMERCMAN]

Thunderstruck,

I know many people are happy with that procedure. I would just like to say I prefer the Merc way. I feel better about the pipe plugs sealing and like the way it is not so obvious it has been repaired. I have done countless jobs over the years and have created a few special tools to turn the swivel lock nut.

I would choice the engine pull method on my personal boat. I know I am old school. I can't help it.