Mercruiser Gimbal Questions.... noob

[mylesm260]

Last year, I bought myself late 80's Regal Medallion 195 at a great price because of a cracked engine block.

Not knowing much about boats, and having a very strong automotive background, I bought the boat. Since then I've marineized a 4.3 Vortec and installed it into the boat with a heat exchanger.

The boat ran very well, managed 62 MPH (GPS) with a 23 pitch prop. And because I retained the vortec automotive fuel injection, fuel efficiency and engine performance (idle, ect) were perfect.

The only actual problem the boat had was a shifting problem (hard to shift to neutral).

Eventually, the engine coupler failed. After doing some research, I went shoping and starting removing my stern drive.

I got a new coupler with a new spline shaft, a shift cable kit and a stern drive seal kit (bellows, ect) as well as new senders and new u-joints.

In terms of taking everything apart, I'm now stuck at the gimbal ring.

I was not originally planning on removing the ring, however, I have noticed two issues with it.

1. There apears to be some play at the top hindge pin. You can move the gimbal ring roughly 5 degrees ether way.(play in the stearing)

2. The ring also has up/down play. I believe there are some seals or bushing missing from the bottom hindge pin area.

Research on the gimbal ring play is alot harder to come by on the internet. Is this play "aceptable" or should I be removing the ring and replacing the lower bushings and the upper pin?

I will be removing the engine (Again) anyway, to retrofit in the new coupler. So now would be a good time to do it (rather than having to do the drill and plug method)

Also How do I remove the lower hinge pin? I got the cotter pin out no problem, but the pin itself won't budge. It apears to have a slot screwdriver slit in the bottom. Am I suposed to turn this? or hit it with a hammer? All manuals just say to remove it.. but how? Maybe mine is "rusted" in... Is this common?

Also, I know boat parts are expensive but is the upper pin really 250 bucks? It's like a 4 inch bolt with some square sections in it.

 

[Haut Medoc]

Re: Mercruiser Gimbal Questions.... noob

Last year, I bought myself late 80's Regal Medallion 195 at a great price because of a cracked engine block.

Not knowing much about boats, and having a very strong automotive background, I bought the boat. Since then I've marineized a 4.3 Vortec and installed it into the boat with a heat exchanger.

The boat ran very well, managed 62 MPH (GPS) with a 23 pitch prop. And because I retained the vortec automotive fuel injection, fuel efficiency and engine performance (idle, ect) were perfect.
HMMMMM....I'm not a EFI guy but is it marine approved?
The only actual problem the boat had was a shifting problem (hard to shift to neutral).
This can be caused by high idle or shift interrupt/cable issues...

Eventually, the engine coupler failed. After doing some research, I went shoping and starting removing my stern drive.

I got a new coupler with a new spline shaft, a shift cable kit and a stern drive seal kit (bellows, ect) as well as new senders and new u-joints.


In terms of taking everything apart, I'm now stuck at the gimbal ring.

I was not originally planning on removing the ring, however, I have noticed two issues with it.

1. There apears to be some play at the top hindge pin. You can move the gimbal ring roughly 5 degrees ether way.(play in the stearing)
Negligable....Tighten the two bolts on the gimbal ring to 50#...

2. The ring also has up/down play. I believe there are some seals or bushing missing from the bottom hindge pin area.
How much?....There are no bushings for up & down play....

Research on the gimbal ring play is alot harder to come by on the internet. Is this play "aceptable" or should I be removing the ring and replacing the lower bushings and the upper pin?
I forget the measurement for that, but it is small....
Forget about redoing the upper pin, it would be cheaper & easier to buy a good shape, fresh water transom shield from that era & replace it as a whole unit.....

I will be removing the engine (Again) anyway, to retrofit in the new coupler. So now would be a good time to do it (rather than having to do the drill and plug method)
Did the coupler fail?....
Alignment is crucial & must be done with an alignment tool....

Also How do I remove the lower hinge pin? I got the cotter pin out no problem, but the pin itself won't budge. It apears to have a slot screwdriver slit in the bottom. Am I suposed to turn this? or hit it with a hammer? All manuals just say to remove it.. but how? Maybe mine is "rusted" in... Is this common?
Yes, add some Kroil....
If you got the cotter pin out without destroying the transom shield, you are way ahead of the game...

Also, I know boat parts are expensive but is the upper pin really 250 bucks? It's like a 4 inch bolt with some square sections in it.

Again, look on ebay & get a suitable vintage bolt on replacement......
Oh, welcome to iboats, btw.......

 

[Mischief Managed]

Re: Mercruiser Gimbal Questions.... noob

Not sure about an Alpha, but on a Bravo, the up and down play is dealt with by the nylock nut on top of the swivel shaft (upper hinge pin). You tighten it or loosen it until there is a specific amount of play at the lower hinge pin, measured with a feeler gauge. The service manual tells you the spec and where to measure it. The steering lever pinch bolt has to be loose to do this.

 

[mylesm260]

Re: Mercruiser Gimbal Questions.... noob

>>>1. There apears to be some play at the top hindge pin. You can move >>> the gimbal ring roughly 5 degrees ether way.(play in the stearing)

>> Negligable....Tighten the two bolts on the gimbal ring to 50#...

I havn't pulled out the torque wrench yet, but I already tightened them down to at least 30... there is still play... I was thinking that maybe that upper pin has warn down a little bit.... I'm concerned if I over tighten these, I will brake the gimbal ring...

The up/down play is about 1/16 - 1/8 of an inch... I think the manual called for .020....

And yes, I have an alignment tool now, This is also why I am so concerned about the up/down play, because the alignment tool relys on the positioning of the bellhousing, so if my gimble ring is lower than it should be, so to then would my bellhousing and my alignment tool might be off aswell....

And no, I don't believe my EFI system is technically marine aproved... but I am using metal fuel filters and braided steel fuel lines, aswell, my injectors are inside of my intake manifold rather than outside.... I also have a working blower fan that I use....

Motor idles perfectly at 600 RPMS (computer controlled) , the shift issue was because of a broken shift bellow (water in the assembly) and a melted shift cable in the inside of the boat... Both of those issues will be fixed when it goes back together (shift kit)

Also, the lower pin.. you said yes and to add kroil... I've added a bunch of WD40 already... but yes what? hit it with a hammer or try to turn it? Would using a blow torch to heat that be a bad idea here?

 

[QC]

Re: Mercruiser Gimbal Questions.... noob

Well the upper swivel shaft is stainless and the Gimbal Ring itself is Aluminum, so I'm thinking the shaft is prolly OK. Also, you can align with the Bell housing off, so I don't think you have to worry about the Gimbal ring's affect on your alignment

 

[Haut Medoc]

Re: Mercruiser Gimbal Questions.... noob

>>>1. There apears to be some play at the top hindge pin. You can move >>> the gimbal ring roughly 5 degrees ether way.(play in the stearing)

>> Negligable....Tighten the two bolts on the gimbal ring to 50#...

I havn't pulled out the torque wrench yet, but I already tightened them down to at least 30...
The proper torque value is 55# for the gimbal ring to upper swivel shaft.....
It will take it........
The upper swivel shaft to steering lever bolts, (located under the hex plugs) is 60#......

there is still play... I was thinking that maybe that upper pin has warn down a little bit.... I'm concerned if I over tighten these, I will brake the gimbal ring...

The up/down play is about 1/16 - 1/8 of an inch... I think the manual called for .020....
.002-.010 (.05-.25 mm)
Two ways to go about this....
With the previously mentioned nuts loose.....
Tighten the nut on top of the steering lever until reaching above measurement, hit the gimbal ring flanges downward with a mallet & tightenen the nut....
Recheck clearance.....
Then tighten the upper & lower nuts on the swivel shaft.....

If you find that you cannot remove the play, (corrosion) then I would install a thicker washer on the gimbal housing mount.....

BTW, the nut on top of the swivel shaft can really only be acessed with the engine out so I would do all of this procedure after you remove the engine......

And yes, I have an alignment tool now, This is also why I am so concerned about the up/down play, because the alignment tool relys on the positioning of the bellhousing, so if my gimble ring is lower than it should be, so to then would my bellhousing and my alignment tool might be off aswell....

And no, I don't believe my EFI system is technically marine aproved... but I am using metal fuel filters and braided steel fuel lines, aswell, my injectors are inside of my intake manifold rather than outside.... I also have a working blower fan that I use....
Like I said, I am not an EFI guy, so I can't really comment, just wantin' you to be safe.....

Motor idles perfectly at 600 RPMS, the shift issue was because of a broken shift bellow (water in the assembly) and a melted shift cable in the inside of the boat... Both of those issues will be fixed when it goes back together (shift kit)

Sounds like you are on top of it!.....

 

[Haut Medoc]

Re: Mercruiser Gimbal Questions.... noob

>>>1. There apears to be some play at the top hindge pin. You can move >>> the gimbal ring roughly 5 degrees ether way.(play in the stearing)

>> Negligable....Tighten the two bolts on the gimbal ring to 50#...

I havn't pulled out the torque wrench yet, but I already tightened them down to at least 30... there is still play... I was thinking that maybe that upper pin has warn down a little bit.... I'm concerned if I over tighten these, I will brake the gimbal ring...

The up/down play is about 1/16 - 1/8 of an inch... I think the manual called for .020....

And yes, I have an alignment tool now, This is also why I am so concerned about the up/down play, because the alignment tool relys on the positioning of the bellhousing, so if my gimble ring is lower than it should be, so to then would my bellhousing and my alignment tool might be off aswell....

And no, I don't believe my EFI system is technically marine aproved... but I am using metal fuel filters and braided steel fuel lines, aswell, my injectors are inside of my intake manifold rather than outside.... I also have a working blower fan that I use....

Motor idles perfectly at 600 RPMS (computer controlled) , the shift issue was because of a broken shift bellow (water in the assembly) and a melted shift cable in the inside of the boat... Both of those issues will be fixed when it goes back together (shift kit)

Also, the lower pin.. you said yes and to add kroil... I've added a bunch of WD40 already... but yes what? hit it with a hammer or try to turn it? Would using a blow torch to heat that be a bad idea here?

Leave it alone for now, that is not the point for adjustment other than adding a thicker washer.....
As long as it swivels, leave it be & worry about it if need be to add the washer......
If you break the lower mount, it is over & you will need to replace the entire transom shield.....

 

[mylesm260]

Re: Mercruiser Gimbal Questions.... noob

Okay so....

The clearance at the bottom is adjusted from the top then, corect? Those two "clamp" bolts that are suposed to be at 55 are so loose right now that the ring moves both up and down as well as left and right on the upper swivel shaft.


So what if I get those down to 55 ft/lbs and the gimbal ring still moves?

Do I then need a new gimbal ring?


So I think what I need to do here is get the ring properly clamped to the upper shaft, then adjust the lower clearance from inside the boat.

And don't try to get the pin out of the bottom unless I have to add a washer down there.

 

[Haut Medoc]

Re: Mercruiser Gimbal Questions.... noob

Okay so....

The clearance at the bottom is adjusted from the top then, corect? Those two "clamp" bolts that are suposed to be at 55 are so loose right now that the ring moves both up and down as well as left and right on the upper swivel shaft.
Push it all the way down to the .002-.010 measurement......
Then you have to tighten the top nut....
Then tighten the two gimbal bolts.....
Then the steering lever........

So what if I get those down to 55 ft/lbs and the gimbal ring still moves?
I doubt if it will, you should have the square pin......
Do I then need a new gimbal ring?
I doubt if you need a new gimbal ring.....

So I think what I need to do here is get the ring properly clamped to the upper shaft, then adjust the lower clearance from inside the boat.

And don't try to get the pin out of the bottom unless I have to add a washer down there.[/quote]
Big no unless you are forced to...
Put the cotter pin back in, even if ya don't bend it yet....
I'm gonna post up the link for your drive, look at section 4-B-27 or so....

 

[45Auto]

Re: Mercruiser Gimbal Questions.... noob

Don't know about Alpha's, but Bravo's are notorious for eating gimal rings if the clamp bolts loosen up. Then the steel shaft wallows out the aluminum gimbal ring. I've installed several rebuilt Bravo gimbal rings from J-R marine

http://www.jrmarine.com/products/gimbal_repair.htm

they've always worked well. $225 vs $800 for a new ring. He also has a high strength stainless upper pin and u-bolt.

 

[Haut Medoc]

Re: Mercruiser Gimbal Questions.... noob

http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf
Here ya go.....
Click on the lettered sections on page seven to download the section you want to view....

 

[mylesm260]

Re: Mercruiser Gimbal Questions.... noob

Don't know about Alpha's, but Bravo's are notorious for eating gimal rings if the clamp bolts loosen up. Then the steel shaft wallows out the aluminum gimbal ring. I've installed several rebuilt Bravo gimbal rings from J-R marine

http://www.jrmarine.com/products/gimbal_repair.htm

they've always worked well. $225 vs $800 for a new ring. He also has a high strength stainless upper pin and u-bolt.

That looks like what I might be dealing with... I will try torquing down the bolts tonight and see if there is still play..

Has anyone heard of this happening on an alpha?

I must admit, I chuckled a bit when I read "I've installed several" and "they've always worked well."

 

[45Auto]

Re: Mercruiser Gimbal Questions.... noob

I had to put one on a 2003 Crownline with a Bravo 3 I bought a few months ago. Apparently the clamp bolts had never been tightened (they were at about 10 ft-lb, should have been 53) and the gimbal ring upper square was worn out. It had about 4 or 5 inches of play at the back end of the outdrive. I replaced my gimbal ring and ended up doing 2 others once they saw how well mine worked out!

 

[mylesm260]

Re: Mercruiser Gimbal Questions.... noob

http://www.boatfix.com/merc/Servmanl/6/6covr3.pdf
Here ya go.....
Click on the lettered sections on page seven to download the section you want to view....

*read that section of manual*
*light go on in head*

I get it now... there's a shoulder on the underside of the top swival pin...

The top pin pulls the whole gimble ring up and THIS is where the clearance is made.

I probably have all this clearance because not only are those bolts loose, but the gimble is probly no longer sitting on the shoulder of the upper pin.... I need to raise the top pin, and smack the gimble housing down to make sure that the ring is sitting properly on that shoulder... THEN once I get the clearance THEN worry about tightning those top bolts to eliminate the stearing "play"

Beauty.... I though I need to spend another 300 or 800 or both but now I guess I just need to do some adjusting once I pull my motor out....

 

[mylesm260]

Re: Mercruiser Gimbal Questions.... noob

I had to put one on a 2003 Crownline with a Bravo 3 I bought a few months ago. Apparently the clamp bolts had never been tightened (they were at about 10 ft-lb, should have been 53) and the gimbal ring upper square was worn out. It had about 4 or 5 inches of play at the back end of the outdrive. I replaced my gimbal ring and ended up doing 2 others once they saw how well mine worked out!

So on the bravo's they're either not tightning the bolts enough from the factory, or the bolts are backing off....

Maybe it would be prudent to start either

A: retorquing these after x hours of use

or

B: Using locktight when assembling them.This might sound like a bit of an automotive idea, but what would the harm be in lock-tightning these upper bolts and nuts when installing the gimbal ring? Llock tight should hold up in a marine aplication, and you would still be able to break it loose later if you had to, just with a little more breaing torque. Sounds like it could potentially save a gimbal housing and/or an upper swivel shaft.

And maybe add 5 more ft/lbs of torque to whatever the specs are....

I think I figured mine out anyway, I"m pretty sure I need to raise my upper swival shaft and corectly adjust the lower clearance, then tighten my top bolts (I will use lock-tight and over torque) and that should resolve my problem.... Hopefully... Otherwise I will be having my gimbal housing repaired aswell.

JRmarine doesn't list the alpha under their gimbal repair page. I hope it's because it's not a common problem on alphas and not that it's because alpha's are too un-common.

 

[Haut Medoc]

Re: Mercruiser Gimbal Questions.... noob

Maybe it would be prudent to start either

A: retorquing these after x hours of use

or

B: Using locktight when assembling them.This might sound like a bit of an automotive idea, but what would the harm be in lock-tightning these upper bolts and nuts when installing the gimbal ring? Llock tight should hold up in a marine aplication, and you would still be able to break it loose later if you had to, just with a little more breaing torque. Sounds like it could potentially save a gimbal housing and/or an upper swivel shaft.

That is part of yearly PM....
I would not use loctite......

 

[45Auto]

Re: Mercruiser Gimbal Questions.... noob

It's advised to retorque them every 50 hours. They have nylock nuts on them, and you install the nuts lubricated. I've never used Loctite on a lubricated fastener before, I always made sure the fasteners were clean before using it. It might help, because they definitly loosen. I've been checking the torque on mine after every trip, just leave the 9/16 socket on the torque wrench ......

I think that the loosening is a result of a poor design. The square shaft in the aluminum might work OK in the lighter drives, but the Bravos, especially the Bravo 3, have a huge moment arm working on that pin and u-bolt. I guess that's why the serious boys run the external hydraulic steering.

 

[mikey.himself]

Re: Mercruiser Gimbal Questions.... noob

are you saying the outdrive shouldnt move side to side? mine does... never really thought about it being a problem until i saw this..

 

[QC]

Re: Mercruiser Gimbal Questions.... noob

Yes, they shouldn't . . . much. I just put a Stainless Gimbal on my Bravo. Previous owner never torqued and it was actually dangerous there was so much slop . . . . Yours doesn't sound bad. If there is wear in the upper swivel shaft "bore" in the Gimbal ring, it will move up and down as well as side to side. It has to.

 

[Mischief Managed]

Re: Mercruiser Gimbal Questions.... noob

It's advised to retorque them every 50 hours. They have nylock nuts on them, and you install the nuts lubricated. I've never used Loctite on a lubricated fastener before, I always made sure the fasteners were clean before using it. It might help, because they definitly loosen. I've been checking the torque on mine after every trip, just leave the 9/16 socket on the torque wrench ......

I think that the loosening is a result of a poor design. The square shaft in the aluminum might work OK in the lighter drives, but the Bravos, especially the Bravo 3, have a huge moment arm working on that pin and u-bolt. I guess that's why the serious boys run the external hydraulic steering.

My Bravo manual does not specifically show those threads being lubricated, but does show the steering arm pinch bolt being lubed. I lubed all three of them though. Worked very well.