Broken Gimbal Ring
 

I had a friend of mine ask me to do some work on his boat he brought a mess of parts and asked me to finish installing the drive and motor. He started and ran out of time. It's an alpha one gen 2 and I believe the gimbal ring busted right in half by the limit switch and sender when I trimmed it all the way up. There was a loud bang. I got it apart putting a good used ring on it but I don't want it to happen again. Does anyone have thoughts on what may cause this? I was thinking trim cyls that are too long but it seems the gen 2 cylinders are longer than the gen 1. Any help is greatly appreciated

you can adjust the trim limit switch to stop where you want,,

I thought about that. And disable the trailer switch just doesn't seem right to me

Ayuh,.... I'd guess it was cracked before you got it,....

Every alpha and bravo I have ever had or heard of has run the trim up till the pump overloaded and stopped without breaking anything. I have heard of people remove stuck drives by jamming the top of gimball ring and running g trim up to pop drive loose. There had to be a crack in that ring ahead of time.

You don't disable the trailer switch,,you adjust it so the length of travel stops where you want it on the trim rams,
I believe the max safe trim ram length,,per mercruiser ,,center to center,, on a Bravo1 is 26.4 inches,, not sure on an Alpha drive

It is a trim limit sender for use underway. The trailer switch overrides the trim limit. There is no trailer limit switch.you run it up till it stops. It won't break the gimball ring. A method to limit yourself is hit trailer button when drive is all the way down. Start counting. 10 to 15 seconds usually till it stops. Then stop a second or 2 before pump stops. As long as trim gauge works. With no trim gauge, hearing pump stop is the only way you are sure drive went up enough to drive up the ramp...

Ayuh,.... 'n when ya hear the pump go into overload,.... tap the down button a couple times to unload the valvin' in the pump,....

That way, next time ya wanta go boatin', it'll run the drive down, without havin' a "Heavy" friend jumpin' on the drive to break free the stuck valves in the pump,...

The cylinders should not go up far enough to make contact and this to happen so my first thought; are the cylinders for a Gen 2 or a Bravo?

Can also install spaces in the cylinders to limit the travel, but this is normally only used when the drive will make contact with the swim platform

The trim limit switch has nothing to do with breaking the GB ring period.

Wrong parts in the assembly is most likely the problem. which gimbal ring are you installing ? gen 1 alpha or gen 2 alpha gimbal ring what application do you have gen 1 or gen 2 alpha and yes trim cylinders are different from alpha gen 1 to gen 2. Just saying not to beat you up --- but prob wrong parts used in the install and prob wrong install procedures.

Have to ask do you have the correct service manual for your app ? that's were I would start and then make sure you have all the correct parts to install per your app.

Proper torque on the hinge pins ? Would look at that also

Alpha Gen 2 TRIM limit is pin center to pin center is 20 - 3/4 inches for alpha gen 2 next is 21 - 3/4 for alpha gen 1 and next is bravo & Blackhawk is 21- 3./4. that trim limit as that has nothing to do with full tilt up position. Tilt is all the way up in which has nothing to do with trim limit . When the rams fully extend thats full tilt up for trailing. Again trim limit has nothing to do with that.

trim limit is for limiting the trim not past a certain point WHEN RUNNING ON THE WATER - why limit - one is limiting stress on the u joints and 2nd not to over trim the drive height so the water inlets suck air instead of water. Also limiting trim position for handling purposes as well. That's what trim limit is for and that's why the unit is called tilt and trim.

Found this -- the specs for trim limit listed is more so at the bottom of the link below when opened. For whom ever to follow the trim limit and its specs . I already posted the trim limit specs but they are listed with pics in the link in which is a better understanding.

https://www.perfprotech.com/store/ap...rim-sender.pdf