Bravo Trim Cylinder Maximum Extension Length Question . . .

[tpenfield]

Hi Folks:

I am doing a little bit of design work for a D-I-Y "mechanical trim indicator system", and in the process I am trying to find any published specification to the Bravo Trim cylinders. (FWIW - I am tired of the inaccuracies of the regular trim/tilt gauge so I want to go with a mechanical system . . . I'm planning on making my own for cost/performance reasons).

What I need to figure out is the difference between the fully retracted length of the trim cylinder (so full trim IN) and the fully extended length of the trim cylinder (so full trailer tilt UP). This distance is the full throw of the trim ram, etc.

Anyway, I have searched the web for several days to no avail . . . I have found that the main housing of the trim cylinder is about 14-7/8", but no info as to how far the rams extend. My guess is that they would be able to extend about 11 inches +/-, based on the housing dimension.

I could measure them on my boat, but I may not be visiting/using my boat for a couple of weeks. So, if anyone has a good source for specification information on the Bravo 3 trim cylinders, I would greatly appreciate it.

T.I.A.

 

[tpenfield]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Also thinking that if anyone had good access to their Mercruiser Bravo 3 outdrive out of the water and did not mind taking a couple of measurements for me . . .



Looking for the bolt-to-bolt distance of the cylinder ends in the 'full down' and 'full up' positions.

 

[Don S]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Put the drive up and measure the distance. The ram fully extended is what stops the drive from going up any further.

 

[tpenfield]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Put the drive up and measure the distance. The ram fully extended is what stops the drive from going up any further.

Correct . . . I was just asking to see if anyone knew the distance, fully retracted and fully extended, (or a reference source of it), since I won't be able to measure it myself for a couple of weeks.

 

[Bondo]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Also thinking that if anyone had good access to their Mercruiser Bravo 3 outdrive out of the water and did not mind taking a couple of measurements for me . . .

Looking for the bolt-to-bolt distance of the cylinder ends in the 'full down' and 'full up' positions.

Ayuh,... I think I've got a set of rams off an '89 Bravo out in the wellhouse,...

If they're there, I'll measure 'em for ya,...

 

[tpenfield]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Thanks, Bond-o.

i hope your summer is going well.

 

[Bondo]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Thanks, Bond-o.

i hope your summer is going well.

Oh ya,... Higher water levels are GREAT,...

I'm almost to the top of the page , I'll run out there, 'n see,....

 

[Bondo]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Also thinking that if anyone had good access to their Mercruiser Bravo 3 outdrive out of the water and did not mind taking a couple of measurements for me . . .

Looking for the bolt-to-bolt distance of the cylinder ends in the 'full down' and 'full up' positions.

Ayuh,... The cylinders look like yer's, 'n best I get is 19, 5/8" to 26, 5/8", center to center,...

 

[tpenfield]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

OK, thanks Bond-o . . . you the man :thumb:

Wow. . . only 7" of travel . . . seems like there would be more, but I'll take it.

 

[Mischief Managed]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Mine measure: 27 1/16" and 19 1/16" center to center on the trim ram holes. I have an older Bravo 1 driveshaft housing that does not have room for the "celery stalk" spacer found in a B3 though.

 

[tpenfield]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

Mine measure: 27 1/16" and 19 1/16" center to center on the trim ram holes. I have an older Bravo 1 driveshaft housing that does not have room for the "celery stalk" spacer found in a B3 though.

OK, Thanks for doing that. With both your and Bond-o's measurements, I am in the ball park for what I need to do.

 

[tpenfield]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

. . . I have an older Bravo 1 driveshaft housing that does not have room for the "celery stalk" spacer found in a B3 though.

By "celery stalk spacer", do you mean the trim cylinder anode? The rams on my outdrives stop short of the space needed for the anodes.

Anyway, I sent you some sketches of the design that I have in mind.

 

[Fun Times]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

You may want to bear in mind that there could be three different items installed on your trim system vs someone else's trim system that could affect trim ram travel.

Two are talked about in here,
http://www.boatfix.com/merc/Bullet/98/98_16.pdf

The third could be but less likely (on your system) item number 27,
http://www.mercruiserparts.com/Show...=260&bdesc=TRIM+CYLINDERS+AND+HYDRAULIC+HOSES

"Crescent Shaped Insert" (AKA "celery stalk spacer").

 

[tpenfield]

Re: Bravo Trim Cylinder Maximum Extension Length Question . . .

You may want to bear in mind that there could be three different items installed on your trim system vs someone else's trim system that could affect trim ram travel.

Two are talked about in here,
http://www.boatfix.com/merc/Bullet/98/98_16.pdf

The third could be but less likely (on your system) item number 27,
http://www.mercruiserparts.com/Show...=260&bdesc=TRIM+CYLINDERS+AND+HYDRAULIC+HOSES

"Crescent Shaped Insert" (AKA "celery stalk spacer").

Got it; thank you. Yea, I am designing for a total of 10" of 'travel' just to cover those bases, as it seems that there are some differences.