Mismatched trim cylinders 120 mercruiser OK?

[tommr]

Trying to get my 1989 mercruiser 120 alpha 1 to function and I have located a replacement trim cylinder but the housing is about an inch shorter than the stock cylinder (14035-1) and the ram portion looks to be a bit longer, based on the paint? The housing looks the same, not round but flat sides and the hydro lines are the exactly the same.
Would using mismatched cylinders cause a problem?
The out drive would not always lift or go down and there was water in the fluid.
I pulled the cylinder that I suspected to be bad based on the fact that it would not retract all the way when I did a bellows job this spring.
With the suspect cylinder mechanically disconnected the starboard out drive functioned perfectly. ( I left the suspect cylinder connected to the pump and while the other cylinder worked the suspect one did not more. )
I took the end cap off and the ram portion would not slide very well in the end seal housing, even with the seals removed.
I buffed it up and now it slides OK.
I am hesitant to install the mismatched cylinder but maybe I should just throw a seal kit in the bad one and see what happens now that the ram is free of any imperfections.

 

[boltonranger]

Personally I would not do this. You would risk putting a twisting force on the drive housing.

 

[stonyloam]

+1 seal kit or have it rebuilt. Could be a problem when you use the trailer function and one cylinder stops before the other.

 

[tommr]

Well I think I have it finally and for now.
I tore the cylinder down to parts and there were bits of rubber, maybe from a broken down o ring or who knows where.
I polished up the ram, carefully, and cleaned everything inside and out, spic and span.
I cleaned up the bolt that goes through the middle of the slider in the relief spring.
I polished up all the pistons and seal surfaces.
Completely cleaned the cylinder barrel and blew it out with air.
I installed all new o rings and the the brass seal and washer at the rear of the cylinder. The clip was fun but a second set of hands made it short work.
Installed on the boat and it goes up and down smoothly and more quickly than ever before.
I am so happy I am going to do the other side at the end of the season and make a proper youtube video.
Thanks to every one and especially to Billy Bond who puts up with my phone calls, but not later than 9pm.

 

[gm280]

Sounds exactly like what others were trying to say. Repair the broken one and they both work in unison and no problems with one moving at a different rate because of a different size piston. Glad you finally done that and it works again. :thumb: