Posted by Poseidon Marine on

This manual is beta form, this means that it is not yet completed. This text will be removed soon as it is finalized.

Removal of cylinders 

  1. Remove the plastic cap on the aft (drive) end of each trim/tilt cylinder. Remove the elastic lock nut and flat washer.
  2. Support the hydraulic cylinder and lightly tap the pivot rod out of the cylinders with a rubber mallet-tap on one side while pulling on the other side. Carefully lower the cylinders down. If the bushings come out with the pivot rod, make sure that you keep the two grounding clips.
  3. Grab the pivot ends of each cylinder and pull them out to the fully extended position. Loosen the manual release valve on models so equipped and then remove the filler plug at the reservoir to relieve any residual pressure in the system. Close the valve and install the cap.
  4. Working at the forward end of the cylinder, unscrew the bolt and disconnect the ground wire. Remove the cylinder cover retainer and lift off the cover. These models will also have a small screw and line retainer over the hydraulic line running to the aft end of the cylinder; remove them.
  5. With the stern drive still in the full DOWN position, place a suitable drain pan under the hydraulic lines, tag and then disconnect the two hydraulic hoses from the end of the cylinder (cover with rag) using the correct size "Flare Nut" or "Line Wrench". These wrenches will prevent damaging the hex flats on the line or hose fittings if they are extremely tight and/or a slight amount of corrosion has built up on the fitting. Most standard open-end wrenches will flex under high torque loads, causing the wrench to slip, damaging the hex fitting on the hydraulic line.
  6. Remove the O-rings on the end of each line fitting. Install plugs into the hoses and/or fittings to prevent draining the trim/tilt hydraulic system any more than necessary.
  7. Pry off (or unscrew) the plastic pivot pin cap (if equipped) on the end of the forward pin. Remove the locknut from the end of the pin and then slide off the flat washer and then the bushing from the pivot pin.
  8. Pull the pivot pin out of the cylinder and gimbal ring, or grasp the cylinder on the inside of each pin and pull it off the anchor pins. Remove the flat washer and bushing on the inside surface of the cylinder ends or the anchor pins


To Install:

Certain models may come equipped with limited tilt cylinders. They will contain a spacer that reduces total tilt rod travel and can be identified by the letter L that is stamped on the end of the tilt rod eye. Limited tilt cylinders must always be installed in pairs and never mixed with standard rods providing full travel.

  1. Press the trim/tilt cylinder bushing into the boss on each side of the gimbal ring. Install bushings into the outer side of each cylinder. Although it is not necessary to replace the bushings unless they are worn excessively or damaged, you may want to consider replacing them anyway while you have everything apart.
  2. Clean the forward pivot pin and then coat it with grease. Apply a light coat of Gasket Sealing Compound to the threaded ends of the pin and then center it in the ring.
  3. Align the cylinder and then press it on to the pivot pin very carefully. You may have to give it a few taps with a rubber mallet.
  4. Install the washers and then the lock nuts (new!). Tighten the nuts until there is an equal amount of thread exposed on each side of the pin and then tighten both nuts to 32-34 ft. Ibs. (43-46 Nm). Replace the plastic caps.
  5. Coat new O-rings with hydraulic fluid and then install them into the grooves on the end of each hydraulic line fitting. Remove the plugs and attach each line to its respective fitting on the cylinder. Tighten each fitting to 14-18 ft. Ibs. (19-24 Nm) with a flare wrench.
  6. Install the aft line retainer and tighten the bolt securely. Also on these models, position and install the cylinder cover.
  7. Install the retainer; and then on all models, install the ground strap and tighten the bolt securely.
  8. Clean the aft pivot pin thoroughly and then coat it with grease.
  9. Make sure that the grounding clips are in position and then press the bushings into the end of each cylinder and into the bore boss in the drive unit. As we did with the forward end bushings, we suggest replacing the bushing as preventative maintenance, although it is perfectly acceptable to reuse the old bushing as long as they are in good shape.
  10. Align the cylinder ends with the bores on each side of the drive and then insert the pivot pin into one end and press it through until it comes out the other side-you will probably have to give it a few taps with a mallet.
  11. Install the flat washers and lock nuts. Tighten the nuts until there is an equal amount of thread showing on each side and then tighten each nut to 32-34 ft. Ibs. (43-46 Nm). Install the plastic caps.
  12. Fill the reservoir with Power Trim/tilt & Steering fluid and run the drive through its full range of motion at least 5 times to purge any air in the system.





If troubleshooting procedures have isolated a problem to the trim/tilt cylinders, for example: a leaking oil scraper seal around the rod or a defective impact valve, it is strongly recommended that the cylinder(s) be removed and replaced with new ones, rather than attempting to disassemble the cylinders. This recommendation is based on the fact considerable difficulty may be encountered in removing the end cap from the cylinder. Even with the aid of the special tool for this purpose, the task is most difficult.

  1. Remove the trim cylinder(s) as previously detailed.
  2. Hold the cylinder over a drain pan with the hydraulic line ports facing down and into the pan; extend, and then retract the cylinder 2-3 times to remove all fluid from the cylinder.
  3. Remove the pivot pin bushings if you intend to replace them.
  4. Place the cylinder in a vise equipped with soft jaws and carefully tighten it.
  5. Obtain a spanner wrench (# 912084) or an equivalent tool PM19877. Removal of the end cap is difficult using the special tool so exercise care. Insert the tangs of the spanner into the holes in the end cap. If needed, slide a long breaker bar onto the tool so the bar is in the same plane as the tool. This position will provide maximum mechanical advantage. Remove the end cap. Tap the breaker bar, if necessary, but bear in mind -if the holes in the end of the cap become damaged (elongated), the cylinder might as well be given the "deep six". Continue to unscrew the end cap until it is held by a single thread. Extend the rod, and then continue to remove the end cap and piston assembly.
  6. Clean and degrease the piston rod thoroughly and then install it in a vise using a rod holder (# 983213). Carefully insert the pivot pin through the hole in the end piece and spin it off the end of the rod. If you are unable to loosen the end piece, heat the shank very carefully with a torch or heat gun and then try it again.
  7. Pull the end cap off of the end of the rod and then pry out the scraper with a small awl. Do the same with the 2 O-rings, one inside and one outside. Discard the scraper and the O-rings.
  8. Move to the end piston and remove the 2 split rings and the O-ring; throw them all away. 9. There are no serviceable components in the assembly, so there is no service procedure. This being said though, if you suspect impact valve leakage there is a quick procedure to try before replacing everything. Install the piston rod in the holder tool again and then loosen the large bolt on the end of the piston just enough to allow the relief check balls to unseat themselves; but not too much. Clean the piston components with solvent and then blow everything dry with compressed air. Tighten the bolt securely until the balls seat themselves.


If you find that the piston rod is slipping in the holder tool while trying to spin off the end piece, wrap a piece of paper around the rod before inserting it into the tool.





  1. Make an effort to keep the work area clean, because any contamination on the piston could lead to malfunction. Inspect the interior of the cylinder for any signs of scoring or roughness. Clean all surfaces with safety solvent and blow them dry with compressed air.
  2. If the piston has any signs of corrosion or damage it must be replaced with a new unit.
  3. Skip this step if you have bought a kit that includes new cap. Clean the end cap threads with a wire brush until you have removed all traces of old sealant.
  4. Lubricate all O-rings and interior components with Power trim/Tilt fluid.
  5. Lubricate the small hydraulic seal and place it inside the channel of the cap. The channeled side of the seal must “look” towards the piston. It is easier to install it from the upper side of the cap. This hydraulic seal is an improvement compared to the OEM O-ring design.
  6. Position a new scraper (end cap seal) so that the lip is facing upward and then using a small seal installer or a socket with the appropriate size, gently push the seal into the cap.
  7. Coat the cap O-ring with fluid and then install into its groove on the outer edge of the cap.
  8. Coat the piston bidirectional seal with fluid and install it in the piston. This seal is an improvement, making obsolete the design of two split rings and O-ring. The installation is significant easier and offers longer lifespan.
  9. Install a seal protector tool over the end of the piston rod and slide on the end cap. Make sure that the rod, O-ring and cap are thoroughly lubricated with hydraulic fluid.
  10. Make sure that the piston rod threads are free of all old sealant and then spray some Loctite Primer on the threads. While waiting for it to dry, secure the rod in the holding fixture again and then coat the threads with Loctite. Screw on the end piece and tighten it securely. Remove the rod and tool from the vise.
  11. Re-clamp the cylinder in the vise and coat the cylinder bore and piston thoroughly with fluid. Grab the piston body and carefully feed it into the cylinder bore. Push the piston and the rod all of the way into the cylinder. Once the piston is completely in, cap the hydraulic line ports and full the cylinder with as much hydraulic fluid as possible.
  12. Slide the end cap down the rod and thread it into the cylinder. Install the spanner wrench and tighten it to 25-30 ft.lbs. (34-41Nm). Once there, continue rotating the end cap until the two holes are parallel with the pivot pin hole in the end piece.
  13. Attach the cylinders, check the fluid level in the reservoir and then run the drive through its full range of motion 5 times to purge any remaining air in the system.

A description of o-ring sizes will be added so that you can determine each one's respective place.



Share this post

Newer Post →