Mercruiser Bravo 1, 2 & 3 Sterndrive Service Guide

Transcription

1 Mercruiser Bravo 1, 2 & 3 Sterndrive Service Guide Please note: These instructions have been compiled by Versatile Marine as a guide to de-winterize and service your sterndrive. They are in no way a replacement for an owner s manual, and we accept no responsibility for damage or injury to persons or machinery whilst following this guide. Versatile Marine advises that this procedure should only be carried out by by persons with a good mechanical knowledge, and we also recommend the use of an engine manual.

2 When and why to Service your sterndrive: The U-joint Bellows should be replaced every few years OR if any leakage or damage is suspected. Symptoms: Leaking U-joint bellows will cause severe damage if not tended to immediately. The two most common symptoms noticed first by customers are water constantly leaking into the boat and noise coming from the back of the engine/drive area. It's important to note that once these things are noticed, that some damage has already occurred. The grumbling noise that so many customers hear is from a rusted gimbal bearing. The noise will get worse as the drive is turned to full left and full right. Sometimes a customer will notice water in the drive lube as well. The front seal of the outdrive is meant to hold OIL in the drive and is NOT meant to hold water out of the drive. What you will need: The Bravo uses an aluminium sleeve to retain the u-joint bellows in place. You will need the Sleeve Removal Tool and the Sleeve Installation Tool. You will also need the Hinge Pin Tool and Bellows Expansion Tool if you are going to install exhaust bellows. In addition, the Bravo requires an Tapered Insert Tool for removing and installing the plastic water hose tapered insert. This tapered insert locks the water hose in place on either end.

3 Removing and inspecting the sterndrive: Inspect the Gimbal Housing Assembly: With the boat hauled, take a good look at the bellows with the drive placed in different positions. Look for barnacle growth, rips and deterioration of the rubber. The bellows should be clean and firm A complete inspection will require the removal of the outdrive. Bravo drives do NOT have to be shifted into forward gear to be removed. After the rams and the six mounting nuts are removed, the drive should come off. If the bellows have been leaking, the drive might be stuck. If the drive is stuck, tilt the drive up by hand and let the drive drop back down freely. The dropping of the drive should free up the driveshaft from the rusted gimbal bearing. If dropping the drive by gravity still won't free the unit, then some downward "slamming" may be required. Note: Slamming the drive is a "close-to-last-resort" and MAY damage other components. Use common sense and maybe a few flat chisels carefully placed to assist in the drives removal. Be patient and save some money. Some drives will require a bit of nursing to get off and sometimes the gimbal bearing will pull right out with the drive! If it's REALLY stuck, you may have to cut away the bellows and heat the shaft and bearing. Heating with a torch is VERY dangerous and all precautions need to be taken. There should be NO GAS in or around the boat. Also, have a hose and fire extinguisher ready. Once the drive is removed, a more complete inspection can be done. Look into the drive shaft hole and notice the inner bellows and gimbal bearing. The bellows should be dry. This means no oil and no water. Reach in and turn the centre of the gimbal bearing. The bearing centre should turn smooth with no looseness or binding. The U-joint assembly should have no rust. Typically, you will find water, milky oil and rust if the bellows have been leaking. If you only find drive oil in the bellows, then you have a bad front drive seal which will have to be fixed. How much can you do yourself? It depends on the tools and mechanical experience you have. The transom stuff isn't too bad but if the u-joints are rusted, then you need a Mercruiser technician. Really though, the internal drive stuff isn't practical for you to do as experience and expensive tools are required.

4 Disassembly Turn the steering to one side and remove the trim sender's two screws. Tie the sender up out of the way. Turn to the other direction and remove the other trim sender. Note: If the trim senders are bad, this will be the chance you have to replace them. Now, take the hinge pin tool with the 1/2" breaker bar and remove both hinge pins. You will have to turn the steering one direction and then the other to get them out. Sometimes the pins are stuck. Really stuck. Some heat may be required to free them up. It may be that you have to actually drill them out! Drilling is tough and the right size cobalt bits will be needed. It's important, when drilling, that you don't damage the bellhousing threads! Now that you have the hinge pins out, take a 1/4" drive 5/16" socket on a long extension and with a swivel to loosen the front bellow clamp. The rear end of the Bravo bellows are held in place with an aluminium retainer sleeve. Look in the large hole where the drive shaft goes and you will see the sleeve. You will destroy/ruin the sleeve taking it out but the new Bellows Kit includes a new sleeve. Use an adequate tool and pry the old sleeve out. It's thin and will fold up easily. Once the sleeve is removed, you can fold and push the lip of the bellows inward. The front end of the bellows should have been glued in place and will require some fuss'n to get them off. Also remove the exhaust bellows and the water hose clamps. The Bravo's water hose is locked in place with an internal plastic retainer. Removal requires a special Tappered Insert Tool. Put your Tapered Insert Tool onto the end of your 3/8" rachett extension and remove the plastic tapered insert. Push the water hose through and towards the front. NOTE: It's a good idea to replace the water hose at this point. You will need to hop up into the boat with a 7/16" socket wrench and a slotted screwdriver. Located the main intake water hose on the inner transom plate. Remove the clamp and pull the hose off of the hose connector assembly. Now use your 7/16" socket and remove the two bolts that hold the connector in place. You will now be able to see (or feel) the very front end of the water hose and the retainer. Use your handy Tapered Insert Tool and remove the plastic insert. Now you can remove the hose from the outside. By now you should have noticed that the shift cable is still attached. If you are not replacing the shift cable, you can work around it. Remove the small shift cable bellows clamp. Carefully pull the bellhousing away from the gimbal housing while pulling some of the extra shift cable though the shift cable bellows. Note! There should be a small clamp on the small end of the shift cable bellows. REMOVE THE SMALL CLAMP FIRST!

5 Now you have great access to the gimbal bearing. Take your new slide hammer and pull the bearing out if you are replacing it. If the bearing is stuck, you may need to use SAFE heat. Another little tick is to drill a series of small holes through and all around the aluminium race. DON'T DRILL INTO THE GIMBAL HOUSING! I have seen bearings so stuck, that we had to pull the engine and hammer them out from inside the boat. Cleaning up: Take the time to clean all the parts before reassembly. Scrape any barnacles from the transom and bellhousing. Some sand paper will be needed to clean the areas where the bellows seat. Look where the gimbal bearing was pressed in. Is there corrosion? If so, carefully sand the corrosion clean so it's smooth. Gimbal Bearing installation: Take the new gimbal bearing and rotate the outer stainless shell until you can see the hole in the aluminium race. This grease hole will NEED to line up with the grease passage in the gimbal housing! I like to mark the bearing with black marker so I can see how the hole needs to line up. Take some oil or light grease and coat the inside of where the bearing seats and the outside perimeter of the bearing. Install your new driver rod onto the bearing driver tool and line the bearing in the housing. Use a good dead-blow hammer and whack the bearing in STRAIGHT!!! When the bearing is fully seated, it will make a different hammering noise. The bearing MUST go in straight. IF it starts to COCK then STOP and pull it back out!! Take some sand paper and smooth any burrs that it made. Regrease and try again. Once it's cocked, you MUST pull it out or aluminium will build up behind the race. Now comes the hard part! Feel the housings where the u-joint bellows are going to seat. Do you feel the groove? That groove must be clean and that groove will determine how far the bellows go on. When installing the bellows you will be "feeling" to see if the rim of the bellows seats into that groove. Put your tools away for the night and get a fresh start in the morning.

6 Good morning! Clean out the holes where the water hose fits. It is important to remove any and all corrosion. Coat the inside of the gimbal housing hole with Bellows Adhesive and coat the outside of the front end of the water hose with bellows adhesive. Quickly fit the hose into place in the correct position. Hop up in the boat with a new plastic insert and your tapered insert installation tool and thread the plastic insert into the hose to lock it into place. NOTE: About 1/16" to 1/8" of the hose should be sticking out. NOTE: Spraying a little Power Tune into the hose will aid in installing the insert. Now it's time to glue your u-joint bellows in place on the gimbal. Do NOT install the bellows without bellows adhesive! It's important to note how the clamp will be positioned The bellows will first be installed on the gimbal housing. When we install the bellhousing to the gimbal housing (transom) we will have to have the clamp positioned with the screw facing down on the starboard side. Now... note that the bellows has a "Forward" and "up" at one end. This means the obvious! Coat the "front" end of the bellows (inside) with bellows adhesive and before the glue dries, push the bellows onto the gimbal housing. It should almost "snap" in place when the grooves line up. Make SURE that they are straight BEFORE the glue dries! Now position the Bell Housing into place and pull the rear end of the u-joint bellows into the hole. Make sure the bellows seats properly in the bell housing. Pull the water hose into the hole in the bellhousing and insert the plastic tapered insert. We like to use a little bit of Mercury Power Tune to aid in the installation of the bellows retainer sleeve. Spray some Power Tune on the rubber where the bellows retainer ring is going to seat. Use your Sleeve Installation Tools and knock the retainer sleeve into place. This will firmly lock the ujoint bellows into position. Now take your 1/4" ratchet set with a long long extension and a swivel 5/16" socket on the end and snug up the front clamp. Inspect carefully to make SURE the clamp is straight and in place. DON'T over tighten the clamp!! Now that the clamp is snug, you can get the hinge pins installed. There should be fiber side washers on either side between the bellhousing and the gimbal ring. If they look worn, replace them. Align the washers and the bellhousing up. Apply a drop of good lock-tight to the hinge pin threads and install the pins. Torque the pins to 40 lbs and install the senders. Grease the hinge pin zirt fittings.

7 Now it's time to inspect your work. Look at the clamps again, are they perfect? Did the bellows seat completely? Is the water hose kinked? If you didn't cut the water hose OR if you didn't get it ALL the way on, then it will kink. It's simple to fix, just redo everything again. We still have to contend with the exhaust bellows. This is where you get to use your new exhaust bellows expansion tool! This tool will pay for itself with just ONE use. Clamp the exhaust bellows first to the gimbal housing (transom). You really don't need adhesive for the exhaust. The clamp should be on the bottom if possible. Now place the other clamp on the rear end and get them position CLOSE to the installed position. Work the bellows expansion tool in through the bellhousings exhaust passage and into the bellows. Expand the tool and place the lock in place. Pull on the tool to work the bellows up onto the bellhousing. Now, slide the metal rod pin through the hole in the tool. This allows you to release the tool so you can tilt the bellhousing up to access the last clamp. Finish up by properly installing the drive and go boating.