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Replacing your Alpha Gen II Ujoint Bellows

Get a Service Manual and do the job right.

Easy Bellows & Transom Seal Repair Kits!
Kits include Bellows, Gimbal Bearing,
Water Hoses (both sizes!), Clamps,
Shift Bellows, Exhaust Bellows and
Drive Mounting Gasket sets!

Part Number D30-803097T1 For MC-I, R, MR & Alpha One with exhaust bellows. Only $263.00  
Part Number D30-803098T1 For MC-I, R, MR & Alpha One with exhaust tube. Only $280.00  
Part Number D30-803099T1 For Alpha One Generation 2 Drives. Only $300.00  
Part Number D30-803100T1 s/s to 8M0095485 For Bravo Drives. Only $399.00  

Remember.... prices are subject to change!

Tools Required to Replace an R, MR, Alpha One U-Joint Bellows.
If all you are doing is replacing the U-Joint bellows, you will find that you
will have to remove the hinge pins with the special Hinge Pin Tool and you will have
to use a Bellows Expansion Tool to install the exhaust bellows.
These tools would also be required to replace your Trim Limit and Trim Sender Switches.
Hinge Pin Tool
Bellows Expansion Tool

Tools Required to Replace Alpha Generation II U-Joint Bellows.
The Gen II Bellows are held in place with an aluminum sleeve.
To replace the Gen II Bellows you will need a Hinge Pin Tool, a Sleeve Removal Tool,
a Sleeve Installation Tool,a Driver Rod with Driver Head, and an Expansion Tool if you are installing the exhaust bellows.
These tools would also be required to replace your Trim Limit and Trim Sender Switches.
Hinge Pin Tool
Sleeve Removal Tool
Sleeve Installation Tool
Driver Rod
Driver Head
Bellows Expansion Tool

Tools Required to Replace Bravo I, II and III Bellows
The Bravo uses an aluminum 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 Expension 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.
Hinge Pin Tool
Sleeve Removal Tool
Sleeve Installation Tool
Driver Rod
Driver Head
Bellows Expansion Tool
Tapered Insert Tool

Tools Required to Replace a Gimbal Bearing.
(R, MR, Alpha One, Alpha Gen II and Bravo)
If you are replacing your bellows there is a good chance that your gimbal bearing
needs to be replace as well. Pulling out the gimbal bearing can be difficult if it's stuck.
You will need a good Slide Hammer Kit to remove the bearing.
You will need 3 tools to install the new bearing. A Driver Head, a Collar and a Rod.
Installing the drive after the bearing has been installed is MUCH easier if you first align the
gimbal bearing with an Engine Alignment Tool.
Slide Hammer Kit
Driver Head
Gimbal Bearing Collar Tool
Driver Rod
Engine Alignment Tool

Bellows Replacement Tips and Procedures

The U-joint Bellows should be replaced every few years OR
if any leakage or damage is suspected.

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.

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.
Place the shifter into forward gear and remove the outdrive.
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.

We have had drives that just won't come off. We call them "junk".

About Tools:
You will need some special and regular tools to do this job.
Without the correct tools, replacing the bellows and gimbal bearing is next to impossible.
You will need:
1. Phillips screw driver.
2. Slotted screw drivers (large and medium).
3. 1/4" ratchet set with extensions and a 5/16" socket.
4. A Mercruiser Hinge Pin tool Part# 91-78310 for $25.00

5. Slide hammer tool Part#91-34569A1 for $212.00
6. Bellows expander tool to install exhaust bellows Part#91-8M0096108 for $87.67.
7. Shift cable socket Part#91-12037 for $43.00
8. Gimbal bearing driver Part#91-32325T for $46.00
9a. Driver rod Part# 91-37323 for $18.00
9b. Gimbal Bearing Driver Collar# 91-30366T1 for $37.00
10. Tube of Bellows adhesive Part# 92-86166Q 1 for $10.00.
11. Dead blow hammer.
12. Perfect Seal sealant 34227Q02 for $20.00
13. 1/2 long handled ratchet or breaker bar with a 1/2" socket.

Shop on-line for the parts and tools you need.

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.
The bearing center 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 Merc tech.

Did I mention we are drive experts? *s* (this "plug" was brought to you by!)

Really though, the drive stuff isn't practical for you to do as experience and expensive tools are required.

We can sell you the drive tool set if you would like! It's $2,300 for the Alpha and we will throw in the service manual as well.

OK.... so you feel brave and you splurged for the tools to do the bellows and bearing....let's "do-it".

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 bellows clamps.

The Gen II bellows are held in place with an aluminum 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.

By now you should have noticed that the shift cable is still attached.
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.

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 aluminum race.

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 aluminum 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 smoothen any burrs that it made.
Regrease and try again.

Once it's cocked, you MUST pull it out or aluminum 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.

We need to first install the water hose.
This is where most people give-up.

The water hose is VERY difficult to get in place!

Put the clamp loosely on one end of the hose...real loose......
and put a little soap and water inside the hoses end.

Now, push and twist the hose onto the transom tube.

This will SEEM impossible.

Be patient and keep trying. It is VERY important to get that hose all the way on!
Now that you have killed yourself and you HATE your boat.... we need to attach the other end of the hose to the bellhousing fitting.

The clamp must be properly positioned to face down. Use a 5/16" swivel 1/4" drive socket to tighten the clamps up.

If you completed correctly the last procedure then you should quit your lucrative desk job and become a Mercruiser Mechanic!

So, here you are with bruised knuckles and an attitude to kill.

Put your tools away for the night and get a fresh start in the morning.

Good morning!

Now it's time to glue your u-joint bellows in place.
Do NOT install the bellows without bellows adhesive!

It's important to note how the clamps will be positioned
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 stb. 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 gimbalhousing.

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 ujoint bellows into the hole.
Make sure the bellows seats properly in the bell housing.

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.

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.

Hey! your practically done!

Finish up by properly installing the drive and go boating.

Change your Alpha Gear Lube
Change your Bravo Gear Lube
Why does my drive lube have white streaks?
Why does my drive lube have gray mush?
Replace Your Alpha One Water Pump
Replace your Alpha Gen II Water Pump
Rebuild your Bravo Raw Water Pump

Troubleshoot & Replace your Alpha Shift Cable
Troubleshoot & Replace your Bravo Shift Cable

Replace your Alpha One Bellows & Gimbal Bearing
Replace your Alpha Gen II Bellows & Gimbal bearing
Replace your Bravo Bellows & Gimbal Bearing
Why does my drive "Growl" when I turn?
Water is leaking into my boat from the transom

Replacing your Trim Sender Switches
My Trim doesn't work but my Trailer Switch does
My Trim Gauge is Pegged

Rebuild your Alpha One Upper Driveshaft Housing Assembly
Rebuild your Alpha One Lower Gear Housing Assembly

Check your Engine Alignment
Check for Excessive Steering Play
Troubleshoot an Overheating Problem
Should I remove my thermostat?
Why do I overheat when going fast?
Troubleshoot a No-Crank Condition
Troubleshoot a No-Start Condition
My Engine Backfires and/or Surges and has Lack of Power
What is an Anti-Syphon Valve?
My Engine blows Steam from the Exhaust
Why do I hear a "clakity" sound while at idle?
Exhaust Manifolds...IMPORTANT Information
How do I Winterize my engine?

What is Galvanic Corrosion?
I have a Bravo III Galvanic Corrosion Problem
What is a Mercathode?
All about Zinc Anodes
How do I check my carburetor?
What carburetor do I have? A Rochester or a Mercarb?
I have water in my fuel
My fuel smells like varnish
My fuel is old
My engine has been sitting for several months without being run.

I have a Mercruiser 470, 485, 488, 190, 3.7L Engine
I have coolant dripping from the front of my engine
Can I install a regular Alternator instead of the Stator-Rotor?

Converting an OMC to a Mercruiser

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