How to coat a rusty U-JOINT Yoke Assembly and new U-Joints to prevent future rust problems?

my u joints are rusty and the snap rings. I have remove the old ones and the u joint assembly is rusty-- 4 years since I replaced the last u joints. I would like to sand and use restore rust primer and use a 2 part epoxy coating on the u joint assembly and coat the new u joints as well. I will protect the holes where the u joints go. Has anyone done this before? It might not stop all the rust but I think it should help extend the life of the u joint assembly and the new spicer u joints I will be installing. I will install a new bellow as well but small leaks seem to happen over time and expose the u joint assembly to rust. your thoughts and suggestions please. thanks tomboat

Find source of leaks... Make sure you only use OEM bellows with their supplied clamps. Make sure the raised molded ridge in the inside of the bellows ends mates with the groove in the drive and transom shield... Make sure this groove is clean as well as the clamping surface for the clamp ring. Bellows don't normally leak during their normal service life...i.e. a bellows leak of any kind is a failure.
To extend bellows life, keep drive down and "straight ahead" when boat not in use.
Bellows are a routine replacement item and should be replaced on a regular basis before leaks develop.

You do not mention which Drive you are working with.
Nonetheless, the real problem is the water leak.

First suspect…… The drive shaft bellows.

Second suspect…… If you have a double bolt helmet pin, excessive length bolts may have been used and have broken out the aluminum in the bearing box collar.

Third suspect…… a flywheel cover bellows snout that is cracked.

Find the source of the water leak and repair it.
If you want your universal driveshaft to look pretty, pull the bearing crosses out of it and have those three components bead blasted, and then give it a nice coating of paint.
Re-install two new bearing crosses and put it all back together.


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I do not have a Volvo penta front snout- I had to have a piece of aluminum pipe welded on so I have to use a sealant since I do not have a groove for the front part of the bellow to seat in so removing the bellow yearly would breach the sealant and I cannot reuse the bellow because the new sealant will not bond to the old sealant causing failure and water leakage however I still ended up with a small amount of salt water seepage over a 4 year time that caused the yoke assembly and u joints to rust therefore my need for a epoxy coating to minimize the rust damage.we use the boat about 8 times a season- 4 times in the lake and 4 times in the ocean=70 hours other wise its on a trailer. I will replace the bellow ever 2 years to save the u joints and yoke assembly--a lot of work but I don't think I have many options.your thoughts and suggestions please thanks towboat

Tom, with all due respect, and said with as much kindness that I can toss in with this:

tomboat said:

I do not have a Volvo penta front snout- I had to have a piece of aluminum pipe welded on so I have to use a sealant since I do not have a groove for the front part of the bellow to seat in so removing the bellow yearly would breach the sealant and I cannot reuse the bellow because the new sealant will not bond to the old sealant causing failure and water leakage.
This is a good example of how make-shift repairs will typically come back and hit us in the behind..... ouch!

First off, the flywheel cover bellows "snout" must extend AFT at the lower area to prevent bellows collapse as the drive is raised and/or lowered.

Secondly, the bellows bead groves (in both snouts... F/C and Transmission) area necessary.
No sealant is used within the grove or on the bead.
It is best to use the Euro style band clamps on these.


Here are some examples:




however I still ended up with a small amount of salt water seepage over a 4 year time that caused the yoke assembly and u joints to rust.
I would be concerned that the rust damage is not limited to the universal drive shaft alone.
Just ahead of this area you have the PDS (primary drive shaft), and a very important set of bearings.
A failure here can be catastrophic and costly (most likely what damaged your original snout in the first place!)

therefore my need for a epoxy coating to minimize the rust damage.
As suggested earlier, cure the water intrusion problem, and your universal drive shaft will not rust up.
During my 24/25 years of AQ series repair, I've pulled many transmissions off only to find nice shiny bare steel universal drive shafts.
Cleaning and painting yours for protection against rust damage, is simply masking the larger problem.
Fix that problem!


we use the boat about 8 times a season- 4 times in the lake and 4 times in the ocean=70 hours other wise its on a trailer. I will replace the bellow ever 2 years to save the u joints and yoke assembly--a lot of work but I don't think I have many options.
your thoughts and suggestions please.

Take the time to remove the flywheel cover.
Either modify the pipe piece (to more closely resemble the OEM as shown above).....
Or....... replace the flywheel cover with one that is in good working condition.

Store the drive fully down and aiming straight forward, and raise the drive no more than necessary, and you will extend the life of your drive shaft bellows.

One last suggestion:
When you get into this area, remove the transmission ONLY. (there is no need to remove the entire drive, unless you have other work to do on the suspension fork, etc.)
And even at that, you'll still want to remove the transmission first, and then when going back together, install the transmission last!
Always replace the O-rings...... they will typically NOT go a second time around.


Good luck with this.
If you need more help or have any questions, post back.

Click to expand...

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thanks for the info.Good news... I can remove the bellow side that fits the groove on the transmission for inspection for water leakage. the pds has plenty of grease and the pds spline shaft is rust free along with the yoke assembly that fits on the pds spline shaft. I have a 1973 bell housing that was custom made for walkasha pleasure craft and a double bearing pds when we did the 275 renovation and install a rebuilt 5.8 l ford engine 4 years ago. It would require pulling the engine to modify the snout so ouch.
question... I marked the 2 yoke assemblies to match up the original alignment but when I wire brush the rust off it removed the original alignment marks
is this ok? I don't think I can match them back up . It would be guess work. your thoughts and suggestions please- thanks tomboat

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tomboat said:

thanks for the info.Good news... I can remove the bellow side that fits the groove on the transmission for inspection for water leakage. the pds has plenty of grease and the pds spline shaft is rust free along with the yoke assembly that fits on the pds spline shaft.
I have a 1973 bell housing
That would be a "flywheel cover" in Marine terminology. (bell housing is an automotive term)

that was custom made for Waukesha pleasure craft and a double bearing pds when we did the 275 renovation and install a rebuilt 5.8 l ford engine 4 years ago.
There was no need to custom make a 335 series Ford flywheel cover (i.e., 5.0L and 5.8L Ford) to work with an AQ series Volvo Penta drive.

There are two options:
...... Borg Warner flywheel cover with the Volvo Penta PDS adapter housing (double bearing PDS).
...... Volvo Penta AQ series Ford flywheel cover (single bearing PDS with pilot nose).



Here is a larger view of what the two components look like when assembled.

It would require pulling the engine to modify the snout so ouch.
Yes, that is correct!
If you were to find and install one of the above, your leaking problem will be solved.

question... I marked the 2 yoke assemblies to match up the original alignment but when I wire brush the rust off it removed the original alignment marks
is this ok? I don't think I can match them back up . It would be guess work. your thoughts and suggestions please
Ideally you would index the components as they were previously.
However, you are probably OK as is.
I have always marked them with a center punch (1 punch each at one end.... 2 punches each at the other end).

Click to expand...

Continued:


As Bob said.... "find the source of the leak!"
Well, I think that we know where the source is.... it's that non-bead-grooved aluminum tube that was welded to your F/C, (whatever that was)!
It may be the TIG weld that is causing it to leak, or it may be a lack of bellows sealing due to the non-grooved snout.

The AQ series engines are relatively easy to R&R. Within several hours you should be able to have it up and out.

If you do remove the engine, you would be able to replace the customized F/C with one that is application correct.
You can find them.
Look on e-Bay or check with Brad at Fairview Marine in Troutdale Oregon. [FONT=&quot](503) 492-4608[/FONT]

Or as another option, you could pick up a 4 cylinder flywheel cover...... these are a dime/dozen, since they just don't wear out.
Brad will also have these!

Then cut the OEM snout off, and then have it TIG welded it in place of the aluminum tube that is now there.




No offense, but what you now have is rather cheesy.

thanks for the info....also on another previous post I have a clatter--in the 275 gear box in neutral.. the pds is tight and the u joints are tight but I am replacing them anyway due the snap rings are rusty I have ordered total of 8 shims--4.small shims for yoke spline shaft and 4 large shims for the aft side of the gear box. from what I can see the gear teeth are wearing in the appropriate location and pattern but before disassembling the yoke assembly when I rotated the yoke assembly that was in the gear box I had about 1/8 inch play and there was some contact noise when I turned the yoke assembly. Is this amount of play normal? It was mention in my earlier post that by removing the shims on one side and installing them on the other side that this could reduce the play?= backlash? your thoughts and suggestions please. thanks towboat