Thread lock on Sterndrive shaft?

[kennyh]

Hi all - I’m fitting some new props on my VP DPH drive and I’m planning on using some Threadlock on the Prop Shaft Nuts.

Q. Can I use big standard blue Threadlock (I’ve some Granville Threadlock) or do I need a stronger / different formula?

 

[madabouttheboat]

Don't do it. The manual does not call for it and you will just create problems down the line when its annual maintenance time. Use new nuts each time and do up to the correct torque. They will not come loose.

 

[kennyh]

Don't do it. The manual does not call for it and you will just create problems down the line when its annual maintenance time. Use new nuts each time and do up to the correct torque. They will not come loose.

The instructions from Volvo say “IMPORTANT: Apply Locking Agent, part no 85145750 to the threads at the end of propeller shaft”

So, I’m going to follow the instructions (albeit I dont have the VP locking agent and plan on using another brand). Thus the questions as whether the stuff I have is sufficient.

 

[madabouttheboat]

The instructions from Volvo say “IMPORTANT: Apply Locking Agent, part no 85145750 to the threads at the end of propeller shaft”

So, I’m going to follow the instructions (albeit I dont have the VP locking agent and plan on using another brand). Thus the questions as whether the stuff I have is sufficient.

Which DPH model do you have? I've never known thread lock to be used, even though the manual does, as you point out, recommend its use (although only in applications where there is no locking bolt)

BTW, 242 Loctite would be the equivalent of the Volvo stuff mentioned

 

[kennyh]

I’ve a DPH-A and fitting a new H series props (replacing the G series). My drive does not have the locking bolt, so probably why the Threadlock is recommended.

If Loctite 242 is the equivalent, then the Granville Threadlock should also do the job.

 

[GrahamHR]

What a load of useless " information". Both DPH and DPS nuts are nyloc locknuts. They can be reused a number of times by simply using a centre punch on the locking ring. Never lost a prop doing that in 15 years

 

[kennyh]

Maybe so Graham - but since I’ve just bought a new set of H series props for a few thousand pounds per set, perhaps I should stick to the manufacturers installation instructions, just in case they decide to fall off.

 

[superheat6k]

What a load of useless " information". Both DPH and DPS nuts are nyloc locknuts. They can be reused a number of times by simply using a centre punch on the locking ring. Never lost a prop doing that in 15 years

My Ship for a hap'peth of tar !

 

[ICTM]

I replaced G series with H series props on my DPH drives last summer and used the thread lock recommended by Volvo as I had the same issue as the OP. They haven’t fallen off yet and my advice is use thread lock !! Sorry can’t advise an alternative Loctite number as Mr Volvo kindly threw in a tube of their own……….

 

[volvopaul]

Don't do it. The manual does not call for it and you will just create problems down the line when its annual maintenance time. Use new nuts each time and do up to the correct torque. They will not come loose.

Oh yes it does state you use thread lock when fitting the new H series props on the rear prop if you have the earlier type shaft thais not internally threaded to take the bolt that comes with the later type plastic prop cone , the reason is that the shaft is slightly shorter where the locking part of the nut runs on it, clean the thread with brake cleaner to remove and grease and apply locktite , you can buy the correct grade from the dealer as the part number in the bulletin you get with the new props .
There is no need to use it on the front prop.

 

[kennyh]

Oh yes it does state you use thread lock when fitting the new H series props on the rear prop if you have the earlier type shaft thais not internally threaded to take the bolt that comes with the later type plastic prop cone , the reason is that the shaft is slightly shorter where the locking part of the nut runs on it, clean the thread with brake cleaner to remove and grease and apply locktite , you can buy the correct grade from the dealer as the part number in the bulletin you get with the new props .
There is no need to use it on the front prop.

Thanks @volvopaul - I’m having fun with this leg (just posted another thread on the Slightly Milky oil).

I’ve also noticed that the thread for the rear prop is slightly damaged on the shaft - not sure if that is due to corrosion or not.

I’ll need to check where the nut sits in relation to this; question is whether the damage is sufficientenough to merit a new (costly) shaft?

But if my milky oil issue needs a rebuild then it would be a bit of moot point!