2006 Verado 250 noisy bearing carrier bearing

[achris]

Hi all,

I have to strip and replace a bearing in a Verado 250 gear housing. Apart from the usual of removing the cover nut and pulling out the carrier, is there any special set up procedure for the rear prop shaft bearing?

If someone could point me at an on-line manual, that would also be great.

Thanks.

 

[Scott Danforth]

https://dmna.ny.gov/nynm/manuals/Mercury_Verado_Manual.pdf

 

[Scott Danforth]

never mind, thats the operators manual

here is a few links to service manual

https://www.scribd.com/doc/151463852/200-Through-to-275HP-Verado

https://docs.google.com/document/d/19vRSEgoBHZPiFot8jpu2wcY2_aKfYGtH13ok-BsSioo/edit

 

[Fun Times]

Chris, just to let you know, Detailed Verado discussions online tend to be relatively on the low side as it's considered a specialty engine model from Mercury and they (at least used to) hold a special service school just for these engine models only 'For the dealers that are "Qualify"/Authorized to work on them.

That mentioned, should the need arise, there is a dedicated Verado outboard forum called veradoclub.com. It's a unique site though as if you become a general member you'll get 15 free posts but they tend to keep the answers as generic as possible. Once you become a Contributor/paying member of I believe to be right around $40.00, You have access to some highly regarded Verado Techs and I believe possibly some service info/manuals for the newer stuff. They do have an sub-forum called The Verado "Library" which you might be able to find something but again i think there's another section with more detailed info should you decide to become a contributing member. http://www.veradoclub.com/index.php?...sg7710#msg7710

Awesome job Scott at finding the manuals online...Completely forgot about that one.

 

[Scott Danforth]

The verado scares me...... especially the CAC. Great concept, however rubber and hot air not the best combination...

 

[achris]

Many thanks Scott and Fun Times. Information is exactly what I needed...

I know how Merc treat these engines and the service thereof. They came out just as we were selling our boat shop, but if you wanted to be a Verado authorized dealer, yes, special school, and about $10,000 worth of tooling.

Chris.....

 

[achris]

The verado scares me...... especially the CAC. Great concept, however rubber and hot air not the best combination...

I don't now... Politicians run on hot air all the time, and from what I see, most are just rubber band wind-up toys anyway....

 

[achris]

Fun Times Scott Danforth

Houston, we may have a problem!

I have discovered what I believe may be a design flaw in the Verado gearbox.

The propshaft is supported at front and back by tapered roller bearings. The forward propshaft roller bearing sits inside the forward gear. While there is a rotational speed difference between forward gear and the propshaft, the bearing spins. But when forward gear is selected there is no speed difference between the propshaft bearing and its outer race. The bearing is sitting still, but now absorbs the thrust generated by the propeller. These types of bearings aren't designed to take load when they aren't spinning. They get damaged. See below a photo of the bearing outer race I have just pulled from the front of the propshaft of a Verado gearbox.

Those grooves appear to have been caused by the rollers sitting in one position and having a constant, high load on them. If anyone has an alternate reason for this damage, I'd love to hear it.

Cheers,

Chris........

 

[achris]

Fun Times Scott Danforth

Just some more follow up.

I have returned the Verado gearbox to its owner and we had a long talk about the bearing. It's unlikely the 'problem' will be seen by many people. It only shows when someone spins the prop by hand and feels the notching. It's highly likely that most of them out there have these notches in the bearing, to one degree or another, but as the bearing is not turning when it's loaded (forward gear) it's unlikely to fail catastrophically. Thus meaning few tech will have seen it unless they pull the box apart for another reason. And even then, they are likely to just toss the bearing and not mention it. It may not be a 'design flaw', but it's still a shockingly bad peice of design.

Cheers,

Chris..........

 

[Scott Danforth]

Chris, I will aske a few people I know if this issue is known

 

[schematic]

overhauled one this past summer with the same failure. Since the bearing is substantially preloaded, I assumed that the assembler beat on the shaft to achieve the preload. Once small indents are present, they escalate over time. Just a guess

 

[achris]

Thanks for the confirmation schematic I have also posted over on the Verado Free discussion forum, but they appear to be more about trotting out the Merc propaganda line of 'there's nothing wrong, it all your imagination'.... Now this very shoddy peice of design by Mercury is out in the open I'm sure we'll see a few more instances.

Chris....