HELP 2000 Carver 350 Mariner Transmission Vibration

[plots10]

Hello all!

I am new to the forum, but excited to see if anyone can help me.

I just bought a 2000 350 Mariner and after one week I found a really bad vibration coming from the port side while underway over 2500 RPM. Anything below 2500 RPM is smooth as silk. I brought her to the ship yard to be hauled out for a quick check of the props and drive lines. After inspection, the props are good, drive lines are straight, cutlass bearings good, but found play in the port side gear when turning the props. The mechanic at the shipyard says that the gear needs to be pulled and looked at (Rebuilt/Replaced). I have a couple questions below I am looking for advice/answers on.

1- Does the motor need to be pulled in this model Carver to get the tranny out?
2- I cannot find the data plate anywhere on the transmission to get model/serial#. What is a good number to call Carver direct to find this information out??
3 - What is a typical cost for a job like this, rebuilt or replace transmission?

Thank you all so much for taking the time to read this and help me out.

[anothernewb]

Congrats! I bought a 2000 350 mariner 9 months ago and today is it's maiden voyage.

First, yes the motor has to be pulled to pull the transmission. If your boat has gas motors the transmissions should be Velvet Drive 71c V drives, the data plate is going to be on the right side looking forward.

As far as contacting carver, if you go on their web site and click contact, fill the form out and they are really good about getting back a hold of you same day.

[mjk1040]

Did you check the shaft and transmission coupler? Also in another vibration topic earlier on here it was strongly suggested to rule out that your engine isn't misfiring and causing the vibration. Not to say you couldn't have a Velvet Drive issue. Can you go past 2,500 rpm and if so does the vibration lessen or increase? Mike

[Viper]

I agree with Mike on both counts. Pulling the transmission would be considered only after the shaft coupler was pulled from the tranny flange and a proper alignment check done. Did they do this? Did they dial the shaft? Did they remove the prop and send it out to get it scanned?...it might look okay but could be off enough to cause vibration. Don't underestimate a poor running engine's ability to cause all kinds of weird symptoms.

Unless they've ruled out the above by doing proper checks, I wouldn't even consider the tranny. While a tranny issue is a possibility, it really sounds like a running gear or alignment issue IMO so I'd be going there first.

[plots10]

Viper and Mike,

I am having the engine alignment looked at this weekend along with a full inspection of plugs and firing.

I also have a hard time believing it is the tranny. It runs smooth up to 2500 RPM and then after that there is a vibration, then cannot get up on plane smoothly. The vibration consists all the way through throttle unless I back it down below 2500 RPM. It will also have the vibration from a quick power up to blast up on plane. It seems like a drive line issue, but when we had it hauled out the shafts were straight and the props were fine. I am hoping to learn more this weekend and maybe it is as simple as alignment or the engine is misfiring. The motors only have 220 hours on them and have been taken care of.

[tomschauer]

I am certainly no expert on the drive line, but I know you could have a bent shaft or prop that you can't "see" that could cause the vibration. Also a little wear on the cutlass bearing could cause it, along with the engine and coupler issues listed above.
Hopefully a very simple fix!

[Viper]

Agreed, as mentioned above, if all they did was "look" at the shaft and props, they could be missing the cause. You can't just look at a shaft to determine if it is straight, it must be checked with a dial at a couple of key locations to rule it out as the culprit.

Just "looking" at a prop tells you nothing except whether it has any signs of an impact. If it's not tuned to spec, it will cause a vibration. This is not something you can see, it requires shop equipment. A good prop machine shop will scan the prop free of charge and provide an estimate for tuning it. Your cost if the prop is fine will simply be for removal and reinstallation. This way, that piece of hardware can be ruled out as a contributing factor.

They should know that in checking engine to shaft alignment, anything more than .003" off is unacceptable IMO. If they check it properly, they will also be able to tell if the shaft coupler and tranny flange mating surfaces are true. If they don't check this and one is warped, it won't matter what you do with the rest of the hardware, you'll still have a vibration.

Don't forget, simply focusing on one item in the driveline such as checking engine alignment, finding that it's off and correcting, doesn't mean you'll no longer have a vibration. If anything else is off such as the prop, shaft, cutlass bearing, strut alignment, etc., you'll still have a vibration, you might just notice it at a different rpm. All of these can be contributing a degree of vibration.

Keep us posted.

[plots10]

Thank you Viper for your quick responses. I will keep you updated on the status after all of the items you suggested are looked at this weekend. I hope it is something simple and not invasive. I haven't had a full days voyage on her yet and the family is getting antsy.

[hausherrs]

I did some google searches for some images of your engine room. From what I found it looks like there is enough room to get the trans out without pulling the motor. I have had my Carver for about 2 months now and what I am finding is mechanics like to take the long road to repair boats because it pays better. This is the parts guy for Carver: btemple@marquisyachts.com email him with your hull ID and see if he can tell you what trans you have.