Volvo Penta 7.4 GL

sweenstar

New member
Joined
19 Jan 2005
Messages
5
Location
Northern Ireland,
Visit site
I have a Chris Craft Concept 27 Foot 1997 with 266 Hours with a Volvo Penta 7.4 GL V8 engine. There was a knocking noice when at ideal a couple of weeks ago. The boat was still going well but you could tell that there was something wrong. They (mechanics) took the back leg off and I have been told that i need a new gear box. Is that normal for this number of hours? A new gear box from what i hear is about 3500? Can the existing one be re-conditioned or do I need to buy a new one? or even a second hand one. As it is going well, even broken, I have a feeling it isnt as bad as being made out. I dont want to fork out that much if I dont have to!!

Any ideas would be greatly received.

Thanks

Chris
chris.sweeney@commercialpropertyni.com
 

BrendanS

Well-known member
Joined
11 Jun 2002
Messages
64,521
Location
Tesla in Space
Visit site
For that number of hours, no, it's not normal

Have you had it serviced regularly or even intermittently. What did last people who serviced it say. If the people who serviced it say you need a new box, think about a second opion. If you already have a second opinion, ask the people who serviced it previously a few searching questions.
 

Its_Only_Money

New member
Joined
11 Aug 2004
Messages
1,097
Location
Leicester - boat on Hamble
Visit site
Coastalrides have a good reputation for being helpful people and are also purveyors of rebuilt/new/used drive components. (I have no connection with them)

First question I'd ask of the crowd claiming you need a new leg is which bit? The volvo leg drive components broadly come as an upper and lower gearbox + the u/j joint in the bellows. It would be interesting to find which bit they think has failed. Silly to specify a whole new leg

Knocking at idle sounds like the u/j to me, chipped tooth on the gears I'd expect to get noisier with revs but geartrain noises can vary.
 

sweenstar

New member
Joined
19 Jan 2005
Messages
5
Location
Northern Ireland,
Visit site
Thanks,

My brother called the company Coastalrides.co.uk as you said. They were brilliant. They really know their stuff. They are looking out for a new one and a re-conditioned one and giving us a call. The drive is a DPS Standard Drive built for the European market.

Thanks

Chris

ps. If anyone else has had history with Volvo Penta gear boxes i would like your views.
 

spannerman

Well-known member
Joined
30 Nov 2002
Messages
3,142
Visit site
Volvo upper units seldom fail, usually only from lack of lubrication, i.e. water ingress. I suspect that its the universal joint that is noisy and that isn't so expensive as you can get repair kits for them,
I would insist on a second opinion, and ask whether there was any water in the bellows, or drive. Usually a universal joint makes the most noise when you turn the steering to full lock, do you remember if it was noisier then, or all of the time.
 

sweenstar

New member
Joined
19 Jan 2005
Messages
5
Location
Northern Ireland,
Visit site
Thanks for the reply

I have been told that the upper gear box is broken, and will need re-newed. Questioning their thoughts as it is driving pretty well. I used to have mercuiser engines and never had any bother with the gear systems. I always thought that if the gear box was broken the boat wouldnt go!!
 

spannerman

Well-known member
Joined
30 Nov 2002
Messages
3,142
Visit site
Again I would want to see the damaged parts, If the boat drove OK I find if it hard to believe it was as damaged as they say, normally when a gearbox collapses its pretty catastrophic and it won't go, ask them to show you exactly what they have found wrong, i.e collapsed bearings and\or damaged gears, clutch assy. There is always the exception to the rule, but it all sounds a bit suspect IMHO.
 
Top