Question for Cummins Owners

NorthernFocus

Well-known member
Joined
Jun 29, 2014
Messages
1,323
Location
Alaska
Website
www.northernfocusphotography.com
Fluid Motion Model
R-25 Classic
Hull Identification Number
FMLT25910808
Vessel Name
Divine Focus
Has anyone had the timing belt changed in their Cummins/Mercruiser QSD engine? If so is it doable with the engine in the boat? Looks like it could be done but hoping to glean knowledge from someone who has been there, done that.
 
I had this looked into when my 2006 R25 was in a yard for something else as it was an maintenance item I wouldn't be doing myself.

'They had a employee they represented as "has done a bunch of these" hop up in the boat and he said "is a little tight but OK." Also, like a lot of yard guys he was a little fellow.

I've been working on boats a while (50 years) and have re-powered several and while access is usually a horror show there's nothing that causes a need to pull the block itself except re-powering. Installers tend to leave just enough, or not quite enough or not enough room at all for access to the various external components of powerplants.
 
Thanks for the response. I'm planning on towing the boat over to the local shop that works on QSDs and getting an estimate from them. But with also 50 years of working on boats my experience has been that almost all yards/mechanics over promise and under perform. So I was hoping someone had actually had this done. It would be really ugly if they said it could be done then got half way through the job and decided the engine had to come out :x

I'm going to push on through this season as is. It took me a while to come up to speed with this little engine and gain confidence in it. Other than a blown hose on the transmission it has run like a top for 900 hours that we've put on it. But now we're at a total of 1200 hours on a 2008/9 engine and I've been thinking about potential age/use related reliability issues. The timing belt and rubber hoses are at the top of the list for potential problems. Most of the hoses I can deal with myself. Not sure I could get to the one connected to the oil drain on the pan. It's getting harder to twist my body into the necessary positions. And when I do succeed invariably get a leg cramp just when I'm in a position that I can't quickly get out of 🙁
 
I’m in my 60s, 6’3”, 240 and I’m beginning to spend some of the thousands I’ve saved on labor over the years by spending some of them now on someone else’s labor.

I’ve hired a garden to tend my 6,000 square feet of lawn, best $80 bucks a month I spend, I take our cars to the Dealer for work I used to do but don’t wanna such as replacing the engine and transmission in my truck and unhappy pay their outrageous $170 an hour charge.

For example, as soon as Yanmar tells me my ECU is OK I’m hiring out an electrical repair on my current R29 and I’m looking forward to it. I’m going to speak with two boat yards and three repair shops to choose one but first I’ll be modern and reverse engineer it by checking their reviews.

The value received in hiring out is you get an explanation of what they found, a repair of said situation and most importantly a warranty all of which give peace of mind which is priceless at my age.

Turns out as my body has worn out my bank account has gained strength so with the exception of maintenance, light repairs and likely anything else that comes up I don’t want to work on boats anymore, I just want to go boating.
 
tugnnaweigh":21vymmco said:
... with the exception of maintenance, light repairs and likely anything else that comes up I don’t want to work on boats anymore, I just want to go boating.
Ditto. I used to enjoy installing equipment, making mods to optimize space/usability, etc. Now I just want to get on the water and use the thing. The only reason I own a diesel inboard RT is the (affordable) nostalgia of it. I used to work on commercial fishing boats and my favorite thing was when we were steaming in/out, particularly at night. I loved sitting at the helm with the diesel purring away, watching the radar, and reading the lights as we threaded out way through the channel. No GPS or chart plotters back then. We had LORAN but it wasn't accurate enough for inshore navigation.

But we digress.....
 
I just replaced belt on my 2009 QSD, a few months back. The biggest problem was removing the shroud cover on front of engine. Once the front step face, and cover are off it was an easy 5-10 mins. to replace belt. Used 1 /2" drive socket and ratchet to take tension off idler pulley and slip old belt off and new one on.
 
RandyG":3dalgf3x said:
I just replaced belt on my 2009 QSD, a few months back. The biggest problem was removing the shroud cover on front of engine. Once the front step face, and cover are off it was an easy 5-10 mins. to replace belt. Used 1 /2" drive socket and ratchet to take tension off idler pulley and slip old belt off and new one on.
Thanks for the info. That's encouraging. I've got a couple of questions that I'll send via PM.
 
I replaced the engine cooling belt, which stated earlier is easy. It mentions the timing belt as a maintinence issue. But I can't find a timing belt in my 2.0 parts breakdown. It looks like the 2.0 uses gears for timing.

Les
 
King Fischer":3cal8ano said:
...It mentions the timing belt as a maintinence issue. But I can't find a timing belt in my 2.0 parts breakdown...
Not sure what you mean by "parts breakdown". Both the service and parts manuals show the timing belt. In the parts manual it's on a page labeled "timing belt and components".
 
I stand corrected.

Les
 
I wish you were right. In addition to the PITA of changing it the belt costs $350. Plus another $300 for tools to lock crank and cam at TDC while doing the job.
 
Just providing follow up for any inquisitive minds who might like to know...

The procedure for changing out the timing belt in the QSD engine manual calls for the use of two "special tools", one to find TDC on the crank and lock it there and one to also lock the cam at TDC. I went ahead and ordered the tools and they made the job straightforward and provided piece of mind that things weren't off by a tooth when the new belt went on. Though the hardest part of the job was finding and removing the plug from the side of the engine block where the crank tool is inserted. It's a real bugger to get at with the limited space in the engine compartment.

The rest of the job was pretty straight forward. The belt tensioner is not the spring loaded type. But it has an indicator on it for putting tension on the new belt which is pretty slick. From start to finish including prep and cleanup only took a couple of hours.

The old belt was in really good shape. No cracks or fraying, no sign of wear on the tooth side and the part number could still be read on the smooth side. We bought the boat in 2014 with about 300 hours on the engine and there was no mention of the belt having been changed(manual says 4 years or 1000 hours). The boat is 10/11 years old and the engine now has about 1300 hours granted most of which is at low rpm.

While I was in there went ahead and replaced the serpentine belt as well. It had about 800 hours on it and looked nearly new.

I have to say the more I get to know this little engine the more impressed I am with its design/construction. One thing that's interesting is that there is a GM part no. on the timing belt. There was also a GM number on the front of the block under the timing belt cover. Will research them a little when time permits...
 
Very Nice. Who did you get crank lock and cam lock from?

Les
 
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