Lehman 135 (American Diesel version) work hours

[Ben]

Dear People-Smarter-Than-Me -(All of you that is)

So, My ADC 136N (The Ford Lehman 135 marinized by American Diesel) was knocking loud and unusually, towards the forward part of the oil pan.

Link - with video connected...
http://www.trawlerforum.com/forums/s6/adc-lehman-136n-knocking-22892.html

Can you tell me how many mechanics and hours this should take or provide experiences of this same problem. I think I might be getting "taken to the cleaners".

1. Haul engine up inside boat on a frame built inside boat to do so.
   1. Build wooden frame with marina blocks.
   2. Disconnect engine electrical, fuel, exhaust, cooling.
   3. Raise engine.
2. Diagnose what is wrong with the engine, why is it knocking in the oil pan?
   1. I was advised the head was removed in the diagnostic process. as the problem was not immediately identified.
   2. Discover it is the harmonic balancer.
   3. When I look where the harmonic balancer is, I see no reason - I believe - to remove the head to find it. But I am not a mechanic.
3. Repair issue and clean up scarring done by balancer.
4. Re-assemble engine and re-install.

Other than adding all the fluids, changing the oil and fuel filters and the exhaust elbow, I really don't know much more. I realize I don't know s--t about deep diesel mechanics, but I know the basics and think I might be getting hosed.

But for comparison purposes, if you know the hours or have had this done, I'd be interested in your ball park hours and costs if you are kind enough to share them. I can take a PM even a phone number if to keep details confidential.


Thanks in advance.

 

[DavidM]

By harmonic balancer, you mean the one between the engine and transmission, often called a torsional damper?


These can usually be replaced by unbolting the transmission, uncoupling the prop shaft and siding both back to get to the damper. You also usually have to remove the prop. Not always possible, depends on how much room you have behind the transmission.


If you don't have enough room then you may have to lift the engine up to get access. But in no case should you ever remove the head.


I would say that you got REALLY taken by a total DS mechanic.


David

 

[Ski in NC]

Could it have been a loose torsional damper on the front of the crank??

 

[FF]

"Could it have been a loose torsional damper on the front of the crank??"

ALL of these have a service life , that may or may not cause knocking.

Replacement is easy , but they are not cheap.

 

[bilge53]

Who did the work?

 

[obthomas]

Harmonic balancer is on the front of the crank. Torsional damper is on the flywheel at the rear of the engine. So what is everyone talking here????

 

[Ski in NC]

Torsional damper is on front of crank. Can also be called a harmonic damper.

Torsional coupling is on flywheel, drives tranny through some sort of flex device.

Six cylinder needs no external balancing.

Ben- What the heck happened here??

 

[kulas44]

Harmonic balancer is on the front. Even if it cant play the harmonica or do any balancing acts, thats still what folks call it. Yep, you got hosed.

 

[kulas44]

Sounds like the mechanic needs a simple stethoscope, and a little more knowledge about the Lehman engine. Unless they have been hydro locked or ingested something large and hard the lower end is just about bullet proof. If a stuck or bent valve is suspected just pull the tappett cover and look. A stuck injector can cause some serious noise and sound like a busted piston, easy to isolate each injector to verify. If it was obvious where the noise was coming from (roughly) the stethoscope would have pinpointed it. I would really not want to pay for his lack of knowledge, and on the flip side if I, as a mechanic, made that kind of mistake you would get charged for the new part and labor to install. I would volunteer to eat the rest of it, hoping you would feel sorry for me and at least pay me a little more.

 

[Ski in NC]

When I listened to the noise on the vid, it was only hitting occasionally, a bearing or piston would be every rev or every other rev. Engine would make several revs, then a "thunk", several more revs, thunk.. and not consistent. Only things that seemed to fit were loose torsional damper on the front, sticking valve, or maybe something wrong with drive coupling on flywheel. It was not a noise I had ever heard on a similar engine.

Then we heard nothing of the issue til this...

 

[Busterbrown]

Could it be broke spring from flex plate in bell housing.

 

[Ben]

Work was done by a large Wilmington boat yard. I need to re-review the paperwork to clear up my confusion on it. My question the same - what need to remove head if the harmonic balancer?

Anyone can recommend a good Lehman mechanic for a second opinion? I'm halfway in the middle of this, engine apart.

 

[Ski in NC]

No need to remove head to access damper on front of crank, or coupling at flywheel. He may have pulled head as part of troubleshooting. That would not have been my first plan of attack, but he may have had a decent reason for doing it.

 

[Ben]

I was told by an out-of-area mechanic to talk to the yard and get a Lehman-knowledgeable mechanic to review what's been done.

The most helpful thing is if anyone knows of a good diesel mechanic in the Wilmington area with Lehman experience who could consult with me on the best path forward.

I'm nearly $7K in, and They're telling me $4K to reassemble and test. Most cost is labor at $90/hour. So figure something like 80 man-hours dedicated already, and they're planning another 40.

A harmonic balancer is $395.

 

[Ski in NC]

Does not sound too good. I can maybe help. I've got some Lehman experience, but not real extensive. Rebuilt one in my shop that sat with water in it, and a bunch of minor stuff on other Lehmans. I'll send you contact info via pm.

 

[Comodave]

$11,000 sounds very high. A friend of mine has his SP225 rebuilt for 18K completely.