Lehman seized

[TopperHarley]

Hi folks,

A few weeks ago my 4cyl, 80 hp lehman made a horrible metal on metal sound during start up, ran noisily for 10 seconds then stopped firm. It is very tightly jammed up, and won't turn at all,.

So far, the only investigation that has been made was to remove the injectors and try to turn it over with a bar. She would not budge.

Valve assembly looked OK with the rocker cover off.

I am unable to get a mechanic to look at the engine in the near future, and have been told the potential problem could be:

1) damaged damper plate
Or
2) some part of the starter gear assembly breaking, causing the jam.

I want to exclude these as the cause before considering more expensive options (rebuild? Etc).

Are any of these problems able to be diagnosed by someone with only elementary mechanical skills?.

Anything else I should consider?

The motor was old, unknown hours, regularly serviced and run weekly very reliably prior to this occurring.

Any advice would be greatly appreciated.

Thanks!

 

[Comodave]

If you have room to slide the transmission back it is fairly easy to separate it from the engine and get a look at the damper plate. i did new damper plates on our last boat. Took a couple of hours to do. There will be bolts holding the bell housing to the engine that will need to be removed. Then slide the transmission back and look at the damper. If it has springs, a spring may have broken and a piece can get into the teeth and that will stop an engine from turning. You can get a couple of long bolts and replace the bell housing bolts with them to slide the transmission back on so you don’t have to hold up the transmission. But some engine setups have motor mounts on the transmission and complicates it.

It can be easy or difficult depending on the available room behind the transmission. Good luck.

 

[Lepke]

Also you should be able to unbolt and remove the starter.

 

[twistedtree]

Also you should be able to unbolt and remove the starter.

I would do this first, inspect the starter drive gear, and get eyes on as much of the flywheel ring gear as you can. If that doesn’t further point to the problem, then check for any inspection holes or plates that can give you a look at the damper plate, etc. I think it’s very unlikely that it’s an internal engine problem.

 

[heysteve]

If you don't already have one, get an endoscope camera. Once you've removed the starter, stick it in the bell housing and look for carnage!

 

[TopperHarley]

Thanks for the great replies !

I removed the starter today and immediately found what looks to be a spring from the damper plate fouling the flywheel.

Will attempt a tranny removal in the next week or so !

Thanks again for the solid advice.

 

[Comodave]

Well, that is really good news. Contact Brian at American Diesel for a new damper.

 

[Nepidae]

I'd also contact Brian to see if he can offer any additional input.
There is no one who knows the Ford Lehman like Brian.
804.435.3107
Good luck.