Reply
 
Thread Tools Display Modes
 
Old 02-01-2011, 03:50 PM   #21
Guru
 
JohnP's Avatar
 
City: Toms River
Country: USA
Vessel Name: D U E T T E
Vessel Model: 1996 36' Island Gypsy
Join Date: Dec 2009
Posts: 1,109
lehman spare belt storage.

Well you learn something everyday!* I went from thinking about where to keep my spare belt to wondering when my original raw water pump drive is going to fail.

At least they both have the same result a shutdown engine due to overheating.

But with only one engine its the when and where that hurts.

Next trip to the boat I will be checking to see if I have the old Jabsco or the newer Johnson.

I am betting on the Jabsco because there seemed to be plenty of room around the Simms for oil changes.

Perhaps in the Spring when I change out the belt and set up my spare, I will pull the pump and check the drive end.* I know I have some new (Jabsco I think impellers so I might as well change that too.)

I am a big fan of "If is not broke don't fix it".** However I got to check this out.* JohnP

-- Edited by JohnP on Tuesday 1st of February 2011 05:18:29 PM
__________________
Advertisement

JohnP is offline   Reply With Quote
Old 02-01-2011, 03:52 PM   #22
Guru
 
JohnP's Avatar
 
City: Toms River
Country: USA
Vessel Name: D U E T T E
Vessel Model: 1996 36' Island Gypsy
Join Date: Dec 2009
Posts: 1,109
RE: lehman spare belt storage.

How much do I have to take apart to upgrade to the Johnson Pump?** JohnP
__________________

JohnP is offline   Reply With Quote
Old 02-01-2011, 07:35 PM   #23
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
RE: lehman spare belt storage.

John--- The Johnson pump is a bolt-on replacement for the Jabsco/Lehman pump and pump drive. You simply unbolt the Lehman drive coupler and the Jabsco pump attached to it from the engine's accessory case and bolt the Johnson pump in it's place. It uses the same mounting holes. You will most likely have to change the hose between the pump and the engine's lube oil heat exchanger because the Johnson pump is shorter so the hose needs to be longer. You may not have to change the hose from the intake sea strainer to the pump, however.

The intake and outflow of the Johnson pump are on opposite sides of the pump chamber so on the FL120 an elbow fitting needs to be installed in each opening. On an FL120 the pump is positioned so the intake is on the bottom and the outflow is on the top. This is why changing the injection pump's lube oil becomes more challenging because the outflow elbow leaves very little room under the injection pump drain plug.

The recommended Johnson pump for the FL120 is the 3/4" model, the recommended pump for the FL135 is the 1" model. However at the suggestion of Bob and our diesel shop, we had 1" pumps put on our FL120s. Slightly higher water flow volume, which doesn't make any difference to the engine since its temperature is controlled by the thermostat, but it made a noticeable difference in the temperature of the transmissions. And any time you can reduce the operating temperature of a Velvet Drive, it's a Good Thing.

If you're interested in this conversion I suggest that you talk to Bob Smith or Brian Smith at American Diesel.
Marin is offline   Reply With Quote
Old 02-01-2011, 08:22 PM   #24
Guru
 
JohnP's Avatar
 
City: Toms River
Country: USA
Vessel Name: D U E T T E
Vessel Model: 1996 36' Island Gypsy
Join Date: Dec 2009
Posts: 1,109
RE: lehman spare belt storage.

The picture I am getting is that the Johnson Pump has the drive gear attached to it. So it elminates the trouble prone Lehman drive for the Jabsco.

Did Bob Smith give any idea as to how many hours before the original drive bearings become worn enough to cause coupler failure.* My engine has 1650hours.

Back before Lehman went out of production, what was the outcome of the recall?
I doubt if they gave everyone Johnson Pumps.* How did they satisfy their customers when lehman was still in business?

I do like the idea of going with a 1" pump,* a lot of the back bays and inland places I go have pretty high Summer water temps.

JohnP
JohnP is offline   Reply With Quote
Old 02-01-2011, 09:53 PM   #25
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
RE: lehman spare belt storage.

Quote:
JohnP wrote:

1. Did Bob Smith give any idea as to how many hours before the original drive bearings become worn enough to cause coupler failure.* My engine has 1650hours.

2. Back before Lehman went out of production, what was the outcome of the recall?* I doubt if they gave everyone Johnson Pumps.* How did they satisfy their customers when lehman was still in business?

1.* No. Our engines had about 2,000 hours on them when we discovered the cracked drive tang on the port coupler.* The starboard coupler was fine.* I don't think the problem has anything to do with bearing wear, it's the cracking of the drive tang that drives the pump that's the problem.

2.* I don't even know if Johnson pumps were around back in the 1960s which is I assume when*the Lehman pump drive was recalled.* Bob didn't tell me why the drive was recalled or what the fix was, only that it was extremely difficult to manufacture and was the only component of the Lehman marinization kit to have had*a factory recall.*I doubt the recall had anything to do with the*potential for*the drive tang to crack--- that probably wasn't discovered for many years.* *My guess is*the recall*was over a defective component due*to a manufacturing problem*and they replaced it.* But you'd have to ask Bob to get the correct story.*
Marin is offline   Reply With Quote
Old 02-02-2011, 07:45 AM   #26
Guru
 
JohnP's Avatar
 
City: Toms River
Country: USA
Vessel Name: D U E T T E
Vessel Model: 1996 36' Island Gypsy
Join Date: Dec 2009
Posts: 1,109
lehman spare belt storage.

I will have to check with Bob Smith.

It just seems that from the start in the 1960s to the time my engine was built 1982, they had 20 plus years and lots of engine hours to know they had a problem.

You think somewhere along the line they would have made a better pump drive tang.
Or corrected what ever manufacturing issue was causing the problem.
Instead of just sending out engines with a potential defect.

I will have to see what Mr. Smith has to say.

-- Edited by JohnP on Wednesday 2nd of February 2011 08:46:26 AM
JohnP is offline   Reply With Quote
Old 02-02-2011, 01:05 PM   #27
Scraping Paint
 
City: -
Country: -
Join Date: Oct 2007
Posts: 13,748
RE: lehman spare belt storage.

Quote:
JohnP wrote:

1.* It just seems that from the start in the 1960s to the time my engine was built 1982, they had 20 plus years and lots of engine hours to know they had a problem.

2.* You think somewhere along the line they would have made a better pump drive tang.


1.* Not necessarily.* Given the average annual use of recreaetional boats which seems to vary from 50 to 100 hours a year, it could take well over 20 years for the problem to become frequent enough to be noiticeable.* Like I said, we had a cracking drive tang on one coupler but the other coupler was fine.* I have no idea what contributes to the cracking.* Harmonic vibration, perhaps?* This could explain why it happens on some engines and not on others* with the same amount of time on them.* Every engine even of the same type is a bit different in some way or another.

I don't hear of these things breaking left and right.* But it's something that occurs just often enough for our diesel shop to be well aware of it (which is why when we needed the pump overhauled they removed the coupler too because they wanted to check it's drive tang) and Bob Smith is certainly aware of it since he's the one who told me about the less-than-ideal design of the coupler (which he designed).* He said it was a logical design at the time but time has shown it to be not as good as it could have been.

2.* Maybe they did.* I have no idea if this problem can surface only in older FL120s or if it occurs across all the years of manufacture.* In any event, it appears to be random and totally unpredictable.* Had our water pump not needed a new shaft seal when it did we would have continued operating the engine with no idea that the coupler was getting close to failing.

The good news is that there is a great cure which is actually better than the original setup.* The Johnson pump is smaller yet moves more water and so far as I know has an utterly reliable drive coupler.



*
__________________

Marin is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Engine Room Storage Nsail General Discussion 15 03-24-2012 07:03 PM
Dinghy Storage Opinions wizard Dinghys and Smaller Boats 32 03-09-2012 07:44 PM
Fuel storage for your tender knotheadcharters Dinghys and Smaller Boats 10 11-05-2011 12:48 PM
spare lehman tomtomterrific Power Systems 4 08-15-2011 04:15 AM
Belt supplier and old numbers Tom.B Power Systems 15 07-28-2010 04:57 AM




All times are GMT -5. The time now is 07:23 AM.


Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.0
Copyright 2006 - 2012