Why does Service Manual 25 have different Torque Specs?

[BRG25]

Good afternoon guys...

On page 3A-2 the service manual has "Torque Specifications 262 cid (4.3L) Engines"

Water Circulating Pump 30 lb-ft / 41 Nm

and later on page 6A-2 under SEAWATER COOLED MODELS Torque Specifications

Water Circulating Pump 35 lb-ft / 48 Nm

I'm thinking the second torque chart is for the alternator bracket to the water pump? I have a Mercruiser 4.3 Seawater (Raw) cooled engine.

Thanks.

 

[Bondo]

Re: Why does Service Manual 25 have different Torque Specs?

Ayuh,... I've never Torqued the circulating pump on, Ever...
But,...
30/ 35 ft.lbs sounds about Right, they're 3/8" bolts...

 

[Bt Doctur]

Re: Why does Service Manual 25 have different Torque Specs?

Look again ,the V6 shows 30ft/lbs on both of my pages for the circ pump
http://www.boatfix.com/merc/Servmanl/18/18A6R2.PDF

 

[BRG25]

Re: Why does Service Manual 25 have different Torque Specs?

The manual I downloaded was from Don's sticky thread however I'm sure I'm making a bigger deal out of this than I need to. Thanks for the information guys!

 

[Don S]

Re: Why does Service Manual 25 have different Torque Specs?

Look again ,the V6 shows 30ft/lbs on both of my pages for the circ pump
http://www.boatfix.com/merc/Servmanl/18/18A6R2.PDF

You have a link to #18 BT, not 25.

Somewhere between 30 and 35 ft lbs will be fine.
Here is what the different V6 manuals show.
Manual #7 shows 30 and 30
Manual 18 shows 30 and 30
Manual 25 shows 30 and 35
Manual 32 shows 33 and 35

I'm like Bondo, have never picked up a torque wrench for a circ pump bolt.

 

[havasuboatman]

Re: Why does Service Manual 25 have different Torque Specs?

"I have a Mercruiser 4.3 Seawater (Raw) cooled engine"

Use the torque specs for your motor. What does it matter why a different model has different spec's?

 

[BRG25]

Re: Why does Service Manual 25 have different Torque Specs?

"I have a Mercruiser 4.3 Seawater (Raw) cooled engine"

Use the torque specs for your motor. What does it matter why a different model has different spec's?

havasuboatman - Not sure I understand your question, Service manual 25 is for my engine and I was uncertain why there were 2 different torque charts. It is unclear in the manual if the charts are for different cooling setups or what. Anyway, like has been mentioned it doesn't really matter for the water pump.

 

[havasuboatman]

Re: Why does Service Manual 25 have different Torque Specs?

Service manual 25 covers the 4.3 L, the 4.3 H. and the 4.3 EFI. It also covers many years. When ever a service manual gives a different spec, or proceedure, for a certian model, it will list that model seperately. This is especially true of torque qualities, or bolt torque patterns.
That's why it's very important to read all of the text in a proceedure. Mid-production changes, part availability changes, materials changes, all effect how things are done later. It could simply be the bracket you mentioned, or it could be they changed the mounting bolt size or hardness.

 

[BRG25]

Re: Why does Service Manual 25 have different Torque Specs?

ok...that makes sense. Obviously a mechanic would have more resources available than just the service manual. On Mercury Parts Express when I enter my engine serial # I get...

809969 98 : 4.3 L/4.3 LH ALPHA/BRAVO (262 CID - GEN + ) -

which is slightly cryptic...however I know I have the 2bbl carb so I am assuming the LH is for the 4bbl and then EFI is self explanatory. Anyway, I'm not trying to beat a dead horse here, just trying to get a better understanding of the documentation. Thanks for the information.