Engine/Transmission (1998.5 - 2002) Thermostat Gasket?

[Shelby Griggs]

Changing all the hoses (Mr. Bob's silicon hoses going back on), coolant and thermostat. The thermostat that I took out has a separate gasket to seal the housing, however the new in a Cummins box I have has a built in sealing surface it appears. Was the design changed or do I need a different thermostat and separate gasket for a 2001 5.9 24v?

In addition, some beautification is happening; valve cover, alternator bracket, thermostat housing and the solid line to the heater from the front of the engine are all off to the powder coat shop in the morning. All are going to be Banks red (close to Cummins red) to match the Banks intake horn recently installed.

SHG

 

[NIsaacs]

The sealing ring is on the thermostat.

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[Shelby Griggs]

The sealing ring is on the thermostat.

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OK, thanks. I have the style as pictured for my replacement, HOWEVER the one I took out was a separate seal and thermostat, so that must have been a revision sometime since 2001.

SHG

 

[BigPapa]

The original part number was 3935824, then 3937171, and the current part number for an ‘01 is 3946849. This is from Cummins QuickServe.

The original looks to have been 2-piece. There should be a part number on it,

 

[Shelby Griggs]

The original part number was 3935824, then 3937171, and the current part number for an ‘01 is 3946849. This is from Cummins QuickServe.

View attachment 138358

The original looks to have been 2-piece. There should be a part number on it,

View attachment 138359

Thanks Scott, yes that is how my original was, two pieces and the replacement is one piece, just wanted confirmation that I have the correct one-piece thermostat before I refill. Just confirmed that I have PN 3946849 for my new replacement.

SHG