Bernd
I think I'll try the spin test and hope everything is fine as the function
test looks a little to much for my liking :-)
Thanks again
Jay
----- Original Message -----
From: "Bernd D. Ratsch" <bernd@texas.net>
To: <dakota-truck@dakota-truck.net>
Sent: March 21, 2003 3:37 PM
Subject: DML: RE: Clutch fan
> The "Official" Tests:
>
> Testing and Inspection
>
> SPIN TEST
> If the fan assembly free-wheels without drag (the fan blades will
> revolve more than five turns when spun by hand), replace the fan drive.
> This spin test must be performed when the engine is cool.
>
> NOTE: For the following test, the cooling system must be in good
> condition. It also will ensure against excessively high coolant
> temperature.
>
> FUNCTION TEST
>
> Drill a 3.18 mm (1/8 inch) diameter hole in the top center of the fan
> shroud.
> Obtain a dial thermometer with an 8 inch stem (or equivalent). It should
> have a range of -18配o 105蚓 (0配o 220蚌) . Insert thermometer through
> the hole in the shroud. Be sure that there is adequate clearance from
> the fan blades.
> Connect a tachometer and an engine ignition timing light (timing light
> is to be used as a strobe light).
> Block the air flow through the radiator. Secure a sheet of plastic in
> front of the radiator (or air conditioner condenser). Use tape at the
> top to secure the plastic and be sure that the air flow is blocked.
> Be sure that the air conditioner (if equipped) is turned off. WARNING:
> USE EXTREME CAUTION WHEN THE ENGINE IS OPERATING. DO NOT STAND IN A
> DIRECT LINE WITH THE FAN. DO NOT PUT YOUR HANDS NEAR THE PULLEYS, BELTS
> OR FAN. DO NOT WEAR LOOSE CLOTHING.
> Start the engine and operate at 2400 rpm . Within ten minutes the air
> temperature (indicated on the dial thermometer) should be up to 88蚓
> (190蚌) . Fan drive engagement should have started to occur at between
> 74配o 82蚓 (165配o 180蚌) . Engagement is distinguishable by a definite
> increase in fan flow noise (roaring). The timing light also will
> indicate an increase in the speed of the fan.
> When the air temperature reaches 88蚓 (190蚌) , remove the plastic
> sheet. Fan drive disengagement should have started to occur at between
> 57配o 79蚓 (135配o 175蚌) . A definite decrease of fan flow noise
> (roaring) should be noticed. If not, replace the defective viscous fan
> drive unit.
>
> -----Original Message-----
> From: owner-dakota-truck@bent.twistedbits.net
> [mailto:owner-dakota-truck@bent.twistedbits.net] On Behalf Of jay & dana
> Sent: Friday, March 21, 2003 5:08 PM
> To: dakota-truck@dakota-truck.net
> Subject: DML: Clutch fan
>
>
>
> So how does one go about determining if the clutch fan is screwed? On
> my 97 since day 1, I get the initial roar at start-up when cold
> (sometimes) and also even when it's warmed up and even in the summer I
> will get that slight roar upon slow acceleration or deceleration (at
> slow speeds) when turning etc. just for a second or two. Since it's
> happened ever since I've had my truck I thought this was normal. Any
> ideas on the best way to determine if it's faulty or not?
>
> TIA
> Jay
This archive was generated by hypermail 2b29 : Fri Feb 06 2004 - 11:46:01 EST