Fan Clutch - Thermal vs. Non-Thermal

[Kris]

So today it was approaching the 100* mark here in Thousand Oaks, and on my way to work I decided to turn on the old AC.
Well, the temp, which usually sits right around 200-215* was starting to cover the top of the 220 mark at 65mph. :rolleyes:
The off ramp had me sitting for about 3-4 minutes and in that time the temp creeped up to just under 260*. :eek:

So Im thinking the fan clutch went, right ? Well this is the 3rd one in 2 1/2 years !!! :mad:

They are Hayden (brand) from PepBoys (lifetime guarantee w/receipt - haha...).

So I go into Pep this evening and explain my problem to the parts guy and he looks up the part #.
Seems that they list a thermal (temp sensitive, what Ive been using) and a non-thermal (engine speed sensitive, disengages above aprox 2000rpm) in their parts guide.

The question he asked me is "Are you sure that your engine came (factory) with a thermal clutch?" and "Mabye you are just runing hot too often and wearing them out"

It had a thermal when I got it... :confused:

Well, I bought the non-thermal clutch seeing that the thermals are'nt working for me and my problem is at slow speeds, but was wondering about experiences of those on the board.

Is everybody using the thermals ?
Anybody else going thru fan clutches ?

kris.

[Millerluck]

I like the non thermal that free spins at higher RPMs.

My old thermal was not doing it's job anymore. It was as free as a bird. So it was over heating at low speed, stop and go driving. The guys at the dunes (CG and Jeepbob) noticed it when I was getting a jump start from Jeepbob.

After putting in the non thermal per Jeepbob's advise, it never over heated agian.

I need to get another cluch later today.
The one I had on there flew apart when my water pump went out. No fault to the cluch. Figure with 1/2 inch slop in the water pump it got all out of wack , and off balance. Then tossed it out.

Go with the non thermal. Me

Later

Larry Miller

[ July 11, 2002, 04:01 AM: Message edited by: Millerluck ]

[Lindel]

Hayden 2797 is the answer. It's for a Chevy 454, living in a motor home. Can you say Super Duty?

That's what I have in mine, and it works good, on 100+ days, in traffic, with no fan shroud.

It does require some modification, but nothing that difficult. The price is over $100, but it's working with the original 3 core radiator. The only thing I did beside's the new clutch was an engine back flush, to clear rust.

[Kris]

Originally posted by Millerluck:
I like the non thermal that free spins at higher RPMs.
Go with the non thermal. M
Later
Larry MillerYeah, thats what I'm doing.
I thought about going with a "super heavy-duty" type off another vehicle, but I am a bit shy about thermals now on the wagon (never had a problem on my yj though).
I bought the non-thermal yesterday and will be installing it later today. I was just wondering if others were having the same problem since there have been alot of posts on overheating lately. And how reliable the non-thermals have been.

Thanks guys...
kris.

[TexasJ10]

Do the two fan clutches look the same? How do you khow which one you have?

[heydave]

The thermal will have a spring coil on the front. Non thermal is flat on the front center.

[Kris]

ok...
Got it in. Sure sounds like that fan is going to launch right out the front of the wagon. :eek:
At least it is pulling air now, turned the AC on and was cold almost instantly at idle so thats a good sign. :D

Hey Larry, what (if anything) do you do during the winter ? Does the non-thermal keep you from warming up on those cold mornings ?
I know it should'nt if the thermostat is working, but thats alot of air moving thru there.

kris.

[Millerluck]

No prob's in the winter. Heater works a little to good.

Later

Larry

[Ralph]

You can also put a spacer in place of the fan clutch. Dutch loaned me his 87 GW to tow my 2400-lbs trailer to Georgia/Florida and back, with a complete 84 GW from Lightnin' on the trailer as well as a pair of front doors from billyrb's parted-out 84 GW).

The additional load on the engine created by the lack of a fan clutch was noticeable, particularly at higher speeds. But it always ran cool, even climbing the hills in the Carolinas and Virginias. I did find the extra noise a bit annoying.

Dutch's 87 GW was really set up to work off-road for long hours as his work truck. The things he did like removing the fan clutch kept the engine running cool at low speeds. The original engine had 199k miles on it when he sold it a couple of months ago, and ran like it was brand new.

[desert_freak]

Not sure if my truck was sold without a clutch (J10) but it doesn't have one and I can creep all day and not get hot. I'm sure it is a huge drag on my tired 258 but I've never driven a 4.2 without one so I don't know the difference :D

I had a crewcab dually (10,000 gvw)with a big block that didn't have a clutch and had a monsterous aggressive fan blade. It sounded like a F14 going down the freeway but always ran cool.

P.J.

[J20fan]

You can also put a spacer in place of the fan clutch Ralph, This spacer, did it relocate the fan itself or leave it in the original position? I had asked in another post if any one had moved the fan blade further into the shroud by spacing. On the industrial diesels we run, the position of the fan blade in the shroud can have a major impact on the amount of cooling air pulled through the rad. I have shrouds on both my rigs and both still seem to run a bit hot for me even with a 165* stat.