Fan clutch, does yours lock up?

On my old Ford pickup truck, when the fan clutch locks it @#$%ing locks up tight and it sounds like a hurricane under the hood. I've never heard my XJ fan lock up like that, and it's been PLENTY hot (collapsing lower radiator hose that I FORGOT to install the spring in). I've got an aftermarket thermostatic fan clutch. Jes says his OEM Jeep unit never really locks tight either.

Are we missing out on extra cooling by not having it lock?

Does your fan clutch lock?

CRASH

CRASH said:

On my old Ford pickup truck, when the fan clutch locks it @#$%ing locks up tight and it sounds like a hurricane under the hood. I've never heard my XJ fan lock up like that, and it's been PLENTY hot (collapsing lower radiator hose that I FORGOT to install the spring in). I've got an aftermarket thermostatic fan clutch. Jes says his OEM Jeep unit never really locks tight either.

Are we missing out on extra cooling by not having it lock?

Does your fan clutch lock?

CRASH

Click to expand...

On my 85 wagoneer when the clutch was new it would never lock up. The only one I have seen lock up in person was on my 81 mustang. It locked up and was very loud.

Kim.

On my 89 it doesn't appear to lock up either.

I've actually been thinking of replacing the clutch in the future to make it lock up, but it now sounds like a new one won't help according to this post.

I've just changed the fan clutch on my 91 for a new one because the old was not locking up, or so it seemed to me, and the new one does not lock up either, so maybe I just spend the money for nothing.

By the way do not use the hoses that requiere a spring to avoid collapsing, they are not stiff enough to resist the higher pressures that develop in the 4.0L engine and it will burst open, I had that experience in the middle of a lonely mountain road and had to rebuid the hose using ducttape, wound wire and masking tape to reach the next town which was 100 miles away. Stick to the original cloth reinforced hoses aor an alternative brand buid specially for our engines.

Cheers

SACEM

sacem said:

Stick to the original cloth reinforced hoses aor an alternative brand buid specially for our engines.

Cheers

SACEM

Click to expand...

OEM XJ lower radiator hoses come with a coil. To this day, when you buy a hose at the dealer, they come with a new spring.

My is loud when its hot out so yes.

About 3 weeks ago I installed a new NAPA clutch because the Carquest clutch that had been in my Jeep for a couple years was not working at all. The NAPA clutch works better than the old one, but I don't think it's locking up like it should. But no matter, I am going to replace it with a Perma Cool 16" electric fan. (2950 cfm) Already have the fan and temp control here. Just waiting for a good time to install it. If I was going to keep the clutch fan, I would go for an aftermarket clutch like Perma Cool, or an OEM clutch. The OEM clutch is $115.00 at the local Jeep dealer. Ouch !

UPDATE.

So, got a new 97+ electric fan ($105), new fan shroud ($13.80) and new lower radiator hose ($15.00). The fan stuff was mail order, MOPART.com, the hose was a dealer item.

While I had the mechanical fan out, I tried a little trick to get it to lock up sooner and harder. I turned the bi-metal temperature sensing coil 180 degrees counter- clockwise to pre-tension the spring a bit. This way, as it expands from heat, it will already have the clutch locked up tighter to begin with. You'll need to cut a slit in the metal tab on the other side of the OEM spring retainer to get it to hold the spring in place correctly.

All the mods together made a 20 degree difference in max temperature under load. The rig also runs about 20 degrees cooler down the highway.

The fan clutch still does not lock TIGHT, but it's definately locking harder than it was. I have found a swap candidate that locks very tightly, and is cheap to attain. Only trouble is that it's a GM part, and I hate running GM parts. I'll report further once that unit is swapped in.

I think I can knock another 10 degrees off of my max temp and never run over 210 loaded, with the trailer, and the A/C on in 110 degree heat. That's my goal.

CRASH

The fan clutch in my 2001 XJ locks up so tight that it noticeably reduces the available power, especially while accelerating. It feels like it uses 30 HP or more. Hot starts in hot weather are the worse; the noise is deafening

Interesting. Wonder if your clutch has a different part number?

None of the OEM or aftermarket XJ clutches I have seen will lock up tight, even when the temp is up at 230-240.

CRASH

mine definitely never locked up tight, went to dual electrics and I'm happy. I'd be interested to hear about the GM alternative though.

I have never heard of one that locks up.

I installed one from a wrekers out of an 2000 cherokee it fit in my 87 no problem I notice a big difference when it reaches 105 degreese celcious it roars britty good but does not lock up tight '' I find on a cooler day the engine has to get hotter for the fan to roar.