This is on a 90 4x4, the fan 'roar' never stops, meaning the fan doesn't turn off; engine isn't overheating, thermostat is brand new and working properly. Is this pointing towards fan clutch replacement? When cold, I can turn the fan by hand with mild resistance. My net searching on this turns up a lot on the opposite problem, eg. fan never runs & engine overheats, but I haven't found much on this issue.

Thanks in advance, any advice appreciated.

 

yep, fan clutch

 

Welcome to Yotatech!!!

Either rebuild it as per 4Crawler.com or score one from a junkyard!

 

Might be the center rod is siezed, my original clutch did that. Pulled it off, removed the fan and used a pair of pliers to gently turn the center rod (where the bimetal coil attaches) and it broke free and worked well after that. That rod changes the internal valving in response to the air temp. to turn the fan on and off. It'll still spin when off, but slower than the engine speed:
- http://www.barneymc.com/toy_root/techneek/fan_clch.htm

 

HA! Beat ya Roger!!!

 

Thxs gents.. as a frequent lurker here, knew I'd get some good advice..

 

you can rebuild a fan clutch? Mine is constantly spinning too. What's the best way to test a fan clutch? When it's cool or hot?

 

Yes:
- http://www.4crawler.com/4x4/Docs/FanClutch.pdf

See the link I posted earlier.

 

Ugh. Thanks for the link. I'm not looking forward to pulling the fan/clutch off.

 

It's not that bad, trust me.

 

I just hate anything having to do with the cooling system. I hate having to drain coolant.

 

No need to drain any coolant, 4 bolts to pull the fan shroud, 4 more hold the fan clutch in place then 4 bolts and the fan separates from the clutch.

 

Dont need to train anything, as 4crawler said just take it off, its quite simple

 

The manual I have makes it look like you need to take out the radiator. I guess removing the shroud will work, but that still doesn't give me much room to work. I'll take a look at it tomorrow if that's the case.

 

DupermanDave- find a 10mm boxed end wrench, long or stubby depends on your dexterity, a ratcheting wrench may be better, and you should be fine. You'll notice that the fan doesn't have blades evenly spaced so just rotate the fan so that the most widely spaced blades are closest to the nut you're loosening and that should give you enough clearance to get your wrench, and your hand, in there.

But you do have to get the shroud off so...

I'm going to add that there may be 6 bolts to get the shroud off- the 4 that hold the shroud to the radiator and two down below the fan that holds a small section of the shroud on to the main shroud that when removed allow the shroud to easily lift up without interference from the fan.

 

Thanks for the rebuild link.

Yeah, pay attention to this. I wish I had noticed it when I put in a new fan clutch many years ago while working around the loosened shroud. That bottom part that otherwise would prevent removal around the fan comes off.

My 86 has clips that hold the piece on. Clips, bolts, whatever -- it comes off.

 

Thank you for mentioning the clips. My 91 has the bolts holding that part to the shroud but my 88 has clips and I forgot about that.

 

Thank Toyota engineers for thinking ahead. Blame the manual writers for not mentioning this feature. The manuals I've seen say nothing about that part being removable, and not looking closely I assumed the shroud was one piece.

Removing and installing a fan clutch with the shroud dangling in the way wasn't fun. If you know to take the bottom part off and yank the shroud out, piece of cake.

 

I have sliced my flesh a bit on the radiator fins before I realized that part of the shroud was removable.

 

I'm just curious, what's the purpose of the silicone fluid in the fan clutch? And is that the only thing that goes bad in the clutch, other than the center rod getting stuck?