Spearos Posted August 3, 2013 Share Posted August 3, 2013 It's being a person I'm not that keen on! Had a spare hour or so today so thought I'd quickly replace the viscous unit as it's permanently locked and tick that off my ever growing 'to do' list. How wrong was I - it's seized solid! Using a large pair of water pump pliers I can hold the WP pulley - there's a handy little hole that the teeth on the pliers can 'bite' into to hold it but try as I might the 32mm wrench just slips so I thought I'd stop before the nut is properly screwed. Done some reading tonight and it appears it's quite a regular problem, however seems to be a lot of conflicting information regarding whether it's a LH or RH thread. So I thought I'd ask the question specifically for an '88 3.5 V8 on carbs? The fan turns clockwise viewed from the front. I tried the nut clockwise and anticlockwise but thought I'd (try to) find out which way the thread is before I continue. Plus Gas is soaking in as I type, hopefully tomorrow I'll get chance to get violent with it!!! Quote Link to comment Share on other sites More sharing options...
Landy-Novice Posted August 3, 2013 Share Posted August 3, 2013 fire up the engine to see what direction it spins.. then you have your answer. Quote Link to comment Share on other sites More sharing options...
jbs Posted August 3, 2013 Share Posted August 3, 2013 I would've thought all viscous fans are LH Thread-A viscous fan spanner will be the way ahead John Quote Link to comment Share on other sites More sharing options...
ballcock Posted August 3, 2013 Share Posted August 3, 2013 You can tell the way a fan spins from the layout of the blades. To undo it it should turn in the same direction as the fan rotates, Quote Link to comment Share on other sites More sharing options...
mikec Posted August 4, 2013 Share Posted August 4, 2013 I think that their normal thread. Ill have a look when it stops raining Quote Link to comment Share on other sites More sharing options...
dirtyninety Posted August 4, 2013 Share Posted August 4, 2013 Normal right hand thread! I removed mine the other evening and had a similar battle, 200/300 tdis are left hand thread and v8's right hand thread. Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted August 4, 2013 Share Posted August 4, 2013 Well my 14J which has the same viscous as a 12J/19J/200Tdi & V8 of some ilk is left hand thread i have just checked it. The engine rotation against the resistance of the fan blades will tighten it, so to undo turn the viscous hub in the same direction as the engine turns it. Quote Link to comment Share on other sites More sharing options...
Spearos Posted August 4, 2013 Author Share Posted August 4, 2013 Hmmm still a bit unclear, it would seem that the thread direction is different from one year to another, one model to another! Just had a 'lightbulb moment' perhaps I can determine the thread from the new part!! Will have a look tomorrow... Quote Link to comment Share on other sites More sharing options...
Spearos Posted August 4, 2013 Author Share Posted August 4, 2013 Curiosity got the better of me! Just been out and had a look at the replacement part and it looks like a LH thread!... Assuming I've got the right replacement part!!! Quote Link to comment Share on other sites More sharing options...
western Posted August 4, 2013 Share Posted August 4, 2013 it should be possible to tell left hand from right hand thread by looking at the direction the thread is cut, the peaks will be angled to the left or right see the diagram below Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted August 4, 2013 Share Posted August 4, 2013 Regardless of the thread you should always be turning it the same way it spins, whichever way that is. Pretty sure all Land Rover engines spin clockwise when you look at them in the engine bay. Otherwise someone changing from a Tdi to a V8 would get a hell of a shock on first start! If it was the other way the thing would unwind itself when running, so it's always got to be as above. Quote Link to comment Share on other sites More sharing options...
ballcock Posted August 4, 2013 Share Posted August 4, 2013 It's dependent on which way the fan turns and not the engine as the water pump can be driven opposite to the crank. Quote Link to comment Share on other sites More sharing options...
mikec Posted August 5, 2013 Share Posted August 5, 2013 Don't know if this helps, but I've just checked my old 3.5 engine from an 86 90 bog standard, the fan blades are the opposite way to the new 3.9 serp front end which also is the same as a p38. So I'm guessing the change occurred with the serp drive belt? Quote Link to comment Share on other sites More sharing options...
daveturnbull Posted August 5, 2013 Share Posted August 5, 2013 If you don't have a special viscous fan spanner, a long punch and a hammer and do the trick nicely. Give the nut a bloody good wallop on the end of one of the flats in whatever direction you want it to turn. Quote Link to comment Share on other sites More sharing options...
Spearos Posted August 5, 2013 Author Share Posted August 5, 2013 If you don't have a special viscous fan spanner, a long punch and a hammer and do the trick nicely. Give the nut a bloody good wallop on the end of one of the flats in whatever direction you want it to turn. I do have a 'special' spanner... and a length of tubing which slips over the end for extra leverage. However I have read that a quick, sharp strike usually frees it off and gets things moving, however I have read concerns about reducing the life of the waterpump bearings through striking the nut/shaft? Quote Link to comment Share on other sites More sharing options...
daveturnbull Posted August 5, 2013 Share Posted August 5, 2013 I guess you could cause some damage if you were to hit it repeatedly, and towards the middle of the nut. One or two sharp strikes to the end of a flat I would have thought would be ok tho. You will probably find the strike rotates the water pump a bit anyway, so the bearings won't be taking the full force of the impact. Quote Link to comment Share on other sites More sharing options...
mikec Posted August 5, 2013 Share Posted August 5, 2013 A tip on here someone posted a while back was to bunch a rag up between the pulley and the belt, which then locks it up, worked good for me Quote Link to comment Share on other sites More sharing options...
ballcock Posted August 5, 2013 Share Posted August 5, 2013 A "V" belt will rotate the same way as the crank but a serpentine drives on the rear of the belt therefore opposite to the crank. I find a sharp tap on a spanner end will normally shift it whilst holding the belt to lock the pump. An adjustable fits on my V8 fan with no problem. Quote Link to comment Share on other sites More sharing options...
Spearos Posted August 5, 2013 Author Share Posted August 5, 2013 Ok... tried once again to loosen nut, pulley started to slip. Tried the rag technique, couldn't get it to grip so I made this to hold the pulley. Idea being the 4 nuts sit inside it and a piece of tube is slid over the end to hold it. It held.... but my fan spanner kept slipping... So, out came the chisel/punch and hammer... Several heavy blows later it finally came free Can confirm it's a LH thread. Looked like someone had used threadlock on it!!! Removed belt and checked waterpump for play as I got pretty agressive with the hammer, there is a little but who knows, might have been there before. Something to keep an eye on. New one installed, used a little copper grease on the threads to prevent seizing. Is this wise? I nipped it up with the spanner and then gave the spanner a couple of light knocks with a hammer to tighten. Tested the fan using the rolled up newspaper technique - it was possible to stop the fan while engine was cold. Fingers crossed job done. Very satisfying when you finally overcome such stubborn fittings. Thank you everyone for your input Quote Link to comment Share on other sites More sharing options...
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