Home Made Fan Clutch Tool for 2002 Trailblazer...

[60dgrzbelow0]

If you own any of the years/makes/models of the 2002 Trailblazer, Bravada or Envoy and you hear a horrendous roaring or jet-engine-taking-off sound from your engine compartment, there is no doubt that your Electro-Viscous Fan Clutch has seized and will need replacing. On the face of it, this would look like a fairly straightforward kind of repair... but plan on busting all your knuckles and inventing new swear words to describe your inability to loosen the single Fan Clutch Nut from its attachment on the water pump take off flange. This flange free-wheels, so in the absence of the superhuman strength required to break that nut loose and the mechanical advantages offered by unavailable Dealership-Style Speciality Tools... I offer another avenue to make this PITA repair as easy as pie!

Please visit my photobucket for all the visual details... I designed the tool in a way that make its functionality obvious so there is no need here for a long explanation on how to construct it beyond saying "measure twice...cut once... and grind down all the sharp edges!" Use either the GM Factory Service Manuals or a Haynes Book for your dis-assembly---re-assembly references... and with this tool...doing this job in a fraction of the time will surely put a smile on your face!

http://s557.photobucket.com/albums/ss19/60dgrzbelow0/TRAILBLAZER_2002/

(I suppose that when not needed for this fix ... it can loaned out as the "Snicker-Snee" used by "The Lord High Executioner" in any local production of Gilbert & Sullivan's "The Mikado" from the movie "Topsy-Turvy")

http://www.youtube.com/watch?v=u1qd3bwv3N4

... and for any of the more sentimental among us who know and appreciate the works of G&S...

http://www.youtube.com/watch?v=EcNtTm5XEfY&feature=related

[RedBird]

cool! another way that's easier(but only if you already have the tool) is to use and air hammer and a stragiht chisel bit. put it on the left edge of the nut and blast it. it'll ding it, but it takes them right off. Done/seen it done 100+ times

[pocket-rocket]

I've heard those things have a higher failure rate than plastic 3x00 LIM gaskets...

[onefastV6]

Yeah, those are horrible.
My brother's 03 trailblazer had the same failure, after beating on it and almost breaking my nuckles, I told him to take it somewhere to let them do it. The shop owner had trouble and it took him two days along with ordering a special tool.

I was half tempted to sawzall the fucker off and replace both the fan and waterpump.

[pocket-rocket]

I was half tempted to sawzall the fucker off and replace both the fan and waterpump.

Lol! You must have a semi volatile temper like me. Let me guess, the only thing stopping you was that it wasn't your vehicle?

[1988GTU]

I use the "swift wack" and its off method or the air hammer and tie rod wrench contraption. That idea has came close to being made, but I just do not want another special "J" tool for yet another special GM vehicle laying around here!

[onefastV6]

Lol! You must have a semi volatile temper like me. Let me guess, the only thing stopping you was that it wasn't your vehicle?

Exactly, If it was my vehicle I would have chopped it.

[geoffinbc]

Re and Re with electric fans.

[pocket-rocket]

I agree. Electric fans. If you were to go to www.therangerstation.com, you would probably get boo'd off the forum though. They will argue every which way AND sideways that engine driven fans > electric, unless you cross deep water. Their argument is an electric won't move enough air compared to an engine driven fan and you run the risk of overheating when moving very slow or sitting still. Their thought is the only time to run electric is if the cooling system was designed for it. Then again all v8 > everything else, right?

[60dgrzbelow0]

Very interesting debate... in a worst case scenario...as long as your fan belts don't break and the rectifier(s) in the alternator stay sharp... the electronics will always run and the engine compartment can still be kept cool...albeit with some loss and added stress and strain from the accessories constantly scavenging horsepower ...regardless of whether idling or redlining the engine. But when the electric motor goes out on these new ones... the air impeller and blades have such jet-engine like angles of attack and fit with such close air motion tolerances inside the carrier shroud that when they lock up to avoid an overheat,,, you can actually feel the engine bogging down from the strain!

On a similar and related note concerning the tool that makes this nightmare go away... I had a similar problem several years ago when my daughter was heading off to the Columbia College of Veterinary Medicine at the University of Missouri and insisted on having a four wheel driver Subaru 2005 Legacy. Of course I bought all the service manuals right away because I knew bupkuss about the car and wanted her not to have any worries for the four years she would be at graduate school. With 84,500 miles on it...and all that country driving to do large animal farm vet treatments... I knew that her drive belts and pulleys would have to be changed at 105,000 miles or risk the belt snapping and lunching the 2.5L horizontal interference motor in the process. But the kicker here is that to do this very touchy repair (SOHC) you simply cannot get "The Jesus Nut" off of the crankshaft pulley/balancer without two special tools to relieve it and later re-torque it back on at 180 Newton Meters of torque. And of course... only the "Stealerships" sport the tools and that meant ... "Here I go again..." So I designed, fabricated and used THIS tool for the job and listed publicly how to make it in order to help others with the problem. ,,,. (template and all):

http://s557.photobucket.com/albums/ss19/60dgrzbelow0/05SUBARULEGACYCRANKBOLTOOL/

[pocket-rocket]

You know, as much as I like OHC engines, I'm starting to hate timing belts... At least the wifes car is done now. It's got 5.5 miles on those nice new probably not so shiny valves now. I bet that Legacy was interesting to time, it looks like an interesting setup and a massively long belt...

[60dgrzbelow0]

You know, as much as I like OHC engines, I'm starting to hate timing belts... At least the wife's car is done now. It's got 5.5 miles on those nice new probably not so shiny valves now. I bet that Legacy was interesting to time, it looks like an interesting set-up and a massively long belt...

"Interesting" is a good beginning on what I was thinking about while looking it all over, P-R... "Frightening" is a more accurate word to describe what I was feeling because I had less than 72 hours to design and build the needed new tool and then rip the front of the engine apart and try my damnedest not to destroy the motor by making a mistake in the belt alignment with both heads. There are only a handful of truly durable belts that can be trusted NOT to tear, shred and end up with catastrophic engine failure when the belt snaps. Naturally, I wanted the "Subaru Factory Fresh" OEM version of the belt... but when I bought one from the local Subaru "Stealership" and could NOT make it fit... I had to google the part number on the belt...and found out that some dipsh*t put a WXR belt in a box marked for the 2005 Legacy!

It goes without saying that after spending too much time trying to figure out how and why it was not going on... I was not happy when I returned the belt for a refund. Trust me... With my full wrath engaged...I scared the living sh*t out of everybody standing behind that counter before I got my money back... glared at all of them,,,and left. A few hours later, I ordered another quality belt off of eBay on an overnight S&H from a company that guaranteed it would last the full 105K miles. Earlier, I had spied and bought a true Subaru OEM Water Pump from eBay for damn near next to nothing, along with the special metal gasket for it (since it was highly recommended that the water pump be changed at the same time the timing belt change-out is done). So with that settled, I was able to dive in...and kill two mechanical birds with a single stone.

Unlike the madness of alignment that occurs on the WXR DOHC engines that requires a special spanner to freeze the valve train on each head during the installation, the "lesser" 2.5L SOHC has a cool "Sweet Spot" that you find slowly and carefully and when the two obscure marks on the engine block are lined up with the cam sprockets... you can begin with those sprockets and as long as you are VERY careful when slipping the belt on and addressing the one bright mark on the belt with the crankshaft...that and about fifteen minutes of careful noodling with the belt...and it will go on properly. I can say that shortly thereafter, since my son would be driving the Legacy behind me and Swee' Pea ahead of him for a 2,000 mile trip in a small UHaul from our home to her new place in Missouri, things were extremely tense in the household in this time frame. You could say that other than the times I was firing up and then test flying the twin T-58 General Electric Jet Engines I had routinely installed on so many USCG Sikorsky HH-3F Helicopters...that this particular repair was a giving me one serious "Pucker Factor". .. actually, you couldn't have pulled a straight pin out of my ass with a Come-Along and a John Deere Tractor! You can well imagine me breathing one hell of a sigh of relief when I buttoned everything up and started the engine...and it ran as smooth and as quiet as a still country pond on a summer day!

[pocket-rocket]

My moms old Isuzu Rodeo with the Honda DOHC (or was it SOHC?) v6 was another interesting timing job I've done. Have you ever seen a system where the only timing reference marks were white stripes painted onto the belt when it was new? I have... I know about the "Frightening" factor as well. Ben can attest to this, after all, it was the first time I let him drive the 91 after he got done tuning it, just to hear that oh so familiar sound (to me) where you only have compression on a few cylinders... Neither of us had done a belt on the DOHC at that time, and what really scared me was when we pulled the front cover and started to crank it and the belt didn't turn at all. Luckily what happened was the teeth on that belt sheared off on the intermediate shaft pulley. I was fearing the worst and thought my timing chain had blown.

[60dgrzbelow0]

Successful automotive repairs can lengthen a man's shadow after all the worry and care that goes into the doing of such things. I'm glad for happy outcome with your vehicle. I don't know what I would have done while under so much pressure to have things work perfectly, had I gotten things wrong. In matters of belt driven timing alignments...if you are nearly correct...then you're precisely wrong.

[pocket-rocket]

Very true. I need to pull the pics off of my phone that I took of the 2 worst bent valves out of the 8 that bent on my wife's car. They were bent so bad they were hung up on the edge of the combustion chamber and when they are placed on a table head down, the stem leans at probably about a 30-40 degree angle. Luckily the pistons and head were fine.