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4.2 Fan Clutch Replacement with Pictures

202K views 56 replies 43 participants last post by  jbwi112 
#1 · (Edited by Moderator)
Hi All, With reading various threads and searching down a problem of my own I noticed there wasn't a good thread on fan clutch replacement with pictures. I did read a lot of posts and people were complaining about this being the worst job they have ever done and it's really not all that bad.

Tool List:
  • 1 7/16" Wrench
  • Hammer
  • Ratchet
  • Torque Wrench (Suggested)
  • 3" Extension
  • 10 MM Socket
  • 13 MM Socket
  • Hose clamp pliers or Channel Locks
  • Long pry bar (Optional)

Notes to remember:

Be careful maneuvering the fan clutch and shroud near the radiator. You can easily damage the delicate cooling tubes in the radiator if you hit them.

When reinstalling the fan clutch to the water pump make sure you thread it on by hand to start and keep it properly aligned while threading. The threads on both the water pump and fan clutch are very fine and easily damaged.

Wash off all spilled anti freeze prior to starting your vehicle. Failure to do so will cause the serpentine belt to slip and squeal.

Top off anti freeze when complete allowing the engine to run, thermostat to open and air pockets to burp.

Comfort and ability to do this job: Low to medium
Time to complete: 1 Hour.


#1 Before renting or buying a bunch of worthless specialty tools. Hit your local tool supply store for this wrench. About $12 at TSC.



#2 Removing your radiator upper core support. 8 Bolts 6 13MM and 2 10MM. A couple different views.







#3 Remove upper radiator hose. They make a specialty tool for the spring loaded hose clamps, however a good quality pair of slip joint (Channel Lock) pliers work fine. Rinse down your spilled anti freeze with water!



#4 Disconnect electrical connector to fan clutch. A few different views.



Simple squeeze of the tab to release. There may be a lock clip to remove, mine didn't have one.





#5 Loosen and release fan shroud. THE FAN SHROUD IS NOT REMOVED YET! That will happen later! There are 2 10MM head bolts at the top corners of the shroud, Two rubber flaps on the sides. and the transmission oil cooler lines on the back face. The rubber flaps are just pushed on to (2) nipples on each side. The long pry bar helps reaching and releasing these flaps. The transmission cooler lines are clipped into the shroud another place to use a prybar to pop them out. When they are released push them down below their retainer.

This first pic is the same as the missing radiator hose. If you look below the neck you'll see one of the tabs where one of the 10mm bolts is fastened. The other tab is simply at the opposite end of the shroud.



The rubber flaps on the side of the radiator were impossible to get pictures of while the still assembled. So the following pictures show the left and right sides of the radiator with the flaps after the shroud is removed. If you look closely you can see the two holes in the rubber flaps where they attach to the tits on the fan shroud. The two tops of the flaps would be easier from above the truck reaching down. The two lower parts might be easier from below, reaching up. THESE ARE HERE FOR A REASON, PUT THEM BACK WHEN YOUR DONE!





The next couple of pictures show releasing the transmission lines from the fan shroud. Push the lines down below their retainer so the shroud will clear them when you lift it out.





#6 Loosen and remove the fan clutch from the water pump. This is where that 1 7/16" wrench and hammer come into play. Put the wrench on the large nut attaching the fan clutch to the water pump and 3-6 good hits with a hammer and the clutch loosens its grip. The clutch loosens counter clockwise, Look at the picture! After the initial grip is freed you can spin the fan and clutch off the water pump by hand. After its loosened completely push the fan clutch forward to clear the water pump and lift it up and over the top of the water pump pulley bolts.It can rest there until you're ready to remove it and the fan shroud together. The fan is integrated into the fan shroud. THEY MUST BE REMOVED TOGETHER. See next step!

CONTINUED>>>>>
 
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#2 · (Edited)
A few different views:





Fan pulled forward and lifted above the water pump pulley bolts.





#7 Removing the fan, fan clutch and fan shroud all as one assembly. This is pretty quick and easy. You should have the transmission cooler lines below their retainer, the fan removed from the water pump and resting above the threads and the water pump pulley bolts as previously mentioned.
There is a lot of wiggle going on here but this all comes out as a unit!
The best place to start is to lift the right corner of the shroud above the upper radiator neck. (Right side of car, left side from your view.) Once thats accomplished its just some maneuvering and everything will lift up and out as a unit.




Note: When reinstalling the shroud should should go down and in with the corner near the upper radiator neck being last! Be careful not to hit the radiator fins during removal or installation, damage to the radiator can occur.

#8 Seperate the fan clutch from the fan and the shroud. Pretty easy, unclip the wiring harness for the clutch from the fan shroud. Remove the 4 fan retaining bolts reverse to install. Tighten the 4 fan retaining bolts to 20 Ft. Lbs. when done. I feel that torqueing these bolts is a important step.Reverse all previous steps to reassemble the unit and reinstall into the vehicle.












#9 Reverse procedures to reassemble and install.
Notes:

Be careful when installing assembly back into the vehicle not to damage the radiator. Take precautions to properly thread the fan clutch back onto the water pump. It threads on clockwise. Use the wrench and hammer with 3-4 solid blows to tighten. There is a torque specification for this however its not practical and it wont loosen once tightened.

Make sure coolant is refilled and thermostat opens.
If you took it apart put it together!

I take no responsibility for spelling, punctuation, missing steps or damage to your vehicle. DO this task at your own risk, this post was meant to be a guide nothing more.
 
#31 · (Edited)
Replacing Fan Clutch on '07 Trailblazer



Great post Bowhunter. I had an intermittent problem with my '07 TB and was concerned that it might be electrical problem, because a couple of months ago, my low beam lights went out while driving down the road and night. It happened a couple of times and since it's an identical relay, I thought it could have be an electrical problem with fan clutch. I also had a P0495 a few times and just reset the code. However, on my way home from work the clutch stayed engaged. So I took it to my local Chevy Dealer, who confirmed it was the clutch. They said they could replace it for a whopping $900.00. They said they could get me an after marked in about 4-5 days. They also charged me $99.00 for diagnosis. I told them no thanks, I'll replace it myself. I found one a couple of blocks from the Dealer at Auto Plus Parts for $173.00.
I can't say it was all that easy, because the clutch nut was really on there. I had to use a large cresent wrench with a 3' pipe over top of it. After that it was all smooth sailing. I'm just keeping my fingers crossed that I don't get another code, only to find out is was an electrical problem.

Your post with pictures was extremely helfpul.

Thank you very much :)
 
#6 ·
Driving my 2002 TB (130K) right now sounds like I have two box fans mounted on either side of my headrest. After reading through most of these informative threads I have concluded that I need a new Fan Clutch.

The step by step instructions and pics are excellent but my question is... does it matter which part I order form RockAuto.com? There seems to me a significant price difference between the manufactures. Any advice on which part to buy would be helpful!

DORMAN Part # 622001 $126.79

FOUR SEASONS Part # 46024 $210.79

HAYDEN Part # 3200 $214.89

ACDELCO Part # 1540133 $272.79

:thx
 
#7 ·
My 2002 Trailblazer fan clutch failed after 130,000 miles, so I put in an AC Delco #1540133 unit (made by BEHR) I bought on Amazon from shopacdelco.com for $220.94 plus $11.79 shipping - best price I found!

I went with the AC Delco part because I heard some negative things about other parts and I am already saving about $500 doing it myself.

The pictures from Bowhunt_Pro were very helpful.

A few installation tips:

1. I used a long pry bay and an adjustable wrench with a 1 1/2" x 30" PVC pipe for leverage and the nut came off easy. Make sure the pry bar is not making contact with the nut as it is very close in there.

2. The 2 rubber flaps on the sides of the shroud are held on by (2) L-shaped "studs" on the shroud - the upper stud has the "leg" turned up and the lower stud has the 'leg" turned down - knowing this will help you get the flaps off and on.

3. The new unit does sit about 1/2" closer to the engine and in my case this caused the fan to make contact with an A/C hose & power steering line clamp that is mounted near the bottom of the fan - what a noise! I shaved a little off the fan before I shut it down, so check that clearance. I just stuck a rod down there and hammered the clamp down to clear, maybe it got bent up somehow in the last 10 years.

4. After removing and then installing the fan clutch I found it easier to relieve the tension on the serpentine belt and take it off the alternator. This allows you to line up the fan clutch nut with the water pump shaft and turn the water pump pulley to thread it on, instead of trying to rotate the fan clutch/fan assembly which I found difficult to do and still keep proper alignment.

5. I didn't upgrade the PCM programming, the fan seems to operate fine, and the SES light went off on its own after about 25 miles and 3 starts.
 
#8 ·
Thanks for the pics and writeup

Tackled this job last Fri nite along with the water pump and thermostat. 02 TB with 145K miles.

Fan clutch had failed, roared most of the time and started setting codes.

New thermostat installed, I removed the alternator which made the job much easier.

New water pump installed, old one was starting to seep a bit.

New belt tensioner also installed, bearing on pully was getting noisy.

New Hayden 3200 fan clutch installed.

Thanks for the pics and writeup, also other posts on the water pump, alternator and thermostat replacement. :thumbsup:

Took about 4 hours or so to complete.
 
#12 ·
I just did this job and the original write up helped immensely. I have a problem though.

I got everything back together and cranked the truck up but now the fan makes a LOUD racket. Sounds like something's hitting the shroud but I can't see what, and everything looks to be in the right position when the truck is off.
 
#13 ·
Sounds like BOX FANS under hood!!

I was getting SES light and Reduced Power light (RP). Code cam up either the fan clutch cable or fan clutch.

I followed the instructions to the tee and the install went well, but when I installed the NEW AC DELCO clutch I started to drive down the block it sounded like HUGE box fans were under the hood.

Can anyone clear something up.....when storing these clutches the nut should be looking up correct? If they are looking down in storage for a long period of time will it damage the clutch?

My part # matched Bowhunt_Pro's (p/n 25790867 / N2575001)but cant understand why it sounded sooo darn loud when I started down the road. It sounded pretty quite in idle....so I installed the old clutch. The RP light is out and has not come back on yet but the SES light remains on. Engine is not getting hot staying around 205-215F

In the past I have found the wires some how loose there insulation (very poor design) and wind up shorting out together. In that case most of the time you just need a replacement wire harness.

I think that will be my next move-- order the wire harness and if that does not cure the SES light then I will pull the trigger on another clutch from AC Delco.

Thx ALL!
 
#14 ·
They do say to store the clutch a certain way....can't remember which.

I can tell you that I replaced mine a couple weeks ago. I've done fan clutches before so I thought I knew what I was doing....

Every time I cranked the vehicle, it sounded like a damn cropduster...fan was hitting the shroud like crazy. I finally had to give up and turn it over to a shop.
Turns out that despite my best efforts and experience, I managed to cross thread the nut on the new clutch. The shop was able to correct it and get me going again for $60.00 . Very embarrassing. May not be the case for you but that's my experience.
 
#18 ·
Well ... I did mine over the weekend, and you are correct. I had to remove my clutch by unbolting the water pump from the engine, put the darng thing in a vise and snapped the water pump shaft trying to unscrew the clutch. Finally cut the clutch nut off the water pump shaft with a die grinder. 4 hrs wasted for lack of never-seize.:mad:
 
#16 · (Edited)
yea it did sound like a crop duster.....and yes I did have some choice words that my 6 year old would tell me "you have a potty mouth".

Cross threaded......?? I'm having a hard time buying into that idea since it screwed on smoothly. Plus I took off the "new" one and placed the older one back in its place. Never did have any issue of cross threading.....

Recap:
old one= SES light, Reduced Power Light on occasions

new one= once installed sounded like a crop duster/window box fans

back with old one= no crop duster/window box fan sound but SES light and no Reduced Power Light on occasions

Any one heard of "The older model years should have had a PCM re-flash from the dealer. If this problem re-occurs after the fan-clutch is replaced then a reflash is needed. There are many cases where the reflash is the only correstion needed and the dealer is the only place it can be done unless you know a PCM tuner shop."
http://wiki.answers.com/Q/Replaced_...ays_run_high_wth_loud_soundofair_limitedpower
 
#17 ·
First off, thanks a ton for the great original post and all of the replies. Replaced water pump and fan clutch yesterday and certainly wouldn't have been able to do it without this site.

For over six months had been getting poor mileage and stuttering/shuddering idle. Last week, the grinding began. Subtle at first, but after two or three days had grown into the "semi truck starting up" racket. SES light would come on every now and again. Seemed to light up when going up a hill or passing on the freeway.

Paid $200 for a Hayden clutch and $50 for a Master Pro pump, both with lifetime warranties, at O'Reilly. Also "borrowed" the pump replacement tool kit for $75.99, which was completely refunded when returned. Aside from the 36mm wrench to get the clutch off the water pump, the rest of the tools I found useless.

A couple of notes:

  • Slide cardboard between the fan/shroud and radiator so you don't damage any of the radiator fins.
  • To stop the pulley from turning when getting the clutch off the pump, use the chain method. Get a one-foot length of medium thickness chain and a carabiner. Attach one end to the pulley using one of the pulley bolts. Attach the carabiner to the alternator bracket.

Everything else was fairly straightforward. Took a bit of muscle and a lot of finagling to get the fan/shroud assembly out and it went back in much easier.

Immediately on startup, the semi truck rumble/grinding was gone and the idle was totally smooth. SES light came on. Went for drive and for the first five minutes, I got the loud "jet engine" whirring but it went away. After maybe five miles, the SES light also went out and has not returned.

Thanks again to everyone here for making my Saturday turn out much, much better than I thought it would when I woke up.
 
#20 ·
I did mine a couple weeks ago. it did not come off easy, and this is a few weeks after it was separated by a mechanic in Chatham ma, who i paid to replace the faulty water pump (500 miles from home without so much as a wrench)

I used a loaner kit from Pep Boys, just the large one, loosenend the water pump fan nuts and tightened the wrench to the water pump, used my half inch socket handle to make it longer, and used a pipe wrench with a six ft pipe on the handle, and it came right apart.

If I had it to do again, i might go with this:

http://www.amazon.com/gp/product/B0...&pf_rd_t=101&pf_rd_p=470938631&pf_rd_i=507846
 
#21 ·
I ended up doing this today. Thank you very much for the write up it was a HUGE help!

Since my water pump kept rotating, I ended up just taking the belt off the water pump and placing a ratchet strap over the pump while loosing the large nut on the fan clutch. It took a lot of arm muscle, but ended up doing this and the TB is running perfect. Again thank you.
 
#22 ·
Not ever again!!

I had my water pump replaced 1 year ago and I didn't do it myself since the instructions said to completely take the front of the vehicle apart. I forked up the money and paid a mechanic to do it. Now, my clutch fan is stuck in the on position and it needs to be replaced. Thanks to this thread, I feel like I can take this project on.

I will let you know how it goes.:thumbsup:
 
#24 ·
Thanks for Pics. Great help.
I checked the serial numbers on the back of the clutch with a dental mirror and determined from the manufacturer that the original clutch had been replaced and the clutch on my (bought used) TB was under warranty. Behr replaced the clutch at no cost to me. (The ******* dealers around here wanted to charge me $1200 to make the SES light go away).
No problems doing the job myself. I did however find that the wiring harness on the clutch end where the wires come out of the rubber tube were badly frayed. This could well have been the problem rather than the clutch itself.
Joe
 
#25 ·
Mission accomplished!

First post on the site (sorry! ) Just wanted to take a moment and say "Thanks! " to Bowhunt Pro and others for creating and contributing to this thread. Just replaced my fan clutch, water pump and serp belt yesterday. Even though it was still a royal pita, this "how to" on the fan clutch replacement made it much, much easier. Water pump is easy-peasy once the fan shroud is out of the way.

I did have to rent the fan clutch tool to loosen the hub nut. Even using my 1 7/16" wrench and hammer with a steel cable securing the pulley to the upper alt bracket wouldn't work....just bent the bracket.

Considering a shop would have charged me about $1200 to do this job, it saved me around $1000 since I got all my parts on Amazon for under $200.

I used the following parts:

Fan Clutch: Dorman #622- 001 $117
Water pump: GMB #130-7700 $37
Belt: Goodyear Gatorback #4060915 $35

'03 TB LT
131K miles (first replacement of fan clutch or water pump)

Steve
 
#26 ·
Steve,

I did my fan clutch at 203,000 miles on my 2003 Trailblazer. Yes the water pump is easy at this point considering it costs $30. No brainer!

I just did my alternator on the way to deer camp in the Autozone parking lot in Gaylord Mi. R/R it in about 65 mins. Make sure that you have a short stubby 15mm ratchet wrench for the bottom lower bolt.....tip! The alternator went out at 259,000 miles and it was the original one.

Bugsy
 
#27 ·
Thanks, Bugsy, for the heads up on the alternator. Mine is fine, other than being a bit "whiney"....lol. I've replaced the power steering pump, tensioner & idler pulleys over the years trying to eliminate that irritating whine, but I suspect the alternator as being the last culprit causing the noise, although the steering pump was definitely responsible for about half the noise. Did you have any noise issues with your alternator before it went out?
 
#28 ·
Made my own tool and mod to simplify job

Thanks for the great tips on this thread along with the pictures.

Thanks to not being able to get the GM clutch fan removal tool in my tiny city of 5 million, I had to make my own. I bought 1.5"x36" and 1/8"thick steel stock. I drilled two 7/16 holes, 2" apart. Then used a jig saw with a metal cutting blade to notch out the center. This ensures the tool does not interfere with the fan clutch nut. I cut the stock length to 20". 36" was a little too long. It held the pulley stationary while I used the 18" crescent wrench to loosen the fan clutch nut. It worked perfect and was plenty strong.

I then used my dremel tool to cut a notch in the shroud. This allowed me to slip the fan clutch out on the right side between the the shroud and the rad by using the notch to get clearance for 1 7/16 nut on the clutch. As much as I tried, I couldn't get the clutch out without doing this. I didn't want to remove the shroud or disconnect any rad hoses or damage the rad. I put some cardboard in front of the rad when slipping the fan clutch out. It helped protect the rad.

Finally, I applied some aluminum duct tape to seal the shroud. I may upgrade this to a small piece of metal screwed into the shroud, but for now this will do.
 

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