Fan Diameter

Fan Diameter

81laredo

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Idyllwild, CA
Vehicle(s)
1981 CJ7 Laredo as built, 1952 Pontiac Sedan Delivery, 1955 Thunderbird, 1958 Airstream, 1996 Tahoe 4X4, 1982 Newell Coach, 1957 Cabin in the Woods what will I work on next?
A little help here, what is the Diameter of the OEM Cooling Fan?
My CJ7 is a Calif. version with the Serpentine Belt. The PO replaced the Fan with a Flex Fan and I would like to make sure it is the correct Diameter. The PO had the Fan installed Backward most likely because he did not have a Spacer.
thanks in advance.
 
My OEM fan is 19.5 inches.
Do you have a fan shroud? The bigger the fan the better but a shroud makes a big difference.
 
Thanks for the diameter, mine is the correct size.
Yes I do have a fan shroud and that is what I suspect the fan is hitting on occasion. The engine also looks to be sitting lower than it should be so I am replacing the motor mounts today (they look to be broken down).

Do you have the serpentine belt? I am having tracking problems with it and could use some advice.
 
The engine also looks to be sitting lower than it should be so I am replacing the motor mounts today (they look to be broken down).
Do you have a body lift?

Do you have the serpentine belt? I am having tracking problems with it and could use some advice.
No I have V belts but I have had belt tracking problems. Make sure all the pulleys are in the same plane. If one is a little farther back than the others it can cause tracking problems.
 
No on the body lift and no lift at all.
I have been working on the alignment and replacing bad parts as I go, the last was the water pump with the shaft moving towards the radiator. After the new motor mounts I will have another go at it.
thanks again:notworthy:
 
OK the Motor Mounts were the problem since the rubber was deteriorating and allowed the engine to sit too low and a bit to the right.
I found the alignment issue as well, the Alternator Bracket has to be adjusted to allow for the Alignment.:D
 
Good to hear you got it going.
:chug:
 
The PO had the Fan installed Backward most likely because he did not have a Spacer.

Be careful here.
The serpentine blades are angled the opposite of V-belt blades due to reverse rotation of the water pump.
So......the flex fan installed may not be pulling any air at all.
Just something to check.
 
A fan that is installed backwords will still blow the correct direction. The blades are just curved wrong for best efficiency.
Now if the fan is rotating the wrong way that's a big problem. When on the highway the fan would try to blow into the wind.
 
Yes the fan was turning backwards!
I have been working on the fan squeal and repairing things like a modified alternator bracket (replaced), bad idler bearings (replaced) and a worn out smog pump (eliminated with Howell EFI). Then I looked and found the shaft on the water pump to be further than it should be so I replaced the water pump and when installing the fan noticed it was backward (oil and dirt showed the previous mounting). I really haven't been driving it much since it wouldn't pass smog so I didn't really notice any over-heating issues but it does run much cooler now.
That is a good "heads up" though.
I am taking the CJ7 to 4 Wheel Parts (in Riverside) today so it will; be the first road test about 1 hour 20 minutes away and up/down the mountain so that should give me a good idea how things are running.
 
Yes the fan was turning backwards!
Did you get this resolved? Is the fan blowing the correct direction now? Just mounting the fan backwards won't make the fan blow the wrong way.
 
yep, thanks for checking. The fan was the correct fan just don't know why it was installed reversed other than he needed a spacer and didn't have one.
I took the CJ7 for a 3-4 hour ride today and it ran flawlessly. The only problem that I had was that the new Bikini Top came loose in a Hail Storm! Bestop and China??? I will have to contact 4 Wheel Parts and ask for help, the Bikini was new when a couple of days ago so they should make it right.
Thanks for the help!
 
don't know why it was installed reversed

The reason I was checking is if the fan was installed backwards it wouldn't blow backwards unless it was rotating the wrong direction. Maybe the serpentine belt was installed wrong or needs a different fan.

Think of it this way: if you are holding a threaded rod and you notice it has right hand threads. If you were to turn the rod around would it have left hand threads? No. The threads wouldn't change.
Same is true of the fan. If you turned it around take another look at it. I am willing to bet it is still blowing the same direction.
If you turn a window fan around it will blow the other direction only because the motor is now on the other side and is rotating the fan the opposite direction.
 
Be careful here.
The serpentine blades are angled the opposite of V-belt blades due to reverse rotation of the water pump.
So......the flex fan installed may not be pulling any air at all.
Just something to check.
Listen to hagar. The serpentine belt rotates the fan and the water pump backwards. If you have a serpentine belt you NEED a reverse rotation water pump and a reverse rotation fan.
Since it sounds like you might have had the wrong fan I would also be worried about the water pump. You can't tell what pump you have without removing it and looking at the blades in the water pump.
Since the CJ never came from the factory with a serpentine belt you need a pump for a YJ with a 258. Here it is:http://www.jeep4x4center.com/water-pump-8134321.html
You will also need a YJ fan to get it to blow the correct direction. Here's a list of parts.
Cooling System Parts - Radiators, Water Pump, Fan, Radiator Hoses & Belts for your Jeep Wrangler YJ by Morris4x4
 
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Hold on a minute I have a California CJ7 and it did come from AMC with a Serpentine Belt. Knowing this I paid close attention to the parts but thanks for the links (they may or may not be accurate for a California CJ).
The Water Pump was not in alignment so it was replaced because it was coming apart. I replaced the Water Pump and Fan Belt with a new ones from NAPA at the same time and I am sure that they are both for the Serpentine Belt and I replaced the Serpentine Belt while I was at it. Here is a link to just the water Pump;
https://napaonline.com/Catalog/Cata...9001+101981+50038+2038003&Ar=AND(P_RecType:A)

The CJ7 with California SMOG :dung: came with a Serpentine Belt but only the California models making some of the parts hard and expensive. I started this thread asking for the Fan Diameter to ensure that the Flex Fan that was on my CJ was the correct size before continuing with my corrections. The PO installed the Flex Fan backward possibly because he did not have a Fan Spacer (at least a 1" Spacer is needed) but at least it was the a correct Flex Fan Easy to check after looking pictures of the Fans.
Again, thanks for the help, I look forward to seeing you on the trail. We will be in AZ this winter and maybe Colorado.:cool:
 
Sorry to sidetrack your thread. I thought I was noticing a problem with the serpentine conversion.
Now I realize there was no conversion. :eek: I never knew CJ's ever came from the factory with a serpentine belt. Guess I never lived in California.
 

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