gwill Posted September 22, 2021 Share Posted September 22, 2021 Hello, I need some help. My nephew is restoring a 1989 Comanche 2WD with the 4.0 motor. He got the motor rebuilt and the rebuilder threw his water pump and pulley away. He installed a pump that has the 2.31" hub height but it appears to be to close to the block for the belt to line up. It has the serpentine belt. I've been trying to find out what pump and pulley were originally on this motor. I'm thinking that it would have had the pump with the 3.72" hub height and reverse rotation. I think it might be the Airtex AW3413. If I am correct, my problem now is locating the proper pulley. Can anyone advise me on this? Does anyone know which part numbers I need? Does anyone have a used pump and pulley they would sell? He got the thing running on his last day before shipping off to boot camp. I'm trying to run it up to temp for him before winter and that's why I'm asking. Any help would be greatly appreciated. Thanks, Greg Link to comment Share on other sites More sharing options...
ghetdjc320 Posted September 22, 2021 Share Posted September 22, 2021 The hub height should be about 2.3x i currently running the AC Delco 252191 pump and it is 2.34. Do you have the correct (smooth) pulley? The pulley does run very close to the water pump housing but obviously with no interference. Link to comment Share on other sites More sharing options...
gwill Posted September 22, 2021 Author Share Posted September 22, 2021 Thank you for the reply. He has the pump with the 2.31" hub height mounted now. When he ordered the pulley, he got one that, as you stated, ran in very close to the pump. The problem we're having is the pulley is too close to the block to line up with the belt's travel. When looking for a pump, they have 2.31" hub height as well as a 3.72" hub height. We have no idea which is needed in combination with what pulley. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted September 22, 2021 Share Posted September 22, 2021 37 minutes ago, gwill said: Thank you for the reply. He has the pump with the 2.31" hub height mounted now. When he ordered the pulley, he got one that, as you stated, ran in very close to the pump. The problem we're having is the pulley is too close to the block to line up with the belt's travel. When looking for a pump, they have 2.31" hub height as well as a 3.72" hub height. We have no idea which is needed in combination with what pulley. Do you happen to have a picture? Link to comment Share on other sites More sharing options...
gwill Posted September 22, 2021 Author Share Posted September 22, 2021 Unfortunately no. I could get a picture with just the pump mounted to the motor, but he returned the pulley when we realized it would not line up. It's just strange that they list at least three pumps but only one pulley. The pumps appear to have different hub sizes, not sure if the bolt pattern is the same. Thank you for your time, much appreciated. Link to comment Share on other sites More sharing options...
75sv1 Posted September 23, 2021 Share Posted September 23, 2021 I thought there were two different water pump heights. So, tow different pully heights. As, I know it, the 'reverse' water pump is for the WJ's and 2000 Wranglers. From my WJ motor, that water pump has an extra bolt hole. Link to comment Share on other sites More sharing options...
gwill Posted September 24, 2021 Author Share Posted September 24, 2021 Thank you. I've ordered another pulley to get a better look at it. I may need to get the longer hub pump as well. Link to comment Share on other sites More sharing options...
Eagle Posted September 24, 2021 Share Posted September 24, 2021 On 9/23/2021 at 7:20 AM, 75sv1 said: I thought there were two different water pump heights. So, tow different pully heights. As, I know it, the 'reverse' water pump is for the WJ's and 2000 Wranglers. From my WJ motor, that water pump has an extra bolt hole. No, the "reverse" pump is for the 2.5L and 4.0L engines with a serpentine belt. The water pump for the early 2.5Ls and the 4.2Ls has the same body and mounting pattern, but those engines used conventional V-belts and rotated in the opposite direction. Since the V-belt configuration goes back to the 1960s, it's considered the "forward" rotation, and the serpentine belt pump is reverse rotation. Link to comment Share on other sites More sharing options...
ghetdjc320 Posted September 27, 2021 Share Posted September 27, 2021 On 9/25/2021 at 9:52 AM, Eagle said: No, the "reverse" pump is for the 2.5L and 4.0L engines with a serpentine belt. The water pump for the early 2.5Ls and the 4.2Ls has the same body and mounting pattern, but those engines used conventional V-belts and rotated in the opposite direction. Since the V-belt configuration goes back to the 1960s, it's considered the "forward" rotation, and the serpentine belt pump is reverse rotation. That’s often a point of confusion. I imagine some parts store “interchange” guides started this rumor. As Eagle said, all the 4.0’s use a “reverse” style pump which just means they turn the opposite direction of the crank since they run on the back or smooth side of a serpentine system. Any serpentine 4.0 will be a “reverse” style water pump setup be it a WJ, YJ, TJ, MJ, XJ, ZJ etc. Link to comment Share on other sites More sharing options...
gwill Posted September 27, 2021 Author Share Posted September 27, 2021 Thanks for the replies. I think we may had the wrong pulley and correct pump. I've got another pulley coming. Link to comment Share on other sites More sharing options...
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