Jeep TJ Overdrive Water Pump Pulley

[Ken G Ford]

Just finished up replacing my TQ Lockup Solenoid due to a P7040 Code.

At the same time I stumbled across the Texas Jeep Products Jeep TJ Overdrive Water Pump Pulley.

Having dealt with elevated temperatures in AZ, and having thrown a lot of parts at the jeep to include the full engine teardown and rebuild from overheating in rush hour traffic.
Completed full flush, pressure flushing the heater core, burping the air from the system, correct Stant Thermostat with hole drilled, no improvement.
I then tried finding a replacement MOPAR radiator without any luck. Eventually I settled on a 2 row aluminum radiator with electric fan and plumbed a digital temp sensor/gauge no longer trusting the Dash Temp Gauge. Electric Fans were a Terrible decision and the engine ran hotter. Electric Fan with shroud was basically useless compared to the amount of air the OEM Fan could move. Lesson Learned. Went back to OEM style radiator from Orielly and that also was crap. Frustrated, I took it all back and ordered another 3 row aluminum radiator and new Heavy Duty Fan clutch, although my original clutch felt fine. Once again, no real discernible change in the temperature. On several occasions temp climbed into the 220+ range sitting at traffic lights and my digital Temp Gauge saved me by sounding an alarm. For the most part it was all ways with AC on and waiting for a traffic light or stop and go traffic. Gave up on the constant search for an original MOPAR radiator and settled on a Single core aluminum radiator. Temperature came back down to 210 to 218 range with AC running but once we hot triple digits, starting seeing spikes in temperature again in the 220+ range with AC running. More reading and came across FlowKooler Water Pumps. Read positive and negative reviews but decided to take a chance. While at it I order the high flow thermostat and radiator hose housing. This actually made the biggest improvement up to this point and was some what manageable when I started focusing on the P0740 code that started appearing.

In the process of testing the TQ Solenoid Replacement I was running 214 to 219 but after adding the Texas Jeep Products Jeep TJ Overdrive Water Pump Pulley, the highest I could get going uphill with AC blasting was 216. As soon as I crested the hill, temp went back down to 210 to 214.

I have to say the over drive pulley has made the single biggest difference.

Granted installing the pulley had its own issues. The back side of the pulley would bottom out against the replacement button head bolt that was provided. So much that when first installed, the water pump refused to even turn. Ended up taking the pulley off and added some blue sharpy to the edge (I'm not a Machinist nor do I have a Lathe) and I sanded the back lip of pulley down using 120 grit and a DA Sander to provide more clearance without grinding the Button head Allen bolt down. In defense of Texas Jeep Products it would be very hard to compensate for all of the different water pump manufactures and there casting out there to know if the pulley would clear or not.

Looks like I need to pull the Pulley off again to clearance it a little more as it starts to grind ever so slightly when I mash the gas pedal hard. Hands down I think the Overdrive Pulley made the biggest single difference in helping to lower temps.

Added a few pictures that show how much I clearance the pulley. Disregard the scratches as I initially started to clearance the angle on the inner edge with a hand file which added scratches more than anything.

Laying pulley against 120 sanding discs on a DA helped me remove most of the material and left a cleaner look. Unfortunately, I could not find my micrometer to make more precise measurements, but you get the idea.

I think one more pass on 120 DA should do the trick and get rid of all contact between edge of pulley and Button Head Allen bolt.

 

[Ken G Ford]

As a side note: If you had the Water Pump out, it would be easy to just use a Spot Face Drill bit and remove some material from the pump housing to allow the Button Head Allen Bolt to thread deeper into the Water Pump Housing.

 

[Ken G Ford]

adding @Jezza

 

[JustDandee]

Sounds frustrating. I am mid radiator change over myself and there is a definite reduction in the fin count from the factory to the aftermarket radiator I have. Nipendenso brand so I will be monitoring post install temps and Just something to note if your not seeing the cooling you used to have.

Possible aid to problem is adding oil cooler another means to get heat out of the block- but I suspect that will be very incremental

 

[Jezza]

Just finished up replacing my TQ Lockup Solenoid due to a P7040 Code.

At the same time I stumbled across the Texas Jeep Products Jeep TJ Overdrive Water Pump Pulley.

Having dealt with elevated temperatures in AZ, and having thrown a lot of parts at the jeep to include the full engine teardown and rebuild from overheating in rush hour traffic.
Completed full flush, pressure flushing the heater core, burping the air from the system, correct Stant Thermostat with hole drilled, no improvement.
I then tried finding a replacement MOPAR radiator without any luck. Eventually I settled on a 2 row aluminum radiator with electric fan and plumbed a digital temp sensor/gauge no longer trusting the Dash Temp Gauge. Electric Fans were a Terrible decision and the engine ran hotter. Electric Fan with shroud was basically useless compared to the amount of air the OEM Fan could move. Lesson Learned. Went back to OEM style radiator from Orielly and that also was crap. Frustrated, I took it all back and ordered another 3 row aluminum radiator and new Heavy Duty Fan clutch, although my original clutch felt fine. Once again, no real discernible change in the temperature. On several occasions temp climbed into the 220+ range sitting at traffic lights and my digital Temp Gauge saved me by sounding an alarm. For the most part it was all ways with AC on and waiting for a traffic light or stop and go traffic. Gave up on the constant search for an original MOPAR radiator and settled on a Single core aluminum radiator. Temperature came back down to 210 to 218 range with AC running but once we hot triple digits, starting seeing spikes in temperature again in the 220+ range with AC running. More reading and came across FlowKooler Water Pumps. Read positive and negative reviews but decided to take a chance. While at it I order the high flow thermostat and radiator hose housing. This actually made the biggest improvement up to this point and was some what manageable when I started focusing on the P0740 code that started appearing.

In the process of testing the TQ Solenoid Replacement I was running 214 to 219 but after adding the Texas Jeep Products Jeep TJ Overdrive Water Pump Pulley, the highest I could get going uphill with AC blasting was 216. As soon as I crested the hill, temp went back down to 210 to 214.

I have to say the over drive pulley has made the single biggest difference.

Granted installing the pulley had its own issues. The back side of the pulley would bottom out against the replacement button head bolt that was provided. So much that when first installed, the water pump refused to even turn. Ended up taking the pulley off and added some blue sharpy to the edge (I'm not a Machinist nor do I have a Lathe) and I sanded the back lip of pulley down using 120 grit and a DA Sander to provide more clearance without grinding the Button head Allen bolt down. In defense of Texas Jeep Products it would be very hard to compensate for all of the different water pump manufactures and there casting out there to know if the pulley would clear or not.

Looks like I need to pull the Pulley off again to clearance it a little more as it starts to grind ever so slightly when I mash the gas pedal hard. Hands down I think the Overdrive Pulley made the biggest single difference in helping to lower temps.

Added a few pictures that show how much I clearance the pulley. Disregard the scratches as I initially started to clearance the angle on the inner edge with a hand file which added scratches more than anything.

Laying pulley against 120 sanding discs on a DA helped me remove most of the material and left a cleaner look. Unfortunately, I could not find my micrometer to make more precise measurements, but you get the idea.

I think one more pass on 120 DA should do the trick and get rid of all contact between edge of pulley and Button Head Allen bolt.

View attachment 626206

View attachment 626207

View attachment 626208

That's interesting. I tried a few different pumps and that's when I determined I needed to swap that lower pump bolt to the button head. I am running into other issues with the differences in water pumps with the billet impellers also. The castings and internal parts are different even on the OE pumps depending on when they were made. I'm working on a set of instructions for the pulleys that may help with installation problems.

 

[Ken G Ford]

I do think that these small issues can be resolved. In my case, the edge of the belt is now riding perfectly along the edge of the pulley that I sanded down which means I can't really sand any more off the pulley. The only place I could remove a smidge of material would be to taper the edge of the area I sanded down on the inside a bit. Much like the way you already machined them. That would be the silver area to the outside of the blue sharpie mark in the pictures. I really do not want to sand down the top of the replacement Button Head Allen Bolt you provided since removing any material from the bolt would only weaken the sides of the Allen slot itself and make it that much harder to remove at a later date.

Thinking to try and loosen the belt tension just a "smidge" since it only scraps when I rev the engine aggressively or accelerate aggressively.
Normal smooth acceleration, it doesn't scrape.

Regardless, your over drive pulley made the biggest single improvement in reducing the temperature of my TJ in this summer heat. The quality of the pulley his outstanding and I highly recommend it to others.

 

[Jezza]

I do think that these small issues can be resolved. In my case, the edge of the belt is now riding perfectly along the edge of the pulley that I sanded down which means I can't really sand any more off the pulley. The only place I could remove a smidge of material would be to taper the edge of the area I sanded down on the inside a bit. Much like the way you already machined them. That would be the silver area to the outside of the blue sharpie mark in the pictures. I really do not want to sand down the top of the replacement Button Head Allen Bolt you provided since removing any material from the bolt would only weaken the sides of the Allen slot itself and make it that much harder to remove at a later date.

Thinking to try and loosen the belt tension just a "smidge" since it only scraps when I rev the engine aggressively or accelerate aggressively.
Normal smooth acceleration, it doesn't scrape.

Regardless, your over drive pulley made the biggest single improvement in reducing the temperature of my TJ in this summer heat. The quality of the pulley his outstanding and I highly recommend it to others.

Thank you, I will take a look at the model and see if I can change it at all to fit better.

 

[Moglocker]

Thank you, I will take a look at the model and see if I can change it at all to fit better.

Interested,does it work ok on a mopar pump?

 

[aston4]

Great info. Thanks for the write up.

It's very weird that a manufacturer will go to all the trouble of tooling up to make a radiator, and not just duplicate the OEM, which is perfectly fine and worked great for decades. Why go to all the trouble of redesigning it, end up with junk, and then sell it anyway ruining your reputation?

The aftermarket parts situation now should be unbelievable... but it's real.

 

[adventureboss]

Thanks for all the information. Could you elaborate on the overheating? In the Phoenix heat (110+) in traffic with the AC on, my coolant temps would get upto around 240 degrees when I'd check through the OBD scanner but pretty much stay at 210 on the gauge. So far I haven't had any related engine issues, and my cooling system seems to be in perfect shape. It's been like that for as long as I've owned it, so the past 100k miles. The Jeep has 211k miles on it now, so I'm not sure if it is actually an issue but seeing temps that high at idle makes me nervous. When it's not triple digits outside it's completely fine.

Did you end up blowing a head gasket or something after overheating? I'm wondering if these cooling systems are not designed very well and these Jeeps just overheated straight from the factory...

 

[aston4]

Thanks for all the information. Could you elaborate on the overheating? In the Phoenix heat (110+) in traffic with the AC on, my coolant temps would get upto around 240 degrees when I'd check through the OBD scanner but pretty much stay at 210 on the gauge. So far I haven't had any related engine issues, and my cooling system seems to be in perfect shape. It's been like that for as long as I've owned it, so the past 100k miles. The Jeep has 211k miles on it now, so I'm not sure if it is actually an issue but seeing temps that high at idle makes me nervous. When it's not triple digits outside it's completely fine.

Did you end up blowing a head gasket or something after overheating? I'm wondering if these cooling systems are not designed very well and these Jeeps just overheated straight from the factory...

I think the TJ cooling system is highly adequate. Mine never gets much past 215ish, even when triple digits outside (105) and at idle with AC on. SO MUCH BETTER than my XJ with the same engine. The XJ was designed in France for a little 4 cylinder engine. With the giant 4.0 shoehorned in there, it is constantly threatening to blow.

When I look at OBD temps on my '97 TJ, they *exactly* match the gauge. You have something weird going on, but I have no idea what. What year is your TJ? Did Chrysler put in a fake temp gauge to match the fake oil pressure gauge in the later years?

I put a new OEM radiator in my TJ 7 years ago, because the original was weeping from the plastic bits, which probably helps. Maybe your radiator is original and a bit clogged... if the OBD reading is real.

 

[adventureboss]

I think the TJ cooling system is highly adequate. Mine never gets much past 215ish, even when triple digits outside (105) and at idle with AC on. SO MUCH BETTER than my XJ with the same engine. The XJ was designed in France for a little 4 cylinder engine. With the giant 4.0 shoehorned in there, it is constantly threatening to blow.

When I look at OBD temps on my '97 TJ, they *exactly* match the gauge. You have something weird going on, but I have no idea what. What year is your TJ? Did Chrysler put in a fake temp gauge to match the fake oil pressure gauge in the later years?

I put a new OEM radiator in my TJ 7 years ago, because the original was weeping from the plastic bits, which probably helps. Maybe your radiator is original and a bit clogged... if the OBD reading is real.

So that’s quite strange because when I looked through the FSM for my 06 it actually explicitly said that the gauge is buffered and not reflective of the actual coolant temperature. It is programmed not to move into the red zone until 261 degrees. So it is “fake”, kinda.

I’m wondering if yours runs a little cooler because you don’t have the weird three piece cat assembly. Everything in my cooling system is basically new though and I’ve been through soooo many chemical cleaners and flushes. Coolant is clean. It behaves the exact same way no matter what though. It’s fine until 110+ temps and then it pegs out around 240 until I start moving again. Done it for the past 100k miles and have tried several fan clutches since.

I also recall there was a service bulletin 15 years ago or so about TJs overheating at idle from the factory in high ambient temps. The solution was to have the dealership install a seven blade fan, which unfortunately is discontinued now. This would point to the factory cooling system atleast in the later TJs not having enough reserve at idle, correct?

 

[aston4]

So that’s quite strange because when I looked through the FSM for my 06 it actually explicitly said that the gauge is buffered and not reflective of the actual coolant temperature. It is programmed not to move into the red zone until 261 degrees. So it is “fake”, kinda.

I’m wondering if yours runs a little cooler because you don’t have the weird three piece cat assembly. Everything in my cooling system is basically new though and I’ve been through soooo many chemical cleaners and flushes. Coolant is clean. It behaves the exact same way no matter what though. It’s fine until 110+ temps and then it pegs out around 240 until I start moving again. Done it for the past 100k miles and have tried several fan clutches since.

I also recall there was a service bulletin 15 years ago or so about TJs overheating at idle from the factory in high ambient temps. The solution was to have the dealership install a seven blade fan, which unfortunately is discontinued now. This would point to the factory cooling system atleast in the later TJs not having enough reserve at idle, correct?

Oh! So you do have a fake gauge. Wow I didn't realize later TJs were like that. I despise fake gauges. So many times I have caught a small problem, before it turned into a BIG problem, just by monitoring an accurate gauge. Fake gauges are same as idiot lights. The only thing they tell you is when it is time for a new engine.

Yeah, trust the OBD. I have never run the 97 TJ in temps over 105, so I don't really know what it would do at 110. Maybe that's the tipping point. You could keep an eye out on eBay for a 7 blade fan. I have found a lot of weird stuff on eBay, though sometimes takes a year or two.

The 4.0 is a big, old fashioned, inefficient beast that loses a lot of energy to waste heat. That waste heat has to go somewhere, but first it sits for a long time in the cast iron. Modern, thin, aluminum engines cool much faster/easier. I have two aluminum engine cars, and they take forever to get warm in winter.

When I was a kid a long time ago, cars overheated constantly, even just in the 90 degree range. The TJ does a lot better than many, many 1970s cars did, back in the day.

 

[aston4]

Another thing, if you are running all the way to 240 all the time, be SURE you have 50/50 coolant mix or better. Not enough glycol, too much water, you can get a flash boil over, even in a pressurized system. Don't ask me how I know

 

[freedom_in_4low]

don't suppose you measured the temperature coming OUT of the radiator/INTO the water pump, did you?

I suspect it actually got warmer, while the ECT dropped giving you the idea that the radiator capacity had increased, the truth is that the flow was already fully turbulent, nothing changed about the actual heat transfer, and you are just dissipating the same amount of heat into a larger mass of coolant. The actual temperature of the iron in the cylinder head and block is very likely unchanged.

No problem was fixed here, it just had a rug put over it.

 

[LJ-MXer]

Just finished up replacing my TQ Lockup Solenoid due to a P7040 Code.

At the same time I stumbled across the Texas Jeep Products Jeep TJ Overdrive Water Pump Pulley.

Having dealt with elevated temperatures in AZ, and having thrown a lot of parts at the jeep to include the full engine teardown and rebuild from overheating in rush hour traffic.
Completed full flush, pressure flushing the heater core, burping the air from the system, correct Stant Thermostat with hole drilled, no improvement.
I then tried finding a replacement MOPAR radiator without any luck. Eventually I settled on a 2 row aluminum radiator with electric fan and plumbed a digital temp sensor/gauge no longer trusting the Dash Temp Gauge. Electric Fans were a Terrible decision and the engine ran hotter. Electric Fan with shroud was basically useless compared to the amount of air the OEM Fan could move. Lesson Learned. Went back to OEM style radiator from Orielly and that also was crap. Frustrated, I took it all back and ordered another 3 row aluminum radiator and new Heavy Duty Fan clutch, although my original clutch felt fine. Once again, no real discernible change in the temperature. On several occasions temp climbed into the 220+ range sitting at traffic lights and my digital Temp Gauge saved me by sounding an alarm. For the most part it was all ways with AC on and waiting for a traffic light or stop and go traffic. Gave up on the constant search for an original MOPAR radiator and settled on a Single core aluminum radiator. Temperature came back down to 210 to 218 range with AC running but once we hot triple digits, starting seeing spikes in temperature again in the 220+ range with AC running. More reading and came across FlowKooler Water Pumps. Read positive and negative reviews but decided to take a chance. While at it I order the high flow thermostat and radiator hose housing. This actually made the biggest improvement up to this point and was some what manageable when I started focusing on the P0740 code that started appearing.

In the process of testing the TQ Solenoid Replacement I was running 214 to 219 but after adding the Texas Jeep Products Jeep TJ Overdrive Water Pump Pulley, the highest I could get going uphill with AC blasting was 216. As soon as I crested the hill, temp went back down to 210 to 214.

I have to say the over drive pulley has made the single biggest difference.

Granted installing the pulley had its own issues. The back side of the pulley would bottom out against the replacement button head bolt that was provided. So much that when first installed, the water pump refused to even turn. Ended up taking the pulley off and added some blue sharpy to the edge (I'm not a Machinist nor do I have a Lathe) and I sanded the back lip of pulley down using 120 grit and a DA Sander to provide more clearance without grinding the Button head Allen bolt down. In defense of Texas Jeep Products it would be very hard to compensate for all of the different water pump manufactures and there casting out there to know if the pulley would clear or not.

Looks like I need to pull the Pulley off again to clearance it a little more as it starts to grind ever so slightly when I mash the gas pedal hard. Hands down I think the Overdrive Pulley made the biggest single difference in helping to lower temps.

Added a few pictures that show how much I clearance the pulley. Disregard the scratches as I initially started to clearance the angle on the inner edge with a hand file which added scratches more than anything.

Laying pulley against 120 sanding discs on a DA helped me remove most of the material and left a cleaner look. Unfortunately, I could not find my micrometer to make more precise measurements, but you get the idea.

I think one more pass on 120 DA should do the trick and get rid of all contact between edge of pulley and Button Head Allen bolt.

View attachment 626206

View attachment 626207

View attachment 626208

In reference to having to modify the pulley or water pump housing, is this only for certain year models of TJ/LJs or more to do with brand of water pump? What brand fan clutch do you end up using and are you happy?

 

[astjp2]

Great info. Thanks for the write up.

It's very weird that a manufacturer will go to all the trouble of tooling up to make a radiator, and not just duplicate the OEM, which is perfectly fine and worked great for decades. Why go to all the trouble of redesigning it, end up with junk, and then sell it anyway ruining your reputation?

The aftermarket parts situation now should be unbelievable... but it's real.

Fins cost more

 

[Ken G Ford]

In reference to having to modify the pulley or water pump housing, is this only for certain year models of TJ/LJs or more to do with brand of water pump? What brand fan clutch do you end up using and are you happy?

To be honest, I think there are just so many brands and manufacturers of water Pumps that some may touch the back lip of pulley and other may not.