New oil pump

[JMBT]

On my truck the new style P.O.S. Pump did actually raise my oil pressure a bit 5 psi at operating temp, but that is compared to my old style with 764,000 miles. The new pump is a completely different pump. It is cast instead of aluminum. The external drive gear is way larger and the idler smaller then the gears on the old style. The TSB 190018 says the oil flows through it differently and that causes the different pressure, so I would guess the passage ways are different inside.
The biggest difference and what I think the main problem is, is that the idler gear is at least 1/8” wider, therefore it will not ride properly on an old crank gear.***(not correct)***
They are selling this pump as a replacement for pumps going all the way back to the CM570. Will it work? Yes. But it is going to make ALOT of noise on an older worn crank gear. I really feel with a thinner width idler gear it would be just fine,***(not correct)*** but that is something Cummins needs to address and quickly, because the old style pump is becoming very rare even as an RX.

[Lonestar10]

My dad's 870 was overhauled about 250k ago his truck sounds like it has a muffled Whipple under the hood untill under power maybe he got one of these or that's normal for 870s there's about 1.7m on his crank.

[marek4792]

My old truck would hum loudly during low idle 700rpm however it would quiet it down if I high idled the engine, my X15 was humming quite a bit at first but has since went quiet. For some reason on them they seem to read low on the gauge haven't verified actual pressure on insite, but when investigating the flow and parts diagram the oil cooler shows it has some sort of screen filter resembiling a plastic coffee strainer inside of where the oil thermostat goes into atleast in my oil cooler and maybe could be causing a restriction before the filter itself and lower pressures on higher rpms?

[JMBT]

Lonestar10: Cummins first made this new style POS pump around October of 2019, so he should have still gotten a good pump when he inframed 250k ago.

Marek4792, I believe X15’s after October 2019 were produced with the new style pump, but if the pump was in there from day 1 of your engine, there shouldn’t be any problems or noise as the crank and oil pump idler would wear together.
It really doesn’t seem like a bad pump, they just didn’t make the gears the proper width to mate to a crank that has wear from the old style pump.

TSB200038 says “they will update it when they have a fix for the problem”..... What do you bet that the “fix” they come up with will be changing the gear on the end of the crank to stop the noise.

[JMBT]

Well, I got my Cummins Reman old style aluminum body pump today. There was only one in the Cummins Midwest Region. One.....There were 0 brand new old style pumps in the entire region and 1 reman. I dropped the oil again and got things set up to drop the pan tomorrow morning. I’ll take some comparative pics of the two pumps and post them tomorrow to highlight the differences.

Guys, if you are planning an inframe soon, or you think you might need an oil pump soon, and you have an older motor with a high mileage crankshaft. ISX15 CM570 through CM2350. I would suggest you try to get your old style pump now. Just my $.02

[jimeneztrans84]

Is there a part number for old style oil pump?

[JMBT]

Jimeneztrans84, Part numbers for the old style pumps: 2881757, 2892706, 3686938, 3680688, 3681293, 3687527, 4026691, 4309500.... There may be even more, those are just the ones I have ran across.

Part number of new style pump: 5532492

[JMBT]

***IMPORTANT*** First and foremost, guys and gals, I apologize. I will be the first to admit, I was wrong on several of the things I stated earlier in this thread and they came to light as I broke each pump down to compare. I will go back to my earlier thread posts and note these things so as not to spread any misinformation. God knows there is plenty of that on the internet already, I don't want to contribute any more. So, again I apologize, I made some assumptions and drew some conclusions that I believe were not correct, but I am learning as I go.... ***IMPORTANT***

Yesterday I removed the new style oil pump, (PN 5532492) and also took apart the Cummins Reman old style (PN 4309500RX) to "make sure" they actually replaced everything inside.(it looks like they did) While they were both cleaned up laying on the work bench I did some comparisons.

***I was wrong on the width of the idler gear on the new style pump. I had stated it was an 1/8" or so wider then the old style. It is not wider then the old style Reman I have here. Infact, the idler gears on both pumps are 9/16" wide. When I installed the new style pump I snapped a picture showing where the new idler gear was running on the crank. In the pic, you could see wear marks on the crank gear, which I thought were from the old pump idler. The theory was purposed from that pic that the gear could be face loading and maybe causing the noise by dancing in/out. I now believe these marks on the crank are from the gear above the crank gear in the gear train and may not related to the oil pump idler gear at all. I say this because upon mounting up the old style Reman last night, I snapped another pic, and the teeth of its idler are even further out of line with the wear marks on the crank.
You will see however in the following pics the teeth of the new style pump, are wider at the point where they contact the crank gear than the old style. They are also a different shape than the old style pumps idler gear teeth. Could this be where the noise of the new style pump comes from? If not maybe it is something they changed in the internal design causing the horrible noise. Cummins TSB 200038, says it is caused by a pulsation frequency but they don't tell us, or don't know yet, what part of the pump is causing the pulsation. The new idler also does ride at a different spot on the crank gear and 1/8" or so toward the rear of the engine vs. the old style. I sure hope one of these things was causing the noise, or I just wasted a lot of time and money for nothing.

Either way the new pump is a completely different monster. You can see for your self in the pics to follow. Here are a few things I noticed, some of which I think look like good changes if they can get a handle on the noise issue. The new style pump really does seem to be built beefier.

External
1. all cast body, heavier
2. smaller diameter idler gear, and larger driven gear

Internal
3. regulator spring is shorter, smaller, and weaker then the old style. regulator valve bore is also shallower
4. high pressure relief ball and spring are much larger and heavier duty
5. both the idler and drive gears are much larger, wider, and have 9 much larger teeth as opposed to 13 smaller teeth on the old style
6. some minor porting changes inside around the gears
7. all of the bushings look to be made better, heavier duty and out of a different metal, maybe bronze?

Here are some pics comparing new style pump (PN 5532492) and the old style (PN 4309500RX)

[JMBT]

Here are a few more: