Shimmed my oil pump.. went from 35psi to 45-46 psi..

[Hammerhead]

(10-09-2016 )slowpoke Wrote:  i shimmed mine 3 weeks ago tried to use 7 us dimes but didnt seem to want to compress ended using 5 dimes oil pressure went up about three lbs when hot was 31 now 34 but at idle not much did notice now after first week when start from cold (70 f) oil pressure 42 lbs at idle 600 rpm bump it to 800 rpm pressure drops to 36 then to 40 then to 36 then slowly back to 42 if i keep it low idle for 30 seconds then this dosnt happen. pump one year old cm871 inframed. could i have done something wrong

jimineztrans as well, did you change the o-ring?
Did you lube the o-ring with Vaseline when you reinstalled it?
Did you check the circumference of the pump where the dogbone/spring/cap Assy installs to see if it had a sharp edge that could potentially damage the o-ring?
If yes, did you chamfer the edge to prevent this?
There really isn't much you can do "wrong" on this procedure.
I reused the o-ring on the first procedure, and installed a new one when I added to get it where I wanted it.
Slowpoke, the spring certainly gets harder to install as you add shim. A little trick I used was I got the Assy pushed in just far enough to start to install the oil pump mounting bolt to hold it in position for me. Then I used a 3/8 extension on a ratchet with one hand laces on the head of the ratchet to do the final "push" to slip the cotter pin into place...

[jimeneztrans84]

When I took out the dog bone and spring it shot out and the o ring was full of oil so I didn't use vaseline. I checked to see if I needed to use the deburring tool I bought but it was really smooth since my pump is only 2 months old. On rawze's video I think he says you won't see idle pressure go up?

[jimeneztrans84]

As long as I'm 40-45 psi crusing down the road at full temp I'm happy.

[Hammerhead]

I honestly didn't pay too much attention to idle pressure. I was more concerned with operating range pressure at operating temperature.
The only time my truck runs at dead idle is first startup, long enough to build air pressure to cut out the engine fan, and enough temperature to remove the "snap" from combustion rocking the pistons BTDC, and at traffic lights & such while waiting to release the clutch. Other than that, I use the PTO idle at 900. I'm ~25psi at 900 RPM, good pressure, smooth engine.
I was taught that with the internal dynamics of large diesel engines, dead idle is not good for the long term health of the engine. At higher RPM's components "float" instead of "rattling around."
Right or wrong, that's the way this wheel nut does it...

[slowpoke]

sorry didn't mean to get in middle of your conversation but thanks for the help. cause i didn't do any of those procedures you mentioned so maybe my oil ring is a little damaged. thanks again.

[Hammerhead]

(10-09-2016 )slowpoke Wrote:  sorry didn't mean to get in middle of your conversation but thanks for the help. cause i didn't do any of those procedures you mentioned so maybe my oil ring is a little damaged. thanks again.

Your not in the middle. IMHO the target oil pressures that we are looking for with this procedure will add to reliability and longevity over OEM targets. The more guys we have that do this and report their findings, the quicker, more reliable, and repeatable results we develop.

Which BTW brings up; I had an oil weep that is now a leak/small drip from my flywheel housing (rear structure). There is an oil galley that pressurized oil passes through from the exhaust side to the intake side of the block. It has become more pronounced as I've increased pressure. If you have this same oil weep, be aware that it probably will become worse with pressure. It is about a 20 hour procedure to replace the gasket. You need to drop the tranny, clutch, flywheel, and remove the oil pan to support the engine as this housing hold the rear motor mounts. If you are doing a clutch job and are considering shimming your pump, I rcommend going the couple hours further and just do this gasket and the rear crank seal while you're at it to save the frustration of doing it again. I haul heavy and have higher than average torque loads, which increases the likelihood of this leak occurring. KW told me that for anybody that pulls B-trains or hauls heavy, this is fairly typical around the 1million km/600k mile mark for these engines. I believe the cold weather and dissimilar metals adds to this.

[jimeneztrans84]

Yeah the only time I idle is to warm up engine and cool down engine. I have a wet kit installed on my truck so to active the wet kit I idle at 900 rpm while I unload the trailer..smooth idle also. Other than that truck never idles for long time @ 600 rpm.

[jimeneztrans84]

@900 rpm idle I'm at 30 psi full operating temp.

[jorden486]

I'm lost-I have done 3 different trucks of mine all cm870's and I didn't see an O ring anywhere while putting dimes in.