3.54s to 3.92 or 4.10s

[JWiegel]

I have always owned manuals in my trucks bought this 2000 3500 with 3.54s 47re in march has 3.54s and I live in Colorado and tow a lot if not everyday so the passes here in Colorado beat most across the nation, with only a 23' 6400lbs camper trailer and 1200lbs atv in the bed cannot pull Berthoud pass or Eisenhower pass up I-70 over 15-20mph if I push harder just overheats and trans temp rises. I have never had problems with any of my manuals I like choosing my gears. My 05 3500 3.73s with minor upgrades and nv5600 pulls it no problem and no overheating, this 2000 has a small banks program but mostly transmission additions, deep pan, extra trans cooler with fan, new upgraded valvebody kit gps and transducer gauges to watch temps I work on ISBs all the time started with Dodge but now work for myself but seen the trans issues why I have always owned manuals. Want opinions on swapping the 3.54s to 4.10s I understand the mileage issue but towing alot is my concern I have never had to pull over on the Eisenhower pass and I am a 4th generation native Coloradoan, to cool the truck down put it in 4low and ran about 20mph kept temp from getting too hot and got us over the pass, I was humbled a lot. Please want pros and cons of other peoples opinion and those who know our passes here.

 

[EGroeneveld]

So the motor overheats AND!! the trans temp rises? How hot does it all get? 220, 240?

I really don't see how the swapping from 3.54 to 4.10s will solve anything regarding it. Not really much of a difference.

I'd be digging into the cooling system and pull apart the front end to make sure the everything is really clean and debris free.

And buddy on his truck just solved his overheating problem by pulling apart everything, cleaning everything and flushing his radiators and a full transmission service.

 

[RustyJC]

I'd be looking at the cooling pack and fan clutch first. If the previous owner never relocated the oil breather catch bottle, I'll almost guarantee the front face of the radiator you can't see without removing it is plugged solid with oil mist, dirt and ???? If you don't hear the cooling fan kicking in under high load (and coolant temperature) conditions, then it's suspect as well, although it can be tricked if there's insufficient airflow through the cooling pack.

Rusty

 

[BarryG]

I live in CO as well have an 01 with an auto and don't have near the problem you have described here. I agree with the others I would check the cooling systems especially the front of the radiator. Sounds like the engine heat is making you slow down which is increasing trans heat.

second or third post down your radiator may look like this http://www.cumminsforum.com/forum/98-5-02-powertrain/391972-over-heating-issues-2.html you cant clean it from behind and expect it to clean out the front. You need to either remove what is in front of it or pull the radiator to clean it well.

I would also check thermostat. As well as the cap perhaps it doesn't hold pressure anymore and as Rusty said check the fan clutch too.

 

[kthaxton]

So the motor overheats AND!! the trans temp rises? How hot does it all get? 220, 240?

I really don't see how the swapping from 3.54 to 4.10s will solve anything regarding it. Not really much of a difference.

I'd be digging into the cooling system and pull apart the front end to make sure the everything is really clean and debris free.

And buddy on his truck just solved his overheating problem by pulling apart everything, cleaning everything and flushing his radiators and a full transmission service.

While I agree that the first thing should be a thorough check of the cooling system, lower gears can reduced heat because the engine and transmission don't have to work as hard with lower gears. Everything is easier for the engine and trans.

Are you running stock tire size?

 

[EGroeneveld]

I agree lower gears ''could'' help a little bit if things were working right. But something in the cooling system; air flow, fans, dirty, sensors, t-stat, is not working correctly.

I have stock 4.10 gears on my 2016 and stock sized tires. But it's a completely different truck compared to a 2000..........

 

[kthaxton]

.

I have stock 4.10 gears on my 2016 and stock sized tires. But it's a completely different truck compared to a 2000..........

My apologies, my tire size question was meant for the OP.

 

[JWiegel]

The cooling system is ok I know about the draft tube clogging radiators pulled many of them to clean I had relocated the draft tube and radiator was pulled and cleaned installed a 180 thermostat, fan clutch is engaging and working properly and when it does you can feel it, radiator cap is good holding pressure at 240degrees transmission never got above 190 I did all this before we left because I did not really have any history on it, have 245/75r16 instead of the stock 235/85r16 which are the same diameter I believe the engine is working to hard to turn 3.54 gears with a automatic under load and think that lower gears would lessen how hard the engine needs to work. It has been running fine in city and stop and go traffic but when pulling heavy loads want to heat up no coolant in oil or oil in coolant don't think there is a head gasket problem last emissions test showed very low opacity in all speeds the highest was 3% at 30mph. Egts never got above 950degrees.

 

[RustyJC]

Egts never got above 950degrees.

Measured post-turbo???

Rusty

 

[JWiegel]

No I installed the probe pre turbo I dropped the turbo down when I replaced the exhaust and installed it.

 

[RustyJC]

If you are only seeing 950 degF pre-turbo on a hard pull and coolant temperatures are abnormally high, that could indicate that injection timing is over-advanced (for whatever reason). If combustion starts too early, the heat of combustion is dumped into the engine's water jackets in the cylinders and head instead of into the exhaust. I would have expected to see pre-turbo EGTs of 1250 (stock engine) or more (bombed engine - my 2002 would hit 1450 @ 34 PSIG boost if I didn't watch it) towing a heavy load up a grade at full throttle (Cummins HO/6-speed with Edge EZ, DD2 injectors, BHAF and Jardine 4" exhaust, 4.10 axle ratio). It's a two-edged sword as not dumping the energy into the exhaust also can leave the engine short on air as there's insufficient energy to drive the turbo - which forces temperatures even higher. The excess air provides a cooling function. You'd really notice this at high altitudes where the engine needs all the air it can get.

Were you noticing any substantial black smoke from the exhaust during the pull?

Rusty

 

[SnoKing]

Having owned a 2001.5 for 14 years and towed a lot, 4:10's with the 47RE are the best setup for towing. This has been a long standing 24V recommendation on this and other RAM/Cummins sites, auto/towing/4.10's..

EGT of only 950 pre turbo is an indication of something strange occurring. I wonder if the pyro is not working correctly. Shoot the exhaust manifold with your heat gun to compare. What boost levels are you seeing. Does the truck have the stock HX35-12W turbo?


:--) Banks :--)

My 2001.5 with 4.10 Stage 1 injectors and Comp in EZ mode at 20-21K combined weight would walk up those in 3rd gear at 45+ MPH without an issue.


SNOKING

 

[jeepit]

If you are only seeing 950 degF pre-turbo on a hard pull and coolant temperatures are abnormally high, that could indicate that injection timing is over-advanced (for whatever reason). If combustion starts too early, the heat of combustion is dumped into the engine's water jackets in the cylinders and head instead of into the exhaust. I would have expected to see pre-turbo EGTs of 1250 (stock engine) or more (bombed engine - my 2002 would hit 1450 @ 34 PSIG boost if I didn't watch it) towing a heavy load up a grade at full throttle (Cummins HO/6-speed with Edge EZ, DD2 injectors, BHAF and Jardine 4" exhaust, 4.10 axle ratio). It's a two-edged sword as not dumping the energy into the exhaust also can leave the engine short on air as there's insufficient energy to drive the turbo - which forces temperatures even higher. The excess air provides a cooling function. You'd really notice this at high altitudes where the engine needs all the air it can get.

Were you noticing any substantial black smoke from the exhaust during the pull?

Rusty

Very informative Rusty! This helps a lot.

 

[RustyJC]

I retired after 42 years with an engine manufacturer. Part of the development process for a new engine model or a major modification is a heat balance study. This heat balance study determines how much of the incoming fuel BTU isn't converted into flywheel power, and where those heat losses take place - radiation from the surfaces of the engine, coolant system, lube oil system and exhaust. This is how coolers (coolant & lube oil) are sized for these engines. Best power and BSFC (brake specific fuel consumption) is normally achieved when timing is adjusted to compensate for fuel burn characteristics to yield a PPA (peak pressure angle - crank angle at which peak firing pressure occurs) of 16 to 18 degrees ATC. In effect, timing is adjusted to whatever is required to bring the PPA into this 16-18 degrees ATC range.

Heat balance studies show that, as timing (and PPA) is advanced, more heat energy is transferred to the coolant and lube oil (through the oil-cooled piston crowns) and less to the exhaust. That may or may not be the OP's problem, but the symptoms he gives certainly look curious.

Rusty

 

[JWiegel]

Pulled the water pump and found the impeller would spin freely but hold the pully and you could still spin the impeller freely I think this was the problem never thought that never seen any temps climb around town so we'll see next pull. But I appreciate the advice and opinions.

 

[RustyJC]

Pulled the water pump and found the impeller would spin freely but hold the pully and you could still spin the impeller freely I think this was the problem never thought that never seen any temps climb around town so we'll see next pull. But I appreciate the advice and opinions.

Glad you've found a problem - hopefully that will solve your towing woes. Good luck!!

Rusty

 

[SnoKing]

Pulled the water pump and found the impeller would spin freely but hold the pully and you could still spin the impeller freely I think this was the problem never thought that never seen any temps climb around town so we'll see next pull. But I appreciate the advice and opinions.

Good find! Snoking

4.10's are still better with the 47RE!

 

[JWiegel]

agree

Good find! Snoking

4.10's are still better with the 47RE!

I agree 4.10s will pull better less drag on the motor and trans.*

 

[fox]

Also, what gear is it in when it over heats? Is it in lock up? Trans can add a lot of heat when unlocked and it is floored.
I also believe you found the issue with the bad water pump.