Visit our Popular Forums

tjdonahoe · 01-07-2015, 08:50 PM

Crispy boy you are right no idling ,or grocery getting,I try to just drive mine towing, or on a road trip,so far only one oxy sensor,in 85000 miles

SteveH · 01-07-2015, 08:55 PM

TJ, Have you had to have the EGR system cleaned yet?

tjdonahoe · 01-08-2015, 04:52 AM

No I have not cleaned the egr system,every seems good other than the oxy sensor,.

SteveH · 01-08-2015, 06:52 AM

I read the '12 models will get a check engine light at 56,500 miles and the EGR system must be disassembled and cleaned, so just wondering if you had that also.

crispyboy · 01-08-2015, 07:17 AM

Quote:

Originally Posted by SteveH

I read the '12 models will get a check engine light at 56,500 miles and the EGR system must be disassembled and cleaned, so just wondering if you had that also.

I believe the EGR cleaning interval is 67,500 miles which includes changing the crank case ventilation filter, cleaning the EGR system and EGR cooler.
I have taken the EGR valve (valve only) apart on my truck to see how much build-up there is and it is ugly.
I have also cleaned the MAF sensor located on the intake horn. It is a 15 minute job. It also gets caked up with soot.

I'm at 56k miles so sometime in the next year or so I will order the EGR cleaning kit from Geno's Garage and get dirty. I have had to do this job several times on a 97 VW Jetta diesel we used to own. Loved the car but was a pain to work on.

SteveH · 01-08-2015, 07:23 AM

Quote:

Originally Posted by crispyboy

I believe the EGR cleaning interval is 67,500 miles which includes changing the crank case ventilation filter, cleaning the EGR system and EGR cooler.

Yes, I think you are right, I just remembered the number incorrectly.

tjdonahoe · 01-08-2015, 08:37 AM

I did change that filter under the valve cover at 70000 miles.. And it didn't look that dirty to me ,I have read the cummins forums and it is about 50 -50 as for taking everything apart and clean .

tjdonahoe · 01-08-2015, 10:44 AM

A good article under 6.7 cummins specs , then go to 6.7 emissions it tells about the DOC, DPF, EGR,SCR very informative. Almost as deep as my cataract surgery..

SteveH · 01-08-2015, 11:48 AM

Quote:

Originally Posted by tjdonahoe

A good article under 6.7 cummins specs , then go to 6.7 emissions it tells about the DOC, DPF, EGR,SCR very informative. Almost as deep as my cataract surgery..

Got a link?

crispyboy · 01-08-2015, 12:00 PM

I found this brochure last year which sheds some light on how the emission components work.

2010 emissions.pdf

tjdonahoe · 01-08-2015, 12:03 PM

Go to, 6.7 cummins specs. Then to 6.7 emissions ..

SteveH · 01-08-2015, 12:39 PM

Quote:

Originally Posted by tjdonahoe

Go to, 6.7 cummins specs. Then to 6.7 emissions ..

Found it, thanks.

SteveH · 02-16-2015, 07:06 AM

OK, many if not most of you will think I'm crazy, and maybe I am, but found a great deal on a set of 3.73 gears, front and rear, on the Cummins forum, and the truck is in the shop having them changed.

The guy had replaced his gears with 4.56's because of the typical young person's lift and big tire/wheel change.

By the Dodge specs for the '12 model that I have, it will increase my towing capacity to 12,550 from 9550, and increase my GCWR to 20,000 from 17,500lbs. This will give me a "comfortable" margin.

If nothing else, this will give me much more piece of mind, and the total will end up costing me a little more than a new set of tires for the truck. However, at this point I think I'm just about done spending money on this truck, or at least I want to be done.

tjdonahoe · 02-17-2015, 03:22 AM

Steve, my opinion is to leave what you have alone,I have basically the same thing only with a 3.73, at 63-64 the tack is about 1550 rpm, and it will pull down to below 1100 if you don't wiggle your toe,that is the same as my 475 cat with 4.11 gears ,runs 65 at about 15-1600 rpm, I pull it down to 11-1200 rpm, it is doing what it is susposed to do..run fast with slow rpm.....the gas motors have to run high rpm to get any power...It also doesn't seem to matter much, where we go, the round trip , will average 12 mpg......

SteveH · 02-17-2015, 06:54 AM

TJ,

A couple of points here so you understand, mine is geared 3.42, and I'm pulling about 1500lbs more trailer than you are. Like I said, it's in the shop and should be ready this afternoon, or tomorrow.

It will be a couple of weeks before our next rally and a chance to tow the trailer, but I will report back with my thoughts on the gear change after that.

xrvr · 02-17-2015, 06:59 AM

Should be a good move. You may or may not notice a difference but it will be an improvement. Peace, Jim

slowmover · 02-17-2015, 09:37 AM

Have you kept track of average mpg? At constant speeds with constant loads? I'm curious about the percentage difference over thousands of miles as I'm playing with going from 3.73 to 3.42.

SteveH · 02-17-2015, 11:32 AM

Quote:

Originally Posted by slowmover

Have you kept track of average mpg? At constant speeds with constant loads? I'm curious about the percentage difference over thousands of miles as I'm playing with going from 3.73 to 3.42.

I have not. There have been too many variables in different trailers, different tire sizes, and different areas driven.

I just know the best I ever got on a long trip without the trailer was 19.5, and that was all highway with speeds up to 80, but mostly 75.

With tail winds pulling the 31 at mostly 67-70 it would get 14, but not with the 34. More like 9 to 10.5.

Everyone would like to get good fuel mileage, but it's not my primary concern.

SteveH · 02-18-2015, 07:40 AM

Picked up the truck yesterday afternoon and just drove it home. It seems at 60 or so in sixth gear it has only increased the RPM by 100, so should not make any major difference in highway fuel mileage. I did notice the gear change more at lower speeds in the lower transmission gears, which makes sense to me, and this should give me what I wanted..... more power at lower hill climbing speeds.

slowmover · 02-18-2015, 10:10 AM

Quote:

Originally Posted by SteveH

I have not. There have been too many variables in different trailers, different tire sizes, and different areas driven.

I just know the best I ever got on a long trip without the trailer was 19.5, and that was all highway with speeds up to 80, but mostly 75.

With tail winds pulling the 31 at mostly 67-70 it would get 14, but not with the 34. More like 9 to 10.5.

Everyone would like to get good fuel mileage, but it's not my primary concern.

Tracking fuel burn versus miles is one of the simplest ways of monitoring truck health, it is not just cost accounting. Engine hours versus miles gives average mph. Those two numbers -- average mpg and average mph -- tell quite a lot about present and likely future costs.

A gear ratio change affects one of them specifically.

If this is a dedicated TV, then analysis is pretty easy.