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Tip Thinking of carrying a spare DEF head?

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Neal

Staff member
RVF Administrator
Joined
Jul 27, 2019
Messages
12,883
Location
Midlothian, VA
RV Year
2017
RV Make
Newmar
RV Model
Ventana 4037
RV Length
40' 10"
Chassis
Freightliner XCR
Engine
Cummins 400 HP
TOW/TOAD
2017 Chevy Colorado
Fulltimer
No
I don't recommend it! For those following the DEF head(er) crisis you may think you should carry a spare DEF head(er). As I recently discussed with someone else, I don't think it's a good idea. If you're in a location where one can be installed, then you're likely in a location where one can be shipped and apparently it's required to be installed by a Cummins certified tech. But the real reason is that vendor(s) continue to try to figure out the sensor and have been coming out with new releases to try and solve the ongoing issues which seems to have been going on for around 4-5 years. So if you spend the $1K+ to buy a spare DEF head(er) (latest I hear is $1325) and it's GEN X for example, and in a year or two you have your DEF head(er) go out, do you want to use your GEN X which is "known bad" (obsolete) and I'm sure you'd rather have the latest installed at the time of the incident. Think hard before ordering a spare DEF head(er) when you can get one due to supply issues. I think it's a bad idea. My $.02.
 
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@Neal ... thanks for this post. I have been trying to keep up with all this and just had a few comments/questions:
  • Is this more of a Spartan issue vs. a Freightliner issue as to having the problem and then getting a new part? (I have a FL).
  • Not sure what I can do to avoid it other than just parking the coach and letting it sit until parts are back in stock. We are currently on the road now and I am starting to think "is it my time" ever time we head out. I do keep the engine running during fuel stops.
  • I guess if we do get the red light all we can do is try and get to a safe place to stop the coach and hope we can still get a new head. Kind of like the @ARD situation out west.
But for now ... all appears to be good so I am not slowing down yet.

FLSteve
 
@FLSteve I'm not the expert on this but I've been reading posts by those affected and also posts by @Brett Davis of @NIRVC who did some internal research to get real numbers. I'll leave it to others to draw their conclusions but I personally am not worried about this situation nor will I change where I get my DEF or letting the tank run down to 1/2 before refilling which is when I add DEF. There is so much hysteria going on over this it's a shame because no one knows the facts of what's causing the failures of those affected.
 
@FLSteve , like @Neal , I am no expert either, but everything I have read ( a lot) indicates there is far less cause for concern with a FL chassis. FL isn’t immune, but the overwhelming majority of failed DEF heads are on Spartans. FL uses a different DEF head, which they claim was developed by them and proprietary. I am not changing any plans nor anything I am doing to manage my DEF consumption.
 
I have thought about having a spare when the stock is replenished. As far as it’s supposed to be installed by authorized Cummins people, I’ll find one locally. I full time and sitting in one spot until there are spares isn’t part of my plan, I’ll take my chances.
 
@FLSteve I'm not the expert on this but I've been reading posts by those affected and also posts by @Brett Davis of @NIRVC who did some internal research to get real numbers. I'll leave it to others to draw their conclusions but I personally am not worried about this situation nor will I change where I get my DEF or letting the tank run down to 1/2 before refilling which is when I add DEF. There is so much hysteria going on over this it's a shame because no one knows the facts of what's causing the failures of those affected.
Did I miss a link to Brett Davis’ post on the DEF “real numbers” he found? I would certainly like to see them and get a better handle on the DEF head situation.

TJ
 
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Looks like the problem appeared on 2016 and newer models?
 
Thanks to all for your feedback ... I now have my confidence back so it's peddle down! Reading Brett Davis's "by the number facts" also helped.

FLSteve
 
Someone asked if Big Trucks are having DEF issues as well. I don't have numbers, but was listening to a driver giving adviice to those looking to get started in trucking or looking to purchase a truck as a new OO. His suggestion was a pre-DEF truck to avoid the higher maintenance costs associated with all of the DEF issues. DEF - another great mandated fix which causes more headache and expense for those forced to use it.
 
My work truck is a 2018 Kenworth with a 6.7L Cummins that I own and maintain as if it were my RV. My def head went out 4 weeks ago. The dealer put in my factory new unopened spare under warranty. The one they ordered still isn't here. I got lucky because they took care of me but I would have paid that bill regardless. With a warranty or not, without a spare I would be down 4 plus weeks as of now and still counting. I have two sensors on order at two different dealers right now, both have been on order 4+ weeks. There is no sensor expectation to replace it. What would you do without a spare? You will need to be prepared to leave your coach and fly home or stay put for extended lengths of time if you don't travel with a spare. My truck has gone through 2 in 52000 miles. This is only an issue to the newer DEF systems that do REGENs not the older DEF systems that just add DEF to the exhaust. The problem is that def crystalizes and ruins the sensors despite whether its fresh or old (old DEF will accelerate the crystallization) and the manufacture cant keep up production with the failures. Also to keep in mind, DEF has a shelf life and if stored it should be stored inside the house in the AC not outside in the elements. If you have a REGEN system, be careful where you purchase your DEF. The level you keep the tank has no bearing on the failure but worse problems happen to the DPF if you run it out of DEF. There's no solution now or in the near future other than frequent replacing of the sensors when they fail. I don't anticipate things clearing up anytime soon. More likely, this is the new norm for a few years. If you don't have a spare, order one so you can have one in hand or one on the way. My spare was about $400 shipped. Its not about if it will fail because it is absolutely 100% going to fail. This is exactly why I ordered a gas A.
 
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Just spoke with my Uncle whose company does truck repairs. Safety's claims (covers FL, NC, GA and SC) said there are no DEF heads in the country. They are dealing with Peterbuilt, Kenworth and Freightliner trucks. He mentioned a company in Ocala, FL has 6 2019 semi's and none are moving - all need DEF heads. I agree with @KR1973, I don't' think there will be a solution now or in the near future. I hope I'm wrong. I wouldn't mind having a spare though.
 
There is a solution in the form of an emulator. Public details are just now coming out, and more will be posted soon.

The device will clear all errors and derates. It does not alter or affect the operation of any emissions systems, and leaves no trace behind of being used.

The device can be used for as long as you need until a replacement head is available.

Best of all....it is open source.

 
In looking for DEF head alternatives so we are prepared in a failure, ran across a post from a OTR driver who found a temporary solution to avoid needing a tow.

Disconnect the speed sensor at the drive shaft.

Yes, as the driver you no longer know your speed, but more importantly, the computer doesn’t know your speed either. For his OTR trucks this has allowed him to keep going and avoid a tow.

Going to crawl under our rig so IF we have a derate I can try this 5 min temporary fix.

Still following these other alternatives too.
 
In looking for DEF head alternatives so we are prepared in a failure, ran across a post from a OTR driver who found a temporary solution to avoid needing a tow.

Disconnect the speed sensor at the drive shaft.

Yes, as the driver you no longer know your speed, but more importantly, the computer doesn’t know your speed either. For his OTR trucks this has allowed him to keep going and avoid a tow.

Going to crawl under our rig so IF we have a derate I can try this 5 min temporary fix.

Still following these other alternatives too.
This only works if you have a manual transmission. Without the speed sensor connected the transmission will not shift gears. It’s been tested on motorhomes and did not work.
 
This only works if you have a manual transmission. Without the speed sensor connected the transmission will not shift gears. It’s been tested on motorhomes and did not work.
Thank you, good to know.
 

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