Dodge Cummins Diesel Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Alright I have a 07.5 2500 with the new unrevised 68(in 2007) in it.. I've come to learn the valve bodies for the first year or two were flawed for longevity in resistance of wear.. Mine was absolutely fine for about the first 125k miles then the problems started.. When I would do some around the town driving with a good bit of low gear shifting up and down then it started randomly goin into limp mode.. Shut it off and back on again then it would be fine for a week or two, but only act up during in town driving conditions.. But at the same time when it would throw it's fits it only put out a code once and it was the general TCM problem code.. Took it to the dealer they scanned it and said I needed a new solenoid pack.. I replaced it, that fixed it for a month or two then right back to its same ol' random fits.. Still no codes but one time, I pulled it myself with my chip and got the TCM general problem code and also the code for the SSV rationality problem (don't remember what the code was).. But I guess what I'm getting at is there is a number of symptoms I'm not sure are related but hoping they are.. I realize a valve body is a must, but just about every time it runs up through the gears it shifts differently, timing to how much throttle I'm into is always the same but the soft or firm shift is always changing.. When town driving and it shifts a lot if it doesn't just have a fit and go into limp mode, it'll slam into drive from park/neutral but only slam into drive (that's how I can usually tell it's about to throw a fit and go into limp).. But it's newest symptom and concern has got me really troubled.. since it always clunks comin out of drive to neutral/park when completely stopped like most 68's do ill pop it into neutral just before coming to a stop then into park when I'm stopped.. But lately when I do that while coasting slowly in neutral just before I stop or stop completely I get a clunk that feels similar to the clunk from drive to park/neutral when stopped.. It's weird, clunks either when I let off the brakes but still slowly creeping forward or if I hold the brakes until I'm completely stopped and as soon as the wheels stop rolling it clunks even with the brakes still applied.. The clunk at a stop seems worse then the clunk when I let off the brakes and the truck is still creeping forward very slowly.. Only does it going forward too, not in reverse at all.. If anyone could please give me some incite or suggestions that would be great.. Need to put my mind at ease with this.. My truck is my livelihood and no way rich and made of money so throwing parts at it is what I'm trying to stay away from the best I can.. Thanks very much to anyone that takes the time to read this and help me out.. Ha I'm new to this forum posting stuff so I'm hoping I posted this correctly.. Thanks again


Sent from AutoGuide.com Free App
 

·
TECH SPECIALIST
Joined
·
3,934 Posts
The clunk you feel while coasting to a stop in Neutral could be the LR clutch applying. This clutch is applied at a stop, but not while you are rolling (above a certain low speed) in Neutral. Usually it comes on at about 8 mph, so your description (clunks right at a stop) doesn't quite match up with that, but the LR applying is the only thing that makes sense to me (transmission-wise).

Could also be a worn U-joint maybe? So as you're coasting down, the rear axle is driving the shaft, but at a certain (low) speed, the drag torque coming through the trans would be enough to put some positive torque on the driveshaft (giving you a clunk if there is some slop there somewhere). So you might check the U-joints.
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #3 ·
Firstly thanks for replying to my post TransEngineer! I was hoping my post would find it's way to you.. Although I don't think the u-joints are the issue.. I figured they were ok (not that old actually) but I did check them earlier anyways just to be sure and they are good to go..

The clunk to me feels like it's coming more from the tranny(or more under me rather then behind in the back).. Kinda like I have something in the bed that rolls up against the bulkhead when I stop in neutral only the thud/clunk is felt and herd from under my feet/seat.. I dunno, I guess I can speculate all I want but won't really know until whatever it is breaks haha.. Just hoping I suppose it's the worn/obsolete valve body that's causing this new behavior..

But with your experience and knowledge do you think all the symptoms I listed in my pervious post are related to the worn valve body needing replaced?? Also is that something I can replace myself? I replaced the solenoids myself and realize the valve body comes out all together, but didn't relearn it other then what my XRT Pro does with the overdrive software.. Does the tranny need a relearn flash from the dealer for the newer revised valve body or is my chip capable of doing that? The only purpose my chip serves is to reprogram the ECM for the couple parts I removed from the truck ha, no extra power or anything.. So I don't think it's the culprit for any extra wear on the tranny and valve body.. I'm just hoping after replacing the valve body all this erratic behavior and mysterious no code limp mode fits will stop and I'll be able to fully trust the truck to go the distances and places I need it to again.. Only 140k on the truck and always taken care of never beaten, need to get a few more miles out of er'.. Gets driven a lot to many different places for my job in the oil/gas field of northern PA (mostly highway) so this trend of fits has got to be solved.. Thanks again TransEngineer for the incite and piece of mind!


Sent from AutoGuide.com Free App
 

·
TECH SPECIALIST
Joined
·
3,934 Posts
For the worn valve body (SSV bore), the typical fault is P0871 (OD Pressure Switch Rationality). If you got that, then yes, I'd recommend replacing the entire VB assy. The solenoid is part of that (part of the top half, basically). So if you already replaced the solenoid yourself, you had to drop the whole VB out to do that, so yes you can replace the VB on your own.

Yes, running a quicklearn is a good idea after replacing the VB. Probably need a dealer to do that.

Could your clunk maybe be fuel tank slosh? I see lots of reports of gas engine trucks with a clunk or thud right after a stop, which is usually fuel sloshing in the tank. Not sure if diesel trucks also suffer from that problem or not...
 

·
Registered
Joined
·
7 Posts
Discussion Starter · #5 ·
Yea, a new valve body is getting ordered Monday.. I've called dodge in the past about ordering a valve body just to check availability when this continued after solenoids weren't the problem, they told me that valve body is on back order and would be a few weeks till it would come in from when I order it... Was surprised to hear that, but I guess they are in high demand.. What do you think about a revmax valve body? I think I could get one of those sooner.. If it's equal or better then a OEM valve body with out the back order wait might be better for the rest of that tranny to get it in sooner so it's not hurting the tranny any longer since this valve body is worn and problematic.. Thanks again TransEngineer for all your input..


Sent from AutoGuide.com Free App
 

·
TECH SPECIALIST
Joined
·
3,934 Posts
I assume the RevMax VBs are reman units, but I don't know how they process them. So call them and ask what they do to address the SSV wear issue. Do they use a NEW valve body housing that is anodized? That would be best, and would be equivalent to a new Mopar VB. Do they bore the SSV oversize and install a new valve and plugs to fit the new bore? That would be OK, but would probably exhibit the same wear issues over time (100K miles or so). Do they rebore the SSV, then anodize the VB, and then install a new valve? That would be good also (equivalent to new anodized VB).

If they just inspect the SSV bore size, and re-use if in spec, that would be less desirable.
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top