I have been reading posts for a week and cant seem to find my exact problem so I decided to see if anyone might be able to help me.

I have a 2008 3500 Megacab Diesel Bluetech with 160K on it and automatic tranny. at 142K I started having issues with the transmission not shifting into overdrive sometimes. Oddly enough I could pull over turn off the truck and turn the key back and forth a few times and start it back up and it would shift just fine.

It didnt seem to really start until I made some trips back and forth with a trailer and used the exhaust brake. I may just be imagining it but I swear at a few points while the issue was occurring It felt and sounded like the exhaust brake was on.

I took it to the Dodge dealer 6 months ago when it first started and they told me it was some sensor (cant find the receipt to say exactly what sensor they claimed it was) however 30 minutes after leaving it did it again, for 4 weeks they had my truck and sent me off 5 times claiming it was fixed.

They never flushed or changed tranny fluid and the final time they stated I probably needed a rebuilt tranny.

I left and deiced to wait and see how it acted. I thought it strange that I needed a tranny when it seemed to be a computer issues since I could stop it with the key trick.

finally about 2 weeks ago it started getting worse and every time I drove it would have the issue and last week the truck started doing a weird downshifting at around 30mph where it would shift down and up and down.

The key trick doesn't work and it will not go into OD at all. Tried disconnecting both batteries for an hour and after reconnecting same issues.

I tried downshifting manually once driving and it doesnt do anything. I can start out in 1st and move to 4th but after that I cant go back down.

I took it back to the dealer last week as I have a 700 credit for their first BS repair not working nor the other 3 attempts to diagnose it and now they say again that it needs a valve body and "probably" a rebuilt tranny??

Note: The check engine light comes on and stays on a few days and then goes off for a few days.

any help would be greatly appreciated.

 

Wanted to also note that I was going weeks at a time with no issues after doing the key trick up until 2 weeks ago. It was not soemthing that I was doing every day.

 

is your check engine light on and if so what are the codes.

Most transmission malfunctions will trip a CEL and might shed some more light on what your issues in particular are.

You may need a rebuilt trans (which wouldn't be a bad idea at 160k miles if you plan on keeping the truck much longer)... It could also be as simple as shift solenoids acting up..

edit** i might also be mistaken but I thought that in the 08 CTD trucks it was a six speed auto once they went to the 6.7L..

 

Moved over to the CTD section for more help hopefully

 

Ben, you're correct, it's a 68RFE (pickup) or 68RC (cab/chassis), either is a 6 speed auto.

OP - you need to go to a dealership that has a tech who really knows these transmissions. Pulling the codes with a generic scan tool won't do you much good, it's undoubtedly one of the codes that says "hey, you've got a transmission code, check it."

Find out what codes the TCM is throwing. It could be a sensor, could be a number of other things.

 

I will have to run it somewhere to get codes tomorrow. I did grab the estimate the dealer gave me and this is what it says:
Performed computer scan and diagnostics. Pr4ovoded estimate of repairs and customer declined at this time.
Replace both 02 sensors & Blankets......400.00
Replace Air Filter,Fuel Filter, CCV Filter...350.00
Clean EGR System and Turbo................692.00
Transmission Overhaul.........................2350.00 (Or Replace with new 5860.00)

 

The EGR system is a nightmare on diesel trucks - it clogs up with soot, injects wear-causing soot particles back into the cylinder, soots up the variable vanes in the turbo, and fills the DPF up which causes the computer to trigger a regen which in turn drops fuel economy and in a lot of cases it dilutes the oil with fuel.

Do you live in an area that does regular emissions testing? If not, I would be highly tempted to rid yourself of the problem (knowing, of course, that you're breaking the law).

Are you handy at all? The CCV filter is about a dozen 8 or 10 mm bolts on the top of your valve cover. It's pie. Air filter likewise. The fuel filter is messier but not all that tough. O2 sensors are likewise easy, as long as they're not seized in there.

The EGR and turbo also probably need to be cleaned out, I gather there are instructions online for doing it.

The trans... does it really need to be overhauled/replaced? Or is it just acting up due to unpredictable input from those other systems that are going awry?

 

I have been away for a bit and not really messed with the truck. I was able to get all previous records from the dealer I took it to and each time the code showing was P0871 and twice it showed P0731

The first visit of 5 they replaced solenoid according to the records. Part # 8059043 and 4x4 filter.

2nd time around the notes say the tested and replaced PCM

In description it shows they replaced they module# TR 8035027

I took it to another location yesterday and it had code P0871. However thos guy told me it could be a million things other than tranny. He was a transmission guy but didnt really seem like it was going to be something he was the most knowledgeable at.

 

Tragically, I just lost my entire post.

Knowing what I know now, that I didn't know a few months ago...

It sounds like you may have issues. The 68rfe tech at Suncoast told me the other day that they were seeing some folks with repeat OD failures that were cured by replacing the valve body with a brand new one - to the point that Suncoast apparently isn't shipping the shift kit anymore with their mega rebuild kits, they're shipping a pre-built brand new valve body assembly.

I recently experienced something similar to what you were explaining in your original post. In my case, it was caused by the Suncoast TCM getting overwritten by a stock transmission program, which wiped out my overdrive clutches. The 4th gear only thing is a limp mode, caused by the abnormal readings the TCM is getting.

With my truck I was getting a different code, P0734 - gear ratio error in 4th. My overdrive clutches were completely smoked, and my 4c clutch pack return spring retaining ring had jumped its groove and the return spring was unsecured, flopping around getting chewed up, and it shattered the plastic thrust washer that sets the input shaft end play.

In your case, you're getting a gear ratio error in 1st gear. In order to trip that code, the correct gear ratio must be registered before it starts having issues - which is measured by input shaft speed versus output shaft speed. If your underdrive clutches are really worn, or if they've been heated to the point where they've warped, you'll have issues. When the TCM detects a gear ratio error, it's going to try and protect itself by locking down into 1:1 which is 4th gear in our trucks.

If you can find someone willing to throw a decent scanner on your truck, ask them to go into the TCM and write down the CVI numbers. If they don't know what CVI is, you probably don't want them rebuilding your transmission. CVI stands for 'clutch volume index' and really what it is is a measure of clearance in the clutch pack. The smaller the number, the tighter the tolerance (and if it's too tight, it's a sign of warped clutches and steels). Obviously too loose and your friction surfaces are gone.

When they replaced the solenoid pack and filter, they would have had to drop the pan, so you should have been billed for ~6 quarts of atf4.


The fact that it's intermittent sounds more like an electrical problem, but like the trans guy said it could be a number of different things, but the way you say it's behaving when it does act up definitely makes me think of my OD clutches which were toast. My OD clutch CVI was 21, and it should be (off the top of my head) closer to 55ish.

 

I appreciate all the insight and had found a company that specialized in truck trannies. I called them and shared with them all input here and elsewhere.

They said they could rebuild for 1497.00 including parts and would look at other issues and they assumed my problem was the valve body.

I agreed to have valve body replaced at 800 plus tax and 1497 to rebuild tranny.

My entire work order consisted of this:
1. Remove Unit 2. Planetary Gears 3. o'ring seals 4. compression seals 5. sealing rings 6. Complete rebuild kit installed 7. Valvebody 8. 1 hour diagnostic 9. converter 10. converter seal 11. test radiator transmission cooling circuit 12. filter 13. 2nd clutch pressure switch 14. 3rd clutch pressure switch 15. tcc lockup solenoid 16. torque converter 17. Replace Clutches 18. Servo Pistons 19. Recondition both Servo Bores 20 ReInstall Unit and Test Drive 21. OBD II test on test drive 22. Replace rear main seal


I picked up truck this morning and drove 21 miles to the house. I just left to go take it to the store and drove 12 miles. I parked and drove off and after driving off the check engine light pops on and the truck was pulling 2500 rpm before shifting into gears and woudl not shift into 5. I stopped turned off and turned on and it ran fine but after 5 miles did it again. o after all this my original issue is back.

Either something is really messed up or I just got robbed on repairs!