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Tranny issues, head scratcher 4 me and dealer

10K views 21 replies 6 participants last post by  Toon tugr 
#1 · (Edited)
OK have another thread going about an engine miss but have talked about more tranny issue than engine over there maybe get more attention here for specific issues.

Started getting P0933 almost everyday for 3-4 days every trip along with either P0734 and P0735 4th and 5th range ratio incorrect.

It has gone into limp mode after warmed up good as well during my last two trips, did it on way to dealer and this morning on way home from there once it kicks down on a hill with cruise set. But once it was shut off at dealer when I got there it reset and then couldn't get it to act up now until I came home, dealer took it for a couple 10-15 mile trips with no luck of getting limp mode or even an active code again.

Took to dealer a couple days ago they saw the logged P0735 but could not get any others to come back nor could they recreate limp mode. They did an update flash for tranny shifting and drivability that it needed and since then seems to be when the P0933 went away but On the way home from dealer this morning I got about 15 miles away and it already had P0735 and it shifted into 4th and stayed there and once I kicked cruise off at the exit it went into limp mode again, it had both codes for 4-5 ratio logged again by the time I got to my house but no P0933.

Pulled in my shop put up on hoist dropped tranny pan and spin on filter, pan was clean as a whistle, no residue of any sort in pan and nothing on magnet as well, it has about 15-20K on it since my last service and has had Amsoil ATF in it since 20K on the rig now has 80K miles on it. Cut open the spin on filter thinking possible tranny lockup clutch issue, found the spin on was just as clean inside not one speck of clutch material or even a noticeable flake of metal. Looked up inside sump filter and it too is clean as new.

Tranny does not nor has it ever felt like it slips either. Wondering if I have an issue inside the valve body or solenoid and want to know my options before going back up with new filter and pan.
 
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#2 ·
It would be interesting to try a different TCM, I mean it's a computer, and computers are not infallible. Or perhaps dealer could reflash it?
 
#4 · (Edited)
First, am I correct in assuming that the problem is with the 2010 5.7L truck, and not the 2005 Cummins truck? P0735 should not be a valid fault for the 2005 truck.

Have them read the DTC Event Data for the P0735 fault. DTC Event Data is a block of data that gets written into memory whenever a trans fault is set. It shows what was happening at the instant the fault set.

As a matter of fact, they should have already checked the DTC Event Data, if they followed the published diagnostic procedure for P0735. Maybe they just didn't find any clues there, but in case they haven't checked it yet, have them look at the turbine (input) and output speeds, line pressure, and desired line pressure in the DTC Event Data. They should look for any obvious problems, like line pressure that was way below the desired LP level, an input speed sensor that was reading zero while the truck was moving, etc.

The P0933 fault may be related to the P0735 fault. There is a counter of some kind (I forget the exact details at the moment) that is related to the P0933 fault. If that counter gets run up to a max value (64 I think), then it will set a P0933 fault if any slippage is detected inside the trans (like when you set the P0734 or P0735 fault). When they reflashed the PCM, that would have reset that counter to zero again, so I think that's why you're not getting the P0933 now. It also means that the P0734/P0735 is the real problem; you can ignore the P0933 for now.

If the DTC Event Data shows only minimal slippage and that the line pressure was OK, and they can't get it to easily repeat, then I would suspect you may have a problem with the solenoid module. Normally I would suspect a leaky OD clutch piston seal (giving you reduced capacity on the OD clutch). But the OD clutch carries much less torque in 4th gear than it does in 5th. So if you were setting a P0734 (Gear Ratio Error in 4th), then it should be really easy to blow the fault in 5th (if it was caused by a leaky seal). So I'm thinking maybe you have a chunk of debris in the OD solenoid that is intermittently giving you low pressure to the OD clutch. In any event, it's much easier to drop the pan and valve body and replace the solenoid module than it is to pull the trans to inspect the OD clutch, so if I were you I think I'd try a new solenoid module first (assuming, of course, the DTC Event Data shows no obvious line pressure or speed sensor problem). While they have the VB out, they can also air check the OD clutch passage to check for a leaky piston seal.

Hope you get 'er back on the road (without limp-in mode) soon!
 
#5 · (Edited)
Thank you for the info, from here I am going to do some of my own troubleshooting before returning to the dealer, I have my own shop and hoist and have the pan off it right now, I am capable of doing this myself, can you get a diagram or picture of which port I need to pressurize and how much pressure is safe to apply to port?

Thank you so much for the info.

I have been getting the 5th gear ratio fairly easy pretty much every time it is warmed up and it kicks down on a hill with the cruise set at 70-75 mph in hills I have noticed or if I get on it and kick it down I saw it would pop up before taking it in to the dealer. I would suspect that when it kicks down under load on some hills is when it sets the 4th gear error as well.

When one replaces the solenoid module does one need to do a relearn or reflash again to recalibrate fill rates and such? I am a heavy diesel tech and work on heavy mine equipment and this is fairly common on a lot of newer equipment.

Also do you know what the torque spec and sequence is when going back up the the VB? Thanks again.

Bill
 
#7 · (Edited)
Transengineer

What are your thoughts on replacing the solenoid bank every 80-100K miles as my link below shows and what are common symptoms of a solenoid bank gone bad on these trannies? I would like your take a bit more before throwing 250-300 bucks at it for no reason.
http://www.cascadetransmissionparts.com/545rfesolenoidblock.aspx

Also what are your thoughts on line pressure boosters?
Scroll down just a bit in the link to find its description.
http://www.transmissioncenter.com/45RFE_545RFE_68RFE_Performance_Transmissions_and_Parts.htm
 
#8 ·
I would not replace the solenoid module as "routine maintenance." I would replace it if there was a problem with it. Typically, solenoid failures involve electrical issues (bad solenoid coil or bad pressure switch) that can be verified with a multimeter. I would not say solenoid failures are "quite common." What is common is solenoid replacements by mechanics who find a solenoid-related fault code and "try a solenoid to see if that will fix it" (it often doesn't).

I am not a fan of line pressure "boosters". They will give you some benefit, but in the long run the TCM will "learn" and adjust to the different pressure readings, so I think much of the initial benefit disappears over time.

The diagram of the case ports is on page 7 of the service manual you found online. I would use about 30 psi to air check the clutches. Note that there is a small air bleed orifice between the OD and Reverse clutches, so when you blow air into OD you will get some air bleeding out of the Reverse port (and vice versa). But you should not hear any significant HISSSS when you air check the clutches, and you should be able to see or hear the pistons move when you apply pressure (usually a dull thud sound).
 
#10 ·
Made an apt with dealer for next Monday again now that the codes are logged and now so the dealer can look at the data now that I see my engine oil sample looks ok I will dig into this tranny issue further now. This is last chance for dealer before going to local custom tranny shop.
Pulled both speed sensors and they looked clean and in good shape put it all back together with new spin on filter and same oil I drained out as it looked like new yet.
 
#11 · (Edited)
Took the pickup to town today to drop it off at the dealer for Mondays apt, live 30 miles out of town and work shift work in the country even further from town so got to do these things when one can. ;)
She ran flawlessly all the way to town and around town a bit until I was merging onto the freeway and got on it just enough for a kickdown to merge with traffic and the CEL came on at that point, still shifted perfect no slippage noticed or anything out of the ordinary, checked codes with BD and still only the 2 codes P0734 and p0735 as usual so the dealer should have more to troubleshoot now since things are logged have an active CEL set. Will wait for the call on Monday to see what the issue is, hopefully just electrical.
I ordered a Pressure booster today as well and will install it after all is figured out and repaired.

The one thing I have noticed the last couple times I have driven it is when I have tow haul activated it will never ever shift into 5th gear no matter how easy I drive it, just stays in 4th all the time, kick tow haul off and it jumps right into 5th.
 
#12 ·
Dealer called back, was able to recreate issue several times, checked out all electrical was fine concluded internal seal leak on clutch or accumulator piston. Will take rig to reputable local tranny shop to be rebuilt, owner of the shop was out sick today will talk to him tomorrow and visit about options price make an apt and go from there. :popc::smiledown:

80K miles on the pickup and the first auto tranny failure I have had in roughly 20 years, not since owning mid 80's GM pickups with the 700R4 have I had a tranny issue. Stock rig and has a fairly easy life other than towing my pontoon and small utility trailers in summer but even then I don't abuse it. Not impressed here now, Tranny shop says nothing new to them on the rigs with the Hemi and Diesel engines.
 
#19 ·
Rig goes to the tranny shop Friday, they charge a set $2395 to rebuild tranny which includes upgraded clutch packs, shift kit and other Valve body mods, a new torque converter set up for individual use and needs and a few other basic upgrades though out.

Then they charge $700 for the R&R and the test and tune and calibration after the rebuild. They don't do carry in rebuilds on the newer rigs that require calibrations as they have had issues in the past with this, so in order to get a warranty they want the whole job in house which is ok with me I have too many irons in the fire at the moment.
 
#20 · (Edited)
Talked to tranny shop and they found two things, 4th gear clutch pack along with lockup clutch in converter showed a lot of slippage.

They will hopefully have it done by weeks end or early next week, they got the new converter in tuesday, they use "Precision" as the company for their converters, anyone have any experience with them and how is overall quality?

I am assuming they have a pretty good product as this tranny shop is very reputable and is known for their quality high hp tranny builds and doubt they would use the company if they had any issues that would affect their reputation.
 
#21 · (Edited)
Picked it up from the shop yesterday for 3200 bucks. New tighter slightly lower stall anti ballooning disc converter with better lockup clutch from Precision converters of new Hampton IA., a better stacked 4th gear clutch pack, he stacks them with more discs like the 68 rfe tranny behind the Cummins but he stacks the discs a bit different to help longevity and dissipate heat better can't remember all of what he said about it, shift kit and a few other in house mods and Sonnax parts into to the valve body as well as improvements to the pump.

He said that 4th gear is the weak point in these trannys and they all fail due to this as they only have 4 clutches and they all slip and burn up. Said he has never seen a 545RFE come in his shop without a failed 4th gear clutch pack. Because of being fully electronic and having no aftermarket come up with an unlock for the ecm to allow much higher pressures there isn't much one can do for these trannies unlike the diesel market.

Just loaded up some updates from Bully Dog on the BD GT Hemi tuner and reregistered it in my name and loaded up the "premium" tune this morning and will give it the first drive with everything hopefully working tonight when my wife and I head to town for a night out together.


Will post back results after I return later tonight or tomorrow.:smileup:
 
#22 ·
Thing drives awesome, I can actually feel all of the shift points now, not harsh at all but they are distinct kind of like older pre electronic controlled auto trannies where you could actually feel the shift points not like most new vehicles or the way it was stock where you could slightly feel the 1-2 shift and nothing from there other than engine differences telling you it shifted not like the soft sloppy sliding in shift points, converter is definitely tighter, throttle response off idle is like running a smarty on the cummins with TQ management turned to lowest setting, very touchy and instant response almost touchy, will take some getting used to and part of it may be the Bully Dog as well but I think most of it is just the tighter converter putting more of the 5.7 Hemi 390+ hp and 407+ tq to the ground now.
Now I need to see how it does with a trailer on behind it should pull nice, I think all said and done I was hearing the tranny issue as I can not pick up on what I perceived as an engine miss anymore either.

Now with the new responsiveness I definitely need the Limited slip diff carrier as I can see a lot more one wheel slip with this setup.
 
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