Transmission problems

[Spencer0526]

I’m probably posting this in the wrong place but
I have a 13 ram 1500 5.7 hemi 4x4 with the 65rfe trans and about 2 weeks ago I was on my way home driving normal and the trans started stuttering and slipping it threw codes so I drove it home and used my Diablo tuner to read codes it read codes p0734,p0735, and p0933 I looked on here and found people saying it was clutch pack instead of changing clutch pack in trans I went and got a different one cause it was cheaper anx what I can afford before I got trans I tried replacing the hydronic pressure sensor and the trans fluid and filters it didn’t fix problem I just finished the trans swap last night and got everything back in and everything used the new transmission filters and replaced trans fluid with new and it’s still doing the same thing it’s taking off fine but once it shifts to second gear it speeds up then at about 30-40 mph it’s like trans slips and acts like it’s in nutral if I give it more gas eventually after I basically floor it it kicks back in but only goes to 50mph and starts redlining and bouncing off rev limiter at 6500rpm I have a hemifever custom tune but shift points are set at 6200rpm I had a local shop hook truck up to there reader and it read that it had low fluid pressure I made sure it had enough fluid and everything I’m at a loss currently I just bought a can of killer kleaner and once I get back home I’m gonna try flushing the trans cooler any help would be greatly appreciated sorry for the long post thanks

 

[Treburkulosis]

For first off can you give us some back story of maintenance on your truck. Please include actual miles. Tnanks.

 

[Spencer0526]

I got the truck with 94k miles on it it now has 130k and some change about a week before trans went out the abs sensor went out and the waterpump went out I changed the waterpump and drove it a week before the trans went out I just changed the abs speed sensor today it didn’t help but I have done routine maintenance changed oil every 3-5k miles haven’t had to do anything else to the truck I got the truck the first of this year and yes I know I’ve put a lot of miles on it I’ve been all over the place I drove it to Daytona beach from western ky 800 miles both ways with no stops back in July and it did just fine

 

[NOV87]

What happens if you load stock TCM file instead of Hemefever one? Probably a far shot, but something quick to check.

 

[Spencer0526]

I tried that it still did the same thing I cleaned the trans cooler out and it shifted into 3rd now but 4th still revs out anx won’t take off

 

[Burla]

I cant understand your post, you replaced the transmission? Maybe try posting what you did to fix without paragraph, like this example, or reread your first post and fix it?

Replaced fluids
Replaced Transmission
Replaced Valve Body
etc

you can be in limp mode, the trans is protecting itself at that point.

 

[Hemi395]

The codes its throwing are: P0734 - Gear Ratio Error 4th Gear, P0735 Gear Ratio Error 5th gear, and the most important one IMO is: P0933 - Hydraulic Pressure Sensor Range/Performance. I think the P0933 is where your direction should go. The RFE trans fluid pressure is PCM controlled and if its not reading correctly, the PCM lowers pressure and your clutch packs start to slip which would give you the P0734 & P0735. Looks like it could be a bad pressure sensor or a wiring problem to the connector for the pressure sensor.

• When Monitored: Continuously with the ignition on, engine running and with the transmission in gear.
• Set Condition: The Powertrain Control Module (PCM) continuously monitors Actual Line Pressure and compares this to Desired Line Pressure. If the Actual Line Pressure reading is more than 172.4 kPa (25 psi) higher than the Desired Line Pressure, but is less than the highest Line Pressure used in the current gear, the DTC sets.

From what I remember the pressure sensor is on the passengers side rear of the trans. Check the simple stuff like corrosion in the connector or a broken wire.

 

[Burla]

Start there, but another likely suspect of low psi in trans is a leaky valve body and accumulator pistons, and can be shift solenoid as well. If you can change the transmission fluid and filters dyi, you can change VB and solenoid pack. The longer you drive it with a leak the more you can hurt clutch packs if not already, but since it is so soon it might be worth a shot to swap VB and Solenoid. Start with easiest and cheapest fixes like hemi395 said and maybe move up, but do it soon, if it is in limp and you keep driving it you may end up needing to replace or rebuild the thing.

 

[Spencer0526]

I have a feeling it might be something with the wiring on that pressure sensor plug. I’m gonna look into it after work. I’ve so far changed the hydraulic pressure sensor plug in the original trans and the fluids which was grey/black/red when I changed it along with the filters and that didn’t help so I went ahead and changed the trans itself along with the torque converter. I did get a used one from 74 auto in Missouri and that still didn’t fix my issues. it started throwing more incorrect gear ratio codes (1st gear 2nd gear 4th and 5th gear and it threw a code for the line pressure low or something along that line of code. I cleaned the trans cooler out completely and now it’s going into 1st 2nd and 3rd fine but if I shift it to 4th gear it revs up real high before the trans kicks in but won’t go any faster than about 70 if I’m up that high in speed but once I shift it to 4th and try to go back down in gears it does the same thing in those gears as it does in 4th gear then I have to come to a almost complete stop and take back off for it to not rev up.
List of things replaced:
:Transmission and torque converter
:Trans fluid and both filters in both transmissions
:Hydraulic pressure sensor but that didn’t fix my problem in the first transmission so I returned that plug
:Cleaned out the trans cooler with a can of koolerklean and a air compressor

 

[Burla]

did the new tranny have it's own valve body and solenoid pack? or you use your old one?

 

[Spencer0526]

The new to me transmission came with one I didn’t use mine out of old trans

 

[Hemi395]

The new to me transmission came with one I didn’t use mine out of old trans

Yeah I would definitely be looking at a wiring problem then. After 2 different trans with 2 different valve bodies/solenoid packs with the same exact problem points it to something electrical. Don't forget the RFE trans fluid pressure is 100% controlled by the PCM. If you look at the trans fluid pressure on a scantool you will see the PCM changes the line pressure a LOT. If that pressure sensor data isn't getting to the PCM the trans will do all kinds of crazy things.

I'll try to find a pin out of that connector...

 

[Hemi395]

@Spencer0526 heres that connector pin out. You can easily check the ground and the 5v reference with any volt meter. The signal wire you might need a scantool to see if the PCM is recieving the right signal from it...

Pin	Circuit	Wire Color	Gauge/Size	Function
1	K900	DB/DG	20	SENSOR GROUND
2	F856	YL/PK	20	5 VOLT SUPPLY
3	T38	YL/BR	20	LINE PRESSURE SIGNAL

 

[Spencer0526]

Thank you I’ll look into it here in a bit

 

[Spencer0526]

What I don’t get is if it’s in limp mode and yes the trucks custom tune is tuned this way but it will still do 100 in 2nd gear and 120mph in 3rd I tried seeing if it would kick itself in up on top end (on a closed road) (for anyone deciding to get rude) but I wouldn’t think that would be limp mode then

 

[Hemi395]

What I don’t get is if it’s in limp mode and yes the trucks custom tune is tuned this way but it will still do 100 in 2nd gear and 120mph in 3rd I tried seeing if it would kick itself in up on top end (on a closed road) (for anyone deciding to get rude) but I wouldn’t think that would be limp mode then

Limp mode in the RFEs is when the trans defaults to 4th gear no matter what speed you're going. How I understand it is its in 4th gear from a stop and it won't shift to any other gear. I believe there are specific codes it will throw when its in limp mode. What you're experiencing is something different....

 

[Spencer0526]

Limp mode in the RFEs is when the trans defaults to 4th gear no matter what speed you're going. How I understand it is its in 4th gear from a stop and it won't shift to any other gear. I believe there are specific codes it will throw when its in limp mode. What you're experiencing is something different....

That’s what I was thinking I’m having to manually shift it right now 1st threw 3rd so it doesn’t shift to 4th gear so im not sure

 

[crackerjack1957]

Maybe a bad wheel speed sensor if scan tool doesn't read codes

Dodge Ram 65RFE Erratic Shifting - Transmission Digest

No trouble codes are stored, however, the scan tool indicated the downshifts out of sixth and fifth gears were commanded.

www.transmissiondigest.com

 

[Canadian-Hemi]

Almost sounds like Torque converter not locking up properly.

 

[Spencer0526]

I just replaced my wheel speed sensor that went out before trans had problems it didn’t fix it and I would think torque converter but it drives just fine in 1-3rd gears