transmission problems???

[molinas hemi]

worth a shot at this point, I wanna wait on taking it to a shop before I get ***** on labor charges, my other friend is rebuilding a motor at the moment so its gonna be a little bit before I get my truck fixed anyway, thank god I have my subie as my daily.

 

[molinas hemi]

forgot to mention, that when I started it to drive to the auto part store to check what code popped up, I came to a stop and it died. it started right back up so I turned home to park it. anyone else have or having the same problem? now im more then confused why it did that

 

[Dusty]

I hope im doing this right, im new on here with a problem. So recently I was driving my truck (2012 1500) and it felt like it shifted hard then my check engine light came on. the code was P0734 (incorrect gear 4 ratio) I replaced the tranny fluid, rear differential (about a week ago) and the kick down solenoid (yesterday). nothing help. the other day I was driving on the freeway and it kicked down to 4th gear and wouldn't shift so I pulled off the freeway turned it off then restarted it and it worked fine but the check engine light came back on for P0734 & P0735 (4th & 5th gear) now. when I speed up so I can hear my tranny shift it bucks/jolts into 4th gear. im at a loss, I tried everything I can to fix it before I take it into a shop. I don't know what could be going on, ive read everything from it being the fluid level, solenoid, clutch or a misfire. if anyone can help me before I spend over a $1000 to take it in id appreciate it

These RFE transmissions are extremely reliable. Based on the codes you could have a line pressure problem. You said you changed the transmission fluid. Did you change the two transmission filters as well? Did you use ATF-4 fluid?

Before I'd suspect the Transmission Range Switch (TRS) or a dirty Valve Body, I'd check the Input Speed and Output Speed sensors. If they get out of voltage range they can hang on the very edge and skip pulses.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Now at: 010497 miles.

 

[AlnSouthCarolina]

I hope im doing this right, im new on here with a problem. So recently I was driving my truck (2012 1500) and it felt like it shifted hard then my check engine light came on. the code was P0734 (incorrect gear 4 ratio) I replaced the tranny fluid, rear differential (about a week ago) and the kick down solenoid (yesterday). nothing help. the other day I was driving on the freeway and it kicked down to 4th gear and wouldn't shift so I pulled off the freeway turned it off then restarted it and it worked fine but the check engine light came back on for P0734 & P0735 (4th & 5th gear) now. when I speed up so I can hear my tranny shift it bucks/jolts into 4th gear. im at a loss, I tried everything I can to fix it before I take it into a shop. I don't know what could be going on, ive read everything from it being the fluid level, solenoid, clutch or a misfire. if anyone can help me before I spend over a $1000 to take it in id appreciate it

I had a similar problem with my 2013 Ram 1500 2 wheel drive. Had to have the valve body replaced. Not a rebuild. Buddy of mine owns a trandmission shop and does excellent work. He diagnosed it and dod the work. No more problems mine had about 130K hope this helps.

 

[fulltow646]

I understand we have totally different trucks. I have a diesel and you have gas unit. What we do have in common is that when I changed the tranny fluid and filter I experienced similar issues as you are having with your truck. It bucked, especially when backing up, was not shifting correctly. Tried everything to determine what the problem was as everything was working just fine prior to changing the fluid and filter. After running the issue by my local Aamco Tranny shop, it was suggested that I check the internal filter installation. Sure enough I had failed to seat the filter properly and it was sucking air with the fluid. Reseated the filter properly and the issue was solved. Bottom line is that the tranny was not circulating the fluid properly. The bucking you mention sound like the same issue I had. Make sure you used the proper fluid, have the right amount, and that it is circulating properly. Again my problem was all about the tranny not getting enough fluid even though it had the right quantity.

 

[molinas hemi]

These RFE transmissions are extremely reliable. Based on the codes you could have a line pressure problem. You said you changed the transmission fluid. Did you change the two transmission filters as well? Did you use ATF-4 fluid?

Before I'd suspect the Transmission Range Switch (TRS) or a dirty Valve Body, I'd check the Input Speed and Output Speed sensors. If they get out of voltage range they can hang on the very edge and skip pulses.

Best regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Now at: 010497 miles.

bought a kit for my tranny flush so replaced the filters used ATF-4 fluid, 2 days later changed the solenoid. it check engine light will come on then go off 2 days later then come back on, so im still at a loss for words

 

[molinas hemi]

I understand we have totally different trucks. I have a diesel and you have gas unit. What we do have in common is that when I changed the tranny fluid and filter I experienced similar issues as you are having with your truck. It bucked, especially when backing up, was not shifting correctly. Tried everything to determine what the problem was as everything was working just fine prior to changing the fluid and filter. After running the issue by my local Aamco Tranny shop, it was suggested that I check the internal filter installation. Sure enough I had failed to seat the filter properly and it was sucking air with the fluid. Reseated the filter properly and the issue was solved. Bottom line is that the tranny was not circulating the fluid properly. The bucking you mention sound like the same issue I had. Make sure you used the proper fluid, have the right amount, and that it is circulating properly. Again my problem was all about the tranny not getting enough fluid even though it had the right quantity.

ill double check the filter I replaced but this problem start about 3 weeks prior to changing my fluid. im seriously hoping its something simple and stupid that's causing these issues.

 

[TX_PW]

I don’t believe you mentioned how many miles are on the truck. I had the same issues at 94k miles and took it for a tear down. The friction packs were toast. Fortunately I had a extended warranty and they paid $3750 of the $3800 rebuild cost. I had them upgrade with a billet valve body, sonnax internals and a line booster kit. If it comes down to a rebuild def upgrade the internals. Just to give you an idea of rebuild cost...it won’t be $5000.

 

[Dusty]

I understand we have totally different trucks. I have a diesel and you have gas unit. What we do have in common is that when I changed the tranny fluid and filter I experienced similar issues as you are having with your truck. It bucked, especially when backing up, was not shifting correctly. Tried everything to determine what the problem was as everything was working just fine prior to changing the fluid and filter. After running the issue by my local Aamco Tranny shop, it was suggested that I check the internal filter installation. Sure enough I had failed to seat the filter properly and it was sucking air with the fluid. Reseated the filter properly and the issue was solved. Bottom line is that the tranny was not circulating the fluid properly. The bucking you mention sound like the same issue I had. Make sure you used the proper fluid, have the right amount, and that it is circulating properly. Again my problem was all about the tranny not getting enough fluid even though it had the right quantity.

Good comment. This a problem I've seen twice myself and a transmission tech. i know has seen it as well. That little spin-on really needs to pretty tight. I think because it's a spin-on people liken it to an oil filter, which really doesn't need to be very tight.

Regards,
Dusty
2019 Ram 1500 Billet Silver Laramie Quad Cab 2WD, 5.7 Hemi, 8HP75, 3.21 axle, 33 gallon fuel tank, factory dual exhaust, 18” wheels. Now at: 010536 miles.

 

[Mitch1204]

I don't know if it applies to you but I'll tell you the story. A friend of mine has a 2002 Dodge Ram 3500 5.9L Diesel. Around 50 mph it would be in 4th gear and buck. It was trying to go into 5th. He had it in a couple dealers and a few other shops with no luck. After searching I started finding articles about what is called the "4th gear hunt". There was about 3 fixes but the general idea is the signal going to the PCM is all distorted confusing the PCM whether to be in 4th or 5th. The cause was the main wiring harness runs on the back of the alternator. The alternator diodes put out distortion and it bleeds over to the main harness.
I tried a YouTube fix and 6 months later it is still shifting perfectly. The fix and it sounds stupid is you remove the harness from the back of the alternator. Wrap it with tinfoil, yes tinfoil, lol then wrap it with electrical tape. You then pull the harness in front of the alternator and cable tie it to the top of the radiator cover. I then ran a new ground wire, 12 awg, from the negative battery post to the PCM mount screw on the firewall. This trick cleans up the signal to the PCM so it functions properly. You can search "4th gear hunt" and find it. It worked for me. I'm not sure if it's just a 2nd generation diesel thing or not. Look and see if your main harness to the PCM runs right behind your alternator. There are other fixes like a filter on Amazon and ebay you can buy.

 

[molinas hemi]

I don’t believe you mentioned how many miles are on the truck. I had the same issues at 94k miles and took it for a tear down. The friction packs were toast. Fortunately I had a extended warranty and they paid $3750 of the $3800 rebuild cost. I had them upgrade with a billet valve body, sonnax internals and a line booster kit. If it comes down to a rebuild def upgrade the internals. Just to give you an idea of rebuild cost...it won’t be $5000.

Im barely at 70500