transmission problems???

[molinas hemi]

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

 

[crackerjack1957]

Sorry to say but sounds like rebuild or new transmission time........going to be more than $1000 unless you can find a good salvage.

 

[Burla]

Dunno, could be shift solnoid, I'd do a line pressure test.

One thing I would do as an absolute, see what local transmsion shops do the upgrades to the 66 and 68rfe, and TALK to them. You wont just want the standard rebuilt kit, it just leaves a bunch of weaknesses and old parts in there. Do some research around here, I think the last 50 pages or so of syn thread, might want to check it out invaluable tranny info, maube even the last 100 pages. We have been talking mainly about tranny's lately.

This is assuming you can invest in your truck, if not then ignore what I said, and go on the cheap, maybe it will work out. But you are loooking between 6 and 10 grand for all the goodies.

 

[molinas hemi]

im going to have my friend who has his own shop look at it before I go through with a new tranny, he looked at it before I replaced the kick down solenoid and said its probably that, he doesn't think I need a new tranny but I did what I could to avoid having to drop it so I guess ill go from there and hopfully its not to the extint of a new tranny. maybe the clutch or torque converter? fingers crossed

 

[Burla]

It doesn't sound like a torque converter to me, and you have to drop the tranny anyway for that. If it is something in valve body area then you can drop VB put in shift kit at a minimum, fix solonoid and that you can do w/o dropping tranny. Past that, you will need ro drop and at that point fix it right. Also, you can pay an hour rate for dealer, maybe there is an update that can fix this and check for recalls.

 

[Scottly]

It's fooked. You're welcome.

 

[Burla]

Just to see the tear down of your transmsion, it is very similar to this one. This is a must watch before you take it in somewhere. Know what you will ask them to upgrade. The one thing I don't believe this does, I could be wrong, but they don't address how important valve body upgrade is. You need a gasket at a minimum, plate at a maximum. shirt kit gasket 150 bucks plate near 600.

 

[molinas hemi]

so it shifts fine 90% of the time, it mainly bucks/jolts when I speed up a hill going into 4th or when speeding up from a stop light itll happen. but if my tranny is bad, wouldn't I hear grinding or whining or something? I just replaced the solenoid yesterday but that didn't fix anything. it shifts into drive reverse and through all gears just fine, but its random, sometimes when I hit 4th it'll did it other times it wont

 

[Burla]

While it is apart, ask then to check the shift linkage detent pin, a 3 dollar part that sometimes fails. I'd just as for a new one, it is the pin that roles along the shift linkage to choose the gear you select, sometimes that pin comes out. The fix is to have a pin that wont come out. cheap part.

 

[Burla]

so it shifts fine 90% of the time, it mainly bucks/jolts when I speed up a hill going into 4th or when speeding up from a stop light itll happen. but if my tranny is bad, wouldn't I hear grinding or whining or something? I just replaced the solenoid yesterday but that didn't fix anything. it shifts into drive reverse and through all gears just fine, but its random, sometimes when I hit 4th it'll did it other times it wont

you dropped the valve body yesterday?

 

[Burla]

Sounds like maybe a piston spring.

 

[molinas hemi]

yes I drained the fluid took out the valve body and replaced the solenoid.

 

[BWL]

Since it happened just after a trans flush I suspect the problem is something got stuck in the valve body in the process. Not unusual for that to happen. Especially if you stretch the interval. There's usually gum and varnish build up in there that can come loose during the flush process.

 

[molinas hemi]

all this started happening before the flush, o' reillys recommended a flush so I did that. the fluid was still nice and reddish-pink with no shavings or anything on the magnet. when I took out the valve body to replace the solenid everything looked good also. Im not that mechanically inclined but I exhausted all my options with the tools I have. so I gotta wait till my friend gets done working on another vehicle so he can look at mine.

 

[Burla]

Absent taking it to dealer and getting updates, I think you have done all you can do. I would ask the local shop on the cost of a line pressure test. Watch that video, sorry I couldn't help, gl with it.

 

[molinas hemi]

thanks Burla

 

[crackerjack1957]

so it shifts fine 90% of the time, it mainly bucks/jolts when I speed up a hill going into 4th or when speeding up from a stop light itll happen. but if my tranny is bad, wouldn't I hear grinding or whining or something? I just replaced the solenoid yesterday but that didn't fix anything. it shifts into drive reverse and through all gears just fine, but its random, sometimes when I hit 4th it'll did it other times it wont

Clutch pack for that gear slipping under load.

 

[U&A]

Clutch pack for that gear slipping under load.

Probably is slipping because of inadequate line pressure

These transmissions keeping the proper line pressure is an issue

Sent while firmly grasping my redline lubed RAM [emoji231]

 

[Burla]

Then the issue becomes what would you do if it was line pressure. Maybe it's leakage, he can drop valve body and put in gasket or plate, and a tune and pressure protection, check valve body pistons, but then that might not solve it anyway. But, it is something he could do, and would benefit the new rebuilt tranny if it came to that as well. Or just look for a plug and play upgraded VB, I do believe if he sends his core to sharadon they will do a valve body upgrade, plug and play. But you will be w/o truck while they do it, maybe a couple weeks. If it was me, I would be prepared to drop some coin, and I would start with VB. Because the next step is dropping tranny, then you have to do VB anyway, or you are just tossing your old used VB at a new tranny, bad idea seeing it is possible no matter what is wrong the problem likely started with VB.

 

[crackerjack1957]

Probably is slipping because of inadequate line pressure

These transmissions keeping the proper line pressure is an issue

Sent while firmly grasping my redline lubed RAM [emoji231]

Line pressure would affect all gears........not just 4th

• 545RFE Code (DTC) P0734 Gear Ratio Error in 4th
  
• 545RFE Code (DTC) P0735 Gear Ratio Error in 4th Prime