66rfe issue

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64on37s

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Hello everyone I have an issue I’m hoping I can get some help with. I have a 2016 2500 6.4. I have 103000 miles and just did my 120000 mile trans service (fluid and filters). After finishing the service the truck isn’t shifting properly. It had some trouble from 1st to 2nd, I check the fluid level and it read low. I added a qt and then it shifted great. After a couple days I noticed it slipping from 2nd to 3rd but not everytime. Then it started hunting for 5th then hard shift, check engine light and then felt like it was stuck in 4th, still let me manually shift all gears but didn’t actually shift. I checked fluid levels and it was high. I removed a little over a qt, reset the light and took it for a drive but same thing (hunting for 5th, hard shift then sluggish). I am going to drain and drop the pan and make sure nothing happened with my filters but Any ideas are appreciated.
 

Daw14

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Check your threads on the screw on filter ,they are plastic and are known to crack or break . There are steel replacements available. Also be sure of the temps you’re checking fluid at ,volume changes greatly with the temperature. Make certain the truck is in neutral when checking fluid.
 
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64on37s

64on37s

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Ok cool I’ll check the threads on that filter. My temps have been around 150 when checking and I’m in neutral everytime. Maybe that’s why I added too much though I read it at a lower temp than actual operating temp making me think it was low. Thank you for the advice
 

Burla

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Sadly, it might not be the issue but if the thread is the issue, you really need to fix it or tranny dies, here is a thread on filters and the metal thread upgrade. Also, did you do the sump filter correctly? Remove the seal and put new seal back? Sometimes guys will leave the seal in and put new seal on, will leak if so. You can try driving in tow haul, but literally only for a short trip or two, you need to fix this and leave evic on trans temp.

@U&A found these and his post still shows them available, this guy sells single pieces I do believe, this is the one you want, do not get other metal thread upgrades, these ones fit tight and other choices fit loose, no good. That guy also sells 3 packs, if you get one of those I know forum will buy 2 off you basically making it free for you. Kyle even made a little dough off buying ten.
 

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What tranny fluid did you use? Was it Mopar ATF+4 fluid? ...or "the other leading brand"?

My money is on a possible fluid compatibility issue ..assuming the level is correct and the tranny filter seal is 'good'. You should definitely check them. A boogered up seal could be sucking air. Make sure it's not over-filled too.

A different brand fluid can sometimes have an ever so slight difference in make up or base-stocks affecting final friction subtly. Or combining it with whatever fluid was left in the transmission can affect the final friction. The transmission clutch packs are made up of many individual clutches and a couple friction bands which are 'bathed' in ATF. It would take only the *slightest* difference in friction multiplied across all those clutches ..to affect the 'smoothness' of shifting. This kind of thing also occurs in manual transmissions too. Some fluids and/or combinations can subtly affect how synchronizers behave ...but impact shifting 'feeling'.

Something to look into ...assuming the level is accurate and the filter was installed properly (sealing properly).
 
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Jeepwalker

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I've seen different fluid create transmission shudder so extreme you swore the transmission was going to blow (only to behave like new after a different fluid was changed). When this occurs on a high-mile tranny people often think the worst. I would too. Therefore if a different fluid was used, I would first try a different fluid. And if it were me, it would be OEM. Smaller Chrysler parts departments will often sell fluid out of their barrel real cheap (bring your own jugs).

I personally would run the remaining fluid in the torque converter out the tranny cooler line (there's a special process for that you'd have to investigate). Or have your dealer do a complete fluid exchange with their machine, ..be the easiest/quickest.

Sometimes a guy can add a friction modifier to the fluid ..or in certain amounts till the problem is resolved, and that's something worth considering too. That's why I generally use OEM ATF fluids nowadays.

 

Jeepwalker

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Did you do any other work to the truck, besides changing the tranny fluid?

You should probably read the codes, or swing by Autozone/OReilly/Napa and have them read the codes ...if you don't have a scanner. And have them also read the tranny codes (different section in the scanner menu). It's possible one of the solenoids is flaking out too. And they're easy to replace. It's so common they even have a 'kit' for it lol. I had a Jeep with the same basic tranny that was shifting like you're describing ..and new shift solenoids later it ran like a champ. And some 10 yrs later, we still have the Grand Cherokee (kids car) and the tranny still works great, 130k miles later.

There could be other things which could affect transmission shifting ...which is why knowing any codes would be helpful. You should probably get the codes before doing anything else ..just in case.

.
 
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HEMIMANN

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If the oil (I dislike calling oil a fluid like it's a magic liquid) hasn't been changed for this long, and especially if the truck doesn't have an oil cooler thermostat bypass, I can assure you there are internal deposit issues clogging things up.o

Get about 3 more filters, including the main flat filter, and a 5 gallon pail of MOPAR ATF+4,
and change every couple hundred hours. If it doesn't clear up, you're screwed and need an overhaul and cleaning.
 

U&A

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If the oil (I dislike calling oil a fluid like it's a magic liquid) hasn't been changed for this long, and especially if the truck doesn't have an oil cooler thermostat bypass, I can assure you there are internal deposit issues clogging things up.o

Get about 3 more filters, including the main flat filter, and a 5 gallon pail of MOPAR ATF+4,
and change every couple hundred hours. If it doesn't clear up, you're screwed and need an overhaul and cleaning.
Hate to say it but im thinking this.

Iv been very absent on the forum but i can say years ago I was heavy into trans fluid research, alternative trans filters options (stock sucks b@!!s) the metal thread vs plastic on and on. Cutting brand new filters open and stock ones. Bla bla….

Biggest….BIGGEST most important thing EVER for the RFE…. Not filter choice. Not metal thread thingy.

#1). Keep it clean.

Only way is changing the fluid……i mean…OIL .. very frequently. The RFE is actually a pretty good transmission minus programming.

Her down side is she will NOT deal with anything but clean fluid. I wont go into the oil debate any more. But i do not use ATF+4 and will not. I changed fluid every 20,000 and filters every other fluid change. Its not crazy. Its a clean trans.

To may known RFE trans failures/problems from dirty fluid.

I remember a fella (passed away) that ran valvoline max life trans fluid in his 8 speed. Heaven forbid maxlife in an 8speed. He changed it often and it ran great.

and Mike nailed it too. Get the metal thread thingy anyway. Just return it if the threads are sloppy. Check it on a new filter. The one Mike gave you a link to is a good one in the sense that the threads are nice and tight fitting as well as the center is broached for an Allen wrench. Makes it way easier to get it on and off the filter and trans Housing. Imagine trying to unscrew that thing with a straight thru hole in the center and nothing to put a wrench on.

And before you drain it again get. UOA kit and send in a sample NOW. Check the TBN too. $30 with postage give or take.
 
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HEMIMANN

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Hate to say it but im thinking this.

Iv been very absent on the forum but i can say years ago I was heavy into trans fluid research, alternative trans filters options (stock sucks b@!!s) the metal thread vs plastic on and on. Cutting brand new filters open and stock ones. Bla bla….

Biggest….BIGGEST most important thing EVER for the RFE…. Not filter choice. Not metal thread thingy.

#1). Keep it clean.

Only way is changing the fluid……i mean…OIL .. very frequently. The RFE is actually a pretty good transmission minus programming.

Her down side is she will NOT deal with anything but clean fluid. I wont go into the oil debate any more. But i do not use ATF+4 and will not. I changed fluid every 20,000 and filters every other fluid change. Its not crazy. Its a clean trans.

To may known RFE trans failures/problems from dirty fluid.

I remember a fella (passed away) that ran valvoline max life trans fluid in his 8 speed. Heaven forbid maxlife in an 8speed. He changed it often and it ran great.

and Mike nailed it too. Get the metal thread thingy anyway. Just return it if the threads are sloppy. Check it on a new filter. The one Mike gave you a link to is a good one in the sense that the threads are nice and tight fitting as well as the center is broached for an Allen wrench. Makes it way easier to get it on and off the filter and trans Housing. Imagine trying to unscrew that thing with a straight thru hole in the center and nothing to put a wrench on.

And before you drain it again get. UOA kit and send in a sample NOW. Check the TBN too. $30 with postage give or take.
Thanks - keeping oil from high temp also keeps it clean from oxidation and shear deposits.

The too-small oil cooler thermostat (that fails closed as well) MUST be removed. There is no margin in RFE transmissions for excessive heat. None. Zero.

My oil was in tough shape @ 35k miles until I learned about the stupid pencil diameter thermostat in the oil cooler line, that is also unreliable to boot. I was stunned at this stupidity for minuscule fuel economy to shorten transmission life in trade. Incredibly stupid if you want repeat customers.

Critical if you load it with towing, which I do during hottest parts of the year. If you do this, use the tow program and lock out of 6th OD, this transmission will live np.
 

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Good point. I forgot that. Kepping us in check i see :anitoof:

I also installed the bypasses removal block so the fluid always circulates thru the cooler. My temps went from 170’s to 120’s on summer days.
 

White six four

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Is the pan filter fully seated? Did you remove the old seal and replace with new? Just throwing it out there since it hasn't been mentioned yet unless I missed it.

I change my trans fluid every year no matter the mileage. I haven't had any problems using valvoline atf4. I still have the stupid thermostat in mine. I'm at 122k now and have a lifetime warranty so when the tranny goes so will the "thermostat" as soon as the new tranny is put in.
 

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Good point. I forgot that. Kepping us in check i see :anitoof:

I also installed the bypasses removal block so the fluid always circulates thru the cooler. My temps went from 170’s to 120’s on summer days.

Listen man, most of us can't afford the new inflated truck prices, and god knows what will happen to their designs with the big EV push.

Milking our current trucks to the bitter end is the sole goal for lots of us. Thankful you guys did all the bull work up front to find the flaws. I was late to the Ram game from GM.
 

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Listen man, most of us can't afford the new inflated truck prices, and god knows what will happen to their designs with the big EV push.

Milking our current trucks to the bitter end is the sole goal for lots of us. Thankful you guys did all the bull work up front to find the flaws. I was late to the Ram game from GM.
Oh i hear ya! I think like you said a lot of is are in that same boat. #1 reason for the crazy amounts of maintenance….truck NEEDS to last a long time the way things are headed.

Find an old diesel and convert it to run on used cooking oil as a backup. :anitoof:
 

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OP,
My course of action ...to summarize things up would be:
1) Get tranny codes (see what comes up)
2) Take it to the dealer and have them replace the filter and do a fluid exchange. If the codes indicate a solenoid issue, replace the solenoid/s when the pan is off.
3) Ensure no other engine-related codes exist.
4) Give it a couple days. BC shift relearning sometimes takes a couple days.

I would be VERY leery of any shop or technician who tries to convince you you need a new transmission w/o doing any of the steps above. Or even doing hydraulic pressure tests. A poor-shifting transmission is a prime target for a pre-mature big-sale opportunity (scam) to an uninformed owner. If they hand you a piece of aluminum and claim it was in your transmission, go to another shop (oldest scam in the book).


4) If you are an advanced DIY guy who doesn't go to the dealer, one can exchange the old fluid home in no time. Age old method people have described (and I'm not recommending this), is to remove the radiator tranny cooling line at radiator. Slip clear vinyl hose over line and run into a white bucket (to observe color change). Overfill tranny a couple courts. Have helper start engine while technician observes fluid color. Helper shuts off vehicle after 10 sec, add a couple more quarts quickly, restart and run another 10 sec.. till fluid runs clear. Age old method since the 60's. Do at own risk. Lot of y/t videos on the subject.
 
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Jeepwalker

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....Just having some fun....he he... (don't anyone take it serious).

Hopefully the OP's got it figured out...or will soon have. :waytogo:

.
 
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