8 speed hard 3-4 shift when cold

[Canuckfe]

2014 5.7 4x4

Been happening for a few weeks. When taking off first thing, even in summer months. Trans shifts fine except when going from 3rd to 4th with light throttle. It will act like it missed a gear and then slam into 4th. Rest of the shifts are smooth as ever. Once trans reaches operation temp things are better.

120km (75k miles). No serious abuse. Just a little towing from time to time.

Any insights? Low fluid? Reflash?

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[tidefan1967]

Since you’re still within the 5yr/100K mike power train warranty I would find a good dealer and have them take a look at it. If I were going to do anything to it I would change the fluid and filter and see what happens from there.

 

[Canuckfe]

Since you’re still within the 5yr/100K mike power train warranty I would find a good dealer and have them take a look at it. If I were going to do anything to it I would change the fluid and filter and see what happens from there.

Warranty is over. Only 5yr/100km on drivetrain.

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[Canuckfe]

Warranty is over. Only 5yr/100km on drivetrain.

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And they want $13-1400 to change fluid.

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[Canuckfe]

Just checked the fluid level as per ZF procedure and it's fine. From couple drips that i let that come out. Fluid didn't look bad at all.

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[KevinInVT]

And they want $13-1400 to change fluid.

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That is crazy money. Have you ever done a filter change on the trans? I think they label it a lifetime fluid but if they made some magic fluid that lasted forever we would use it in everything. If the truck has never had a filter swap I would start there.

 

[Canuckfe]

Havent driven truck in a while. Today driving it stuck in 3rd gear. Wouldnt shift up or down. Check engine light came on too. First time for that.

Hooked up reader and P0733 code came up
Gear ratio error in 3rd.

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[Canuckfe]

Oh yeah restarted and back to normal.

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[Wild one]

Oh yeah restarted and back to normal.

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Did you jack the rear of the truck up till the tranny pan rail is level.You're supposed to have the pan rail level with the ground front to rear and side to side before you pull the plug.The instructions that came with my new ZF stress the fact the pan rail has to be level.I had to put a new ZF in my 14 last summer,they aren't cheap in Canada,lol.Where abouts are you in Canada?

 

[Canuckfe]

Yes i levelled the pan. Not the truck.

I just don't want to change the fluid and filter for nothing if it has to come apart again to change valve body or something

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[Canuckfe]

Im on west coast.

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[fghtlm]

I have the exact problem in my 2014
dealership looked at it, said fluids were fine and since no code their best guess was shift selenod wss bad, and want to change valve body for $1600.

 

[jashoff]

I have the exact same issue with my 2016 5.7l/8-speed with only 40k miles. Only when the ambient temperature is cold (around 40 deg or less) and it's a cold start. A hard 3-4 shift that seems to hang then hard into fourth. It did it for a few weeks then it locked in third gear and threw a CEL. I'm still under the power train warranty so I took it in. They looked and said it was either the fluid or the shift solenoid. Fluids checked out good so they changed the valve body and it seemed fixed.

Fast forward another month and it's starting with the same symptoms again. Hanging 3-4 shift on cold starts in cold temps but it hasn't yet locked in third and thrown a CEL again. I'm waiting till it gets consistently colder and will drop it off at my dealer overnight so they can experience it themselves.

Once I get it back into the dealer and they try again I'll let everyone know what they do.