42RLE rebuild, no fourth gear

Tiny
AB AUTOMOTIVEREPAIR TRANSMISSIONS
  • MEMBER
  • 2008 JEEP WRANGLER
  • 3.8L
  • V6
  • 4WD
  • AUTOMATIC
  • 12,345 MILES
We just rebuilt a 42RLE for the vehicle listed above. The installer called and said that all the gears 1, 2, 3, and rev run perfect, but when he goes into 4th, it revs up and then enters limp mode.
First gear: underdrive is engaged.
Second gear: the 2/4 and undergear are engaged.
Third: under and OD.
Fourth: OD and 2/4.

But if the 2/4 and OD is working in the other gears, what could be the cause of this?

Thanks in advance guys.
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Saturday, January 23rd, 2021 AT 12:45 PM

11 Replies

Tiny
KASEKENNY1
  • EXPERT
It is because the overdrive is applied with the underdrive in third and that opposing force will lock it up and cause the 1:1 ratio. However, when you remove that opposing force the overdrive is slipping.

They should be getting some codes. If you can get those, that will help confirm this before they pull the unit back out. At least at that point we will know exactly what to go after if they have to send it back.

Take a look at the attachments below and look at the third gear vs fourth gear and you will see where in 3rd they are applying UD and OD that are basically opposed from each other.

Let us know what the codes are and we will know for sure what is happening.
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Sunday, January 24th, 2021 AT 6:04 PM
Tiny
AB AUTOMOTIVEREPAIR TRANSMISSIONS
  • MEMBER
There's no codes coming on, but let me show this to Alex and see what he says. Thank guys :)
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Monday, January 25th, 2021 AT 10:12 AM
Tiny
AB AUTOMOTIVEREPAIR TRANSMISSIONS
  • MEMBER
Alex thinks it's something inside, so we're having it come back in and do it again. Bummer, thank you for getting back to us. You guys always are on top of it. Been seeing your YouTube videos popup a lot too. Keep up the awesome work. You have my loyalty :)
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Monday, January 25th, 2021 AT 10:16 AM
Tiny
KASEKENNY1
  • EXPERT
That is never fun to redo things but I think he is correct. Most likely a cut seal so if he doesn't see anything, I would just reseal it again just to make sure.

Thanks for your support and continuing to come back. I always like answering your questions because you provide the info needed to assist.

You don't just tell us that "it doesn't shift right" and then ask what to do. :)
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Monday, January 25th, 2021 AT 1:42 PM
Tiny
AB AUTOMOTIVEREPAIR TRANSMISSIONS
  • MEMBER
I'll keep you updated. We're back to working on that 1998 Wrangler, from the summer. It kept getting pushed to the back of the todo. Ended up buying a whole other Jeep and going to swap the motor (not sure if you remember it. Fun times) Stay safe. Xox
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Monday, January 25th, 2021 AT 2:48 PM
Tiny
KASEKENNY1
  • EXPERT
That sounds familiar. Thanks for the update. Glad you are back on it. Let us know how it turns out.

You stay safe as well.
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Tuesday, January 26th, 2021 AT 3:00 PM
Tiny
AB AUTOMOTIVEREPAIR TRANSMISSIONS
  • MEMBER
We have the transmission on the bench, removed the front drum and everything is air checking. I hadn't mentioned before that this transmission was rebuilt prior to us rebuilding it. What are we not seeing? Could it be the valve body or bad sensor? Perhaps something in the vehicle causing it not to hold 4th. We're kind of pulling threads at this point. Any of your expertise would be well appreciated. Thanks
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Thursday, January 28th, 2021 AT 11:35 AM
Tiny
KASEKENNY1
  • EXPERT
If the unit air checks okay then you don't have a cut seal so then that means it would be the valve body.

The only thing that worries me is you are only looking at the unit and not looking at the entire vehicle. Sometimes there is more to the story that we are not getting when you only have the unit without the vehicle. Did they say there were any codes?
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Thursday, January 28th, 2021 AT 4:45 PM
Tiny
AB AUTOMOTIVEREPAIR TRANSMISSIONS
  • MEMBER
There weren't any codes, but Alex found the problem (beyond my scope of knowledge) but it was something with a clearance that was off.
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Thursday, January 28th, 2021 AT 4:53 PM
Tiny
KASEKENNY1
  • EXPERT
Got it. That can be deceiving on the air checks because the clutch pack can have clearance issues but still pass the air check. Thanks for the update because I am sure that will help others, including me because I clearly didn't think about checking the clearance. Now that we know what it is, it makes perfect sense.

Talk to you next time.
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+1
Thursday, January 28th, 2021 AT 5:22 PM
Tiny
AB AUTOMOTIVEREPAIR TRANSMISSIONS
  • MEMBER
So glad we figured it out. Now if we can only teach people how to properly install a torque converter, we'll be sailing. Stay safe and thank you for your time.
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Thursday, January 28th, 2021 AT 6:14 PM

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