Auto Transmission Swap

[JTenn]

Long story short, my buddy has a 20 Rubicon. Trans started a high pitched whine that turned into bucking and slamming between gears. He takes it to the dealer that tells him trans needs replaced. The useless 3rd party extended warranty is denying the claim because he can't prove he changed the air filter at 60,000 miles. So I've sourced him a used trans with 54 miles on it from a Hemi conversion. I'm going to change it for him. So a few questions:
1. Will a 23 or 24 trans be electronically compatible with a 20? (ECM changed in 21)
2. With no dipstick tube, how do I verify fluid level once installed?
3. Are our transmissions rebuildable? I'm sure the short answer is yes but has anyone here ever had one rebuilt? And would trans shops even do it?
4. Anyone have any "watch out for" tips when pulling/installing the transmissions?

Thanks for any answers or tips.

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[Hootbro]

Below link is to my Google Drive with all the Tech Authority data on the transmission and transfer case.

I will leave it open for awhile before closing it.

Edit: (Link Removed)

 

[JTenn]

Man you're a life saver!! I can't thank you enough. You can close the link. Thanks again!!

 

[JTenn]

So all mopar parts is showing the identical trans part numbers from a 20 JT rubicon and a 24 JL Rubicon. They don't have a 24 JT listed but I'm confident they're the same year over year based on this.

 

[ShadowsPapa]

He takes it to the dealer that tells him trans needs replaced. The useless 3rd party extended warranty is denying the claim because he can't prove he changed the air filter at 60,000 miles.

That's so funny it's really sad. Seriously, can't prove AIR filter replacement so a transmission that doesn't need service for the life of the transmission (don't shoot me, quoting JEEP!!) is reliant on an air filter - but the transmission requires no service and that's what broke?
Man, he needs to broadcast the name of that so-called warranty company (they aren't a warranty, they are a service contract) and let the world know their name.

 

[ShadowsPapa]

Long story short, my buddy has a 20 Rubicon. Trans started a high pitched whine that turned into bucking and slamming between gears. He takes it to the dealer that tells him trans needs replaced. The useless 3rd party extended warranty is denying the claim because he can't prove he changed the air filter at 60,000 miles. So I've sourced him a used trans with 54 miles on it from a Hemi conversion. I'm going to change it for him. So a few questions:
1. Will a 23 or 24 trans be electronically compatible with a 20? (ECM changed in 21)
2. With no dipstick tube, how do I verify fluid level once installed?
3. Are our transmissions rebuildable? I'm sure the short answer is yes but has anyone here ever had one rebuilt? And would trans shops even do it?
4. Anyone have any "watch out for" tips when pulling/installing the transmissions?

Thanks for any answers or tips.

A forum member has posted his methods for checking fluid levels in these. @GladiusMaximus I believe posted that info. He's done it more than once.

 

[JTenn]

That's so funny it's really sad. Seriously, can't prove AIR filter replacement so a transmission that doesn't need service for the life of the transmission (don't shoot me, quoting JEEP!!) is reliant on an air filter - but the transmission requires no service and that's what broke?
Man, he needs to broadcast the name of that so-called warranty company (they aren't a warranty, they are a service contract) and let the world know their name.

Yeah it's sad these dealers push this crap and even call it an extended factory warranty in alot of cases. Dishonest crooks!

 

[Escape.idiocracy]

3.6 Jeep 8 speed is a 850re
3.0 zf 8hp

2013-2023 hemi shares the zf 8hp.

Are the electronics straight across when changing trans types like this?

 

[JTenn]

3.6 Jeep 8 speed is a 850re
3.0 zf 8hp

2013-2023 hemi shares the zf 8hp.

Are the electronics straight across when changing trans types like this?

Not positive but according to All Mopar web site, 20-24 JT to JL is the exact same part number.

 

[JTenn]

3.6 Jeep 8 speed is a 850re
3.0 zf 8hp

2013-2023 hemi shares the zf 8hp.

Are the electronics straight across when changing trans types like this?

Oh, he's not changing trans types. I found an 850RE that was removed for a Hemi swap.

 

[arosen1997]

Sorry for the necro, but @JTenn did you end up doing this for your buddy? Mine needs a transmission and I've got a line on a good hemi swap take off for not a terrible price.
Did you need to do any programming or anything or was it plug and play?

 

[Stan H]

A forum member has posted his methods for checking fluid levels in these. @GladiusMaximus I believe posted that info. He's done it more than once.

I just bought one out of a 24 Wrangler that had 6000 miles on it . Took the VIN and my VIN called my dealership and they verified it is the exact same transmission. So I bit the bullet and ordered it and they are just waiting on me to bring it in and have it put in. I am rather confident that my valve body TCM and D clutch are all in the near wore out position hard shifts , no reverse at times, and occasionally throw a code for no TCM message so looking at the parts to fix verses getting used it was cheaper to go used . Yes to answer your question everything time a transmission is changed the Afaptive values have to be reset . The dealer can do this or it can be done with a Jscan app . Blue tooth obd II reader and a connecter cord .

 

[arosen1997]

I just bought one out of a 24 Wrangler that had 6000 miles on it . Took the VIN and my VIN called my dealership and they verified it is the exact same transmission. So I bit the bullet and ordered it and they are just waiting on me to bring it in and have it put in. I am rather confident that my valve body TCM and D clutch are all in the near wore out position hard shifts , no reverse at times, and occasionally throw a code for no TCM message so looking at the parts to fix verses getting used it was cheaper to go used . Yes to answer your question everything time a transmission is changed the Afaptive values have to be reset . The dealer can do this or it can be done with a Jscan app . Blue tooth obd II reader and a connecter cord .

So if I'm understanding you correctly it should be fine to just install it and then trigger a relearn with JSCAN and we're good to go?

 

[Stan H]

So if I'm understanding you correctly it should be fine to just install it and then trigger a relearn with JSCAN and we're good to go?

Yes give me a second I will take a couple screen shots of where ypu need to be in JScan to do that . Be right back

 

[Stan H]

In first screen :
shot go under adaption,
And then select, Vehicle Maintenance *
Next screen shot :
All the way to the bottom choose adaptive value reset
The third screenshot:
Clearly say this is only to be done AFTER REBuild. Possible ypu could do the quick learn Long version which is the first one I circled No on. This may be a question for @Charles 236

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