4WD not engaging/ No lights on dash/ VIDEO

[mudfish]

I have been using 4x4 all winter with no issues, Yesterday I tried to shift into 4H and nothing. It seems like there is something hanging up and blocking me from doing anything. It won't engage no matter how hard I try. There are no codes, no lights.

I have a 2020 Manual Rubicon. NO Auto 4WD.

HELP!!!

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[Bulletbill]

Have you tried getting a little forward roll, shifting to neutral and then trying to engage while it was very slowly rolling forward?

 

[mudfish]

I have. I've tried while rolling, driving and in reverse.
It just seems stuck.

 

[jeepoch]

@mudfish

Brian, I'm not trying to troubleshoot your transfer case, just giving you some background information upon which to noodle on.

A Transfer Case is not like a transmission, it doesn't have clutches and hydraulics to shift. And there really are no gear changes from 2Hi to 4Hi. Hi gear uses the same gearing, it just engages the front drive shaft (on the JL). The low gear is engaged only when shifting from 4Hi to 4Lo.

In order to make this gear change the Hi gear is disengaged (Neutral) before the Lo gear is engaged. However, when in Neutral the input shaft speed from the transmission must match the output shaft speed to the wheels. If / when they do, then (and only then) can the teeth and the cogs of the gearing 'mesh'. If these teeth don't align with the cog, the gear change will be hard and difficult, if not impossible. The force used to insert the teeth into the gog is your muscle strength applied at the shift lever. Noting that the harder you push or pull on the lever when the teeth and cogs are out of alignment, the higher the potential for shaving some metal of the gears.

Only when this alignment happens, the shift will be easy and seamless. When stopped this alignment is fixed. It is either aligned or not. When not, forcing the shifter essentially requires either moving the vehicle (output shaft) or working against the transmission (input shaft). Neither, will be seamless and resulting in a very hard shift.

That's why a very (very) slow roll (vehicle velocity, either forward or reverse) is typically the best strategy. However, if the vehicle is 'stuck' and no roll is possible, taking the transmission out of Neutral will work as well. Of course, the engine should be at idle, or gear shaving is more than likely.

Recall, any really slow movement between the input and output shafts are needed to allow the teeth and cogs to synchronize and mesh. When they do the resistive force on the shifter should be practically zero. When performed properly, each and every shift from Hi to Lo, or vice versa, should be easy, quick and effortless.

The trick, and magic secret sauce, is for the driver to supply the low velocity necessary to make the meshing smart and succinct. Forcing anything at the shifter is doing it wrong'.

Hope this helps,
Jay

 

[mudfish]

Thanks for all the info, It makes sense, not I just need to figure out the "WHY".

 

[Heimkehr]

Yesterday I tried to shift into 4H and nothing. It seems like there is something hanging up and blocking me from doing anything. It won't engage no matter how hard I try. There are no codes, no lights.

Years ago, I experienced an almost identical problem when attempted to engage 4HI in my YJ-era Wrangler.

In my case, moving the transfer case lever from 2HI to 4HI would cause a mild grinding sound to occur. Also like you, the problem occurred spontaneously, with no prior warning (or change in how I was using the vehicle.)

I ceased my efforts immediately after two attempts and made an appt. at a local Jeep dealer. They quickly diagnosed something in the transfer case assembly, to include the lever itself, as "being out of adjustment". The fix, whatever it was they did, was equally quick...and effective. I never had the problem recur.

Just something to keep in mind.

 

[mudfish]

Thanks, I feel like that might be my next step.

 

[mudfish]

Good call. It's been below freezing for the last few days so maybe I'll park in the garage overnight and let it warm up.

 

[Terrymo]

In case you haven’t already seen this thread regarding adjustments
https://www.jlwranglerforums.com/forum/threads/jl-transfer-case-shift-linkage-adjustment.70964/

 

[mudfish]

In case you haven’t already seen this thread regarding adjustments
https://www.jlwranglerforums.com/forum/threads/jl-transfer-case-shift-linkage-adjustment.70964/

Thanks, I'll take a look at that in the morning.

 

[6.2Blazer]

Do you mean the actual lever in the cab will not move and feels like it's stuck? If so I would look underneath the vehicle and see what it looks like. Maybe one of the bushings or linkage is bound up?

 

[mudfish]

I think you may be right. From what I've been searching I think it may be the linkage. As soon as the temp is above freezing I'll take a look.

 

[mudfish]

FOUD IT!!! I pulled up the trim to see if I needed to make adjustments and found the linkage broken. Looks like I need to take it in to my local shop and have it replaced. Too cold to do anything myself unfortunately.

 

[jeepoch]

@mudfish

Brian, any worry that the dealer may claim abuse or abnormal use? Not knowing the details of how this happened, but something really stressfull appears to have occurred from the single pic.

Hope all goes well.

 

[mudfish]

@mudfish

Brian, any worry that the dealer may claim abuse or abnormal use? Not knowing the details of how this happened, but something really stressfull appears to have occurred from the single pic.

Hope all goes well.

I don't have a warranty, so I just want them to fix it. Abnormal use or not, they have the part and the knowledge and I don't.

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