2011 JK Rubicon has death wobble at 45-55 MPH

HEY GUYS,
IVE COME TO A LOSS ON WHAT THE HECK THIS ISSUE IS. I AM NOT STOCK ANYMORE AND HAVE DONE SOME INTERMEDIATE UPGRADES.
NEW: 4 INCH RC LIFT , N3 SHOCKS, COIL SPRINGS, CONTROL ARMS. TACK BAR, RELOCATION TRACK BAR BRACKET, DRAG LINK
NEW: BATTERY-ALTERNATOR-MANUAL SWAY BAR REPLACMENT. STERRING STABALIZER.
OLD: TIE ROD
PROBLEMS: STERRING WHEEL NEVER STAYS AT CENTER POSITION AFTER CORRECTING DRAG LINK-WILL HOLD FOR A BIT BUT AFTER NOT "NOTICING" FOR A BIT IT GOES COCKEYED
DEATH WOBBLE AT AROUND 40-55
NEW PROBLEM*** AFTER THE TRANNY HEATS UP AND IM IN SECOND GEAR GOING 40-55 I FEEL A CHUG/JOLT IN THE WHOLE VEHICLE AND THE RPMS SEEM TO DROP AS IF IT CANT GO INTO THIRD GEAR-THIS ONLY HAPPENS WHEN I HAVE LET THE TRANNY WARM UP.
I HAVE HAD HOT OIL WARNINGS ON LONG DRIVES WHERE I HAVE TO PULL OVER AND TURN OFF THE JEEP FOR AT LEAST 20-30 MINS TO COOL DOWN.
I HAVE OCCATIONAL GAS CAP WARNINGS - WHICH THE CAP HAS NEVER BEEN VISIBLY OR PHYSICALLY LOOSE FEELING.
I HAVE OCCATIONALLY GOTTEN A ENGINE CODE FOR TOO MUCH FUEL.
ANYWAYS-THE BIGGEST ISSUE IM NOW HAVING THE JOLT FEELING WHEN THE TRANNY IS HOT...
I HAVE A 2011 JEEP RUBICON 120K MILES- YES I OFFROAD AND DRIVE ALLOT-THATS WHAT JEEPS ARE FOR LOL
PLEASE POST UP REPUTABLE COMMENTS ON SUGGESTIONS SO THAT I MAY ORDER PARTS FOR FIXING ASAP. THANK YOU

JeepJeezy said:

Welcome! Nice looking rig! Is your front track bar adjustable? What is your front caster set at? Did you get an alignment after the lift? Did you adjust your speedometer when the bigger tires were added?

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Hey ! The track bar is adjustable- unfortunately I tried to get an alignment three times since the lift went in BUT with my OEM tie rod the linkage is seized so they cannot adjust. I am waiting for that replacement at the moment which goes with the caster angle. The speedo was refigured for the 37s.

JeepJeezy said:

OK. Your death wobble will get fixed once you get your caster close to 4 to 4.5. Your steering will go to normal when your drag link gets adjusted correctly. How was the speedo reconfigured? The gas cap light should go away with a new Mopar OEM gas cap. Don't get an aftermarket replacement. They don't always work. Have you checked the color of your tyranny fluid lately?

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Yea the tranny fluid needs to be changed. That’s the project for this weekend.

FishFam JKU said:

Hot oil usually equals hot transmission. Once transmission fluid is burnt it will never recover and I would suggest changing it if you suspect it was over heated. Simply check for a a burnt smell and color. Also, looks like you like the mud. Be sure the transmission vent tube is up high enough and has vent cover. One deep water/mud crossing without a proper vent tube can cost thousands of dollars.

As far as overheating. Looks like you have about 50% of your grill covered with the decorative covers. Did this by chance correlate with your overheating?

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Yes they did. Once I took them off the rest of the trip back from Cali was fine. I do love the mud so that’s a great suggestion about the transmission vent tube

Dirty Dog said:

Vent tubes are easy to forget about.
We don't really do mud in Colorado (mud runs downhill to Kansas, and leaves us with rocks...). But we do cross a lot of creeks and rivers. The trail from St Elmo to Tincup used to go along the edge of Mirror Lake. The water level varied, of course. Some times, you'd be on the land side of the edge, sometimes the water side. I've gone through that with 3-3.5' of water. They've moved the trail, now.
When I built our YJ, I included water in the plans. So the vent tubes were all brought up into the engine bay, capped with small breathers, and mounted as high as possible. I could go park in a lake and not have to change the diff fluid after.
View attachment 122472

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Thank you so much for this response. I am adding this to this weekends swap out project list