The fires are caused by overheated transmission fluid. Pre-2012 3.8L JK automatics have insufficient transmission cooling capacity. Fluid overheats in certain operating conditions, most common is operating under load in 4HI. Fluid overheats and pours out the dipstick tube, right onto the passenger exhaust manifold, and ignites. The plastic pressure side fuel line from the tank to the fuel rail is (stupidly) located right behind the exhaust crossover. The flames hit the fuel line and melt through it allowing fuel at high pressure to spray onto the exhaust. POOF!!!!
The trans fluid overheat warning was initially just a chime, with no dash indicator. Chrysler should have recalled every one of them and installed an auxiliary trans cooler, but instead got away with just adding a "hot oil" indication on the dash to supplement the chime. The Feds have an open investigation on this and to my knowledge have yet to rule. FCA has tried two dodges, 1) the vehicles were designed by the former, bankrupt Chrysler, not their problem, 2) stalled for time in hopes most will simply be scrapped or accumulate so much mileage the Feds will dismiss the issue. Bottom line, if you own a pre-2012 JK automatic and have not installed an auxiliary trans cooler, do it NOW!
'09 JKRU. 4" Teraflex long arm, Teraflex R44 housing, Teraflex / Fox Resis, Poly Performance skids, Nemesis Billy Rockers, Nemesis flares, 37" ATZ P3s on 17" 5x5.5" Trailready HDs, Spyntec hubs, Teraflex BBK, Mopar BBK master/booster, Superior front & Alloy USA rear axle shafts, CTMs, Reids, Synergy drag link & tie rod, WTOR hydro-boosted steering, 5.38s, TF Dual Rate front bar, TF bumpers, Warn Powerplant, Tom Woods shafts, AA xfer case cable, Kilby canister relo, RH4x4 cage.
Last edited by SoK66; 11-05-2015 at 06:53 AM.