Alright, this one has me stumped. I am by no means an inexperienced mechanic. I have worked as the lead fabricator in an offroad shop building high end crawlers, built more engines, axles, doublers, transmissions, t-cases, etc, than I can count, I worked as a machinist for years and have been heavily into turning wrenches professionally and as a hobby for over two decades.
However, this one has stumped me. There is 5 feet of snow outside and I no longer have a garage. I have exhausted my ideas and before I drive an hour to the nearest garage and tear this thing apart for the 4th time looking for this issue, I'd like some advice from Jeep TJ experts.
I have a 1999 TJ with a dana 44 rear. every single suspension component is brand new with a factory replacement. Springs are a 2" lift and the whole thing sits on a set of 31s. Its my DD. On random occasions with no rhyme or reason, when I hit the brakes, the pedal has a quicker engagement and the rear axle will bang, with the rear brakes getting extremely grabby. The bang is similar to leaving the rear seat folded then having it flop down to the floor. Its attention getting, loud, and can be felt through the vehicle. I have made sure the latches were latched on the rear seat, I have disassembled the rear brakes looking for any issues or fluids, and it checks out. I checked the drums for cracks, I checked the control arm bolts for correct torque. I have excellent pedal feel all the time but on the occasion the brakes get grabby there is a less travel. When the rear end does bang, the pedal drops to its normal place. When it does happen, if I apply the brakes lightly I can keep them from locking. when they do grab, it locks the whole rear axle. This whole scenario is random. I'd say 10 our of 1000 brake presses, but they happen in clusters, still random but with more frequency then they pretty much go away for a while. I don't believe it to be a issue with the read diff because I can modulate it. Every single time it happens, its below 35 mph. Never has happened above that.
I am stumped. Any ideas are welcome.
However, this one has stumped me. There is 5 feet of snow outside and I no longer have a garage. I have exhausted my ideas and before I drive an hour to the nearest garage and tear this thing apart for the 4th time looking for this issue, I'd like some advice from Jeep TJ experts.
I have a 1999 TJ with a dana 44 rear. every single suspension component is brand new with a factory replacement. Springs are a 2" lift and the whole thing sits on a set of 31s. Its my DD. On random occasions with no rhyme or reason, when I hit the brakes, the pedal has a quicker engagement and the rear axle will bang, with the rear brakes getting extremely grabby. The bang is similar to leaving the rear seat folded then having it flop down to the floor. Its attention getting, loud, and can be felt through the vehicle. I have made sure the latches were latched on the rear seat, I have disassembled the rear brakes looking for any issues or fluids, and it checks out. I checked the drums for cracks, I checked the control arm bolts for correct torque. I have excellent pedal feel all the time but on the occasion the brakes get grabby there is a less travel. When the rear end does bang, the pedal drops to its normal place. When it does happen, if I apply the brakes lightly I can keep them from locking. when they do grab, it locks the whole rear axle. This whole scenario is random. I'd say 10 our of 1000 brake presses, but they happen in clusters, still random but with more frequency then they pretty much go away for a while. I don't believe it to be a issue with the read diff because I can modulate it. Every single time it happens, its below 35 mph. Never has happened above that.
I am stumped. Any ideas are welcome.