br1anstorm
NAXJA Forum User
- Location
- United Kingdom
I asked a while ago in this post http://www.naxja.org/forum/showthread.php?t=975842&highlight=auto+lockup
about what I described as "driveline shunt" in my 93 4.0 auto XJ. When in 'D' and up to 4th, above about 40-45 mph, lifting off the gas while cruising along produces a definite clunk. Felt as if the tranny was kicking out of lockup. But replies suggested the TPS, or maybe a worn/failing U-joint in the driveshaft.
Well it's definitely not a U-joint - there's no play or movement when I try to push, pull or turn the driveshaft by hand under the vehicle.
Now I've noticed another symptom. When cruising in 4th above about 40 mph, if I touch the brake pedal even the tiniest bit, the revs kick up by about 150, then drop back again. It's clear that something (electrical switch?) linked to the brake pedal is making it do this. NB I don't have cruise control. But it feels like touching the brake pedal is causing this brief rise in the rpm.
So I went searching, and in a post here http://www.naxja.org/forum/showthread.php?t=972809&highlight=auto+lockup
I found this quote:
"If you have an auto, this switch [on the brake pedal] also tells the tranny computer to disengage the torque converter lockup."
Now I wonder, are these two symptoms related? And if so, does this mean the TCC lockup solenoid is faulty, or the switch on the brake pedal? Or both? Which should I look at first?
And if the symptoms point to the solenoid, can anyone tell me where to find a simple step-by-step guide to checking and if necessary replacing it?
Any advice would be welcome!
br1anstorm
about what I described as "driveline shunt" in my 93 4.0 auto XJ. When in 'D' and up to 4th, above about 40-45 mph, lifting off the gas while cruising along produces a definite clunk. Felt as if the tranny was kicking out of lockup. But replies suggested the TPS, or maybe a worn/failing U-joint in the driveshaft.
Well it's definitely not a U-joint - there's no play or movement when I try to push, pull or turn the driveshaft by hand under the vehicle.
Now I've noticed another symptom. When cruising in 4th above about 40 mph, if I touch the brake pedal even the tiniest bit, the revs kick up by about 150, then drop back again. It's clear that something (electrical switch?) linked to the brake pedal is making it do this. NB I don't have cruise control. But it feels like touching the brake pedal is causing this brief rise in the rpm.
So I went searching, and in a post here http://www.naxja.org/forum/showthread.php?t=972809&highlight=auto+lockup
I found this quote:
"If you have an auto, this switch [on the brake pedal] also tells the tranny computer to disengage the torque converter lockup."
Now I wonder, are these two symptoms related? And if so, does this mean the TCC lockup solenoid is faulty, or the switch on the brake pedal? Or both? Which should I look at first?
And if the symptoms point to the solenoid, can anyone tell me where to find a simple step-by-step guide to checking and if necessary replacing it?
Any advice would be welcome!
br1anstorm