Haldex Clutch Noise
We have a 2012 Land Rover Evoque with a rear diff noise coming from the rear differential coupler. When the unit is disconnected, the noise goes away. The noise sounds like random clunk/banging noise. The fluid looked bad so we sold a new (rebuilt) unit from Land Rover. When we installed it and finally got the correct fluid in it, it was nice and quiet until we programmed the unit as required. Now the noise has returned. Watching Data Pids, the was no command for the engagement of the Haldex Clutch, WSS sensors looked good, and no codes are setting. This is not a slight clunk, but rather pronounced and gets worse the faster you drive. When we disconnect the terminal to the control module, everything is quiet and no noise - which makes us think that everything is good within the rear differential. Short of suspecting a defective unit, any ideas?
Have you tested the wiring at the unit while driving for any signals, commanded or not, at the unit? The same symptoms indicate the unit may very well be okay. In this case scan data may hide the problem, or the controller may be bad. Tires correct front and rear?
I recall reading about this issue some time back, but could not locate the entry. Any TSB's? Here is a forum entry: babyRR.com - The Range Rover Evoque Forum - Gearbox Fault "Traction control reduced"
Not sure if this is the same set up but we had a similar fault on a freelander and it was the coupler between the gearbox and the transfer box,it was a splined tube and we noticed rust between the gearbox and the transfer unit from the tube failing. I was sure the noise was fron the rear but it was just been carried through the driveline.
Paul, How are you? Hope you are well. A couple things come to mind not only does the system look at wheel speed sensors for traction control but also looks at stability control as well so check all those inputs. Seems odd there is no command in scan data, I think I would put a lab scope with an amp probe to see if it was actually being activated. If it is I would check wiring and controller. If…
Take a close look at the tire sizes. Its too often that on a vehicle that takes xxx/55/xx sized tires, a single xxx/50/xx gets thrown in without being noticed. That WILL cause issues in transmission operation and AWD engagement. Also, if three tires are bald and one is new (or vice versa), the vehicle interprets the one different wheel speed as slip and operates the clutch.