ATC300/ATC400/ATC500/ATC700 clutch common issue
The ATC300/ATC400/ATC500/ATC700 transfer case clutches are structurally similar and, therefore, have common weak points. Oddly enough, in most cases, their failure is caused not by friction plates but by the wear of the clutche's metal parts. Having extensive experience in their repair, we were the first on the market to offer the optimal kits for their professional repair.
Illustration 1 shows a typical case of worn parts on an ATC400(ATC300/ATC500/ATC700) transfer case. The arrows show the grooves on parts 75 (Actuator ring/Lever/Grip) and 76 (Piston) and the needle bearing that caused the formation of these grooves. Without going into details of the reasons for this phenomenon, we can only state that, as a result, the gap in the clutch increases and goes beyond the boundaries provided by the correction algorithms of the xDrive system. The clutch engagement becomes rough, and there is occasional slippage. You feel it as twitching or jerking when (mostly) accelerating and cornering.
Illustrations 2 and 3 shows a slightly different problem — wear of the hardened (carburized) layer, which manifests itself in the rapidly progressive appearance of pitting. As in the previous case, the process causes a violation of the gap with an avalanche-like contamination of the oil with metal particles.
Illustration 4 shows the rare case — damage due to overheating. Most often, this is due to the actuator jamming or a lack of oil. In some cases, the clutch overheating can cause the drive sprocket to break, in which case you will have to replace the entire assembly.
