hello i have a question i have a 2007 sprinter 3500 runs great, however i think the lockup clutch solenoid is bad, it rumbles and vibrates at times abouve 30mph, is there any tests i can do to check to see if its working correctly?
If this occurs under heavy acceleration or climbing steep hills at full throttle, you likely are experiencing shudder.
Shudder is usually caused by old, overdue for change, fluid. This can happen (and I see this often) when a overworked tech (and I'm being kind here) skips the fluid change in the torque converter and only drains the pan. That's only half the fluid. All 8 quarts need to be drained and changed.
On the other hand, if this occurs under very light throttle at neighborhood speeds, it is likely RSN. Check fluid level, '07 Sprinters still had the early style, prone to leakage, o-rings in the electrical socket connector. If fluid level is OK, then you likely have glazed TCC linings and a torque converter replacement is required to mitigate the symptoms.
Doktor A