Why Won't My Vehicle Move?

Jim Jennings Transmission Baltimore

A "won't move" condition can be caused by many different things and I'll list those that can occur with both automatic and manual transmissions first.

If it is a front wheel drive car or mini-van, either of the front axles could pull out of the Transaxle (transmission) or break. You would instantly stop moving forward and reverse. A telling symptom of this problem is while the gear shift is in drive and engine is running, the speedometer needle moves as if you're driving down the road and it will roll when placed in park. You would experience the same symptoms if the differential section of your transaxle failed but it will probably make lots of clanking noise.

Now lets focus on why an automatic transmission won't move.

  1. The transmission has leaked two or more quarts of its 8 to 16 quart capacity and it can't develop the hydraulic pressure the transmission needs to operate. You will normally see fluid on the ground and it may try to move once the fluid has warmed up. Verify the cause by adding fluid till its full and if it moves, the low fluid and the resulting lack of hydraulic pressure was the problem.
  2. If it stops moving when hot, the problem may be a clogged filter. This may be accompanied with a whine and if you turn the engine off for a few minutes, it may want to move again for a short distance. This problem is usually indicative of a transmission wearing out.
  3. Another reason a vehicle won't move that you can check yourself is to see if the gear shift for the 4 wheel drive control has been accidentally knocked into neutral.
  4. The other causes of a no-move condition usually have to be diagnosed by a professional. They include hydraulic pump failure, cracked flywheel, failed sun-gear shell, worn out clutch plates, linkage problem and a variety of other internal problems.

Now its time to talk about why a manual transmission won't move.

  1. The number one cause is the clutch components have worn out and no longer have enough friction material to overcome the weight of the vehicle.
  2. A second possibility is the transmission can be stuck in two gears at the same time and it won't move.
  3. The shift mechanism can malfunction and keep you from selecting a gear.
  4. Finally, any number of internal gears and shafts can fail resulting in no movement. This can be caused by driver abuse, operating the transmission with low lube, abnormal wear and sometimes the cause is unknown.