How do you tell if your transmission was damaged in an accident?

Earlier this year, we were asked to examine a vehicle that was involved in a two vehicle accident and make a determination of the condition of the transmission pre-impact. The vehicle that was involved was a 2008 Buick Enclave that had already been repaired by the owner’s insurance carrier. The issue of the condition of the transmission arose after the vehicle had been returned to the owner and the owner subsequently drove the vehicle an additional 3100 miles. The transmission became noisy and then failed to move the vehicle after being placed in “Drive”. While investigating this incident, it was learned that the vehicle had been taken to a Valvoline Instant Oil Change Center where all the fluid levels were checked and documented. The transmission was found to have been “full” shortly before the accident occurred.   It was further learned from the body shop that repaired the vehicle that no transmission fluid came out of the transmission fluid cooler lines when the cooler and radiator were removed for replacement – the fluid level was already “low” when the vehicle arrived at the shop. Furthermore, after the new cooler and radiator were installed, no transmission fluid was added before the vehicle was returned to the owner. The vehicle left the body shop with the transmission at some fluid level below “full”. Normal wear and tear on a transmission is a very gradual process. The speed of the wear process is increased when the transmission is forced to operate without lubrication, which is the purpose of the transmission fluid. However, when there is documentation of the fluid level, the process of determining transmission condition becomes a lot easier. The damage to the transmission most likely occurred as a result the accident. The transmission was leaking fluid after the vehicle was returned to the owner.

What Happened Here?

Recently, we have been investigating an incident that took place almost one year prior to our involvement. A two vehicle accident occurred in which one of the vehicles involved was a 2008 Chevrolet Cobalt. The vehicle was subsequently repaired at a local body shop and returned to the owner. Approximately three to four days later, the engine overheated. According to the owner, the vehicle was returned to the shop where it was determined that the shop’s mechanic had forgotten to add coolant to the radiator before returning the vehicle to the owner. Once the coolant issue had been resolved and the vehicle returned to the owner, the owner began hearing a rumbling noise that turned out to be a damaged catalytic converter. A large crack developed in the expansion joint just below the flange that connects the converter to the exhaust manifold. It was also discovered that the exhaust manifold had cracked in four places (see attached photographs).

Based upon the owner’s description of the vehicle’s performance after the vehicle was initially returned, the rumbling noise was not present and did not occur until after coolant was added and the vehicle was returned for the second time.  It appeard that the damage to the catalytic converter and the exhaust manifold was caused when the engine overheated.