AUTO: Listeners Have Transmission, Engine Woes

Listen to Russ, Chris, and Shannon – the “Motor Medics” each Saturday from 10AM until Noon on Radio for Your Neighborhood – AM 1380 and FM 103.7 – WTYM, Kittanning.

Dear Motor Medics,
My transmission failed while on vacation. The failures not the end of the world, I understand things break but most of the vacation was spent dealing with the truck. I use it to pull my camper and boat together and when it stopped so did the vacation. This 2008 ¾ ton GMC truck has 90,000 miles and I never changed the transmission fluid because when I bought it they said it’s good to 100,000 miles. Is there anything I should’ve done to prevent the failure? They told me I needed a rebuild because it was burnt up.
Terry in Fargo, North Dakota

Dear Terry,
First, what is the recommended tow rating for the truck? Compare this to what you are towing and if you are exceeding it get a bigger truck or less of a load. Make sure you take into account your fully loaded setup with all fluids and your family included at the time you weigh it. Tow ratings should also not be at 100%, more like 80% to allow for headwinds and such. Over pulling is a number one failure cause but you can still have transmission failures even without towing. We recommend changing the fluid when towing every 30,000 miles or so and observing the condition of the fluid between changes. The fluid in this truck is meant for extended life but some circumstances will reduce that life. Also be sure the transmission cooler is the proper size.
Take care, the Motor Medics


Dear Motor Medics,
I’m having starting issues with my 1991 Chevy full size truck. I have a 350 engine that was just rebuilt about 10,000 miles ago. When we performed the rebuild we also replaced the battery, alternator and battery cables. The starter was replaced about five years ago so we opted not to replace it at the same time. When the vehicle has been running for a couple hours and is shut off it will crank very slow and sometimes not start at all unless you let it sit until the engine cools off. The problem seems to be worse if I have driven it harder such as towing or highway use. What do you think is wrong and how can I fix it?
Ray in Pierre, South Dakota

Dear Ray,
It sounds like you have a starter that has failed. The first step is to verify there are no problems with your cables or battery by performing voltage drop checks on the cables and a capacitance test on the battery even though they are new. Once you know they are all good then check the current draw of the starter both hot and cold. If it is pulling too much current when hot you may have either bad bearings in the starter or a bad armature. Did you install headers when you did the rebuild? If so, there may be too much heat reaching the starter and it may need to be shielded.
Take care, the Motor Medics