How to Fix Car Transmissions

Transmissions will fail over time due to high mileage, but many transmission suffer premature failure due to poor maintenance. If your vehicle transmission is not operating correctly, there are a few maintenance and diagnostic actions you can take to see if you can restore proper operation. If these efforts fail, you may need to have the transmission rebuilt or replaced, which is an extremely complex procedure best accomplished by a dedicated transmission specialty shop.

Instructions

1

Check your transmission fluid level. If your transmission fluid is low, this will cause the transmission to act erratically by shifting hard, slipping, or making unusual noises. The transmission dipstick will be in the engine bay, and is read in the same way as the engine oil dipstick; the metal stick will have low and full markings. Transmission fluid does not burn off like engine oil, if your transmission fluid is low, it means there is a leak in the system.

2

Replace your transmission fluid. While some cars have transmission fluids rated for 100,000 miles, most transmissions should see service every 30,000 miles or even 15,000 miles for severe duty. Transmission fluid contains additives which break down over time, and this can result in shudder, chatter, and poor shifting. You can get a very rough idea of the condition of your transmission fluid when you check the fluid level on the dipstick; it should look red. If it is dark or if it emits a burning smell, the transmission is overdue for a servicing.

3

Read any check engine light codes. Some cars may throw a check engine light code, which will be a yellow warning light on the main dashboard. You can have this code read at many automotive supply stores for free, or you can have it read at a independent shop or dealership. Depending upon the vehicle, it may trigger the light If there is a failure in a transmission control module. A shop may be able to replace this module without having to actually open up your transmission.

4

Visit a transmission shop. If you cannot identify a problem based upon a check engine light code or identifying old transmission fluid, take your car to a transmission shop, which can diagnose the problem. If your vehicle has 100,000 or more miles on it and has never been serviced, it may need to be rebuilt since there will be wear on the transmission's internal clutch packs.