Chapter 11 Manual Transaxle Problems, Troubleshooting, and Service 227 Copyright by Goodheart-Willcox Co., Inc. Drain plug Fill plug Transmission oil Fill plug hole A B C Low fluid level or water contamination can also cause harm to the transaxle. If the transaxle lubricant level becomes too low, moving parts will wear prema- turely. If the vehicle is driven through deep water, the water can enter the transaxle through the vent. Water will contaminate the oil. As a result, the gears and bearings may be destroyed through pitting and poor lubrication. Always begin diagnosing manual transaxle problems by finding out why the vehicle was brought in for service. Get the customer to describe the transaxle problem. When test-driving a vehicle, determine in what gear and at what speed the problem occurs. If possible, take the customer with you and have him or her point out the particular prob- lem while it occurs. During a road test, try to isolate transaxle problems from CV axle, engine, tire, and other vehicle problems. For example, rumbling or roaring noises that increase and decrease with road speed are usually caused by bad wheel bearings or defective tires. Vibrations that cycle according to vehicle speed are usually caused by faulty CV axles. Slippage is caused more often by the clutch than the transaxle. Problems that seem to occur in one gear only are usually caused by the transaxle itself. Warning: When road testing a vehicle, always obey all traffic regulations. Also, try to choose roads that are not congested or empty parking lots for testing. Do not become so engrossed in diagnosing the transaxle that you end up having an accident. Once you have identified the problem, check out the cause with the easiest solution first you should always pro- ceed from easiest to hardest. Consider all possible causes, even the most unlikely. Many manual transaxle problems can be solved by simple linkage adjustments or by adding transaxle lubri- cant. Every manual transaxle that is brought in for service should have its clutch and shift linkage adjusted and its fluid level checked. A manual transaxle may have a dipstick or just a fill hole for checking the level. If needed, the proper grade and type of oil should be added, Figure 11-2. If the oil level is low, check for leaks. Note: If the transaxle has a separate reservoir for differential lubricant, the fluid level in this reservoir should also be checked. Common problems encountered in the manual trans- axle are similar to those seen in the manual transmission and rear axle assembly. Some of these problems and their possible solutions are presented in the following sections. Lubricant Leakage Lubricant leakage is an unwanted loss of lubricant from the transaxle. Transaxle lubricant levels may drop slightly over long periods of time because of evaporation. If the lubricant level is very low, the transaxle is probably leaking. Always make sure the leak is actually coming from the transaxle. Engine oil, brake fluid, power steering fluid, or engine coolant could be dripping down onto the transaxle. If the transaxle case is wet but its oil level is normal, some- thing else may be leaking. Once you are sure the leak is coming from the transaxle, check to determine the location and cause. Transaxle leaks are most commonly found at the case and end cover gaskets. Sometimes the case or cover has been gouged or otherwise damaged. Other causes of leaks are bad CV axle or shift rail seals, lack of sealer on bolts, loose drain or fill plugs, and cracks in the transaxle case. Leaks are often caused by a high lubricant level in the transaxle. A high fluid level can cause oil to leak from good seals or from the transaxle vent. If a seal or gasket is leaking, or if defects in other trans- axle parts are causing the leak, the transaxle may have to be removed to gain access to the parts. The CV axles can usually be removed to replace the axle seals without remov- ing the transaxle. Figure 11-2. Transaxle lubricant levels must be maintained to prevent severe damage. Some transaxles must have lubri- cant changed periodically. Consult the manufacturer’s service manual for instructions on how to check the level and to ensure you use the right kind of lubricant. A—Typical drain plug location. B—Typical fill plug location. C—Lubricant level should just wet the bottom of the fill plug threads. (Chrysler)