How do I stop my transmission from slipping?

ANSWER : Hello. From what you describe, it would appear that your transmission is beginning to slip. This can be caused by many things. The first thing I would do is check the vehicle’s transmission. Automatic transmission use fluid pressure to operate, and will have all sorts of issues if the fluid is low or dirty. If the fluid checks out, I would then move on to looking at the transmission itself. It may be possible that one of the components, such as a sensor or solenoid may be going out and causing your issue. It may also be possible that the transmission is simply worn out and can no longer hold the engine torque, perhaps due to a worn clutch pack, valve body, or torque converter. In these cases of removal and overhaul of the transmission is required. You may be able to continue driving the vehicle, however, because it may cause the symptoms to worsen over time if the issue is not quickly addressed.

ANSWER : Both of these additives are designed to block small leaks or seepage from a gasket or rubber seal an not to fix major leaks or leaks where there will be excessive pressures, such as coolant leaks into the combustion chamber of the cooling system or leaks in high pressure areas of the transmission.

I would not recommend the use of these products unless a manufacturer specified to use them, like how GM did on their earlier models of the modular motors that had coolant leaking through the pores of the engine block from defective castings.

Before adding any of these additives I would recommend having a mechanic check the transmission fluid leak to see what the proper repair should be. These additives can sometimes clog systems and make matters worse in the long run.

ANSWER : Hi there, thanks for writing in.

The reason is starts slipping at 30 is this is where it needs to change to second gear or third gear. The problem is most likely the servo piston for the second gear engagement is binding in the transmission housing due to a worn housing. The fix is to overhaul the transmission and have a sleeve put into the housing during the overhaul with an oversize servo kit. The only other fix would be to replace the transmission with a new or rebuilt unit. The reason it works after turning the car off and back on is because it sets a fault for itself and goes into limp mode, and turning it off will erase that fault until its seen again, at which point it will go into limp mode again. You can have this diagnosis verified by a qualified technician, such as one from YourMechanic, who can then provide you with a suggested repair plan.

ANSWER : Hi there. Most transmissions have shifting issues with the fluid being dirty. First replace the transmission oil filter and do a transmission oil flush. If the fluid is black, do not attempt to change the fluid as it will make the transmission no longer work. Then drive the vehicle and see if the transmission will act up again. If it does, then either the transmission control system (valve body – brain of the transmission) has a mass cross leak or the transmission is slipping and needs rebuilt or replaced. I recommend seeking out a professional, such as one from Your Mechanic, to help you diagnose your transmission.

ANSWER : You can certainly use transmission stop leak, however depending on how bad the leak is or the amount of pressure coming from the leak, this may be only a temporary fix. I would suggest having a professional from YourMechanic come to your location to take a look at the vehicle.

ANSWER : Hi Jose: Thanks for your question. Below is some additional information in addition to that sent to you by John yesterday. Installing used parts, particularly a part as complex as a transmission, is not the best practice. If you have a transmission fault, the first thing to do is get the cause of the fault professionally diagnosed because some transmission faults are easy to fix, such as low fluid level, replacement of burnt fluid, or needed fixes on engine controls or wiring (transmissions are electronically controlled). YourMechanic offers that service as a transmission diagnostic and you can schedule that at your convenience.

After you know, for sure, what is wrong with the transmission then a decision can be made as to the most economic and effective repair strategy. That is, if the fix is not amongst the simple causes of transmission breakdowns, but rather is due to something like a worn out band, or a leaking clutch piston, then the transmission has to be removed, completely overhauled and re-installed, usually with a new torque converter. Without a diagnostic, even installing a new transmission may not resolve your issue if the fault lies in an engine control or electronic control component and this is why you need to first get the problem identified. Hope we can assist you with this.

ANSWER : Hi there. In most cases when you overfill the transmission fluid it can cause excessive foaming of the fluid or possible internal component failure due to excessive pressure inside the hydraulic lines. Sensors like the speed sensors however are rarely impacted by this situation. However, in regards to the possibility of probability of this; I would say perhaps a 10% chance.

ANSWER : Hi there. If the transmission is shifting into 1st gear and 2nd gear, then it is not slipping. The transmission shift pack solenoid ’B’ has failed and only the 1st and 2nd gears work. The 3rd and 4th gear needs to have an overdrive clutch engaged and is obtained by the shift pack ’B’ solenoid. The harsh down shift is the low / reverse clutch engaging as the vehicle is slowing down. This clutch will activate on in the event the downshift solenoid stops working. I recommend replacing the shift solenoid A and B pack and also replacing the down shift solenoid. If you need further assistance with your transmission not shifting into 3rd and 4th, then seek out a professional, such as one from Your Mechanic, to help you.