If you do not replace certain parts in each rebuilt transmissions, it is very likely that over time the transmission will be damaged again, and when it is damaged the first thing that affects is the belt and pulleys, which are the most expensive parts of this transmission. The first part that must be changed in each rebuild is the upper piston in the primary pulley. Let’s see why rebuilt transmissions are the ideal solution.
The main flaw in many damaged pistons is that the internal diameter increases. If so, its internal part, that is, the diameter where it makes contact in the center of the pulley, wears out causing the piston to go to the bottom of the pulley and it totally loses its sealing function and causes the pulley to not make the variations of distance correctly, for which the vehicle will present pressure loss failures and also slippage of the belt on the pulleys. This will cause them to scratch and be unusable.
Now imagine that you repaired the transmission and it worked correctly, but soon after it came back with an immensity of faults and strange noises and you check the transmission again and you see that the bearing was damaged all by not replacing it on time. Now, you will not only have to change the bearing, but also the shaft, stator, pulleys and even the torque converter. And that's not counting oil, labor and most importantly your time!
Last but not least, the damaged pressure regulating valve should be changed. This valve is already well known for scratching and causing loss of main pressure, which translates to failure in the transmission. The most common is that the belt slips on the pulleys. This valve is located in the oil pump., If the manufacturing material is extremely bad and damaged, one option is to change it for a new and improved one offered. This new valve will increase the seal up to 22 in Hg as long as the pump is in good condition. The correct way to know if it is in good condition is by checking the vacuum, so you will be sure that it will work as it should.
In case it does not work only by replacing the valve, an oversize one will have to be installed, but we have seen that in 90% of cases all pumps work by simply replacing the valve with a new one without the need to oversize. You can see that the concept of rebuilt transmissions is quite complex, if you don’t solicit the help of an expert with the best used transmission reviews https://reman-transmission.com/reviews. So, it is best to seek out an expert for assistance so that it is done right the first time around. https://www.historicvehicle.org/sticktory-the-evolution-of-classic-transmissions/