What I learned 20234 adjustable modulator, TF400 transmission, Torque converter
I just wanted to post what I learned while installing my rebuilt TF400 Transmission into my 1973 Jeep J2000 pick up. These are things that I searched for but could not find anywhere on the internet so I thought I would post something for others just in case they were searching as well. Please feel free to correct me, I am a newbie at this and am willing to learn.
1. When installing the Torque Converter into the Transmission make sure it's fully seated before trying to bolt the tranny on to the engine. When I tried to put the screws in to bolt the torque converter to the fly wheel my screws would not reach. I pulled the toque converter forward just a little (just enough so the bolt would reach it). Then I was able to pull the torque converter the rest of the way when I screwed in the bolt. I did gently use a flat headed screw driver just a bit to move the torque converter forward just a couple of millimeters. After I got the first bolt in I wasn't sure what to do next because I couldn't get to the other bolts because of the engine and covers. I tuned the crank at the front of the engine. It's the biggest belt Pully right in the center and bottom at the front of the engine. There is a big nut deep in the center that you can turn using a large ratchet. When you turn it it moves the flywheel and converter and you can get to the other bolts.
2. When I drained the Dana 20 Transfer Case red Transmission fluid came shooting out and it drained and drained and drained. There should be gear oil in the Transfer Case not Transmission fluid. What happened is that the rear seal of the Transmission gave out so it was forcing Transmission fluid into the Transfer Case causing the Transfer Case to leak pretty bad. When it was leaking I noticed red tranny fluid coming out. Gear oil does come in different colors. I would recomend getting clear so that you can tell when tranny fluid is getting into the Transfer Case .
3. The Dana 20 Transfer Case bolts right on to the Transmission . I was surprised how easy it went on and I did not have to line up any of the gears inside. I am still wondering if I did that right. I did line up the drive shafts and make sure they were placed back the same way as when I took them off.
4. The modulator that came with my rebuilt Transmission from the shop was a BM 20234 Adjustable Modulator. When I test drove my truck after I re-installed the Transmission it seemed like it was taking forever to shift through gears, waiting until the RPMS were really high. If you follow the vacuum hose down to the modulator, take the vacuum hose off. Right inside the intake tube at the top of the modulator is a screw. You can use a small flat head screw driver to turn that screw and adjust the modulator. In my case since my car was shifting at too high RPM's I turned the screw COUNTER clockwise. I turned it about 5 complete rotations and that seemed to fix the issue. You may want to try turning little by little as I may have turned it too much here. DON'T TAKE THE MODULATOR OFF. In this tranny on this truck there is an adapter between the modulator and the Transmission . Inside that adapter is a curved flat piece of metal that rides on a big roller bearing. The modulator pushes this odd shaped strip of metal in and out which then pushes the pin inside the Transmission in and out. If you take off the modulator, that flat piece of metal may come out as well and is difficult to get it to sit just right. BELIEVE ME I KNOW!!! Also don't take the Modulator and Adapter off unless you are ready to drain the tranny fluid...it comes pouring out as I learned. What I did to fix this while I was under the truck was turn the adapter down towards the ground, put the strip of metal into the modulator where it will seat, then feed the strip of metal, modulator and all up into the adapter. After the modulator is back in turn it right side up. That's what worked for me anyway.
5. One more think I can think of is be careful while installing the Torque Converter Bolts. When I torqued them down I stripped two of the three bolt holes and then had to use a tap and die kit and install Heli coils into the Torque Converter. It sucks because I had to pull that tranny out 3 times to get it right.
Please Correct me if I am wrong on any of this stuff. The reason I did this myself was not only to save money but mostly because I wanted to learn how to do it. So if I did it wrong or you know of a better way I am happy to hear it.
Thanks,
Jimmy
Oh yea P.S. The TF 400 takes 12-14 quarts of Tranny fluid. This is when the Torque Converter is empty. When I pulled the Torque Converter out of the box I thought there was fluid in it. Still it took 13 quarts of oil to fill my tranny.
1. When installing the Torque Converter into the Transmission make sure it's fully seated before trying to bolt the tranny on to the engine. When I tried to put the screws in to bolt the torque converter to the fly wheel my screws would not reach. I pulled the toque converter forward just a little (just enough so the bolt would reach it). Then I was able to pull the torque converter the rest of the way when I screwed in the bolt. I did gently use a flat headed screw driver just a bit to move the torque converter forward just a couple of millimeters. After I got the first bolt in I wasn't sure what to do next because I couldn't get to the other bolts because of the engine and covers. I tuned the crank at the front of the engine. It's the biggest belt Pully right in the center and bottom at the front of the engine. There is a big nut deep in the center that you can turn using a large ratchet. When you turn it it moves the flywheel and converter and you can get to the other bolts.
2. When I drained the Dana 20 Transfer Case red Transmission fluid came shooting out and it drained and drained and drained. There should be gear oil in the Transfer Case not Transmission fluid. What happened is that the rear seal of the Transmission gave out so it was forcing Transmission fluid into the Transfer Case causing the Transfer Case to leak pretty bad. When it was leaking I noticed red tranny fluid coming out. Gear oil does come in different colors. I would recomend getting clear so that you can tell when tranny fluid is getting into the Transfer Case .
3. The Dana 20 Transfer Case bolts right on to the Transmission . I was surprised how easy it went on and I did not have to line up any of the gears inside. I am still wondering if I did that right. I did line up the drive shafts and make sure they were placed back the same way as when I took them off.
4. The modulator that came with my rebuilt Transmission from the shop was a BM 20234 Adjustable Modulator. When I test drove my truck after I re-installed the Transmission it seemed like it was taking forever to shift through gears, waiting until the RPMS were really high. If you follow the vacuum hose down to the modulator, take the vacuum hose off. Right inside the intake tube at the top of the modulator is a screw. You can use a small flat head screw driver to turn that screw and adjust the modulator. In my case since my car was shifting at too high RPM's I turned the screw COUNTER clockwise. I turned it about 5 complete rotations and that seemed to fix the issue. You may want to try turning little by little as I may have turned it too much here. DON'T TAKE THE MODULATOR OFF. In this tranny on this truck there is an adapter between the modulator and the Transmission . Inside that adapter is a curved flat piece of metal that rides on a big roller bearing. The modulator pushes this odd shaped strip of metal in and out which then pushes the pin inside the Transmission in and out. If you take off the modulator, that flat piece of metal may come out as well and is difficult to get it to sit just right. BELIEVE ME I KNOW!!! Also don't take the Modulator and Adapter off unless you are ready to drain the tranny fluid...it comes pouring out as I learned. What I did to fix this while I was under the truck was turn the adapter down towards the ground, put the strip of metal into the modulator where it will seat, then feed the strip of metal, modulator and all up into the adapter. After the modulator is back in turn it right side up. That's what worked for me anyway.
5. One more think I can think of is be careful while installing the Torque Converter Bolts. When I torqued them down I stripped two of the three bolt holes and then had to use a tap and die kit and install Heli coils into the Torque Converter. It sucks because I had to pull that tranny out 3 times to get it right.
Please Correct me if I am wrong on any of this stuff. The reason I did this myself was not only to save money but mostly because I wanted to learn how to do it. So if I did it wrong or you know of a better way I am happy to hear it.
Thanks,
Jimmy
Oh yea P.S. The TF 400 takes 12-14 quarts of Tranny fluid. This is when the Torque Converter is empty. When I pulled the Torque Converter out of the box I thought there was fluid in it. Still it took 13 quarts of oil to fill my tranny.