Need help verifying a torque converter issue
02-04-2012, 01:17 AM
#1
Need help verifying a torque converter issue I have a powerglide with a turbo input shaft(accepts TH400/TH350 converters) and i just switched converters. After bolting up the transmission i realized that i can not move the converter forwards towards the flywheel. I unbolted it tonight and realized that the converter is longer than my old one. From end of shaft to the nose of the converter is 6 15/16" inchs. My old converter measures 6 3/4". Both are for a LS1, meaning they have the larger nose to accept into a LS crank.
If anyone could possibly measure there converters and tell me what yours measures at it would be greatly appreciated. I just want to make sure that my new converter is wrong and not the old one.
If anyone could possibly measure there converters and tell me what yours measures at it would be greatly appreciated. I just want to make sure that my new converter is wrong and not the old one.
02-05-2012, 09:05 AM
#3
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Did you change the input shaft when swapping converters or was this same shaft used with the old setup?
This is what I would try first. When checking build height you need to check from the tip of the converter hub to the mounting bolt pads. To do this place the converter on a flat surface with the hub down. Then measure from flat surface to the pads. This will tell you if your two converters have the same build height. You certainly can put them side by side as well.
Looking at a book I have here I get build heights between 6.100 and 6.150 for PG, th350 and th400. Now being that you have a custom converter and also a PG was never an option behind these motors there are some things you need to look at.
If they are both the same height then take the converter by itself and place it up to the flex plate to make sure that the pilot is not what is causing you an issue here and also that its going into the crank. Also that the pads sit flush on the FP. If that seems fine then you need to determine if turbo shaft you have is all the way in the unit or not.
They can be a PIA to get all the way in at times. I would also try to install the converter with the shaft out to make sure that the shaft is in fact your issue or if you are getting hung up on the pump gears for some reason. Also trying the old converter might not be a bad idea. You could also try placing the shaft in both converters to see how much sticks out.
You can always take some measurements from the face of the bell to the mounting pad. Then reverse this by doing the same off the back of the engine block. I believe you should have a measurement from the face of the bell to the converter pad of 1.125. From the back of the engine to the front of the flex plate the measurement should definitely be more than the 1.125 mentioned above. I hope this helps you some not sure if this info is spot on but its a place to start.
This is what I would try first. When checking build height you need to check from the tip of the converter hub to the mounting bolt pads. To do this place the converter on a flat surface with the hub down. Then measure from flat surface to the pads. This will tell you if your two converters have the same build height. You certainly can put them side by side as well.
Looking at a book I have here I get build heights between 6.100 and 6.150 for PG, th350 and th400. Now being that you have a custom converter and also a PG was never an option behind these motors there are some things you need to look at.
If they are both the same height then take the converter by itself and place it up to the flex plate to make sure that the pilot is not what is causing you an issue here and also that its going into the crank. Also that the pads sit flush on the FP. If that seems fine then you need to determine if turbo shaft you have is all the way in the unit or not.
They can be a PIA to get all the way in at times. I would also try to install the converter with the shaft out to make sure that the shaft is in fact your issue or if you are getting hung up on the pump gears for some reason. Also trying the old converter might not be a bad idea. You could also try placing the shaft in both converters to see how much sticks out.
You can always take some measurements from the face of the bell to the mounting pad. Then reverse this by doing the same off the back of the engine block. I believe you should have a measurement from the face of the bell to the converter pad of 1.125. From the back of the engine to the front of the flex plate the measurement should definitely be more than the 1.125 mentioned above. I hope this helps you some not sure if this info is spot on but its a place to start.
02-05-2012, 10:16 AM
#4
Vince is right, a stock converter should be about 6.150. Measure again not including the converter pilot and let us know. For an LS motor, the converter pilot should stick out past the converter pad about .500. Your other converter may have been special built for a mid plate setup.
Chris
Chris
02-05-2012, 02:17 PM
#5
When the converter is mated to the crank and FP it goes all the way into the crank and stops with 1/4" of gape on the bolting locations of the torque converter to the fp. The shaft in the glide is fine. I believe the only way to solve this issue is to ether take off 3/16" to 1/4" off the nose of the converter where it enters the crank, or install a midplate to space back the transmission 3/16" to 1/4". The converters nose is really long, and i dont see any downsides to just putting it on a lathe and taking a little off, then putting the 45* chamfer back on. Any downside to this?
