Found solution to Tranny Model 4T45E oil pan leak
10-26-2010, 03:05 PM
#1
Thread Starter
Join Date: 04-22-2010
Location: FLORIDA
Posts: 2
Found solution to Tranny Model 4T45E oil pan leak
An small ATF leakage problem I encountered after replacing the ATF while trying to reuse the factory gasket and later trying to use a new factory replacement gasket with the original factory Tranny pan is now resolved.
Problem:
Factory gasket can only be use once and a mistake if buying and installing same (new). The gasket has metal sleeves that print grooves in the Tranny mounting surface and deformed the Tranny metal pan. The grooves are the leakage path for the ATF to leak out. Using RTV or any other compound will not stop the leak because when position the factory gasket it will seat different due to the tolerance of the sleeve circle. Factory gasket was designed for one time use or for the 100000 miles ATF replacement, DUH!
Solution:
Use rubberized thin gasket for 4T45E model Tranny. NAPA has a good quality gasket for this application. Coat the new pan surface with contact cement and set gasket over. Then coat the gasket with red RTV 26B and allow to get tacky. Make sure the aluminum mounting surface on the transmission is completely free of ATF. Applied a coat of antisieze paste to the 12 fasteners. Install tranny pan, parallel all the time, to the tranny surface and install 4 fasteners. Then complete installing the rest of the fasteners in a cross pattern. Torque all fasteners to 40 in-lbs "ONLY". Then enjoy no more leaks. You can buy a tranny pan from Rockauto with a drain plug for better ATF replacement. Drain plug torque to 60 in-lbs using synthetic fiber gasket. Make sure to chase threads on the aluminum before reinstalling the fasteners since GM did not use any antisieze compound between steel and aluminum. Hope this helps to the forum folks.
HeRosBug Performance Co.
Problem:
Factory gasket can only be use once and a mistake if buying and installing same (new). The gasket has metal sleeves that print grooves in the Tranny mounting surface and deformed the Tranny metal pan. The grooves are the leakage path for the ATF to leak out. Using RTV or any other compound will not stop the leak because when position the factory gasket it will seat different due to the tolerance of the sleeve circle. Factory gasket was designed for one time use or for the 100000 miles ATF replacement, DUH!
Solution:
Use rubberized thin gasket for 4T45E model Tranny. NAPA has a good quality gasket for this application. Coat the new pan surface with contact cement and set gasket over. Then coat the gasket with red RTV 26B and allow to get tacky. Make sure the aluminum mounting surface on the transmission is completely free of ATF. Applied a coat of antisieze paste to the 12 fasteners. Install tranny pan, parallel all the time, to the tranny surface and install 4 fasteners. Then complete installing the rest of the fasteners in a cross pattern. Torque all fasteners to 40 in-lbs "ONLY". Then enjoy no more leaks. You can buy a tranny pan from Rockauto with a drain plug for better ATF replacement. Drain plug torque to 60 in-lbs using synthetic fiber gasket. Make sure to chase threads on the aluminum before reinstalling the fasteners since GM did not use any antisieze compound between steel and aluminum. Hope this helps to the forum folks.
HeRosBug Performance Co.
10-26-2010, 03:11 PM
#2
Thread Starter
Join Date: 04-22-2010
Location: FLORIDA
Posts: 2
Found Solution to Tranny model 4T45E Leaky pan
An small ATF leakage problem I encountered after replacing the ATF while trying to reuse the factory gasket and later trying to use a new factory replacement gasket with the original factory Tranny pan is now resolved.
Problem:
Factory gasket can only be use once and a mistake if buying and installing same (new). The gasket has metal sleeves that print grooves in the Tranny mounting surface and deformed the Tranny metal pan. The grooves are the leakage path for the ATF to leak out. Using RTV or any other compound will not stop the leak because when position the factory gasket it will seat different due to the tolerance of the sleeve circle. Factory gasket was designed for one time use or for the 100000 miles ATF replacement, DUH!
Solution:
Use rubberized thin gasket for 4T45E model Tranny. NAPA has a good quality gasket for this application. Coat the new pan surface with contact cement and set gasket over. Then coat the gasket with red RTV 26B and allow to get tacky. Make sure the aluminum mounting surface on the transmission is completely free of ATF. Applied a coat of antisieze paste to the 12 fasteners. Install tranny pan, parallel all the time, to the tranny surface and install 4 fasteners. Then complete installing the rest of the fasteners in a cross pattern. Torque all fasteners to 40 in-lbs "ONLY". Then enjoy no more leaks. You can buy a tranny pan from Rockauto with a drain plug for better ATF replacement. Drain plug torque to 60 in-lbs using synthetic fiber gasket. Make sure to chase threads on the aluminum before reinstalling the fasteners since GM did not use any antisieze compound between steel and aluminum. Hope this helps to the forum folks.
HeRosBug Performance Co.
Problem:
Factory gasket can only be use once and a mistake if buying and installing same (new). The gasket has metal sleeves that print grooves in the Tranny mounting surface and deformed the Tranny metal pan. The grooves are the leakage path for the ATF to leak out. Using RTV or any other compound will not stop the leak because when position the factory gasket it will seat different due to the tolerance of the sleeve circle. Factory gasket was designed for one time use or for the 100000 miles ATF replacement, DUH!
Solution:
Use rubberized thin gasket for 4T45E model Tranny. NAPA has a good quality gasket for this application. Coat the new pan surface with contact cement and set gasket over. Then coat the gasket with red RTV 26B and allow to get tacky. Make sure the aluminum mounting surface on the transmission is completely free of ATF. Applied a coat of antisieze paste to the 12 fasteners. Install tranny pan, parallel all the time, to the tranny surface and install 4 fasteners. Then complete installing the rest of the fasteners in a cross pattern. Torque all fasteners to 40 in-lbs "ONLY". Then enjoy no more leaks. You can buy a tranny pan from Rockauto with a drain plug for better ATF replacement. Drain plug torque to 60 in-lbs using synthetic fiber gasket. Make sure to chase threads on the aluminum before reinstalling the fasteners since GM did not use any antisieze compound between steel and aluminum. Hope this helps to the forum folks.
HeRosBug Performance Co.
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