Quick Service on GM Hydra-matic 350 and 400 Turbo Hydra-matic Automatic Transmissions
The GM Hydra-Matic 400 series automatic transmissions were a proud badge of Vehicle advanced and incredibly reliable automotive technologies and engineering. The 400 series itself was set up in different automotive items from the Vehicle GM divisions’ items in the years 1969 right through to 1976.
The Hydra-Matic 400 itself spurred on growth and development of the Super Turbo 400 (THM 400.) A popular still within the drag racing and auto racing fraternities where it’s happily known to because the “Turbo 400”, the tranny continued to propel lower the streets and freeways a group of established as well as luxury automotive items including Ferrari, Comes Royce & Bentleys, and domestic auto items for example Jeeps and early American Motors Sports Utility SUVV innovative models.
The roots of the bit of Americana automobile history still highly regarded as today around the automobile racing circuits basically developed and morphed from the predecessor the Turbo Hydra-matic 350 . 350’s were first set up in GM factory items in 1969 when they did run fully to 1976. The 400’s went from 1969 too as well as managed to get in to the mid 70’s.
Initial step of quick service with this unit series would be to check fluid levels. Fluid levels ought to be in the “full “mark with transmission at “normal operating temps”. With cold fluid, the amount ought to be roughly inch underneath the “ADD” mark. Only Dexron fluid ought to be used.
Possible points of oil leaks can happen in the following points transmission oil pans , oil pan gasket and components “O” rings which have experienced damage in renews or possibly simply have worn-out from many years of driving or just time.
Also check governor cover “O” rings, pan gasket mountings or faces not flat or flush which bolts happen to be correctly torqued.
Lastly to notice if oil arrives from the vent pipe, this trouble might be triggered by overfilling of fluid that’s an excessive amount of Dexron automatic transmission fluid within the transmission, water within the liquids itself or lastly a pump to situation gasket that was improperly installed or mis-situated.
Lastly transmission leaks triggered by actual aluminum situation porosity happen to be effectively fixed using the transmission itself still around the vehicle through the use of the next procedure: First road make sure bring the transmission to operating temps. Enhance the vehicle, along with the engine running, first locate the origin from the oil leak itself. Fully and completely look for leaks in most operating positions. Using a mirror may be useful to find leaks themselves.
Next turn off the engine and completely clean the region having a solvent after which let it fully and completely air dry. Following a instructions from the manufacturer, mix an adequate amount of standard epoxy cement. This is often acquired with a few effort out of your local GM dealer or acquired on eBay if required.
Lastly as the transmission continues to be good and hot, use the epoxy towards the area, ensuring the region is fully covered. Permit the epoxy cement to dry fully for at least three hrs.
Retest for leaks again and when sealed correctly you’re good and able to hit the street again with this particular Americana automobile industry vintage classic.