I'm about to service the transmission on our Olds. Does anyone know if the factory torque converter on a '76 Cutlass had a drain plug? If there is no point in wrestling that plastic torque converter cover off around the exhaust crossover pipe "just to find out", then I'd rather not.

Jeff

 

Hey Jeff, No drain holes on the torque converters.

Eric

 

 

Thanks, 76olds and Randy.

Okay, so Randy: with what do I plug the newly-drilled 1/8" holes afterward . . . without throwing the torque converter out of balance?

Jeff

 

Pop rivet.

 

Hey Jeff, I myself wouldn't feel the need to drill holes, drain then rivet for a trans service. The TH350's are awesome especially behind our smog 350's . I would just drop the pan change the filter, gasket & possibly install a nice shift kit then button it up, top off to the dipstick level.
JMO
Eric

 

Okay; thanks, guys.

Jeff

 

You can use the trans pump to pump out most of the trans fluid (before you drop the pan). Disconnect the upper line to the radiator. Install a pipe nipple (barbed) into the upper radiator bung. Run a hose off of that into a 5 gal pale with a lid on it, hose secured to lid. Turn car on: let it pump oil out 'till it burps (20-30 seconds generally). This will drain most of the pan, the converter and the cooler. Now drop the pan and service it. Refill, reattach the line and go.

Second pump drain method; Pull the main-line pressure port plug (rear plug, passenger side of trans, TH350). Thread in a pipe nipple or barbed fitting. Attach a section of tight fitting hose, turn car on for a few, this will evacuate most of the fluid same as the above.

None of this is necessary if the fluids in good shape. If the trans fluid is in good shape just drop the pan, change filter and go. If your real worried install a drain plug in the pan or purchase a pan with the drain plug. Run the car for 10-20 miles on the new fluid, drop the pan contents via the plug and repeat a couple of times (or pump it down as mentioned above). The pan plug makes filter service much easier and neater. Pumping the fluid out as described above is a great alternative as well.

I dont recommend drilling/tapping a torque converter, no reason to.

This method works on most automatic transmissions.

Note: If your trans is close to its expected service lift e.g. the fluids burnt or real dirty, as in silvery red/brown with a bad burnt odor, leave it alone, (Condition also verified by reading the line pressures). Run it till it blows then rebuild. You could get a little more life out of it if left alone. If trans fluid is changed when the fluid condition is as just described it will blow shortly after changing the fluid. Reason being is the frictions and steels are using the heavy contaminates to compensate for the worn frictions. Eliminating said contaminates forces the trans to use whats left of the friction material which generally isnt much. Many times you will hear reports of a trans blowing (slipping or no longer shifting) right after a service. Thats is why.

 

We used to drill and tap the torque converter and install a 1/8 pipe plug.

 

Thanks, drolds and Eric. I will do use the purge method while the pan is still in place.

Jeff

 

Pop rivet better be the closed-end type... not mentioned above?

Seems like a lot of hassle for little gain to me.

Use the tube/spew method and call it good.

PS they do make 1/16" NPT fitting also if one were inclined, I have several dozen recess hex drive plugs in stainless steel.


http://www.mcmaster.com/#standard-me...plugs/=11ky6j4

Post #8 is spot-on regarding end of life also. No touchee.

 

I agree, Octania. My trans is (seemingly) nowhere near its end-of-life; rather, the car sat for 4.5 years and I intend to change all of the fluids as a matter of course.

Jeff