Dynaflow Question

It's time to change the fluid in my 1950 Buick Special with a Dynaflow transmission. My question is, can this be done by any garage/mechanic or should it be brought to a transmission shop? Also, before getting this done is there anything I should know?
Any help would be greatly appreciated
Thanks
Scott

 

If the pan has a drain plug, or the filler tube connects at the pan, then I would think any good mechanic could do a partial refill. The converter might have drain plugs too, if so that could also be drained and the transmission fully refilled with new Dexron III fluid. Don't use Dexron IV or V. Should be too expensive.

 

Well I took the dive and did it myself. Wasn't too bad at all. Thought I'd post the steps for anyone else who can use this information.
1. Warm up transmission; remove bell house cover
2. Loosen one converter drain plug, through opening in the flywheel, (the other plug is diametrically opposed to the first) then turn the flywheel until opposite drain plug is straight down and remove this plug to allow converter to drain completely. HINT: Spray a little Marvel Mystery Oil on both plugs and let them set for awhile - otherwise you risk stripping the head of the plug. Also, I cranked it until the plug was just on one side of the oil pain and used a deep 7/16 socket and a breaker bar to free the plug.
3. Remove drain plug and allow oil pan to drain completely. DO NOT REMOVE THE AC***ULATOR PLUGS - they are the two large plugs on either side of the transmission pan.
4. Install and tighten all drain plugs and install bell housing cover.
5. Put 3 quarts of Dexon III Type oil in the transmission. With engine idling and transmission in park complete the refilling to bring oil level to 1 3/4 below "FULL" mark on the gauge rod. When transmission is warmed up, the oil level should be at "FULL" mark on the gauge rod.

The Series 40-50 transmission requires approximately 8 1/2 quarts total and the Series 70 transmission requires approximately 10 quarts total.

Well that's it! Wasn't too bad at all. Hardest part was spraying the plugs and waiting for the Marvel Mystery Oil to loosen them up.

 

Another hint for the converter drain plugs: Use an impact 6 point socket with a breaker bar. This will reduce any damage to the drain plug heads. The penetrating oil is still recommended before removing plugs.

When changing the fluid next time, get a filter and pan gasket. You never know what lerks in the bottom of the pan.

Good job!