4bear1 Posted January 18, 2019 Share Posted January 18, 2019 My '49 RoadMaster 70 Sedan's Dynafow Tranny has a number of leaks. When driving, it shifts well and is not noisy but going around corners or up steep grades, it tends to slip. When the car sits, the tray underneath it seems pretty full with transmission fluid. Any ideas anyone? Link to comment Share on other sites More sharing options...
old-tank Posted January 18, 2019 Share Posted January 18, 2019 If it slips on corners and hills, it is either low on fluid or the pickup screen is defective (usually at the attachment to the transmission). 1 Link to comment Share on other sites More sharing options...
4bear1 Posted January 18, 2019 Author Share Posted January 18, 2019 The car was in storage for over ten years. I’m wondering if the seals and gaskets need to be replaced in both the transmission and torque ball. Thank very much for your quick response. 4bear1. 1 Link to comment Share on other sites More sharing options...
Buicknutty Posted January 18, 2019 Share Posted January 18, 2019 (edited) A couple of things I'll add. The rear seals often leak on these, and it can be very difficult to get them so they don't leak at all. If the car has been sitting for some time, the seals dry out, and will leak badly, but with regular use, the seals might recover somewhat. Make sure that the fluid level is correct, if its' leaking bad, you can loose a lot, and these trannys take quite a bit of fluid. Lastly, about slippage, are you familiar with Dynaflows? As they are kind of a "lazy feeling" transmission. Because of the action of the torque converter, when you step on the gas, it feels like the engine accerates, and then the car kind of catches up. This is normal, but if it really is slipping, it should be checked. Either way, it would be wise to take the oil pan off for a check and cleaning. Edited January 19, 2019 by Buicknutty (see edit history) 2 1 Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted January 18, 2019 Share Posted January 18, 2019 (edited) 4baer1, if your Dynaflow is shifting, something is wrong.. A Dynaflow does not shift. The only shift is if the driver moves the lever from D to L or the other way. You probably know this but others new to Dynaflow may not. Ben Edited January 19, 2019 by Ben Bruce aka First Born (see edit history) 3 1 Link to comment Share on other sites More sharing options...
gdmn852 Posted January 19, 2019 Share Posted January 19, 2019 Also drop the inspection cover at bottom of flywheel housing and check the bolts holding the torque converter to flywheel,mine loosened up and was slipping and lost about 3 quarts in 30 miles!! I replaced all nuts with the nylon lock type so far this stopped most of the leak,Dynaflow do leak, Buick wouldn’t repair them if the were leaking less than pint in 1000 miles, according to service repair bulletins.After sitting for some time this will also let the seals dry out,keep an eye on the fluid level and go from there.First born is right Dynaflows never shift,all the work is done in the torque converter they do have somewhat of a slipping clutch feel to them ,engine revs up without immediate gain in speed but they are smoother than the Hydromatics of the same era.Gary 1 Link to comment Share on other sites More sharing options...
Ben Bruce aka First Born Posted January 20, 2019 Share Posted January 20, 2019 For a faster takeoff, use L until about 40 or so. You may be surprised. Ben 1 1 Link to comment Share on other sites More sharing options...
DrBlast Posted May 15, 2019 Share Posted May 15, 2019 Hello, my name is Joey and I am aware the thread is old but I’m in a bind. I’m working on a 1955 Buick special and servicing the Dynaflow transmission. I have searched far and wide and can not find the pickup screen for the life of me and was wondering where I could find one and/or if I could fashion one by myself. Link to comment Share on other sites More sharing options...
gdmn852 Posted May 17, 2019 Share Posted May 17, 2019 Did you try Bobs out of California?Sometimes he has parts not in his catalogue,give him a call 805 434 2963 email bob@bobsautomobilia.com Link to comment Share on other sites More sharing options...
old-tank Posted May 17, 2019 Share Posted May 17, 2019 Jim Hughes dba Jim's Dynaflow Service Perrysburg, OH.419-874-2393 David Edwards Link to comment Share on other sites More sharing options...
Harry p Posted June 20, 2019 Share Posted June 20, 2019 What's recommended oil for dynaflow trans ? Link to comment Share on other sites More sharing options...
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