Borg Warner DG250 Locking up

[Ovalrace25]

This automatic transmission was used in a few cars in the early 50's. The one in this car worked great three years ago when the car was put away. NOW, getting the car out and going, the transmission LOCKS up and stalls the engine as soon as you select  "D"   --  If I quickly pull it down to  "L" I can drive the car up to 15+, then shift up to  "D" and go fine UNTIL I drop speed back down to where it downshifts....   Then it tries to lock--- BAN BANG BANG----   I have to put it into  "N" really fast so it stops the lock-up attempt.

I hope someone out there has WORKED on these or knows what this can be???? 

[1939_Buick]

In a Jag, Stude or ??

 

http://www.charlietranny.com/Automatic Drive.htm

 

https://forums.jag-lovers.com/t/saloon-lovers-borg-warner-dg-250-gearbox/38155

 

https://www.ebay.com/itm/Borg-Warner-DG150-DG250-Jaguar-Transmission-Manual-1951-61-Copy-of-AUTOBOOKS-/152059271005

[jp928]

With any auto trans that has stood for any length of time I recommend a thorough fluid change, including the converter and cooler, and change filter if fitted. This can do wonders for every aspect of the box. My 35 year old 3 speed MB box (Porsche 928) has only one vice - if left for more than a couple of weeks, its slow to take up in reverse; there are couple of leaks of 1 drop a week coming off the cooling hose fittings.

jp 26 Rover 9

[Frank DuVal]

I agree, change the fluid. I say use modern ATF of the Dexron lineage, since literature of the time lists Type A as the fluid to use, which morphed into Dexron. There are some who say use type F. Probably makes no difference at the moment. 

[Ovalrace25]

Changed fluid after checking pressures. Checked detentes to be sure linkage was moving into correct positions. Pulled valve body to check if any springs of valves were stuck.

Did air pressure test--  Seemed to be OK..   This one is in a Jaguar.  Thanks 39_Buick I am checking out the links you provided.

[Ovalrace25]

Anyone drive a Studebaker? Anyone had your Borg Warner transmission rebuilt? The DG200 and DG250 are similar. BOTH have a lock-up converter. I am thinking this is where the problem is. Keep in mind, the car sat for a few years. But in a dry clean garage. Before it was driven, all fluids changed. BUT the converter was not drained. Only after the first test drive when the problem was found, then major transmission service, including valve body inspection, governor inspection and air pressure test to ports. 

[Alan Barker]

Hi from New Zealand. I have a 1964 Austin same DG transmission & same exact problem.!

Did you sort problem?

Suspect worn governor.

Regards Alan

[John Allen]

The Borg Warner DG 250 has a clutch in the torque converter.  Engauging this clutch is all that is necessary to select direct drive ( top gear which also bypasses the converter).  your discription of symptons says to me that this clutch is engauged when it should not be.

The clutch is engauged by passing high pressure oil down the dual shafts into the torque converter, this oil is via a valve that is detented and activated by the flyweight governer in the transmission when the road speed exceeds 20mph or so..

By selecting low gear, I think the oil from the governer activated valve is not put to the direct drive clutch in the converter.
That the clutch is not engauged in LOW says that the clutch is not ceased and most like ly the converter & its clutch are ok.
This leaves the valve. - stuck / by passing oil , or the governer - stuck or broken spring>>.
As a last thought, any application of high pressure oil to the converter clutch (eg some other internal leak) could cause this, but I think unlikely given your discription)

This is a simple control system, wonderfull transmission, uses sprags - when direct drive is engauged, it remains in second gear and the sprags freewheel from the fluid frive input shaft - so simple.