Post by stagdriver on Apr 11, 2019 8:54:06 GMT
I am a 1975 Triumph Stag owner and have been reading with great interest the Rover technical articles on the Borg Warner type-35 gearbox; it would seem that both cars suffer with the same problem of leaving transmission fluid on the garage floor. The Triumph Forum has very little on this subject hence this asked for help from you Rover chaps. My gearbox have leaked oil for several years but other that it works fine, after reading the various articles on the Rover forum I diagnosed that the gearbox selector shaft seals were the major contributor to the leaking problem, a secondary leak area was the breather pipe connection to the gearbox. I have replaced the seals on both ends of the selector shaft and installed a longer breather pipe secured on the gearbox with a clip.
After reading about the function of the converter check valve I decided that as I had the car on the ramps I might be prudent to see if my car has one fitted, I could also clean or replace the gauze filter and adjust the bands if needed. After removing the gearbox sump the valve block was very simple to remove and strip down on the bench, you will probably not be surprised that the “check valve was not fitted”. There is another similar ball valve located in the middle of assembly which is called the ( 3-2 Shift Restrictor Ball and spring ) it’s has an extremely weak spring not sure what is does as I could not find any technical reference to the items function in the two workshop manuals I have.
I have read several technical manuals and none of them give the principles of operation of the check valve, I do know however from the forum that it was to stop drain back from the converter.
I am also missing the magnet that is supposed to live somewhere in the sump area, can someone tell me where it should be located.
Now the 64K-Dollar question:-
Can I make a homemade check valve with a suitable steel ball and spring? The pressure in the hydraulics must quite high, the spring would have to strong enough to stop the fluid draining back but not too strong to interrupt the correct function of the Converter, The ( 3-2 Shift Restrictor Ball ) is ¼” in diameter and fits in the Check valve pocket all I have to source is another 1/4” steel ball and a suitable spring that puts just enough pressure on the ball to stop the fluid leaking.
It begs the question why do so many gearboxes have the check valve missing, did Borg Warner stop installing them because of technical improvements or did it cause other problems? It has been reported that it was never was 100% effective.
Any thoughts would be greatly appreciated; I might just be wasting my time even thinking about installing one.
After reading about the function of the converter check valve I decided that as I had the car on the ramps I might be prudent to see if my car has one fitted, I could also clean or replace the gauze filter and adjust the bands if needed. After removing the gearbox sump the valve block was very simple to remove and strip down on the bench, you will probably not be surprised that the “check valve was not fitted”. There is another similar ball valve located in the middle of assembly which is called the ( 3-2 Shift Restrictor Ball and spring ) it’s has an extremely weak spring not sure what is does as I could not find any technical reference to the items function in the two workshop manuals I have.
I have read several technical manuals and none of them give the principles of operation of the check valve, I do know however from the forum that it was to stop drain back from the converter.
I am also missing the magnet that is supposed to live somewhere in the sump area, can someone tell me where it should be located.
Now the 64K-Dollar question:-
Can I make a homemade check valve with a suitable steel ball and spring? The pressure in the hydraulics must quite high, the spring would have to strong enough to stop the fluid draining back but not too strong to interrupt the correct function of the Converter, The ( 3-2 Shift Restrictor Ball ) is ¼” in diameter and fits in the Check valve pocket all I have to source is another 1/4” steel ball and a suitable spring that puts just enough pressure on the ball to stop the fluid leaking.
It begs the question why do so many gearboxes have the check valve missing, did Borg Warner stop installing them because of technical improvements or did it cause other problems? It has been reported that it was never was 100% effective.
Any thoughts would be greatly appreciated; I might just be wasting my time even thinking about installing one.