Митя Posted December 20, 2023 Report Share Posted December 20, 2023 (edited) Every day I repair old cars. Of the large number, today there are three special cars. Windsor 1949 DeSoto 1949 Windsor 1950 Sometimes questions arise regarding the repair of these cars. Now I can’t figure out why sometimes there is no pressure in the gearbox. The piston does not come out and does not push the fork. There are only 1st and 3rd gears. The electrical part works. And when the pressure appears, the car drives well. Often does not work after a cold engine start. Perhaps someone has encountered such a problem. Edited December 21, 2023 by Митя 1 Quote Link to comment Share on other sites More sharing options...
greg g Posted December 20, 2023 Report Share Posted December 20, 2023 What you are dealing with are know as M6 semi automatic transmissions. They are dual range with 2 gears in each range. They are designed to operate in high range for normal driving. Low range being reserved for high load hauling or compromised traction ( snow, mud, loose gravel) situations or when greater compression braking is needed. Most faults are external, corroded wiring terminals, or too high idle rpm. Low fluid can be a cause also. Today most people are finding universal tractor hydraulic fluid is a replacement for for the original fluid. It will work as a top off fluid as it will mix with the original fluid. Go to the Imperal Club website repair section. They have very comprehensive trouble shooting procedures archived there including the factory supplied technician training audio visual program. https://www.web.imperialclub.info/ This forum has a few folks who are well acquainted with these transmissions. Hopefully they will join in this discussion. A secondary source can be found at the Allpar.com website. Search transmissions. 2 Quote Link to comment Share on other sites More sharing options...
Митя Posted December 21, 2023 Author Report Share Posted December 21, 2023 (edited) The car arrived from the USA, the gears did not turn on. The problem was an incorrectly installed clutch. The synchronizer did not engage. I corrected this part. oil is filled 10w40 (according to European classification). I have 2 more of these gearboxes in service. The cars have traveled 10,000 km since purchase. I think the problem may be with the pump valve. it is intact, but may be stuck. I don’t know how to check this point. the effect is observed only after stopping the engine. it must stand for a while. it turns out that the oil is drained from the piston chamber. When the motor is running the pump does not work. it is driven by a secondary shaft from the wheels. I don’t understand why the oil supply does not occur after stopping the engine. If the pump does not work, there will always be no pressure. but then it appears and the car changes gears. Edited December 21, 2023 by Митя Quote Link to comment Share on other sites More sharing options...
greg g Posted December 21, 2023 Report Share Posted December 21, 2023 I believe the specified fluid for the transmission was SAE 10 non detergent motor oil. Not sure but maybe the multi viscosity modern oil might be causing some issues. Finding SAE 10 might be an issue. Try places that deal with old tractors or self powered harvest machines. The earlier reference to universal hydraulic fluid was for the fluid drive unit, not the transmission. This always causes confusion. 2 Quote Link to comment Share on other sites More sharing options...
Митя Posted December 21, 2023 Author Report Share Posted December 21, 2023 1 hour ago, greg g said: The earlier reference to universal hydraulic fluid was for the fluid drive unit, not the transmission. This always causes confusion. yes, I know it 1 Quote Link to comment Share on other sites More sharing options...
keithb7 Posted December 21, 2023 Report Share Posted December 21, 2023 (edited) If I recall there is a steel ball with a spring behind it that acts as a relief for the hydraulic oil pressure. Maybe the ball's spring is weak, broken? Maybe there is dirt/oil build up in the ball's seat, causing it to intermittently not seal properly? Just a guess. The ball is located beneath the plunger pin of the 6V solenoid. Best practice would be to measure and record the transmission hydraulic pressure. It should be 38-40 psi at about 8 mph. You jack up the rear wheels to get them turning as the pump only makes pressure when the driveshaft/rear wheels are turning. You can actually do a simple visual test. Remove floor access cover to transmission. Remove the electrical interrupter switch. It threads into the piston cylinder. With the rear wheels jacked up, put the transmission in low range. Throttle up to about 8 mph. Watch the piston through the interrupter switch port in the transmission housing. The oil pressure made by the hydraulic pump (38-40 psi) should force the piston piston forward. If the piston does not move forward, piston is stuck, or the hydraulic pump pressure is low. There are 2 springs inside the cylinder. When the oil pressure is dropped behind the piston, the piston return spring in the cylinder pushes the piston back. There is also an engagement spring for the shift fork rod. As the piston moves forward the shift fork spring is also compressed. When you let off the engine throttle, the shift fork spring enlarges, while mating gears synchronize, then it completes the shift, sliding the clutch gear forward. Its quite a system. Edited December 21, 2023 by keithb7 2 Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted December 22, 2023 Report Share Posted December 22, 2023 A damaged, worn direct speed syncro ring, sleeve and input shaft will seriously affect upshifts too. Too high a cold idle speed or oily governor points will delay upshifts too. 1 Quote Link to comment Share on other sites More sharing options...
Митя Posted December 22, 2023 Author Report Share Posted December 22, 2023 10 hours ago, keithb7 said: If I recall there is a steel ball with a spring behind it that acts as a relief for the hydraulic oil pressure. Maybe the ball's spring is weak, broken? Maybe there is dirt/oil build up in the ball's seat, causing it to intermittently not seal properly? Just a guess. The ball is located beneath the plunger pin of the 6V solenoid. Best practice would be to measure and record the transmission hydraulic pressure. It should be 38-40 psi at about 8 mph. You jack up the rear wheels to get them turning as the pump only makes pressure when the driveshaft/rear wheels are turning. You can actually do a simple visual test. Remove floor access cover to transmission. Remove the electrical interrupter switch. It threads into the piston cylinder. With the rear wheels jacked up, put the transmission in low range. Throttle up to about 8 mph. Watch the piston through the interrupter switch port in the transmission housing. The oil pressure made by the hydraulic pump (38-40 psi) should force the piston piston forward. If the piston does not move forward, piston is stuck, or the hydraulic pump pressure is low. There are 2 springs inside the cylinder. When the oil pressure is dropped behind the piston, the piston return spring in the cylinder pushes the piston back. There is also an engagement spring for the shift fork rod. As the piston moves forward the shift fork spring is also compressed. When you let off the engine throttle, the shift fork spring enlarges, while mating gears synchronize, then it completes the shift, sliding the clutch gear forward. Its quite a system. I also think about the ball. Perhaps it is releasing pressure because the piston does not come out. I unscrewed the switch. Quote Link to comment Share on other sites More sharing options...
Митя Posted December 24, 2023 Author Report Share Posted December 24, 2023 I don't know where to place it correctly. I'll put it in this place now. We came up with a project in our country, traveling in old cars. from April 2023 to December 2023 we drove 10,000 km. We are planning to travel to 5 countries next year. The purpose of our trip is the Atlantic Ocean, Portugal. https://youtube.com/shorts/_wp6NgbbMzs?si=yu0M407FsY0TEDdY 2 Quote Link to comment Share on other sites More sharing options...
Митя Posted January 19 Author Report Share Posted January 19 I have a new car in my workshop. fluids need to be inspected and replaced. 1 Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted January 19 Report Share Posted January 19 Nice looking straight eight C49 NewYorker or Imperial! Cannot read the fender nameplate... Quote Link to comment Share on other sites More sharing options...
Митя Posted January 19 Author Report Share Posted January 19 25 minutes ago, Dodgeb4ya said: Nice looking straight eight C49 NewYorker or Imperial! Cannot read the fender nameplate... this is Chrysler NewYorker Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted January 19 Report Share Posted January 19 (edited) 16 minutes ago, Митя said: this is Chrysler NewYorker AND we still do not know what name is on the fender script..Highlander maybe? Edited January 19 by Plymouthy Adams Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted January 19 Report Share Posted January 19 Is the exhaust manifold cracked? Quote Link to comment Share on other sites More sharing options...
Митя Posted January 19 Author Report Share Posted January 19 1 hour ago, Plymouthy Adams said: AND we still do not know what name is on the fender script..Highlander maybe? 1 Quote Link to comment Share on other sites More sharing options...
Митя Posted January 19 Author Report Share Posted January 19 2 minutes ago, Dodgeb4ya said: Is the exhaust manifold cracked? I can’t say anything on this issue. In a few days I will put it in the workshop and carry out all the research. When loading into the container, the exhaust system fastening was damaged. So far these are all the defects that I have found. Quote Link to comment Share on other sites More sharing options...
Митя Posted January 26 Author Report Share Posted January 26 The long-awaited car. Tomorrow I'll start exploring and tidying up the car. 1 Quote Link to comment Share on other sites More sharing options...
Митя Posted January 28 Author Report Share Posted January 28 Does anyone know where to find a wiring diagram for a Chrysler 1935? In what year did they start installing turn signals on Chrysler? Quote Link to comment Share on other sites More sharing options...
Ivan_B Posted January 28 Report Share Posted January 28 (edited) What specific model is this? The signals were installed somewhere in mid/late 40s, I think. Some older manuals are available here: https://chrysler.oldcarmanualproject.com/manuals/index.html Edited January 28 by Ivan_B Added info. 1 Quote Link to comment Share on other sites More sharing options...
Митя Posted March 18 Author Report Share Posted March 18 I started assembling the interior. All interior parts were made new. 1 Quote Link to comment Share on other sites More sharing options...
Ivan_B Posted March 18 Report Share Posted March 18 What are you planning to do for the rubber floor mat, up front? Quote Link to comment Share on other sites More sharing options...
Митя Posted March 19 Author Report Share Posted March 19 On 3/18/2024 at 10:02 PM, Ivan_B said: What are you planning to do for the rubber floor mat, up front? The rug will be different. I can't find tires like they were. Quote Link to comment Share on other sites More sharing options...
Ivan_B Posted March 19 Report Share Posted March 19 Same here. Those were custom-made, so I just used a standard rubber carpet, sold by meter, cut to size. 1 Quote Link to comment Share on other sites More sharing options...
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