Shade Tree Mech
Active Member
Gentlemen, experts too, This forum is the best I can do for my early 70's motorhome. It has the info I need for the Dodge running gear. The trans had fried and melted the clutches in the rear clutch pack. I have seen many causes for this condition in the forum here, the manual, and in other net postings. I will replace the pump with OEM parts to get the pressure back up. No, I didn't check before I disassembled. (First timer, learning as I go.) I have modified the valve body in accordance with instructions in the TF-1 TransGo kit. While cleaning, I found that the 'regulator valve throttle pressure plug' was sticking. It was not a contaminant. It was a fit issue. I polished the plug in the lathe with some 1500 grit paper. It took a few iterations and a couple hits with a fine Cratex wheel on a Dremel tool to bring the clearance to a sliding fit. I was not able to measure the difference with a .0001 reading micrometer. Note: The sliding valve components are deeply hardcased and extremely hard at the surface. They were easily held in the chuck jaws without any indications of marring on the surfaces of the valve bosses. Light jaw pressure, of course.
Now, the question: Is the sticky 'regulator valve throttle pressure plug' coupled with the low pump pressure the likely/obvious source for the rear clutch failure?
Next: There is an additional subassembly attached to the valve body that is not identified in the TransGo instructions. It is attached to the valve body directly above the 1-2 and 2-3 shift control valves. In it, are at throttle valve and a limit plug. In Mr. Munroe's book, it is described as "used in some V-8 models." Question: Will this additional subassembly interfere with the functional intent of absolute shift control incorporated in the TransGo TF-1 modifications?
Finally, Imagine yourself at the wheel of a 14,000 lb lumbering inverted bathtub. You are approaching a steep grade. I.E. typical white knuckle grade, say, 7% for the next five miles. The old beast is equipped with the latest early '70's vintage brakes, and as you enter the slope, everything is fine. The slope gets steeper, and you know the brakes are heating up. Thirty seconds later, they start to fade. You downshift to second. Then you realize you should have gone to second before starting the whole deal. Too late for that now. Second kicks in ok. You're fine. Thirty seconds later, brakes are fading again. Speed is fifty plus. Your only option is to drop it into first. Question is: What will happen given the instructions in the TransGo modification sheet to not modify the '1-2 shift valve governor plug' when the trans is used in heavy duty applications. I missed that part of the instructions. I did the modification. That's where I found that the valves are hardcased. According to the instructions, the transmission will shift to first no matter what the speed. Question is: Will the trans survive a 2-1 downshift at 55-60 MPH? I don't know enough about the operation of the trans to know where the greatest stress will manifest. Is the overrunning clutch involved? I've read that they will disintegrate under certain very stressful circumstances. Opinions and speculations appreciated. Trans code: PK 3410668L 2964 2655
Now, the question: Is the sticky 'regulator valve throttle pressure plug' coupled with the low pump pressure the likely/obvious source for the rear clutch failure?
Next: There is an additional subassembly attached to the valve body that is not identified in the TransGo instructions. It is attached to the valve body directly above the 1-2 and 2-3 shift control valves. In it, are at throttle valve and a limit plug. In Mr. Munroe's book, it is described as "used in some V-8 models." Question: Will this additional subassembly interfere with the functional intent of absolute shift control incorporated in the TransGo TF-1 modifications?
Finally, Imagine yourself at the wheel of a 14,000 lb lumbering inverted bathtub. You are approaching a steep grade. I.E. typical white knuckle grade, say, 7% for the next five miles. The old beast is equipped with the latest early '70's vintage brakes, and as you enter the slope, everything is fine. The slope gets steeper, and you know the brakes are heating up. Thirty seconds later, they start to fade. You downshift to second. Then you realize you should have gone to second before starting the whole deal. Too late for that now. Second kicks in ok. You're fine. Thirty seconds later, brakes are fading again. Speed is fifty plus. Your only option is to drop it into first. Question is: What will happen given the instructions in the TransGo modification sheet to not modify the '1-2 shift valve governor plug' when the trans is used in heavy duty applications. I missed that part of the instructions. I did the modification. That's where I found that the valves are hardcased. According to the instructions, the transmission will shift to first no matter what the speed. Question is: Will the trans survive a 2-1 downshift at 55-60 MPH? I don't know enough about the operation of the trans to know where the greatest stress will manifest. Is the overrunning clutch involved? I've read that they will disintegrate under certain very stressful circumstances. Opinions and speculations appreciated. Trans code: PK 3410668L 2964 2655