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I have to ask, did you check the oil level in the trans?
Sm465 knocking while in reverse
- Thread starter Jarrett Melvin
- Start date
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I have to ask, did you check the oil level in the trans?
Jarrett Melvin
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Just filled it when I put it in the other day, but it wouldn't hurt to double check
Jarrett Melvin
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I've went back and double checked the u joints and drive shaft. All good. There is a little slop in the pinion and some play in and out on the output shaft.
Tightened by u bolts as well. Still making making same noise. Reverse only, high,l or low rpm, clutch in or out
Tightened by u bolts as well. Still making making same noise. Reverse only, high,l or low rpm, clutch in or out
trukman1
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This probably was a once in a lifetime thing but my automatic did that only in reverse. Turned out the bellhousing bolts weren't tightened all the way. Worth a check.
Dan Brown
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I put a Muncie M20 in a 55 Chevy years ago and had a clicking in first gear. Turned out to be a chipped tooth in first gear. Just some food for thought.
Too, if your new one piece drive shaft is longer than 72 inches it's too long. I assume your truck is a long wheel base. If so, that's why the two piece shaft with center bearing support.
More food for thought. I worked for a Military Truck Manufacturer, again, years ago, and we had lots of problems with the deuce and a half rear drive shaft. Kept throwing them off. Turned out to be the weenie U bolt type U joints. After going to what's called 'Full Round' joints, problem solved. That being said I was in charge of the program, along with Rockwell, the manufacture of the shafts, to solve other problems. I did lots of research and learned a hell of a lot about drive shafts and U joints, which is why I know that 72 inches is crowding it. Too, with too long a drive shaft, you can hit what's called 'critical speed', which causes the drive shaft to look like a banana while tuning and eventually fly off. Had that happen a bunch on these trucks.
Keeping the U joints in phase, as the pictures show, and the shafts well balanced, is also very important.
Good luck.
Too, if your new one piece drive shaft is longer than 72 inches it's too long. I assume your truck is a long wheel base. If so, that's why the two piece shaft with center bearing support.
More food for thought. I worked for a Military Truck Manufacturer, again, years ago, and we had lots of problems with the deuce and a half rear drive shaft. Kept throwing them off. Turned out to be the weenie U bolt type U joints. After going to what's called 'Full Round' joints, problem solved. That being said I was in charge of the program, along with Rockwell, the manufacture of the shafts, to solve other problems. I did lots of research and learned a hell of a lot about drive shafts and U joints, which is why I know that 72 inches is crowding it. Too, with too long a drive shaft, you can hit what's called 'critical speed', which causes the drive shaft to look like a banana while tuning and eventually fly off. Had that happen a bunch on these trucks.
Keeping the U joints in phase, as the pictures show, and the shafts well balanced, is also very important.
Good luck.
