MM U302 Super Ampli-torc is now working but!!!

Jeremy L

Member
I finally got my U302 back together and everything seems to be working properly. My only concern is that when I put the tractor into low range there is some gear noise coming from the ampli-torc. The ampli-torc low range on this tractor has not worked in probably 40 years (sprag was damaged and it has since been locked into high range until now) so I am wondering if this is normal since the gears are now running against one another in the ampli-torc and have just not worn evenly against each other due to lack of use over the years. Would this make sense OR does anyone know why I would be experiencing this gear noise?

Thanks in advance for your assistance,
 
It seems to me that most MM's make "noise" in high range when sitting idle, low range is usually quiet. The only thing I can think of is that did you get the thrust washers. needle bearings back in the right spot and do you have somewhere near the correct end play for the A/T assembly?

What kind of oil did you put into it?
 
It is quiet in both high and low when sitting idle but makes some gear noise when moving in low range. Yes, all new thrust washers where used, the old needle bearings were kept and a new sprag was put in along wiht the new needle bearing and washer at the front of the clutch cover. Everything seemed to be back in where it should be. The end play we checked and it was very close to the low end of the range specified in the book (around 0.008" I believe maybe a bit tigther than the low end but based on the shims it was either a wee bit tighter or a bit loose and we thought a bit tigther would be better as it will wear into range eventually).

I have heard of drive gear noise if you change a gear in the rear end and leave all others since they will not mesh perfectly due to there wear. Considering this I was wondering if that is all it is in my case or not. The gears on the ampli-torc have not rotated in the hub for a very long time since it was stuck in high range for the last 40 years.
 
I bought a M-5 with the same problem, had been locked in high forever but I split it and fixed the ampli-torc several years ago. It worked great in low now but it does make a whirring noise in high all of the time, It hasn't quit yet or anything but I have always wondered what might be making that sound too and if I did something wrong? I had no history on it because the engine was locked when I got it so I fixed both the engine and A-T the same time. Maybe just keep running it and see if yours quiets over time.
 
There may be some corrosion / flat spots on the gears from sitting that is showing up. I agree most MMs make noise with the ampli-torque. Usually it is a whining noise. I would use it a little and see if it improves or gets worse.
 
Whining is typical and I wouldn't worry about it at all, if that's the noise you are referring to. I would recommend a lighter oil. I run IH Hytran in mine. I have a 4Star Super that's quiet and another one that whines. I have not had any problems with either of them so I really can't identify the cause of the whine. The one that whines is one I put new rollers and springs in. I've always wondered about that shaft end play. Maybe I'm too tight. They say better tight than loose on bearings so I'm just living with the whine. When it's blow zero and you're running a snow blower, you don't even notice it, LOL.

CC
 
The transmission and A/T compartments on the U302 do not have a pressure lubricated system, thus there is no transmission filter on these tractors.

If you wish to keep the 80w-90 gear oil in it, do not use the A/T in the winter time at all. I'm you're going to use the tractor its self in the winter I would dump the gear oil and replace with hytran or equivalent. It's also a good practice of only using the A/T to aid in easier shifting of the transmission in the winter time.
 

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