Torque amplifier fixin agian, er still

A couple of days ago I asked about replacing the clutch on a 450 farmall's torque amplifier, thanks for the helpful replies. It is slipping on the low side but only under load. Driving on flat level ground it appears to operate as it should (tractor slows down but keeps moving when engaged). When you come to a hill with the TA engaged, however, it will start to go up the hill to a point, then you can hear it begin to slip while the tractor slows to a stop and begins rolling back down the hill. The only noise you hear is a spinning noise from inside the rear end (no grinding, squealing, etc). Now to my point: every parts dealer I have talked to has been telling me that you really cant know all that is wrong with it until you actually pull it out. My thoughts are that since there is no sound of failed gears or bearings and since it seems to be working until load is applied, its gotta be the sprag clutch that is failing. I'd like to know what others are thinking because I'd like to have all the parts ready and waiting so we can hopefully get her done in a day. I also dont want to buy a bunch of parts I may not need because they are all saying they will not take returns. Any thoughts are much appreciated, sorry for the long post.

-Dan

no such thing as knowing what you need till it comes apart. i have yet to see a mechanic walk to the parts counter and order his parts before the tractor comes apart. maybe the genie will wiggle her nose and can tell you. thats my thoughts on the matter.

Absolutely no way of knowing exactly what you need until you tear it down. Now days it is usually least expensive to replace the unit with a rebuilt one. The sprag (actually not a sprag but a roller type over running clutch) consists of the ramp with rollers and they engage the highly machined end of the planet carrier. Any slight wave like wear on it and the rollers keep moving back and forth and wear out rapidly. The planet gears may be worn out, along with the direct drive 7 inch clutch. Just no way of knowing.

You will need oil seals too. If a bearing is getting rough, it is time to replace it. You will never know until it is all apart. Just do it right.

Thanks, I guess I'll have to wait and see.

The only way you will be able to take it apart, fix it, and put 'er all back together again in a day or two is to buy a complete, rebuilt TA unit.