slight whine.

[macibell111]

just installed my rebuilt Pto and notices a slight whine at around 30 mph,I think it had the same whine before the install but maybe not as much,I chimmed it with 2 30 thousenths gaskets to give it the proper gear lash ,my question is even with proper clearance would it whine a little? will it hurt anything ? sure don't want to take it out again .any help thanks Jack

[tbone1004]

did you put enough oil in it? If the gear oil is too heavy and isn't thinning out at temperature you could hear a bit of a whine due to lack of oiling. Shimming to .020 gaskets doesn't necessarily mean that it has the right gear lash. I'm not familiar with what the actual spec is for gear lash on the PTO but if you just put .020 shims on there and called it good, it very well could be off on gear lash which would also cause whine. Could also be the transfer case whining or just about anything else in the driveline. What makes you point it straight to the PTO? If you didn't have the pto on there and it just started doing it when you installed it then that's obviously the culprit but there is a whole host of things. What gear oil did you put in the tranny?

[jacksauto]

it did have a whine before I put in the PTO,and when I drove it the cover was un attached so I figured I would get some extra noise ,I put in 70-90w gear oil and filled it until the oil came out of the filler hole, about 4.5 quarts.I live in northern calif so the weather never gets below 25 degrees here and averages 75.I also haven't ever had the truck up to 30 or 35 MPH before,so I am hoping all the noise is normal...jack

[JimC]

The noise is normal.

[MSeriesRebuild]

Tbone asked very valid questions, but you offered no answers. If indeed you did use two .020" shims and called it good without a proper back lash check; most likely you have issues with the proper shim pack. No one can truthfully tell you a whine is normal just because, and that is poor advice for you to follow. Even if you have a correct installation, a whine could be real evidence of some other issue going on. If you have never internally inspected the trans, and was the PTO a used unit you picked up and never went through, God only knows what you may have going on. Installing an unchecked component as a subassembly onto an unchecked component is hardly ever a smart decision. Unless you have the proper tooling and knowledge to properly set up the backlash, I would strongly suggest you either educate yourself concerning a proper installation of a PTO or get professional help from someone who has proper tooling and experience to do the job right. If you run a PTO with too little backlash, you can do some major damage to the trans and the PTO. Running a PTO with the backlash SLIGHTLY on the loose side is not a problem, but it will never produce a whine from a slightly loose set up. A whine will be quite obvious if the set up is too tight.

[macibell111]

I am going to check the backlash which I read is 1/32 .I will drain the fluid and take off the opposite inspection plate on the transmission to be sure it is properly set,and in answer to your question the PTO was rebuilt (by a professional) before I installed it,the transmission was filled and I used 75-90 w . thank you for your input......jack

[MSeriesRebuild]

I am going to check the backlash which I read is 1/32 .I will drain the fluid and take off the opposite inspection plate on the transmission to be sure it is properly set,and in answer to your question the PTO was rebuilt (by a professional) before I installed it,the transmission was filled and I used 75-90 w . thank you for your input......jack

A true backlash measurement must be checked with a dial indicator mounted on either a clamp type or magnetic base, correct spec is .003" - .008" clearance. This must be checked at the idler gear with the counter shaft locked so it can not move. Any other method will give an inaccurate measurement. Not sure where 1/32 came from; I've looked at many manuals over years, never heard of that one.