I had to change the rear pinion seal the other day and now I'm getting a bit of gear whine. I didn't know what the torque spec was on the pinion nut so I took a measurement from the end of the pinion shaft to the top of the nut before I removed it. I did this because I didnt want to over tighten the nut when reinstalling.

Is it whining because its too tight? I was also told it can whine if its to loose.

any advice?
thanks

 

Doesn't take much to overtighten it. Next time count the threads and scribe a mark on the end of the pinion and on the nut that way it's exactly where it was.

 

thats pretty much what I did, i counted the threads and measured with a machinist ruler. So its got to be real close.

 

If we are talking about the same seal, check out: https://www.ford-trucks.com/forums/s...64&postcount=3

 

I *thought* that there was a 'crush to fit' type gizmo in there somewhere that was a one-shot. Torque to xxx foot/lbs, and get automatic bearing pre-load. Had to be replaced if the pinion yoke was removed.
Am I thinking of something else?
tom

 

Rock

That is what I am talking about. But I did not take any kind of reading with a torque wrench before I took it apart. I read that link but I am a little confused about the preload part. Since I have the same bearings in it should I torque it to 8-14lb the rotate it a couple times and do this again, and for the final torque goto 22lb?

I was told by someone that the gear whine can be from being to loose as well as too tight is this true?

 

Good question. I went back and looked at the Ford manual, and it's still a little confusing to me. But I think I got it now.

First, note that it's 8-14 inch-pounds when setting old bearings. To set the bearings, you want to be spinning the pinion itself, which means you have to rig up a way for your torque wrench to spin it (I would think another nut locked against the pinion nut would work for that). The torque being measured when setting the bearings is the force it takes to spin the pinion.

Then, to finally tighten the nut to 22 foot-pounds you obviously want to keep the pinion from spinning.

Make sense?

 

yes I get what you mean, I will have to try and rig up a way to do the intial preload.

Whats your take on the gear whine?

 

It can whine from tight or loose. You need to replace the crush sleeve to set it correctly. With a new one in place you will have to use the torque setting for old bearings. It needs to be tightened untill the torque needed to rotate the pinion is the reading you stated. There would be no need to add a nut to take your reading as the torque needed to tighten it will exceed the inch lb reading. Since you don't have the ring gear out of the housing I would try and get the rotational reading in the lash area of the pinions movement since the readings are gotten with just the pinon in the housing. kotzy

 

Kotzy,

Were is the crush sleeve located? When I took the nut off and poped out the oil seal i saw a thin shim. How do I take a rotational reading in the lash area? This is becoming to confusing. I think at this point I am just going to back the pinion nut off and retorque it to 22 ft lb.

 

The thin shim your talking about is the slinger located between the yoke and the seal. The crush sleeve is located between the outer pinion bearing cone and the pinion shaft' It compresses to allow preload to be placed on the pinion bearings, this is what causes the rotational torque. By holding the yoke with a pipe wrench or something that will grip the yoke and allow you to tighten the pinion nut you will compress the sleeve. By tightening until first the up and down play begins to disappear and the drag on the shaft is more than what the seal causes, you start to see what torque it takes to move the pinion shaft thru that small area wher nothing is being rotated except the pinion. Then increase it until you arrive at what you want in inch lbs. Had you noted the ft lbs required to loosen the nut you may have been able to return to the spot it was assembled at originally. The reason I would replace the sleeve is if you get it too tight you'll ruin the pinion bearings, too loose and out goes the seal and then a bearing. kotzy