Hey y'all. I'm taking apart my rear end investigating a loud whine. The whine comes at any speed above 25 or so. It happens accelerating, decelerating, and coasting. It gets louder and higher pitched as I gain speed. Sound doesn't change under load or while turning.

I took the truck to a mechanic and had him look at it a while ago, and he told me the pinion bearings were going bad. He cleaned out the diff and found metal shavings all in there. He cleaned those out and changed the oil, and the noise decreased but was still there.

So then, being the DIY kind of guy I am, I took the differential apart to try and correct the issue. I did a lot of research on this before I got started to make sure I do it right. I got the ring an gears out, leaving the pinion gear inside along with the pinion shaft. Spinning the pinion yields the loud noise I could hear going down the road, so that narrowed down the problem to the pinion bearing. The drive shaft is disconnected and the pinion nut is out.

Here is where I'm stuck. The pinion flange is stuck on and the pinion shaft is stuck inside the diff housing. Gear pullers, pry bars, and a 5 lb sledge hammer with a block of wood all have been fruitless. How the heck do you get the pinion shaft out? I've heard it should tap out but this is obviously not happening. I think it has something to do with the bearings not letting it slide out. Any idea what would cause this to happen, and how to get it out? Thanks!

 

A little more information:

2004 F-150 SCrew Lariat 4x4 5.4L w/ 101,000 miles
9.75" ring
3.71 gear ratio

 

Not to bag on you, but...you are putting the puller in the flange and not the gear end, right.
They can be tight some times. Put the puller in the yoke, apply pressure and heat, then tap the end of the puller with a hammer. Make sure to use a good sized puller and lube the threads on it.
Once the yoke is off the shaft should come out with just a little tap.
Sounds like it might have spun a bearing and could be welded, or at least stuck, to the shaft. If so it's new pinion time plus the ring gear.

Good luck

 

yup as my new found nj prankster jgger has stated you need a good sized puller placed over the yoke and pushing down on the center of the threaded portion of the pinion shaft. apply some pressure on the puller and then tap the end of the press screw into the pinion to "shock" it free. sometimes you will need to add some heat to the yoke as well to help free it up. you are obviously replacing all the parts there anyways so don't worry about them. best heat source is a rosebud tip on the acetylene. patience and liquid courage goes a long way when dealing with this..... too bad the liquid courage isn't allowed on the clock while i'm working lol.

 

If you've never setup a set of gears it would be in your best interest to not just read off the internet and attempt your self but to find someone who KNOWS what there doing to oversee you and check everything out for you...

 

Thanks for the help everyone! I finally got the pinion out. We had to remove the rear end from the truck. Took it out, laid a piece of oak hardwood flooring across the pinion and hit it with a 12 pound sledgehammer. Turns out the pinion was glued to the flange with some kind of seal compound. Anyway, all the gears were slightly worn but not necessarily in need of replacement. The one real bad pinion was the outside pinion. Deeply pitted and stuff. I got a rebuild kit and dropped it off with a good mechanic friend for him to put back together for me. I was going to take his instructions on aligning the gears, but decided I didn't have the time. Good experience digging into such a complicated piece of mechanical genius!

 

some have loctite on the splines but a little propane and a 3 jaw puller and a impact pops them off every time. a shop cold have swapped the large pinion bearing for you and then after putting the carrier back in with the outer shims on the right side (one side is bigger) you would probably be pretty safe to run it but a little marking compound and a dial indicator would verify the contact pattern and back lash were in spec.

 

My shop is having a tough time finding the correct bearings. I took it to two different shops, and neither one has the inner bearing or either side carrier bearing listed in their books. All they have listed is the outer pinion bearing and races for the other bearings. Am I going to have to go to Ford to get these? Again, mine's a 9.75 ring with 3.73 gears. The second shop I went to says it looks like a F250 rear end because of the size of the pinion. Interesting...

 

Summit Racing.com, about 2 day delivery. I was happy with their prices.