What Did I Break In My Front Diff?

[BarryCarey]

Hey all,

So I screwed up my front diff after changing the pinion seal.

I believe I over tightened the pinion nut. I had a hard time getting a clear reading on the beam torque wrench I used.

Now when driving around 40mph I get a grinding/groan from the front end. Also, when applying the brakes to come to a stop there's a good grind that sounds like the rotors are really rusty (they're not).

Any idea's what I might have damage? I'm not too familiar with the inner workings of a diff.

The only thing I can think is I may have gotten some crud in the rear pinion bearing. But I'm not sure if that would account for the grinding/groaning.

It's currently too cold out so I don't feel like pull it apart in my driving way.

Spoke to a local shop and he believe the whole thing needs to be pulled apart and checked over. Around 6 hours of labor to break it down and put it back together. I was hoping to get away with just putting in a new crush sleeve and re-torquing the pinion nut properly.

 

[Turdle]

Thread moved.

Bump

 

[corkey]

overtightening would probably put excess pressure all the pinion bearings, and probably change the pinion depth as well,,

this can lead to all kinds of problems,,
bearing failures,
ring and pinion gear failures,
to start with,,
it's gotta come out , get taken apart ,

or ,,,

get one from an auto wrecker and replace it,, (easiest and cheapest option,)

drive using it ,and it could fail pretty seriously, maybe causing a pretty serious accident,,,

 

[BarryCarey]

overtightening would probably put excess pressure all the pinion bearings, and probably change the pinion depth as well,,

this can lead to all kinds of problems,,
bearing failures,
ring and pinion gear failures,
to start with,,
it's gotta come out , get taken apart ,

or ,,,

get one from an auto wrecker and replace it,, (easiest and cheapest option,)

drive using it ,and it could fail pretty seriously, maybe causing a pretty serious accident,,,

Thanks you. That's along the lines of what I was thinking.

I just dropped it at the shop 30 minutes ago. They'll be tearing it apart to have a look. Fingers crossed the gears are okay and I can get away with just bearings. I only drove it above 40 miles so I'm hoping damage isn't too bad.

 

[BarryCarey]

Got it back this afternoon. Pinion nut was very loose. It is much better now. There is a very slight noise when driving which I can only assume was done due to me driving it with the pinion nut so loose.

I had tightened it with a beam torque wrench to 30lbs I did it with axels in and calipers off. Not sure if it needs axles out to set proper preload.

Also had rear flange, straps, rear pinion bearing, pinion seal, crush sleeve, and nut replaced with parts I already had.

 

[VCOSH28]

My diff needs to come out as well.

My mechanic just informed me my diff needed to be pulled to see why it is making noise. Would you mind sharing how much it cost to have yours pulled, rebuilt and replaced? I just looked at my truck to see what it would take to pull it myself and save some labor cost. Of course it's the coldest day of the winter (6 degrees). I was quoted $500 to $1k.

 

[BarryCarey]

I only paid around $140ish which was for 2 hours of labor since he didn't have to pull the diff apart. I already had the parts laying around.

I was told originally it would be about 6 hours of labor to pull the diff, strip it down, put it back together and back on the truck. 6 hours at $70/hour would be $420. Then you have parts on stop of that. A full rebuild kit on RockAuto is around $200 so I'd expect a mechanic to charge upwards of $300.

I replaced my rear diff over the summer with a junk yard unit. Paid $200 for it and put it in myself. A bit of a pain to do and I wouldn't even consider doing it in the winter unless I had a garage to work in.

 

[VCOSH28]

Did you pull the diff yourself?

Thanks for the quick response. I've got a line on a used one. Doesn't look too difficult to remove. Not looking forward to doing it. I have a garage but it's not heated...and it was -5 when I got up this morning.

 

[Turdle]

Just in case you overlooked them, be sure to replace the end seals on the "new" front diff.

I especially feel for you having to work in the cold.

In case you haven't heard of these, they are made for about all body parts. One wrapped to your lower back will help keep your body core warm for several hours.