Fox Rear End Troubles

RangerJoe

I leave the horn on while driving
15 Year Member
Apr 26, 2010
2,560
1,168
184
Georgia
8.8 that is. Started to work yesterday and had a sudden noise appear. Kinda a clunkin or hitting noise, pulled over and couldn't see anything visible. Started back to the house and noticed it was speed dependent regarding the repetiveness of the noise. It appears to be coming from the rearend. I assume it's going to be the ring gear with broken teeth or a broken spider gear. Seeing as it's still driving, I'm leaning towards ring gear. Any guesses as to which goes first?

Rebuilt 31 spline limited slip with carbon fiber clutches BTW.

Joe
 
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I have seen the clutches cause a hell of a racket without the proper additive in the rear diff. I thought I had the same issue as you but when I pulled the rear cover and inspected the rear diff I could not find anything wrong. Filled with new gear oil and some 'fish oil" additive from Ford and the problem instantly went away.
 
This started all at once. Rears been together 1.5 years, and has additive. I would be grateful if that's all it ends up being.

Joe
 
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Have to admit the title "rearend trouble" brought a smile to the 12 year old still hiding in my head:D Hopefully it's just the fluid but when mine started making that noise it was the ring gear.
 
Well, for all of you who cared, that makes two of you, it was a ring gear bolt. It backed out and was hitting the inside of the pumpkin, it finally fell out and got jammed between the ring gear and the carrier. I'm pretty lucky really. I am currently reapplying red locktite to all the bolts and re-torquing them. I need to source one bolt at them moment.

Joe
 
Well, for all of you who cared, that makes two of you, it was a ring gear bolt. It backed out and was hitting the inside of the pumpkin, it finally fell out and got jammed between the ring gear and the carrier. I'm pretty lucky really. I am currently reapplying red locktite to all the bolts and re-torquing them. I need to source one bolt at them moment.

Joe
Didn't break a tooth or anything? Wow you did get lucky! That could have been nasty. Glad you caught it in time
 
Was it just the one bolt that was loose, or did you find others that were loose as well? If it was just the one bolt, then maybe it was inadvertently skipped during the torque sequence when installing the gears. I always run through the final torque sequence at least 2 times when doing ring/pinion jobs. I have never had ring gear bolts come loose. Count yourself lucky that this did not cost you a ring and pinion job or even a diff housing.
 
Oh no, this was completely my fault. I've done two gear swaps in this car. The last time, 1.5 years ago, I put them back on with an impact, not a torque wrench. I was having trouble keeping the carrier locked down while torquing the bolts and didn't have a friend to help that go around. So I resorted to the impact.

Stupid me cutting corners. I am very lucky indeed. The teeth are clean. It made a mark on the front of the pinion and another on the limited slip housing where it jammed up between the ring gear and the housing.

Only me to blame on this one.

Joe
 
I once had a ring gear bolt back out on a Chevy 12 bolt truck rear. That rear had a cast aluminum cover. The bolt got jammed against the cover just as I pulled out of my driveway. I heard a clunk but didn't realize the bolt had blown a hole in the cast al cover. I noticed that traffic behind me backed off but I didn't know why. Luckily my work place is only about 3 miles from my house. Later in the day a fellow worker said he saw oil dripping under my truck. That's when I discovered what actually happened. I too got lucky. I put a new bolt in, new cover, filled with oil and back on the road no problems. When I went home I noticed the oil streak on the road. Ahhhhh, that's what that loud clunk was, and that's why traffic backed off so much.
 
You got 61 views. Don't assume that because no one answered, no one cared. Not too many people had any advice to give, that's all.

Kurt

My comment was just a result of my dry humor. I've posted a little over 1000 posts in 4 years, but I am on this site 2 or 3 times a day reading, everyday. I understand that most just read, as do I.

Joe