Rear end problems?

[Magnetic]

Anyone else's rear end come apart on them? I have a GT pp car and it has less than a 1000 miles on it and my rear end exploded doing 30mph last night in traffic. Sounds like a tin can full of bolts. Just dropped it off at the dealer an hour ago. Waiting on the call from them.

Also the tow truck driver told me this is the 3rd 2015 pp car he has towed with the same problems in less than a month.

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[IvanCRF]

I hope it gets repaired quickly, brother!
Keep us posted on what they find out.

 

[EXP Jawa]

Saying "my rear end exploded" tells us little, unless you've been eating Mexican (then it tells us too much!). When the dealer gets back to you, it'd be helpful to know what actually failed - was it the diff, the ring rear, a CV joint, bearings, etc.

There are a lot of things that can fail in the axle assembly and lead to the car being unable to move.

The only time I've seen something that could qualify as an "explosion" was a diff case failure in a Ranger, where chunks of iron perforated the stamped steel diff cover. A lot of the times I've seen that phrasing used was for a "mere" bearing failure or broken pinion teeth, which don't really qualify.

How about starting with what happened when it occurred? Drivetrain failures rarely occur when things are easy and the loads are light, so detailed info is key!

 

[Magnetic]

Well the "Exploded was just going by sound lol" because it sounded like someone put a stick of dynamite inside it. I was crusing in traffic at maybe 40 mph and I heard a weird noise I've never heard before, almost like a rock was stuck in my rear brake caliper. So I pulled into a parking lot to look around and see if anything looked out of place. Nothing did so I got back in and put the car in reverse. Once I started to back up it sounded as if a bolt fell out of the driveshaft and hit the exhaust. So I pulled back up and there was no signs of anything on the ground. I drove away and the noise was gone for about a minute. That's when I heard the strange noise again. So I pulled into another parking lot to have another look. Again, couldn't see anything abnormal. Got back in the car and the noise instantly came back. I decided I must get home to get this thing onto Jack stands and get underneath it. I didn't even make it a mile at 30mph when catastrophic failure came on all at once. The rear end sounded as if it imploded. The driveshaft just freewheeled. Had it towed home and got it onto jack stands and sure enough the rear end only drives the right wheel. Left wheel has zero friction. Had it towed to the dealer and I'm awaiting diagnosis.

 

[GoBlues38]

reminds me of my 1982 GT. I was doing a burn out as I left school one day. the 7.4 inch rear end did exactly as you describe. But I did it in front of a few hundred school mates.

Tried to swap for a 8.8 from an 1985 GT, but the cost was too much.

 

[EXP Jawa]

Are you saying that you could turn the left wheel forward or backward without any reaction from the other side or prop shaft? Was the transmission in gear or neutral when you did that? If neutral, it could still be final drive related. If in gear, then it at least sounds like it points to the diff. There are about a half dozen things I could tell you to try to attempt to narrow it down, but if its already at the dealer then they'll probably do the same thing. When did the dealer say they would get to work on it?

 

[MSMStannyl]

Well the "Exploded was just going by sound lol" because it sounded like someone put a stick of dynamite inside it. I was crusing in traffic at maybe 40 mph and I heard a weird noise I've never heard before, almost like a rock was stuck in my rear brake caliper. So I pulled into a parking lot to look around and see if anything looked out of place. Nothing did so I got back in and put the car in reverse. Once I started to back up it sounded as if a bolt fell out of the driveshaft and hit the exhaust. So I pulled back up and there was no signs of anything on the ground. I drove away and the noise was gone for about a minute. That's when I heard the strange noise again. So I pulled into another parking lot to have another look. Again, couldn't see anything abnormal. Got back in the car and the noise instantly came back. I decided I must get home to get this thing onto Jack stands and get underneath it. I didn't even make it a mile at 30mph when catastrophic failure came on all at once. The rear end sounded as if it imploded. The driveshaft just freewheeled. Had it towed home and got it onto jack stands and sure enough the rear end only drives the right wheel. Left wheel has zero friction. Had it towed to the dealer and I'm awaiting diagnosis.

I'm just curious if you're expecting it to be covered under warranty (whatever the issue ends up being)? I assume the diff is stock? I see in your signature that you have quite a few mods. Many may not have anything to do with the drivetrain, however, I'd be curious if the dealer/Ford will touch it with those heavy duty axles on the car.

It's a crappy situation, especially for such low mileage. Just to be clear, I'm not trying to be rude, I'm actually just wondering what your expectations are. My GT is bone stock but I've been debating modding it little by little but have been concerned with voiding the warranty.

 

[Magnetic]

The car was UT on jack stands, started then put into gear. Left wheel does nothing. Right wheels moves. Put the car back on the ground and tried to move, car doesn't move but has noose coming from diff.

I am expecting ford to cover this. Why would axles cause a diff or gear to fail? It shouldnt. Why would ford sell upgraded axles? Because they know they fail. I installed them because I heard people were breaking at stock power levels on the street. My car is not a drag car but I do "enjoy " it.

 

[MSMStannyl]

The car was UT on jack stands, started then put into gear. Left wheel does nothing. Right wheels moves. Put the car back on the ground and tried to move, car doesn't move but has noose coming from diff.

I am expecting ford to cover this. Why would axles cause a diff or gear to fail? It shouldnt. Why would ford sell upgraded axles? Because they know they fail. I installed them because I heard people were breaking at stock power levels on the street. My car is not a drag car but I do "enjoy " it.

I would hope so but I'm just wondering with that being a mod so "close" to the part that failed. Keep us posted. I'm definitely curious how this will play out.

Did you install them yourself? Not sure if that matters but just wondering.

 

[EXP Jawa]

The car was UT on jack stands, started then put into gear. Left wheel does nothing. Right wheels moves.

This, in and of itself, tells us nothing. This is a PP GT, right, so it has a Torsen instead of the Traction Lok? In which case, the diff will react to whatever drag load is on the axles. The scenario you're describing can/does easily happen when there's a little more brake drag on one side, or if one side has more inertia to overcome to get to spin. Remember, there's no preload in the Torsen, so if there's very little torque on the ring gear, it will behave like an open diff.

Now, if while you were doing this check, you happened to put some drag across the right tire (say, you held it from turning or just pushed your show against it) to force the left to spin and still nothing happened, then that would indicate a problem. When you do this, you're making sure that the right side has higher drag, and the diff should prefer to spin the left tire if it can. Of course, it stands to reason that if the diff had broken a gear such that one axle was no longer driven, the entire assembly had CATO'd and probably nothing would drive (because the ring would probably disconnect from the pinion), so this is odd. In my experience, when a helical gear diff case breaks, the whole thing comes apart and there's no more connection to drive the axle shaft.

Similarly, if an axle or CV joint had broken and completely disengaged, then that side gear within the diff would have no drag to react against and it would would free spin, leaving the other side stalled. That means the diff would spin up inside the carrier, but nothing external would move.

So, I'm stumped so far to come up with an internal failure of a Torsen that would drive one wheel but not the other. If you have any more information, it would help. Was there noise on jackstands, or just when you tried to move it? You said earlier that the driveshaft freewheels. What did you mean, under what conditions? I assume you mean the prop shaft and not the axle shafts (I've seen "driveshaft" applied to both).

 

[Anthony@HTM]

I don't understand the point of these threads.

It doesn't matter if other people have had this problem. The only concern you should have is if the dealer will take care of it for you.

Everyone's situation is different and every dealer is different.

Just wait for the dealers diagnosis and report back. That way we don't have 5 pages of speculation before getting to the actual solution of the issues along with the cause of it.

 

[Magnetic]

The purpose of this thread was to see if anyone else has had or heard of this problem.

 

[Magnetic]

Well after getting it to the dealer to have it looked at, come to find out it was my drive shaft shop axles that came apart with less than 500 miles on them. All of the inside housing bolts were loose on the passenger side. But on the drive side they fell completely out and one sheared off. Pics to.come.

 

[mustang_guy]

That's a shame. DSS makes great products. Id contact them and see what they say.

 

[EXP Jawa]

Well, at least it isn't something inherently flawed in the car's OEM driveline. I'm guessing, then, that the tow truck driver was towing other DSS customers?

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