problems with stage-3 rear end

[p51mus]

I have a 07 stage-3 with about 25k on it. It sounds like the rear end is getting some strange growling type of noises-- or somewhere in the drive-line in the back of the car. I can really tell it when I am slowing down to a stop. at first I thought it may be my tires, but after rotating ,nothing changed. Ford fixed a leak in the pinion seal about 12-15k miles ago under warranty,and I am wondering if they may have done something? I do tend to drive it hard at times though and maybe the stock rear-end just isn't strong enough. The only thing I have done is the 435hp upgrade. Has anyone else had any problems like this? I may just put in a Currie crate rear-end and be done with it. I might as well put in the new drop in 6-speed tranny also, I hate the 5-speed, and I worry about the strength of it as well. Any ideas will be appreciated! Thanks.

[Pentalab]

What is the story on these rear ends. How often does the oil have to be changed in em. How do you check the level. Can you replace with synthetic.

Jimbo

[motorhead213]

I believe there is a crush sleeve that should be replaced when changing the pinion seal,if they did not replace it that could have created a problem.I had a dealer put a set of gears in my gt500,it took them 3 try's and 2 sets of gears to get it right.They ruined the first set because they did not get the pinion bearing preload right.

[AutoXRacer]

Has anyone else had any problems like this? I may just put in a Currie crate rear-end and be done with it. I might as well put in the new drop in 6-speed tranny also, I hate the 5-speed, and I worry about the strength of it as well. Any ideas will be appreciated! Thanks.

Does it only make the sound when you are turning? I haven't heard of any issues like this. The most typical failure are worn clutches in the limited slip.
The 5 spd and rear end are plenty strong for the 4.6L and M90; even a maxed out M90.

I would suggest you take it back to Ford and have them fix whatever they broke' obviously its Ford doing.

What is the story on these rear ends. How often does the oil have to be changed in em. How do you check the level. Can you replace with synthetic.

Jimbo

Fluid is lifetime according to Ford...its synthetic so you don't have to change it. Unless you do extreme racing.

[Roush'n Red 07-342]

I have a similar problem: directly speed related and constant. It, too, sounds like tires failing. I have had tires rotated as well, and the noise did not track with the tires (unless, of course, ALL my tires are performing alike. I did put them on as a four tire set). It is very annoying, especially at 40 - 45 mph since other noise sources are much less. I also just noticed two (related??) things. The first occured two weeks ago when I lifted the car to inspect for problems. Aside from blow-out fluid at the axle housing breather, the only thing I found was the bushing of the swaybar to frame connector had shifted to the driver's side by the full width of the bushing (compared to the obvious old wear area). The other item I noticed today approaching the car from the rear; the driver's side tire is flush with the outer edge of the fender lip while the passenger's side tire is inboard about 1/4 - 1/2 in. (????) I did not have time to measure as I was heading to work (while I still have work to head to). This past winter, as I reported at the time, I went off-roading in the snow. I slid down an imbankment, leaving the roadway at about 50mph. I turned 90 deg to the left and slid downhill. Watching the world come at you through the passenger window is a VERY unnatural occurance. :-) I barely scooped up snow and grass when I did, motoring back up the embankment without any drama. I suppose I **could** have shifted the axle right to left...??? The big questions are: could this cause the noise (due to wheel mis-alignment), and, how hard is it to put it back into proper alignment??

Patience with me, please, I did a quickie search on the forum and no one address my issue, until, that is, I found this thread.

Help?? Please??

[Ct. Rich]

The off center rear is normal in these cars. It's caused by the lowered suspension. You can fix it with an adjustable panhard bar.

[10Roush427r]

The first thing I would do is check the fluid level. I had a 2004 GT and the output shaft seal from the manual transmission (I believe that's what it's called) was leaking. I took it to the dealer to get it fixed under warranty. A week later the transmission started whinning so, I took it into my shop and checked the level and it was more than half way low. There might be a good chance that they didn't top it off after they did what they did to your differential. Or, they topped it off but didn't install the friction modifier. If those two things check out to be ok, then I would suspect the issue to be mechanical and request the dealership to check their work.

Jimbo........The rear differential fluid is a synthetic gear oil (75w/140) with 4oz's of friction modifier. Ford recommends changing the fluid under "Severe" driving conditions every 150k miles. There is NOOOOOOO WAYYYY I would EVER go that long before I changed my differntial fluid (IMO). I'm going to try to go to 30K miles before I change the fluid but I'll probably end up changing it at 15K miles (I'm extremely anal and want to keep the inside of the vehicle's components just as clean and pirstine as the outside).

[p51mus]

Thanks for the info guys. I will do some more checking.

[gtncpa]

I changed my rear fluid around 100K when I went to the Eaton and did a gear change. (I had it refilled with Ford OEM) I track my car 5 or 6 times a year. The mechanic was surprised how good the fluid looked. I know looks don't mean much .. it can look good and be bad ... but if it is bad ... it will look bad.

[Dangerroush]

Mine occurred only when decelerating, and it was just after the dif lok clutch pak had been changed, they were fitted wrong, taosted my gear set as well, so now have a trutrack going in with new gears, no more clutch issues, better traction, win win....