Diff hum problem has crept back...

[MrBluGruv]

So I've noticed over the past couple of weeks that that humming/moaning noise that was coming from my diff on slow tight turns is back. I feel pretty sure that the S-spring broke again.

That being said though, anyone have any ideas as to what could cause one to snap, much less two back-to-back?

I've been trying to think of what else would be causing that noise, one thing that comes to my mind is still insufficient amounts of fiction modifier, as symptom-wise the problem seems to sometimes only be present and always is much more pronounced after I've been driving a bit. Occasionally though, yesterday as an example, the diff is completely silent on the tight turns. I hate to keep throwing away like 10 bucks at a time on a whim that that's the problem though. If that is though, or something were causing excessive heat, do you figure it would be enough to damage the spring and ONLY the spring and have no detrimental effect on any other part of the rear end?


For a bit I thought I could just tune this noise out, but I can't stop thinking about it for one, I don't like to just ignore problems on my car for two, and I'm paranoid about little things now after having had this car for so long with the endless list of problems it's given me.

[MrBluGruv]

No ideas guys?


Does anyone know also if it would be possible to purchase an s-spring by itself instead of throwing away cash for an entire rebuild kit? :(

[Got_1]

first thing you gotta do is pull the cover and acutally diagnose it. Its no good to you to just guess.
Where ALL of the bearings and races replaced when you had the 4.10s installed?

[CBT]

No ideas guys?


Does anyone know also if it would be possible to purchase an s-spring by itself instead of throwing away cash for an entire rebuild kit? :(

Check the local shops, see if they have any old ones they might give ya? Or maybe someone on here may have one?

[MrBluGruv]

first thing you gotta do is pull the cover and acutally diagnose it. Its no good to you to just guess.
Where ALL of the bearings and races replaced when you had the 4.10s installed?


Yeh I basically replaced EVERYTHING with that swap. Gears, clutch rebuild kit, new axles too because they had that soft-axle problem. The HD s spring broke not too too long after it was installed, then about a month and a half ago it was replaced by the stock one (we had just figured out that that had happened at that point), and over the past two or three weeks almost the same exact symptoms have crept up to become very noticeable. I think I'll try to get a sound byte of the problem, but it's VERY hard because my exhaust isn't exactly quiet.

[BlueFusion]

Are you running regular or carbon fiber clutches? What brand and weight diff fluid? How much friction modifier did you add, if any? Are you running the clutches and steel disks in the order that Ford recommended or a different way? Did you add an extra clutch plate to the carrier?

You can buy a S-spring seperately at the dealer. An F-150 S-spring is like $12 if I remember correctly and will be the tightest option for tire roasting burnouts if that's what you want to do. The car S-springs should be around the same price.

[Blackened300a]

Usually a humming noise is a bad bearing or axle. Do you get one legged burnouts?

[MrBluGruv]

Usually a humming noise is a bad bearing or axle. Do you get one legged burnouts?


I get no burnouts, I can't light these tires up to save my life. :(


And the axles were bad before the install, but they were replaced. Consequently, it was confirmed that the first case of these symptoms was cause by a broken s-spring, because after the broken one was replaced the noise went away for a while. This noise, by the way, only happening on turns, and usually VERY tight low-speed turns.


I think I may go for the F-150 spring like mentioned. I honestly have no idea about the way the clutches were installed, but I do know I used the cobra rebuild kit with CF clutches. I will call and ask about what weight of lube was used tomorrow, and also before they replaced the s-spring they put a bottle of friction modifier in with no difference made (obviously because the spring was broken and that was causing the problem, but still at some point an extra bottle of FM was put in.)

Are there any negative effects that could come from using the F-150 spring? And also, given that my current one is broken as the cause for my problems, would that spring be more resilient and more likely to stand up to abuse if there's something else going on in there that caused my other ones to go?


The first spring that broke snapped literally right in the middle. Do any installer errors come to mind that could specifically cause that? I can try to find where I put the pieces to snap a picture later on.

[Marauderjack]

I am no expert and have little experience but have heard that the clutches should be soaked in friction modified before assembly......the groaning you are hearing is probably shuddering as the clutches slip and will go away in time??:cool:

Add another bottle of Ford Friction Modified and give it awhile and it will clear up if my hunch is right....if not the extra FM won't hurt a thing!!:shake:

Good Luck!!:beer:

[Got_1]

I get no burnouts, I can't light these tires up to save my life. :(
.

You have a 4.10 gear and a tune and you can't do a burnout? what size tire are you running?

[GreekGod]

...I feel pretty sure that the S-spring broke again...

That being said though, anyone have any ideas as to what could cause one to snap, much less two back-to-back?...

I've been trying to think of what else would be causing that noise, one thing that comes to my mind is still insufficient amounts of fiction modifier...

If that is though, or something were causing excessive heat, do you figure it would be enough to damage the spring and ONLY the spring and have no detrimental effect on any other part of the rear end?...

1) If the spring broke, it was probably broken (or damaged) during installation (yes "installer errors come to mind"). They are difficult to install. I broke one trying to get it in. Most differential parts are available separately, including the spring.

2) One bottle of friction modifier is plenty.

3) The spring is bathed in lube, and would never get hot enough to lose it's temper.

4) as Got_1 said "first thing you gotta do is pull the cover and acutally diagnose it. Its no good to you to just guess".

5) A "trick" spring & special lube are irrelevant & unnecessary. A good & reliable expert technician is mandatory. You should get an OEM Ford shop manual and study it. Clutch set-up is critical, and the manual explains everything.

[MrBluGruv]

You have a 4.10 gear and a tune and you can't do a burnout? what size tire are you running?


Yeh I know, it's actually really disappointing. :( The car isn't slow, but it's HORRID from speeds below about 20.

I've actually had two different size tires on since the 4.10 swap, and even with 3.55 gears I couldn't do a real burnout until my clutches wore out (one-wheel-peels). Anyway, my first tire size was 245/45/18, those were Falkens and they handled CHAMP. The tires I have now are 255/55/18, and these are Nitto 420S.


I guess this really is gonna come down to me calling the shop up (not a bad thing, but it'd be nice to just once have things be a simple, overlooked solution with the car. :( ) Anything I should be keeping an eye out for to somehow tell if it was installer error?

[Blackened300a]

Yeh I know, it's actually really disappointing. :( The car isn't slow, but it's HORRID from speeds below about 20.

I've actually had two different size tires on since the 4.10 swap, and even with 3.55 gears I couldn't do a real burnout until my clutches wore out (one-wheel-peels). Anyway, my first tire size was 245/45/18, those were Falkens and they handled CHAMP. The tires I have now are 255/55/18, and these are Nitto 420S.


I guess this really is gonna come down to me calling the shop up (not a bad thing, but it'd be nice to just once have things be a simple, overlooked solution with the car. :( ) Anything I should be keeping an eye out for to somehow tell if it was installer error?

I broke a spring during installation, you have to get a big channel lock and then hammer it in. Its a PITA so its not rare for it to be broken. The center pin should drop right in, If someone hammered it in to move the spring into place, there would be hammer marks on the top.

BTW, who's tune are you running that you have no power off the line? Even with my car bone stock, I would be able to smoke the tires. A mail order tune made my car act like yours, a new dyno tune made the car light the tires at will with mimimal effort.

[MrBluGruv]

I broke a spring during installation, you have to get a big channel lock and then hammer it in. Its a PITA so its not rare for it to be broken. The center pin should drop right in, If someone hammered it in to move the spring into place, there would be hammer marks on the top.

BTW, who's tune are you running that you have no power off the line? Even with my car bone stock, I would be able to smoke the tires. A mail order tune made my car act like yours, a new dyno tune made the car light the tires at will with mimimal effort.

Right now I'm running the Zack tune. Overall it felt like it pulled MUCH harder than my Lidio tune, even after I added timing to the Lidio tune. One strange thing that happened with the Lidio tune though that was kinda funny/cool, if it was wet and I punched it in 2nd gear it would start to gradually break traction past about 50, but that was with the 245/45 tires.


I don't know, there's things I REALLY like about that tune, but there's things I also really like about the Lidio tune. I think the Zack tune is more aggressive in the trans scheduling, and it seems to do a lot of back-and-forth with locking the TC, at least in my case, but I kinda got comfortable with the Lidio schedule and I may be going back to it soon.

[Blackened300a]

I think the Zack tune is more aggressive in the trans scheduling, and it seems to do a lot of back-and-forth with locking the TC, at least in my case, but I kinda got comfortable with the Lidio schedule and I may be going back to it soon.

That was my issue with his tune also. I don't know if that was corrected recently, but my car was undrivable because of it. I had to go back to my present dynotune which is now way off due to the spaz intake.

[MrBluGruv]

eWmn0suunmQ


So there is a video of the first s-spring that came out of the rear end. The symptoms are the same now that lead me to find that, and looking more closely at it I can understand why now it sort of worked but also didn't seriously f-up the rear end. Also, seeing how damn tough this thing is, I can't help but thing it was damaged or something during the install.

I'm gonna be setting up another appointment ASAP.

Any other thoughts from you guys, or am I on the (unfortunate) right track? :P

[Blackened300a]

Wow. Thats probably the worst damage to a S spring I have ever seen. Usually it will break in the center, but still hold its shape.

[MrBluGruv]

Wow. Thats probably the worst damage to a S spring I have ever seen. Usually it will break in the center, but still hold its shape.


Sweet, so I'm just lucky probably twice in a row now huh? :P


I think I'm gonna be calling one of the local Mustang shops to see what a spring swap will run me, at least they should know how to do the install right.

[Blackened300a]

I have a used S spring I can send you to get you going if you want.

[MrBluGruv]

I have a used S spring I can send you to get you going if you want.

I appreciate it very much, but I'll pass for now. I'm taking the car in to the shop on Friday where they will fix the problem (for little to nothing I'm pushing for if they are screwing this up) and we will have a nice talk about how they are installing these parts in detail.

If it's the same problem, I'll try to put up pics of mangled spring #2 when I get it back.


Correct me if I'm wrong, but pretty much, if installed correctly, there's no way it could essentially work "too well" would it? This shop is still under the impression that I hot rod the car a lot, and I don't see how the locking rear differential locking and doing it's intended purpose would be detrimental to itself if setup properly.

[Blackened300a]

I appreciate it very much, but I'll pass for now. I'm taking the car in to the shop on Friday where they will fix the problem (for little to nothing I'm pushing for if they are screwing this up) and we will have a nice talk about how they are installing these parts in detail.

If it's the same problem, I'll try to put up pics of mangled spring #2 when I get it back.


Correct me if I'm wrong, but pretty much, if installed correctly, there's no way it could essentially work "too well" would it? This shop is still under the impression that I hot rod the car a lot, and I don't see how the locking rear differential locking and doing it's intended purpose would be detrimental to itself if setup properly.

Working too well would result in chirping the tires going around turns like as if you welded the spiders. I doubt any spring would be strong enough to hold it on turns.
I think it cracked during installation and it got worse and worse over time.

[SamF]

Working too well would result in chirping the tires going around turns like as if you welded the spiders. I doubt any spring would be strong enough to hold it on turns.
I think it cracked during installation and it got worse and worse over time.

Yep, my truck works a bit too well sometimes with the extra steel and clutch disc I added on each side ;) But the Merc rarely does that on the rebuilt rear...

Really curious to hear what the issue turns out to be on BluGrv's ride...