Problems with Urethane IRS Swaybar Bushings

[03 DSG Snake]

I saw it mentioned (I think in Bruce's thread) that Urethane swaybar bushings on the IRS make the bar VERY difficult to move by hand.

I bought an installed the Urethane (Prothane) bushings offered by MM some time ago. Looking at their site today, it looks like they are not the correct ones for 2003/2004 Cobras:



* These 25mm bushings fit the stock Ford IRS rear swaybar and its mounting brackets on the 1999-01 Cobra models.

Note: Does NOT fit 2003-04 Cobra models. Those years have a 26mm rear swaybar. Urethane bushings for those models are coming soon.



IRS urethane swaybar bushings, 1999-01 Cobra [6-1157-BL] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

 

[black 10th vert]

Interesting... I have those black prothane ones too, that were supposed to be for the irs, but didn't realize that we have a different set, specific to the '03-'04 models. Oh well, the irs will be out in the next day, or so, so I guess, I will see if they fit. If not, I will most likely open the bores up larger so that they will work, rather than not use them at all.

 

[SeankySnake]

I saw it mentioned (I think in Bruce's thread) that Urethane swaybar bushings on the IRS make the bar VERY difficult to move by hand.

I bought an installed the Urethane (Prothane) bushings offered by MM some time ago. Looking at their site today, it looks like they are not the correct ones for 2003/2004 Cobras:



* These 25mm bushings fit the stock Ford IRS rear swaybar and its mounting brackets on the 1999-01 Cobra models.

Note: Does NOT fit 2003-04 Cobra models. Those years have a 26mm rear swaybar. Urethane bushings for those models are coming soon.



IRS urethane swaybar bushings, 1999-01 Cobra [6-1157-BL] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

Good chatch and thanks for posting this:rockon:

 

[Jimmysidecarr]

No wonder I have popped a bracket off twice!

I thought they were overly tight too but the way nearly all speed equipment fits, I shrugged it off.

Very few bolt on items just bolt on without generous massaging.:nonono:

I wonder if you can get that Prothane grease in a cartridge tube?
oops .. yes... Prothane Super Sticky Grease, 14oz. Tube [19-1751] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

 

[black 10th vert]

No wonder I have popped a bracket off twice!

I thought they were overly tight too but the way nearly all speed equipment fits, I shrugged it off.

Very few bolt on items just bolt on without generous massaging.:nonono:

I wonder if you can get that Prothane grease in a cartridge tube?
oops .. yes... Prothane Super Sticky Grease, 14oz. Tube [19-1751] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

I'm not surprised to hear that, especially given the fact that they are only held on with a single bolt!:rollseyes

 

[03 DSG Snake]

No wonder I have popped a bracket off twice!

I thought they were overly tight too but the way nearly all speed equipment fits, I shrugged it off.

Very few bolt on items just bolt on without generous massaging.:nonono:

I wonder if you can get that Prothane grease in a cartridge tube?
oops .. yes... Prothane Super Sticky Grease, 14oz. Tube [19-1751] : Maximum Motorsports, the Latemodel Mustang Performance Suspension Leader!

I noticed during installation the fitment seemed whacky, like the split end wanted to overlap some. I torqued down the brackets anyways.

Now with the IRS out I can see how hard it is to get the bar moving.

I sent MM an email when I posted this asking about the availability of the correct part. Prothane does not list anything on their site as of now.





And yes, I picked up the Prothane tube from MM, Summit and Jegs also have it.

I have it in one grease gun, and another gun with Mobil 1 Synthetic that I juiced up my new Delrin with.

 

[greengt88]

there are other 26mm bushings available. pics of factory brackets/bushings please!! I'll find something for us.

 

[greengt88]

Eibach also makes a rear swaybar for us........... EIB 3590.312 anyone using this? Is it necessary? working on rear suspension and chassis now, input appreciated.

 

[3Dglasses]

Eibach also makes a rear swaybar for us........... EIB 3590.312 anyone using this? Is it necessary? working on rear suspension and chassis now, input appreciated.

I have the Eibach sway bar both front and rear. Don't know if it was needed, but it was part of a list of things to get my body roll under control. I had a little fitment/rub issue at the center of the rear sway bar and had to offset the bushing from the mount with small spacer on both sides.

 

[greengt88]

did the rear sway bar come with new bushings? what diameter is it? stock diameter?

 

[Jimmysidecarr]

For what it's worth my sway bar brackets have not come off these 1mm too small "wrong bushings" since the first two times.
In other words they are working, even with massive suspension travel from...
"2 tons O fun" plus slightly cut stock springs combined with Kumho 710s.

They very slightly increase rear roll stiffness for a fraction of the price of the Eibach bar. I don't think the suspension drag is much of an issue, it's there but I didn't feel it was significant. It's still freer than it was with stock IRS bushings.

From feed back I've read: the Eibach bar does work pretty good at decreasing understeer but does it, NOT by increasing front grip, but decreasing rear grip.

Balance is balance so 6 of one and 1/2 dozen of another = same result.

If I were to really get serious about my understeer I would have to spend some serious ching.

Most likely on this: (There is no drool smiley!) Carlos is rocking one of these front suspensions and it is truly BAD ASS!! This does it by INCREASING FRONT GRIP.
SN95 Suspension

 

[greengt88]

^^^Scenario of Homer Simpson Drooling over doughnut Noise. I have a huge steeda frt. bar and mounts now, was looking for something to compliment the rear, mods in my sig. What should i do yoda?? --no offense

 

[racebronco2]

The stock size is 26 mm and the eibach is 28mm. I to had to use a small washer so that the bushing wasn't so tight.

I found out that the rear bar is the only needed for most of us. If you autox then you would probably use both front and rear bars.

 

[greengt88]

so basically, eibach bar is worthless, and i should just wait til MM releases correct size rear bushings and be done with it? I also plan on installing adj. swaybar endlinks from FTBR along with everything else he sells. I don't need an alignment just for adding the swaybar links do i? just toe links right?

 

[ac427cobra]

I had the bound up poly sway bar bushings in my IRS for about three years. When I pulled the IRS a couple of weeks ago to change gears and make a rear diff hard mount, the poly sway bar bushings were still bound up. I took them out and put the stock rubber back in. Now the sway bar goes up and down again smoothly and effortlessly just like it should.

I have yet to meet a poly part I like! :fart:

Sway bar mounts are about the only place you can have OEM factory rubber in your IRS assembly.

FWIW

:thumbsup::coolman::beer:

 

[jrgoffin]

did the rear sway bar come with new bushings? what diameter is it? stock diameter?

Stock Front sway-bar: 29mm
Stock Rear sway-bar: 26mm

Eibach Front sway-bar: 35mm (3518.310)
Eibach Rear sway-bar: 29mm (3590.312)

Both Eibach sway-bars come with new bushings. The complete kit is 3590.320.

Eibach Springs : EPS Application Look-up | suspensions | springs | dampers | stabilizers | shocks | sway bars | anti-roll bars | wheel spacer | coil over | engine valves

Easy to find the information if you search!!

Use the thicker rear bar if you want to minimize some of the under-steer.

 

[Jimmysidecarr]

^^^Scenario of Homer Simpson Drooling over doughnut Noise. I have a huge steeda frt. bar and mounts now, was looking for something to compliment the rear, mods in my sig. What should i do yoda?? --no offense

Have you already installed it?
If not I would see if you can return it for a stiffer rear bar.
But even then I would wait to install it until after your first event.
The seat time is money spent far better, and with a vert there is the roll bar issue looming, that must be addressed.
After that there is the rear passenger safety issue, of course if there are other vehicles to drive it may be a non-issue.

Everyone I know who has run a larger aftermarket front sway bar has taken them back off and returned to stock, because of too much understeer, even with an aftermarket adjustable rear bar on full stiff. Perhaps I don't know enough people running SN95 IRS cars.:shrug::dw:

Both cars were on full coil overs with over 450ppi front springs and 5 or 600 ppi rear.(this is a fairly high wheel rate) It is my understanding that the stock front bar is about as stiff as you would want to go. If the car is significantly lightened I could envision it being possibly too stiff unless a stiffer rear bar is also used.

I know nearly all of you guys already know this stuff, but whatever end of the car gets increased stiffness, that end will lose grip.(as a general rule)

stiffer front bar and springs = more understeer
stiffen the rear only and you can reduce understeer.

Please don't flame me this is for the newbs.

 

[greengt88]

So i should ditch my Steeda Frt. bar?? I still have the stock one in the garage. hate to take it off, i have the nice billet mounts and relocation brackets for it as well. Even had it powder coated yellow.

 

[Jimmysidecarr]

So i should ditch my Steeda Frt. bar?? I still have the stock one in the garage. hate to take it off, i have the nice billet mounts and relocation brackets for it as well. Even had it powder coated yellow.

I would not run a stiffer front bar unless I had oversteer problems that I was unable to correct any other way.

Plus you can not effectively test this stuff on the street without risking arrest.

I wouldn't change anything FURTHER until you track it and establish a baseline for comparison. IMHO you have already changed WAY more than I recommend.
Except brake fluid!:-D


The car is going to scare you, yes they are that fast.
Mine scared the crap out of me.

 

[greengt88]

looking forward to needing a diaper change!!