easy to replace the rear IRS subframe bushings & bolts?

[geepaw]

just won a bid on 2-18x9's & 2-18x10.5's afs's :rockon: .

I called steeda about the lower profile screws for our rear suspensions.
they only sell the whole kit not just the screws.

Is this an easy job to do...replacing & installing the rear subframe bushings & bolts?

steeda.com --->Cobra Rear Subframe Bushings

thanks

 

[ModsAway]

not at all easy. 4-6 hours... MAYBE a little quicker if you've done them a few times.

Lots of cussing and beer will help ease the job a bit.

 

[BreBar21]

just won a bid on 2-18x9's & 2-18x10.5's afs's :rockon: .

I called steeda about the lower profile screws for our rear suspensions.
they only sell the whole kit not just the screws.

Is this an easy job to do...replacing & installing the rear subframe bushings & bolts?

steeda.com --->Cobra Rear Subframe Bushings

thanks

The screws that come with that are not lower profile. They are the same 14mm screws that "should" have come with your car.

 

[geepaw]

The screws that come with that are not lower profile. They are the same 14mm screws that "should" have come with your car.

I think you are mxxing up the 14mm screws, I could be wrong but I believe their
screws for the bolts that get in the way of tires are smaller.



Read from Steeda:

Steeda IRS Subframe bushings improve handling, reduce wheel hop, and improve tire clearance on the 1999-2004 Mustang Cobra. The entire rear suspension of the Cobra is attached to a steel subframe, which in turn is attached to the car with just four rubber bushings. The rubber bushings deflect under load, leading to wheel hop and less predictable handling. Our polyurethane bushing kit substantially reduces unwanted subframe movement and wheel hop. You will notice an immediate improvement in car control after installing these bushings.

Steeda’s Subframe bushing kit includes two other important features. First, we include the correct 14mm bolts to fit the car. The forward factory mounting points on the Cobra have 14mm holes but many cars were assembled from the factory with 12mm bolts. We provide new grade 10.9 nuts and bolts of the correct size. This ensures correct alignment of the subframe and prevents the bolts from shifting in the large 14mm holes. Second, Steeda subframe bushing kits include new rear bolts with a low profile round head to increase tire clearance. The low profile allows bigger tires to be installed and the rounded head prevents the tire from being torn by occasional contact with the bolt.

 

[BreBar21]

I think you are mxxing up the 14mm screws, I could be wrong but I believe their
screws for the bolts that get in the way of tires are smaller.



Read from Steeda:

Steeda IRS Subframe bushings improve handling, reduce wheel hop, and improve tire clearance on the 1999-2004 Mustang Cobra. The entire rear suspension of the Cobra is attached to a steel subframe, which in turn is attached to the car with just four rubber bushings. The rubber bushings deflect under load, leading to wheel hop and less predictable handling. Our polyurethane bushing kit substantially reduces unwanted subframe movement and wheel hop. You will notice an immediate improvement in car control after installing these bushings.

Steeda’s Subframe bushing kit includes two other important features. First, we include the correct 14mm bolts to fit the car. The forward factory mounting points on the Cobra have 14mm holes but many cars were assembled from the factory with 12mm bolts. We provide new grade 10.9 nuts and bolts of the correct size. This ensures correct alignment of the subframe and prevents the bolts from shifting in the large 14mm holes. Second, Steeda subframe bushing kits include new rear bolts with a low profile round head to increase tire clearance. The low profile allows bigger tires to be installed and the rounded head prevents the tire from being torn by occasional contact with the bolt.

You're right. I was confusing the two.

You could just shave off a little from the stock bolt like others do.

 

[Jpjr]

or you could just measure the bolt and go to an industrial supplier and buy it for about 50 cents.

sizes= head width (in.)/threads per inch

example= "quarter-twenties"

i've got the new bolt sitting at home, maybe i could measure it for you this weekend when i'm back in town.

 

[geepaw]

good idea...

I was thinking of that...but I do not know what the grade of the bolt is.
I want to make sure it is as strong as the original bolts.

I have many of screw suppliers around here.

Does anyone know the grade & material & threads of these screws?

 

[Top_Fuel]

The factory bolts are very unique in their design/strength. Many people have tried to find similar bolts with smaller heads...and all have failed. We even tried to get ARP to make some but they declined.

Bottom line: Machining .25" off the bolt heads is the best solution. Forget those cheesey Steeda bolts. There must be hundreds of people running around with this setup (shaved stock bolts) and nobody has ever reported a failure. Not to mention the fact that it's a FREE modification.

What are the characteristics of the IRS bolt that interferes with 315 tires?

Ford Part #: N802293-S426
Bolt Grade: 10.2
12mm x 1.75 x 4.045 UHL
The head takes an 18mm socket
The head of the bolt is .500" tall
The thread length on the bolt is 2.20”
The thread outside diameter is .467”
On the top of the hex head is stamped “10.9” and an F inside a circle
The bolt is torqued to 75 ft-lbs
Cost: $3.99/each through fordpartsnetwork.com (plus $7.99 shipping)



Why not just use a replacement bolt with a smaller head?

Changing chassis fasteners is a complicated matter, as well as a major safety issue. There are lots of variables that must be considered (bolt material, diameter, strength, stress factors, fatigue life, sheer load, etc). Just because a bolt fits doesn’t mean it’s acceptable for the application. Replacement bolts may not as strong as the factory bolt under all load conditions. At least one board member reported a buttonhead bolt failure. For these reasons, a buttonhead bolt (or other replacement bolt) is not the recommended solution.

 

[geepaw]

thanks. You kinda verified what I was thinking.

 

[BO TY KLR]

Grinded stock bolt here also with no problems. Just unbolt them when you have the wheels off for the swap and grind them down enough to just get a socket on them. Works great.

 

[Jpjr]

Bottom line: Machining .25" off the bolt heads is the best solution. Forget those cheesey Steeda bolts.

Changing chassis fasteners is a complicated matter, as well as a major safety issue. There are lots of variables that must be considered (bolt material, diameter, strength, stress factors, fatigue life, sheer load, etc). Just because a bolt fits doesn’t mean it’s acceptable for the application. Replacement bolts may not as strong as the factory bolt under all load conditions. At least one board member reported a buttonhead bolt failure. For these reasons, a buttonhead bolt (or other replacement bolt) is not the recommended solution.

Hmm... I would take my chances with a true 14mm bolt than the error 12mm bolt a lot of people were stuck with from Ford. Steeda has sold way too many IRS bushing sets to have the not thought about bolt strength. This isn't some sawdust joint.

 

[Top_Fuel]

Hmm... I would take my chances with a true 14mm bolt than the error 12mm bolt a lot of people were stuck with from Ford...

We might be talking about different bolts. The ones I'm talking about are the two rear IRS mount bolts that sometimes interfere with wide tires. As far as I know, these are supposed to be 12mm. The forward mounted IRS bolts are the ones that are supposed to be 14mm...not the ones that are pictured above. If all 4 IRS bolts are supposed to be 14mm, then someone set me straight.

I still wouldn't use Steeda's "low profile" bolts in my car. No way those things are as strong as the factory fastener. A good discussion of this can be read HERE.

-Greg

 

[Bonefish]

subscribing for future use

 

[Annihil8or]

.... As far as I know, these are supposed to be 12mm. The forward mounted IRS bolts are the ones that are supposed to be 14mm...not the ones that are pictured above. If all 4 IRS bolts are supposed to be 14mm, then someone set me straight.

I still wouldn't use Steeda's "low profile" bolts in my car. No way those things are as strong as the factory fastener. A good discussion of this can be read HERE.

-Greg

You are correct and I agree your assessment of Steeda's "low profile" bolts. I am not even sure that it's safe to machine .25" from the bolt head for that matter. Who knows what conditions might precipitate a failure.

 

[Mr. Mysti]

I got 4 12mm bolts. Two of them are F#$%ed up. I just took the car in for service for a diff leak and now I dropped my IRS to replace some bushings on my own and the frickin bolts were stripped for the rear IRS. Damn dealers. If you want something done right do it yourself!

I'll be maching my bolts down! :rockon:

 

[blk04cobra1]

The shop that put mine in luckily quoted me before doing the install...my buddy laughed saying the bushings wanted to fall out everytime they tried to put it all back together...took them 7hours...i laughed, he told me they were gonna charge $500 to the next person who wanted them done...mine was $150 :-D

 

[Jpjr]

this one is still a toss up to me. i suppose i'll grind down the stock bolts and ditch the steeda one's that came with the new bushings.. but whether you shave down the stock bolt or use aftermarket bolts.. you can kiss warranty coverage goodbye in the event of a failure.

 

[Mr. Mysti]

this one is still a toss up to me. i suppose i'll grind down the stock bolts and ditch the steeda one's that came with the new bushings.. but whether you shave down the stock bolt or use aftermarket bolts.. you can kiss warranty coverage goodbye in the event of a failure.

What warranty coverage. Ford supplies a 12mm bolt and a 14mm crush sleeve and they won't warrenty it @ all. Will they make it right and install 14mm bolts or replace the 14mm crush sleeve with a 12mm one? :bash:

Cutting the head down a reasonable amount should be acceptable and not give any problems. As long as you torque the bolts correctly you wouldn't expect the head of the bolt to shear off. And it shouldn't go through like a flat head might. After all, you still have the same bolt with the same type of thrust washer? under the head.

 

[SALEENGTROUSH]

damn... TTT good write up... ill be using this info

 

[Jpjr]

What warranty coverage. Ford supplies a 12mm bolt and a 14mm crush sleeve and they won't warrenty it @ all. Will they make it right and install 14mm bolts or replace the 14mm crush sleeve with a 12mm one? :bash:

Cutting the head down a reasonable amount should be acceptable and not give any problems. As long as you torque the bolts correctly you wouldn't expect the head of the bolt to shear off. And it shouldn't go through like a flat head might. After all, you still have the same bolt with the same type of thrust washer? under the head.

all i'm saying is if something failed, ford would still blame you irrespective of this argument. you altered something.. it failed.. you pay for it.