DUW: IRS bushing install with pics

Discussion in 'SVT Tech Forum' started by wjfawb0, Dec 8, 2003.

  1. OK. Where to start. I installed maximum motorsports IRS bushings, steeda differential bushings and a borla stinger catback exhaust I got from davidmax’s xtreme motorsports. Total install time was two full days.

    Tools used to lift and hold:
    Asymmetrical frame lift
    Tall homemade jack stands
    Transmission jack
    Floor jacks
    Regular jack stands

    Power tools:
    Pneumatic craftsman drill
    Snap-on impact gun
    Makita electric drill

    Hand tools:
    A schitload of metric wrenches, sockets and fun stuff
    Craftsman 25-250lb torque wrench
    Coping saw (could substitute a jigsaw here)
    6” C-clamp
    Large C-clamp (8” or larger)
    Prybars and steel spikes to line up bushings and bolt holes
    Rubber mallets

    Assorted attachments and junk:
    1.5” wire brush (radial or cup)
    5/16” drill bit
    WD-40 (lubricating drill bit and coping saw)
    Ether (starting fluid) for cleaning
    1.5” PVC coupler
    1.5” to 0.75” PVC adapter
    Some big thick flat washers (at least 1” in diameter)

    If you read this entire thread however, it should be easy to do in a day or less with the right tools.

    Okay, cars on the lift Friday:


    Stock view:


    Exhaust off (use WD-40 on hanger studs to make removal easier):



    First, I installed the differential bushings. The instructions from steeda didn’t seem to be real clear on the 03 Cobra, so I just took off the brace between the front IRS subframes and swapped the bushings. It is pretty easy.

    Remove the brace bolts, then remove brace and the dogbone and stock bushings which come in two parts. In order to get the top halves out, I just pulled down slightly on the driveshaft to get clearance between the IRS braces on top of the diff.

    Stock bushings in differential:


    Grease the new bushings well and then install them similar to what the steeda directions say. Slide the top red bushing and two washers in up top(pull down on drive shaft slightly to get clearance).


    Press in the black smaller center bushing into the differential casing and then insert the crush sleeve. I pressed them in using my fingers to start. After starting them, you can use a c-clamp to press them completely in.


    Install the dogbone and then the bottom red bushings and washers. The finished product:

  2. OK. Now onto the fun. To start the install of the IRS bushing, we got the car up high, removed the wheels, and used a transmission jack to take the IRS weight off the rear two IRS bushing bolts. The two stands in the pictures were home made tall stands that we used to support the IRS subframes at various times during the install.


    We couldn’t get adequate clearance with just the bolts removed, so we had to go into the trunk, remove the lining and unhook the shocks. This allowed us to lower the IRS far enough to work on the stock rubber bushings. We used a floorjack and steel pipe inserted into the lower control arm spring perch to compress the spring and disconnect the shock.
    NOTE: Be careful and support the IRS well. Besides the 4 bolts holding the IRS to the car, there is the drive shaft, your parking brake cables, abs sensor cables, and your brake lines. Don’t drop the IRS, or lower it too far. You could royally f-up your ride.


    (My cousin taking advantage of me while taking the interior of my trunk apart):


    Cousin unhooking shocks (friendly guy):


    Now the fun begins. Lets try and remove those nasty rubber bushings. Our weapon of choice was a craftsman pneumatic drill with a 5/16” bit. This one bit survived the entire install, but we regularly coated it with WD-40 to keep the heat down and lubricated it while drilling:


    The first two bushings (the rears) took about 2 hours to remove each. Why? We tried drilling them out as much as possible and then twisting out pieces of rubber. Don’t do this. Read below how to remove one of these bushings in 10 minutes.


    The hole saw didn’t work worth a crap either. Kept on jumping around and the rubber slowed it down too much once it got started into the bushing.


    (My cousin being friendly again):

    We did eventually get most of the rubber out:


    Here is how to remove the rubber bushings with ease (we did this on the two front bushings).

    1.) Drill holes concentrically around each rubber bushing (do not walk the bit or try to waller the holes. Use WD-40 to lubricate and cool bit every hole).

    2.) Insert coping saw (or jig saw) and cut to connect all your holes, freeing the center of the bushing (WD-40 helps get the balde going and keeps it moving).

    3.) Tap center of bushing out with hammer.

    4.) Use a decent sized flathead screwdriver to pry rubber away from inside of shell (very easy).

    5.) Clean inside of shell with 1.5” wire brush on drill (quick and clean).
  3. OK. We then used Ether to clean the insides of the shells to prepare the sleeves for the new bushings and grease.

    I applied the supplied polythane grease liberally and only used 1.5 of the 2 tubes provided by MM.


    Here is how we pressed the new bushings in:


    After greasing the sleeve and bushings, we used a large clamp, a 1.5” PVC coupler, 1.5” to 0.75” coupler and some large flat washers to press the bushing in. After we got close to fully inserted, the bushing gets tough to push in cause it tapers to a larger size. Then we swapped the large clamp for a 6” C-clamp that was easier to turn. The PVC couplers allowed the bushing to extend into them and the bushing to be fully seated in the sleeve. The washers were placed on the end of the bushing and the end of the couplers when the 6” C-clamp was used to prevent damaging the bushing or couplers with the smaller contact surfaces on the 6” clamp.


    After fully seating the bushing, we inserted the greased crush sleeve (note how the bushing sticks out past the sleeve on both sides, this is the reason for the PVC couplers).


    To get to the front two IRS bushings, we used the transmission jack to once again take the weight off the bolts and remove them. We used a 2x4 to bridge the gap between the two front IRS subframes and jacked it up using the tranny jack. We left the rear of the IRS unattached and lowered to get clearance.

    We let the IRS down far enough that the springs became unseated so we removed them to prevent them from falling on someone’s head. Be careful not to lower the IRS too far. You could damage the brake lines, parking brake cables, abs sensor cables, or the driveshaft/transmission/differential. We actually undid the parking brake cable rubber supports, the brake line brackets and the ABS sensor wire fasteners from the car/IRS to give us more room to drop the IRS. If you do not undo the fasteners/brackets, you may pinch or damage the cables/wires/lines when lowering the IRS to get to the front bushings.

    The springs are easy to put back in. The markings from the castings on the lower control arms tell you exactly how they came out, and the dirt on the bottom should tell you up from down. Just make sure the isolators are properly seated when reloading the spring and suspension during re-assembly.

    We removed the bushings using the drill, coping saw, screwdriver, wire brush method and got them out in less than 30 minutes. We installed the new ones with the Clamps.

    OK. Our last difficulty. Getting the IRS back together and attached to the car.

    We stuck the springs back in and started to raise the front of the IRS. The front bushings reinserted easily and we lined them up and inserted the new 14mm bolts from MM one at a time using the steel pointy ends of our prybars. These were more difficult to get in than the 12mm stock pieces because they actually filled the holes in the subframes.

    As we began to raise the rear and try to seat the rear bushings, the car began to lift off the rear pads on the frame lift. To counter this, we lowered the car close to the ground. In order to do this, we had to tie the rear IRS subframe to the spring perch boxes with a nylon ratcheting strap to hold up the rear of the IRS while lowering the car.

    You can see the strap here wrapped around the subframe. Be careful to make sure the strap is strong enough to hold the weight of the IRS and the slightly compressed springs:


    After we got the front two tires on the ground we placed regular short jackstands and floor jack under the rear IRS subframe (see picture above). Make sure you reattach the shocks to the shock towers during this lowering. You’ll need to guide the shocks back into the towers as the car is lowered. We also used a floor jack with a steel pipe seated into the underside of the spring perch on the lower control arm to compress the spring to make attaching the shock easier.

    We lowered the car until the bushings started to come into the gaps. Guess what? The drivers side bushing started to catch on the inside of the subframe of the car. The whole rear of the IRS was shifted about 0.25” to the passenger’s side. We farted around for a while trying to take care of this, but eventually just used a prybar with a wide face between the bushing and subframe as we lowered the car to guide the bushing in. A floor jack was used to push the rear of the IRS up(see picture above).
  4. We looked through the bushings to line up the holes with the jack and inserted the bolts. The nuts on the rear of the IRS have tabs welded to them and are located inside the rear connection point on the car. Just grab the welded on tab and line up the nut with the hole to insert the bolt. Be careful to hand start the bolts and line up the bushing crush sleeves with the car connection points. Be patient, otherwise you could screw the threads up on your bolts. I actually hosed the threads on the rear bolts during removal by rounding off the threads cause the rear wasn’t perfectly unloaded when I began to back out the bolts with my socket wrench. I had to use the front stock 12mm bolts to put into the back locations.

    After finishing the bushing install (woa), we raised the car back up and put the borla stinger exhaust on. I got the exhaust from xtreme motorsports when davidmax advertised a special on shipping. The exhaust came UPS all the way from Arizona (I installed in Frankfort, KY). Not a scrath or dent on it. Great looking and easy to put in. The tips lined up perfectly when we just pieced the exhaust together under the car. We tightened the clamps and flanges on the tubing and lowered the car. Replaced the wheels and put it on the ground. (Hallelujah)


    We spaced the rear tubes apart more before lowering the car to the ground. No rattles please:


    Started the car and it sounds great. Took it for a spin (about 30 degrees and frost covered outdoors). The wheel hop has been significantly reduced as far as I can tell. I basically get wheel spin most of the time now. A little hopping but nothing as violent as before.

    The exhaust is sweet. I wish I would have done it sooner.

    Thanks to all the IRS bushing installers before me that I picked up some tips from when I read your posts on svtperformance.

    The install crew (they failed to inform me of my grease mustache after the install):


    Let me know if you have any specific questions. I probably forgot something in this post.

    In summary, it is a pain in the arse. If you have the tools ready and the time, however, it isn’t a big deal. You just need lots of patience. Be prepared for bolts not lining up, difficulty manipulating the IRS, etc. These things will piss you off the most, but you can get through it. Good luck if you undertake this adventure and be careful.

  5. Well, can you tell a difference as far as the bushings go? I am interested. I hate wheelhop.
  6. The wheel hop has been significantly reduced as far as I can tell. I basically get wheel spin most of the time now. A little hopping but nothing as violent as before.
  7. Very thorough writeup, :nice:
    That grease moustache is da bomb
  8. This has been the most significant mod I've done to the way my car handles and rides....

    Besides the Steeda Sports and Bilsteins...

    No wait - I think the IRS bushings STILL made more of a difference.
  9. Nice write up. :nice:

    Sounds like something I would like on my car. But there is no way in hell I would install them after reading that. Anyone have any idea how much a shop would charge to do the install?
  10. OK man.... I'm driving up to Tennessee with the MM bushings that have been sitting on my bench for over a year now! What are you going to charge me for install????

  11. Well, I did my install in my cousin's garage in Frankfort, KY. I believe they estimated the labor cost would be a few thousand dollars. :p
    If you have the time and tools, you can do it yourself. Just don't expect to get it done in a day, especially if you do it on the ground.
  12. Uncle Meat, if you really want to install them and have a place or the tools in your garage to do it, I'd be glad to help. Like I said above (I think I did), knowing what I know now, I am sure I could do it in a day with some help from others. It would probably be a full day, but it could be done.

    Maybe you could rent some space in Tim's garage for a day and make use of his new frame lift??? :D What are you doing this weekend? :shrug:
  13. Awesome mod, :nice: and yes it can be a pain...

    now some good dampening shocks and higher rate springs and your wheel hop should virtually be a thing of the past.

    Its amazing how much the IRS "moves" from side to side in hard turn with stock bushings... people have reported up to 2" of play there..

    We found a place in Austin that has Delrin IRS bushings now :D

    and from talking to Maximum Motorsports, they indicated they might carry them also in the future....

    if you think urethane tightened it up, just think about delrin :hail2:
  14. Jason

    Thanks for having someone do them and not me :D
    What a PITA it was yes?

    Jeff T&J Performance
  15. Maybe Uncle Meat can come over and let you all get some experience on his car. ;) :D

  16. The MM bushings made a big difference in my book. Install was about the same as posted except I had the whole subframe out so that makes a world of difference. If you have a buddy, you can drop it out pretty fast. This works well especially when you don't have access to a lift.
  17. Thanks for the offer wjfawb0! I'm going to wait a little longer before I jump into this mod. Hell, I've had the bushings now for over a year, what's another month or two!? My anti-hop shocks from HBH seem to be doing a good job for the time being...

    I did want to add that I read another post over on SVTPerformance.com a few months back where they had installed the MM bushings and if I remember correcly they didn't have to disassemble as many components as you did!? Basically they unbolted the rear of the IRS and let it hang on the shocks, replaced those bushings, re-installed rear and disconnected the front, lather, rince, repeat. Sounded pretty easy the way the guy described it actually. His biggest gripe was getting all of the stock bushing cleaned out of the supports!

  18. We tried just dropping the rear, but I didn't think we could get the new bushings in with the little clearance between the gas tank and the IRS tubes. :shrug: Probably could have gotten it done that way, but just decided to make access to the bushings a little easier.

  19. Looks like about as much fun as I had installing my upper rear control arm bushings on my GT. That took me a day just to get the bushings out. I tried using a torch to melt them out but I got a little scared with the gas tank 5 inches away. I ended up muscling my bushings out with a drill spinning it in a circle. I wish I would have had that metal drill brush attachment you had. I used a dremel to clean the leftover rubber. After removing those bushings, I understand why this could be a $500 job. What a pain!!!!

    Very nice writeup.
  20. Thanks. If I had another cobra in the same shop, I am sure I could remove the bushings and clean the sleeves out in less than an hour after I dropped the IRS. We just had to learn the best way to do it. Removing the core with the coping saw relieves the pressure and allows the sides to be pried out very easily.