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Had someone give me 600 cash and a 98 GT 8.8 rear end complete with everything. Well alot of it was trashed like the rotors, ABS etc. This is a very easy swap and well worth it for some. This is my write up and opinion on the situation. Please fell free to comment/give suggestions or tell me things you do not agree with!
Why swap to a SRA? It is done for people who are more drag strip orientated and do not want to deal with the high costs of making a indestructible IRS.
How much more would it cost to just build my IRS?: Well for someone like me in the 450-600rwhp range who wants to launch on slicks, I would need level 5 half-shafts, a IRS brace, a bushing kit diff cover etc. The list goes on. Leve 5 halfshafts are around 1500 alone. To build a SRA that will not break at that power level you need 31 spline diff and axles. This can be done for 550 in parts new or 100s used (explorer or ranger)
What is an SRA: Solid rear axle
Why would someone want my IRS?: Well for some they believe that the IRS is the best handling rear end around and like to get IRS's for autocross or other handling reasons
Are the IRS's any different from year to year?: yes i will not go to far in this subject but the 03/04 cobra's have a 31 spline setup unlike the 99's 28 spline setup.
Is this costly?: To some it can be. For me i ended up with new brakes, rotors, control arms, shocks, and 250 bucks positive. For others who do not receive cash on top of trades or buy a SRA new you can get pretty deep in your pocket!
What SRAs work?: Many 8.8 rear ends from mustangs will work, but 94-04 is nice because you wont have to deal with a 5 lug conversion
Will my break lines Work: 94-04 calipers are the same and the brake lines will switch over
Are the rotors the same?: No cobra rotors are the same height but thicker, Different brake pads will be needed if you want to use the 94-04 GT rotors.
Difference in 99-04 and 94-98 8.8s: 94-98 8.8s are nice because they are 1/8" shorter on each side and people like it because they can "tuck" there slicks in more
Will my IRS catback work?: No you will need to switch to a SRA catback.
Will My driveshaft bolt up: Yes 99-01 cobra driveshafts will bolt up, However 03/04 cobra guys will You will need to buy a special ujoint to convert the yokes over. The one i would use is from Oreilly Auto Parts but I'm sure whatever part store you have can cross reference the numbers for you. the part is a Precision 448 ujoint. Pic:
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how to remove the IRS in one nice piece, also the tools i used/needed:
Creeper
2 floor jacks
2 jack stands
1/2" Impact Gun
Air compressor (The impact can't run off a small one to well)
Sockets:
10mm 12pt
12mm 12pt
13mm
15mm
18mm
21mm
Wrenches:
10mm
12mm
13mm
15mm
18mm
21mm
3/4
Next for removal of the IRS:
1. Get the car on jack stands (sub frame connectors work great)
2. I removed my cat back which consisted of 4 3/4 bolts and some washers
3. I dropped my drive shaft from the diff with 4 12mm 12pt bolts
4. Remove the back seat. Its easy just push in the little button under the lip of the seats (2)
5. Remove and unplug the ABS wire and put it through the floor
6. Take out your e brake line from your caliper and tuck it away
7. Remove rear shocks. ( you may have to support the lower control arms with the jack to remove the lower bolts from the shocks.)
8. Remove the calipers and hang out of way.
9. Remove the top bolt from the IRS. Its on the frame and a 18mm i believe
10. Lower jack slowly
11. Remove springs (be careful they are spring loaded and accidents can happen)
12. Raise jack putting IRS back in place.
13. Remove front bolt in frame where the lower control arm mounts.
14. Lower the IRS out!!!
How to Remove SRA. Follow steps backward for installing!
1. Begin by placing the stands at the factory jacking locations.
2. Place jack under the pumpkin to support the weight of the axle.
3. Start by removing the driveshaft. This requires a 12mm 12pt socket or wrench to remove bolts.
4. Remove the shocks. The top is a 15mm and the lower bolts are 18mm.
5. Remove the rear seat and disconnect the ABS sensor wires and feed the through the floorboard of the car. Leave them attached to the stock location on the axles, they will be swapped as part of the unit.
6. Disconnect the ebrake cable from the caliper and tuck it out of the way somewhere. ( there is a "E" clip that has to be removed )
7. Remove calipers but do not open the brake lines. Just hang the calipers out of the way. 12mm and 15mm
8. Remove rotors.
9. Take off the quad shocks. This requires a 18mm top and bottom.
10. Remove the quad shock mounting bracket from the frame. 15mm socket is needed.
11. Lower jack to remove the springs.
12. Raise jack up to take weight off suspension parts.
13. Take front bolt off the upper control arms. 18mm
14. Take front bolt off lower control arm. 21mm.
( NOTE: You may have to remove or lower the stock catback at this point to be able to access the control arm bolts from inside the frame. The bolts for the catback should be a 15mm )
15. Lower the axle assembly out of the way.
16. Finish removing the catback
Pictures of my swap!
Where i started on jack stands:
![]()
Removed the dirty stock IRS:
![]()
Poor Bare Car
![]()
New rear end from a guy in the wild horses club!
![]()
Some paint, getting ready to take off blow shocks, torched control arms and quad shocks:
![]()
New parts together, Monroe gas shocks, UPR Adjustable LCA's, new gasket/fluid, new caliper bracket bolts and new ceramic brake pads:
![]()
Mocked up in the car:
![]()
Boo Boo from pulling on the ebrake cable with vice gribs Got some stiches! Talk about blood and sweat into a car!
![]()
In the car on stock springs, lost my H&R IRS springs...
![]()
And cut a 1/2 coil off the stockers but not much of a difference:
![]()
Why swap to a SRA? It is done for people who are more drag strip orientated and do not want to deal with the high costs of making a indestructible IRS.
How much more would it cost to just build my IRS?: Well for someone like me in the 450-600rwhp range who wants to launch on slicks, I would need level 5 half-shafts, a IRS brace, a bushing kit diff cover etc. The list goes on. Leve 5 halfshafts are around 1500 alone. To build a SRA that will not break at that power level you need 31 spline diff and axles. This can be done for 550 in parts new or 100s used (explorer or ranger)
What is an SRA: Solid rear axle
Why would someone want my IRS?: Well for some they believe that the IRS is the best handling rear end around and like to get IRS's for autocross or other handling reasons
Are the IRS's any different from year to year?: yes i will not go to far in this subject but the 03/04 cobra's have a 31 spline setup unlike the 99's 28 spline setup.
Is this costly?: To some it can be. For me i ended up with new brakes, rotors, control arms, shocks, and 250 bucks positive. For others who do not receive cash on top of trades or buy a SRA new you can get pretty deep in your pocket!
What SRAs work?: Many 8.8 rear ends from mustangs will work, but 94-04 is nice because you wont have to deal with a 5 lug conversion
Will my break lines Work: 94-04 calipers are the same and the brake lines will switch over
Are the rotors the same?: No cobra rotors are the same height but thicker, Different brake pads will be needed if you want to use the 94-04 GT rotors.
Difference in 99-04 and 94-98 8.8s: 94-98 8.8s are nice because they are 1/8" shorter on each side and people like it because they can "tuck" there slicks in more
Will my IRS catback work?: No you will need to switch to a SRA catback.
Will My driveshaft bolt up: Yes 99-01 cobra driveshafts will bolt up, However 03/04 cobra guys will You will need to buy a special ujoint to convert the yokes over. The one i would use is from Oreilly Auto Parts but I'm sure whatever part store you have can cross reference the numbers for you. the part is a Precision 448 ujoint. Pic:
how to remove the IRS in one nice piece, also the tools i used/needed:
Creeper
2 floor jacks
2 jack stands
1/2" Impact Gun
Air compressor (The impact can't run off a small one to well)
Sockets:
10mm 12pt
12mm 12pt
13mm
15mm
18mm
21mm
Wrenches:
10mm
12mm
13mm
15mm
18mm
21mm
3/4
Next for removal of the IRS:
1. Get the car on jack stands (sub frame connectors work great)
2. I removed my cat back which consisted of 4 3/4 bolts and some washers
3. I dropped my drive shaft from the diff with 4 12mm 12pt bolts
4. Remove the back seat. Its easy just push in the little button under the lip of the seats (2)
5. Remove and unplug the ABS wire and put it through the floor
6. Take out your e brake line from your caliper and tuck it away
7. Remove rear shocks. ( you may have to support the lower control arms with the jack to remove the lower bolts from the shocks.)
8. Remove the calipers and hang out of way.
9. Remove the top bolt from the IRS. Its on the frame and a 18mm i believe
10. Lower jack slowly
11. Remove springs (be careful they are spring loaded and accidents can happen)
12. Raise jack putting IRS back in place.
13. Remove front bolt in frame where the lower control arm mounts.
14. Lower the IRS out!!!
How to Remove SRA. Follow steps backward for installing!
1. Begin by placing the stands at the factory jacking locations.
2. Place jack under the pumpkin to support the weight of the axle.
3. Start by removing the driveshaft. This requires a 12mm 12pt socket or wrench to remove bolts.
4. Remove the shocks. The top is a 15mm and the lower bolts are 18mm.
5. Remove the rear seat and disconnect the ABS sensor wires and feed the through the floorboard of the car. Leave them attached to the stock location on the axles, they will be swapped as part of the unit.
6. Disconnect the ebrake cable from the caliper and tuck it out of the way somewhere. ( there is a "E" clip that has to be removed )
7. Remove calipers but do not open the brake lines. Just hang the calipers out of the way. 12mm and 15mm
8. Remove rotors.
9. Take off the quad shocks. This requires a 18mm top and bottom.
10. Remove the quad shock mounting bracket from the frame. 15mm socket is needed.
11. Lower jack to remove the springs.
12. Raise jack up to take weight off suspension parts.
13. Take front bolt off the upper control arms. 18mm
14. Take front bolt off lower control arm. 21mm.
( NOTE: You may have to remove or lower the stock catback at this point to be able to access the control arm bolts from inside the frame. The bolts for the catback should be a 15mm )
15. Lower the axle assembly out of the way.
16. Finish removing the catback
Pictures of my swap!
Where i started on jack stands:
Removed the dirty stock IRS:
Poor Bare Car
New rear end from a guy in the wild horses club!
Some paint, getting ready to take off blow shocks, torched control arms and quad shocks:
New parts together, Monroe gas shocks, UPR Adjustable LCA's, new gasket/fluid, new caliper bracket bolts and new ceramic brake pads:
Mocked up in the car:
Boo Boo from pulling on the ebrake cable with vice gribs
Got some stiches! Talk about blood and sweat into a car!
In the car on stock springs, lost my H&R IRS springs...
And cut a 1/2 coil off the stockers but not much of a difference:
