IRS Center section problem

[slpro1207]

I am once again reaching out to Guru's of the build for help. After many hours of effort trying to install the center section of the IRS (1 rear bolt goes in, but #2 bolt won't) I measured center of sleeve and center of holes on the ears of the center section. The holes on the center section are 3/16 of an inch wider than the center of the sleeves in the bushings. Any ideas?

[edwardb]

I'm assuming you're describing the center section for the newer 2015 and up Mustang based IRS. It's a tight fit to be sure, and I too struggled to get the bolts to line up. I also thought they were maybe off a bit dimensionally. I made up some tapered pins though and it was really easy to get it lined up and the bolts all installed. Discussed in my build thread here: http://thefactoryfiveforum.com/showt...l=1#post209902

[slpro1207]

Hi Edward. Yes it is the newer 2015 center section. In this case the rear bolts are the issue. I will try the tapered pins but I will have to be careful not to destroy the treads in the case. But measuring center to center on the bushing sleeves and the same on the bolt holes in the case are off a touch more than 1/4 inch. Doing more measuring today.

[slpro1207]

I have taken more measurements and found the holes for the threaded bolts are 13 1/2" apart and the sleeves in the bushings are 13 3/8" apart. The 1/8" difference stop the bolt from being able to thread in. I have thought about shaving a little bit of material on the outside of each bushing to expande the distance but don't know if this is feasible. Thoughts?

[CraigS]

I would try that. The main torque loading that the diff needs to handle is trying to make the rear move down and the front move up on accel. So having a little extra play sideways shouldn't be a problem. See how the stock bushings in the Mustang allow movement here.
https://youtu.be/jEF_47B0K3Y

[slpro1207]

SUCCESSThanks CraigS. I did get it in . I started the right bolt then used a ratchet strap to pull the case to the left compressing the bushing enough to get the left bolt started. The front went in with just a little persuading. Ratchet straps are my friend.