IRS Install Help, Please

[karlos]

Refer to the photos shown below. The first two show a gap between the IRS knuckle bushings and the lower control arm. Gaps are on the inner lug of the control arm clevis on both sides. Easy enough to shim out, I suppose, but wanted to check to make sure this isn't an indication of some larger problem.

The third photo shows a gap between the LCA rod end bearing and its mounting clevis on the chassis. The FFR install manual says to place 3 shims on the forward side of the rod end (which you can see in place here), but makes no mention of what to do after that. I'm guessing I should shove the LCA/rod end up against the 3 shims and then shim out whatever gap remains on the opposite side. Anybody know the correct procedure?

Thanks much.

-Karl

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[2bking]

I didn't worry about the gaps at the knuckles and tightened the bolts to draw them together. The gaps at the rod ends are there for alignment purposes and are shimmed using the supplied washers. The 3 shims on the front side of the forward rod ends are the starting point for alignment and the rear rod end moves on the through bolt as the track width is changed by screwing in/out the forward rod end. The rear rod end is screwed in/out to change the toe. You can leave all the shims out at the rear rod ends until the alignment is done.

[rich grsc]

I would not just torque the bolts down at the knuckles. Thats way too much space, shim it with a couple washers. Best to keep the ears as parallel as possible.

[Mesa Mike]

use shims. I think they are provided in the kit for IRS, mine were.

[bcsellie]

Are you sure you used the proper knuckle bushings?

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44323


Refer to the photos shown below. The first two show a gap between the IRS knuckle bushings and the lower control arm. Gaps are on the inner lug of the control arm clevis on both sides. Easy enough to shim out, I suppose, but wanted to check to make sure this isn't an indication of some larger problem.

The third photo shows a gap between the LCA rod end bearing and its mounting clevis on the chassis. The FFR install manual says to place 3 shims on the forward side of the rod end (which you can see in place here), but makes no mention of what to do after that. I'm guessing I should shove the LCA/rod end up against the 3 shims and then shim out whatever gap remains on the opposite side. Anybody know the correct procedure?

Thanks much.

-Karl

44287

44288

44289

[Markie D]

It looks like your bushing are to narrow. I just completed my install, and had to use a bit of grease to help slide them into place. Where did you purchase your bushings?

[Hotyacht]

x2 - I have just fitted mine and they required some lithium grease and a fair amount of effort to get them to slide into the LCA.

[karlos]

Bushings came installed with the Ford Racing M-5970-A kit car knuckles. Looks like you guys are using the polyurethane bushings whereas the stock Ford bushings are rubber. Maybe I need to swap out the bushings. Sigh...

[grluisi150]

I bought my bushings from energy suspension and I have the gap so I will use washers to fill the gap.

[karlos]

I bought my bushings from energy suspension and I have the gap so I will use washers to fill the gap.

Well that's interesting. I wonder if I could ask one of you with no gap to measure the width of your LCA clevis (inside dimension between the lugs)? All four of mine measure about 2.5" (2.495" according to my caliper). Maybe it's not the bushing...

[Alig2]

Well that's interesting. I wonder if I could ask one of you with no gap to measure the width of your LCA clevis (inside dimension between the lugs)? All four of mine measure about 2.5" (2.495" according to my caliper). Maybe it's not the bushing...

Mine are similar, 2.45". With the bolts torqued, the clevis ends are angled slightly closer at the open end but not really enough to need a washer. The bushings are from FFR, so supposedly are the Energy Suspension ones. Had more of a problem getting both knuckle bushings in both clevis ends as the same time, chalked it up to the hand made nature of the parts. Since the bushings have a steel tube in the center that matches the width of the bushings, I would look at the installed width of the bushings, they might be wrong.

[karlos]

Thanks much for the measurement. I still don't have a bead on what's going on here. Doesn't seem to be the control arm, and the same brand bushing has no gap in one installation, a gap in another. Even if there was variability in the polymer/rubber bushing width, the sleeve that goes through the bushing should measure about 2.5" to match the clevis and should be very consistent. My sleeves are short enough that I need two 0.060" washers to fill the gap. Weird.

[karlos]

So I received a set of the Energy Suspension polyurethane bushings today and the fit is exactly the same as the stock rubber bushings. The clevis on the lower arm measures 2.5" and the sleeve that goes in the bushing measures 2.4", resulting in a 0.10" gap. I'm becoming convinced this is just the way this goes together. Any body have a picture that shows otherwise? Not trying to be contrary but it just drives me crazy that I can't figure this out...

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[Saul S]

Hello Karlos,

This what mine look like with the Energy Suspension polyurethane bushings, as you can see the metal sleeves inside the bushings are the same width, I remember having to muscle them into the lower control arms as they were a tight fit and had no gap.

I hope this helps

44522.

[2bking]

Hello Karlos,

This what mine look like with the Energy Suspension polyurethane bushings, as you can see the metal sleeves inside the bushings are the same width, I remember having to muscle them into the lower control arms as they were a tight fit and had no gap.

I hope this helps

44522.
That's an interesting picture - grease zerks on rubber bushings. I don't remember mine from Ford Racing having that. I'll have to go inspect them now.

[Saul S]

Hello 2bking,

I added those myself, poly not rubber

[bmcglone]

I have the Complete Kit IRS with new Ford Racing knuckles and Energy bushings. Mine were very tight.