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Discussion Starter · #1 ·
When I unpacked my LCAs for the IRS, I set them on the concrete slab and noticed one did not sit the same as the other. I assumed that it was due to differences in weld material. Now they they are on the car I've noticed that there is a 2.5 degree angle between the frame and knuckle tabs on the driver's side and 6.5 degrees on the passenger side. This corresponds to the passenger front knuckle ear being about 3/16" higher than the driver's side when the rear tabs are at the same height. Also the passenger rear knuckle bracket has a noticable twist that prevents a 1/2" steel rod from passing thought all 4 ears of both knuckle brackets. I'm worried that poly bushings won't work.

I used a magnetic protractor on both the frame and the LCAs on both sides and took the difference. I am not relying on the garage slab or my chassis dolly to be precise. There was a 1.5 degree difference from side to side and that is already taken into account.


Mike

[ April 03, 2007, 12:49 AM: Message edited by: Michael Stora ]
 

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No! I hope thats not normal. The rod not passing through should be your first clue. I built all my own stuff, so I hope others chime in but I'm going to say call them. 2.5deg seems normal not 6+. Patrick
 

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Discussion Starter · #3 ·
In addition to the twist in the LCA, the ears are twisted relative to their own arm segments.

Driver's side:
.....Front Ear: 0 degrees relative to frame (horizontal)
.....Rear Ear: +0.5 degrees relative to the frame (high in front)

Passenger's side:
.....Front Ear: +2.0 degrees relative to frame (high in front)
.....Rear Ear: +6.0 degrees realative to frome (high in front)

A 1/2" rod passed through the passenger front ears, strikes the rear ear about about 3/16" high. On the driver's side, do the same and it is about 1/4" low. There may be hole alignment issues on the ears themselves.

It looks like there will be a castor difference of about 4 degrees from side to side (is that adjustable on the IRS?), but I'm even more worried about a poly bushing binding in the knukle in the passenger aft ear mount with it's significant twist.

Mike
 

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Discussion Starter · #4 ·
I've been taking more mesurements and looking at the way things work and I think I am OK. The arc that the suspension moves in is defined by the suspension mounts. The ball joints kind of take the average of the three. A 4-deg difference in the twist of one LCA over the other is not going to change the inclantion of this arc (the equivilent angle to caster in the front), it is just going to change the clocking of the knuckle by 4 degrees, which I think is absolutely harmless.

Now on to those pesky ears . . . If I can't get the bolts started, I'll call FFR and holler. If I can get the bolts started, the ears are soft enough to bend more than 6 degrees to allign themselves square . . . I've seen it with my own eyes on the front.

I've got more important things to worry about like getting the front lower LCAs to actually work.

Mike
 

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Something like this? I received 3 sets of LCAs and they all looked identical. I spent ungodly amounts of time over the course of months trying over and over and over again to get Factory Five to fix the problem. They just continued to send me the same crap over and over again. I finally got fed up with the utter incompetence around FFR and gave up on them completely. I'll fix the problem myself.

By the way, my experience was almost 2 years ago. I hate to say it, but it doesn't surprise me at all that the problem still exists.



 

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Discussion Starter · #6 ·
Yea, but worse on the right side. I think the ears will bend when the bolts are torqued down.

Mike
 

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Listen to Greg. Those hole better line up or things will bind badly. Call and get new ones or find someone to fix the ones you have.
 

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Originally posted by Larry N. Johnson:
Force fit those arms on the frame and be done with it. They work fine. 14000 miles, no issues. There are bigger fish to fry.
So, how is the knuckle supposed to rotate on 2 different axes at the same time? If you're still running rubber bushings, then no problem as nothing in the rubber bushing actually pivots/rotates. Hammer away.

But, if you're running urethane bushings and looking to get the best suspension you can get (i.e. smooth, non-binding movement) rather than half-assed crap, then the holes need to align.
 

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What I did using Ford stock rubber bushings:

Forced the ears bigger using a threaded rod and nuts to spread it out some. Installed the spindle and tightened.

Maybe mine were straight...did not have any issues. Ready to install spindle:


Spindle installed:


These projects can get a person down if every fitting has to be exact. Some places we just "get er done".

Michael, I'll have my roadster in Maricopa 1st week on May. If it would help, I would be happy to stop by.
 
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