IRS kicks right sometimes during hard acceleration

scottydsntknow

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I just went through the IRS, did ftbr bushings, new cross axis links, new swaybar endlinks, new subframe bushings, and new grade 10.9 metric hardware from Fastenal. Everything is tight... Torqued to specs on the FTBR site. This is my first IRS I've owned and driven regularly. Is this normal or a known issue that can be fixed? Happens in the straights, car goes around corners like noones business.

2000 Steeda GT #0048. 4V swap, FTBR IRS swap, suspension/tune.
 

hotcobra03

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i found wheel bearings will do this also.

i had 1 inner link have the slightest movement cause this. also went ftb rod.

rear alignment also will steer under hard acceleration
 

01yellercobra

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What hotcobra03 said. My driver side hub bearing went bad and it would cause some weird issues. I had to pull the hub to find it though. There was no noticeable movement with things tightened up. Mine got bad enough that I could feel the rear end shift under a hard corner.
 

Dave.O

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Check alignment. Slightly toe'd in will help rear track straight, out will help with tun in but make the car really squirlly at high speeds or straight line acceleration. Basically unless you are doing only tight auto cross go toe'd in. If not that sounds something is binding and letting go. Check torque on rear hub bearing nut 36mm 250 ftlbs


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scottydsntknow

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Yeah ftbr links are getting ordered. New hubs too huh... They seemed fine and have longer studs but I suppose I'll do them too and arp studs. Longer studs in there now are not arp...

Thanks all, do you guys have any actual alignment specs you can share? Street car on street tires.

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Dave.O

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1 1/4' neg camber, 1/18 - 1/16" toe in. I actually can't get much more neg camber than that in the rear on both sides matching


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52merc

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Refurb Knuckles LR.jpg
FTBR sells compete new or rebuilt knuckle-hub assemblies with new studs. I think they are a little pricey, but no press is needed.

I did my own rebuild as I have a press. Went for 30 years without one. Love having it around, although it does take up room in my garage. Here is what mine looked like after the rebuild.
 

01yellercobra

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Shit they aren't 1 piece bolt on replacements? Oh well I need to order a shop press anyway...

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Like 52 said, you can get the whole knuckle assembly. But I'm a cheap bastard so I just did the bearings. I'd still get the press. Once you have one you wonder how you lived without it.
 

scottydsntknow

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Which press? I'm limited in what I get get at an overseas FPO address shipping wise. There are a million auto repair shops around here tho, I'm sure it would be pretty cheap to just get the new bearings and studs done.

But then when I want to do the rear gears I still need a press and I do NOT trust the Spanish shops here to properly do gears in a USA domestic that was never available in Europe lol.
 
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hotcobra03

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Which press? I'm limited in what I get get at an overseas FPO address shipping wise. There are a million auto repair shops around here tho, I'm sure it would be pretty cheap to just get the new bearings and studs done.

But then when I want to do the rear gears I still need a press and I do NOT trust the Spanish shops here to properly do gears in a USA domestic that was never available in Europe lol.
here harbor freight sells a cheap 20 ton.

what about rental tools. any stores there.
 

scottydsntknow

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Yeah I'm gonna have to do some detective work around here, I'm sure there are stores like HF that sell them, I just never looked. Too many ppl stationed here think its a 3rd world country or something lol.
 

52merc

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I wasn't originally going to change out the cross-axis joints, but when I got everything apart there were several bad ones, so I ended up doing all of them. After the fact, I'm glad I did - one less thing to worry about. I got the bearings on Amazon for a good price, Timken Set 49 (you need qty-2 to do both sides). They are the same as what I pulled out and less expensive than the Ford or Motorsport ones.

FTBR claims that sometimes the hub can get damaged when you pull it out of the bearing, but I didn't have any problems. Just make sure you take the retaining ring out first before you pull the bearing out of the knuckle.

If you are going to do the bearings yourself, keep one of the old ones to use as a fixture to press the new ones in. Just grind a little off the OD so they will slide freely into the bearing bore. That way they will not get stuck in the bore when you seat the new bearings.
 

scottydsntknow

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Yeah that is what I was planning. Cross axis joints I did with FTBR ones when it was all apart, the ones in there were originals and completely shot.

As far as doing the gears... still on the fence with that. I might just replace the clutch pack in the diff and leave the 3.27s in there. Not great for acceleration but out here I routinely do 100mph on these euro highways so....
 

04torchred

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I wasn't originally going to change out the cross-axis joints, but when I got everything apart there were several bad ones, so I ended up doing all of them. After the fact, I'm glad I did - one less thing to worry about. I got the bearings on Amazon for a good price, Timken Set 49 (you need qty-2 to do both sides). They are the same as what I pulled out and less expensive than the Ford or Motorsport ones.

FTBR claims that sometimes the hub can get damaged when you pull it out of the bearing, but I didn't have any problems. Just make sure you take the retaining ring out first before you pull the bearing out of the knuckle.

If you are going to do the bearings yourself, keep one of the old ones to use as a fixture to press the new ones in. Just grind a little off the OD so they will slide freely into the bearing bore. That way they will not get stuck in the bore when you seat the new bearings.

Are you able to verify if your cross axis joints are bad prior to removing the knuckles and removing the cross axis joint? I am still on the original cross axis and have 60k miles on the car. I have a slight clunk noise that has just started prior to parking the car. Its noticeable when I let the clutch out and get going. You can hear it if you clutch out, clutch in back and forth. So I have slop in my driveline somewhere now that I didn't prior.

It most likely not the cross axis but was wondering if you can verify prior to removing them.
 

01yellercobra

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Are you able to verify if your cross axis joints are bad prior to removing the knuckles and removing the cross axis joint? I am still on the original cross axis and have 60k miles on the car. I have a slight clunk noise that has just started prior to parking the car. Its noticeable when I let the clutch out and get going. You can hear it if you clutch out, clutch in back and forth. So I have slop in my driveline somewhere now that I didn't prior.

It most likely not the cross axis but was wondering if you can verify prior to removing them.
Check the front cradle mount bolts. Did you install the larger bolts in there?
 

04torchred

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Check the front cradle mount bolts. Did you install the larger bolts in there?

I believe I have the larger ford bolts 14mm. I may swap those out for the FTBR 9/16 bolts I have a pair at home.

Going to have a friend sit in the car, its up on jackstands and clutch in and out while I lay underneath and see if I can find the noise.
 

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