Has anyone installed a bump steer kit in their early mustang? I ask because i had to use a TON of shims to get it near perfect. I have the global west upper control arms with the shelby drop, a heim joint strut rod and poly bushings in the factory lower control arms. My car still has the stock power steering gearbox that is used as a manual. Has anyone else ran into the stack of shim issue to get theirs correct? What setup do you have and how many shims did it take?
bump steer in early mustang
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How big of a drop did u do on your upper control arm. Did you also lower the car with the coil springs?
I'm in the process of doing the 1" drop. I know if you go with a bigger drop than a 1" you need the angle shim kit for the upper ball joint. Is that what your talking about?
I'm in the process of doing the 1" drop. I know if you go with a bigger drop than a 1" you need the angle shim kit for the upper ball joint. Is that what your talking about?
I installed the global west upper arms and dropped them about 1 3/8". I also lowered the car with global west springs front and rear. That's not what I'm talking about though. The bump steer kit lowers the outer ball joints to cure the bump in the steering everytime you hit a bump in the road.
I've never tried it on a classic Mustang. As I recall, the bump steer was rather harsh on my old '67. Those cars are old enough now that if I had one that was not rotted out, I'd probably be more concerned with keeping it as stock as possible to enhance the resale value.
Case in point....I just helped a buddy return an old Mustang to 4 wheel drums. Someone along the way had ghetto-rigged front discs, monkeyed around with the proportioning valve, etc. The car was downright dangerous to drive under heavy braking in the rain. He tried to sell it like that and was getting lowball offers. We picked up front drum brakes from a junkyard and returned it to stock. That (and returning the trans to an original C4) got him an additional $7500 when he sold it a few months later.
So....if it's something you want to drive and you don't care at all about resale, then by all means do whatever you think will improve your enjoyment of the car. If it's something remotely collectible, I'd think long and hard about changing it.
Best,
Case in point....I just helped a buddy return an old Mustang to 4 wheel drums. Someone along the way had ghetto-rigged front discs, monkeyed around with the proportioning valve, etc. The car was downright dangerous to drive under heavy braking in the rain. He tried to sell it like that and was getting lowball offers. We picked up front drum brakes from a junkyard and returned it to stock. That (and returning the trans to an original C4) got him an additional $7500 when he sold it a few months later.
So....if it's something you want to drive and you don't care at all about resale, then by all means do whatever you think will improve your enjoyment of the car. If it's something remotely collectible, I'd think long and hard about changing it.
Best,
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I've done a ton of work on my 66's front suspension and I've set it up myself. I'm more then happy to pass along anything I can. I'm not a suspension expert but I have done a ton of reading up and learning from the school of hard knocks. Here goes.
At the time I didn't have a lot of money but I had a lot of time to learn. One of the issues that kept creeping up is the inability to get caster. It seemed to me in order to keep camber in check, you compromise caster. It became clear aftermarket parts were going to be needed. I thought about GW and know someone who helped design them and has either GW's first pair or proto type on his car. In a cost cutting measure, GW made them interchangeable side to side. What I don't like about the GW lower arm is the lack of a mono bearing. IMO, this is needed because the LCA follows the arc of the strut. I ended up going with Street or Track control arms. They have spherical rod ends that you can adjust to built in extra caster. They're beautifully made, come reassembled, marked left and right with what looks to be 3* caster already adjusted into them. I also purchased adjustable struts.
:crying2:
I wasn't planning on buying Street or Tracks lower control arms but during my build I discovered the old lower arms were completely shot. That was an unexpected expense. I finance my parts by selling a lot of scrap steel as well as literally picking up pennies off the floor. Don't laugh it adds up
OK, getting to bump steer. Basically you need to get the distance between the inner and outer tie rod as far apart as you can. That's either by lowering the outer tie rod or moving the outer tie rod closer to the wheel. lowering it is easier. After fooling around with my front suspension I'm a firm believer part of the problem on these cars is simply there's just too much travel in the suspension to the point you're not going to fix it reasonably. The easiest thing to do is to limit droop some how. On my 66 I'm running 72 disc brakes with a Baer bumpsteer kit. Just put all the spacers in. Don't waste your time with a bumpsteer gauge. Getting back to there being too much droop, I noticed with the Baer bumpsteer when I unloaded the suspension, the rod end actually ran out of travel and bound up before the suspension ran out of travel
Seeing that, it makes one wonder if that happens with a stock tie rod end and can't see it because of the boot?
I used some 1" spacers under the shocks to help limit travel. I would like to use some sort of bump stop on the control arms. Oh, when the rod end bound up, the tires would toe in and I would observe some positive camber.
On spindles, the difference between 65&66 spindles and 67-73 spindles is that 67-73 spindles have .500" less offset on the tie rod ends. The angle is the same. Here's where caster gets interesting. As you add caster, the outer tie rod moves closer to the road surface. I calculated for each 1* of caster, it lowers the tie rod .100" closer to the road surface. At 5* caster, bumpsteer should be about equal to a stock 65-66 with stock caster of 0*. As far as shims go on a 65&66, each 1/32" shim on the front and back bolts is good for 1/3* camber. and each 1/16" difference between front and rear shim packs is good for 1* caster. I've also added a camber kit which mimics the 67 & up camber adjustment system and the kit comes with blocks in 1* increments.
I found doing your own alignments is invaluable! I never did one before this. it's fairly easy. On these cars as the suspension compresses, the ties toe out. As it goes into droop, the tires toe in. Once you lower the UCA 1", it's going to lower the front by about 5/8". I run GT coils which lowers my front a little more. Right now I have my toe set at 1/16". I was thinking setting toe at 0" would also help with the bumpsteer since it's limiting toe in just a little. I think I was on the right line of thinking because I read that on mustangsteve.com on using Granada spindles on 65&66 cars. BTW, the Granada spindle is the same fordging as the 70-73 mustang disc brake spindle. Just the bolt holes for the caliper bracket are different as well as the tie rod.
On your car I would suggest adding as much caster as you can, limit travel of the suspension , use a stiffer, shorter soring to reduce stored energy to help keep it out of the area where the suspension just doesn't work. On my car I can set my alignment to what ever I can dream up. I have my caster set at 4*, camber is 1.25* neg camber and 1/16" toe with all the spacers in the bumpsteer kit. It drives very well. One last comment. Other then what GW recommends lowering their arm 1 3/8", I don't think you really need to lower the arm more then 1" with today's parts and tires. Back then, I'd agree, trying to get those skinny hard tires to bite. I think it brings more problems to the table for some one who is not doing their own alignments. The more you lower the UCA, the more other things change in the whole mix.
This is how my car sits. The rear springs are the stock sagging originals. My whole front suspension is all bearings, no rubber bushings anyplace. What's surprising is the car just rides so nice and smooth, just the opposite of what you would think. despite going with stiffer front springs, since there is no binding from rubber bushings, it rides softer then it did with stock springs
At the time I didn't have a lot of money but I had a lot of time to learn. One of the issues that kept creeping up is the inability to get caster. It seemed to me in order to keep camber in check, you compromise caster. It became clear aftermarket parts were going to be needed. I thought about GW and know someone who helped design them and has either GW's first pair or proto type on his car. In a cost cutting measure, GW made them interchangeable side to side. What I don't like about the GW lower arm is the lack of a mono bearing. IMO, this is needed because the LCA follows the arc of the strut. I ended up going with Street or Track control arms. They have spherical rod ends that you can adjust to built in extra caster. They're beautifully made, come reassembled, marked left and right with what looks to be 3* caster already adjusted into them. I also purchased adjustable struts.
:crying2:
I wasn't planning on buying Street or Tracks lower control arms but during my build I discovered the old lower arms were completely shot. That was an unexpected expense. I finance my parts by selling a lot of scrap steel as well as literally picking up pennies off the floor. Don't laugh it adds up
OK, getting to bump steer. Basically you need to get the distance between the inner and outer tie rod as far apart as you can. That's either by lowering the outer tie rod or moving the outer tie rod closer to the wheel. lowering it is easier. After fooling around with my front suspension I'm a firm believer part of the problem on these cars is simply there's just too much travel in the suspension to the point you're not going to fix it reasonably. The easiest thing to do is to limit droop some how. On my 66 I'm running 72 disc brakes with a Baer bumpsteer kit. Just put all the spacers in. Don't waste your time with a bumpsteer gauge. Getting back to there being too much droop, I noticed with the Baer bumpsteer when I unloaded the suspension, the rod end actually ran out of travel and bound up before the suspension ran out of travel
Seeing that, it makes one wonder if that happens with a stock tie rod end and can't see it because of the boot?
I used some 1" spacers under the shocks to help limit travel. I would like to use some sort of bump stop on the control arms. Oh, when the rod end bound up, the tires would toe in and I would observe some positive camber.
On spindles, the difference between 65&66 spindles and 67-73 spindles is that 67-73 spindles have .500" less offset on the tie rod ends. The angle is the same. Here's where caster gets interesting. As you add caster, the outer tie rod moves closer to the road surface. I calculated for each 1* of caster, it lowers the tie rod .100" closer to the road surface. At 5* caster, bumpsteer should be about equal to a stock 65-66 with stock caster of 0*. As far as shims go on a 65&66, each 1/32" shim on the front and back bolts is good for 1/3* camber. and each 1/16" difference between front and rear shim packs is good for 1* caster. I've also added a camber kit which mimics the 67 & up camber adjustment system and the kit comes with blocks in 1* increments.
I found doing your own alignments is invaluable! I never did one before this. it's fairly easy. On these cars as the suspension compresses, the ties toe out. As it goes into droop, the tires toe in. Once you lower the UCA 1", it's going to lower the front by about 5/8". I run GT coils which lowers my front a little more. Right now I have my toe set at 1/16". I was thinking setting toe at 0" would also help with the bumpsteer since it's limiting toe in just a little. I think I was on the right line of thinking because I read that on mustangsteve.com on using Granada spindles on 65&66 cars. BTW, the Granada spindle is the same fordging as the 70-73 mustang disc brake spindle. Just the bolt holes for the caliper bracket are different as well as the tie rod.
On your car I would suggest adding as much caster as you can, limit travel of the suspension , use a stiffer, shorter soring to reduce stored energy to help keep it out of the area where the suspension just doesn't work. On my car I can set my alignment to what ever I can dream up. I have my caster set at 4*, camber is 1.25* neg camber and 1/16" toe with all the spacers in the bumpsteer kit. It drives very well. One last comment. Other then what GW recommends lowering their arm 1 3/8", I don't think you really need to lower the arm more then 1" with today's parts and tires. Back then, I'd agree, trying to get those skinny hard tires to bite. I think it brings more problems to the table for some one who is not doing their own alignments. The more you lower the UCA, the more other things change in the whole mix.
This is how my car sits. The rear springs are the stock sagging originals. My whole front suspension is all bearings, no rubber bushings anyplace. What's surprising is the car just rides so nice and smooth, just the opposite of what you would think. despite going with stiffer front springs, since there is no binding from rubber bushings, it rides softer then it did with stock springs
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5 Posts
Awesome review of front suspension mods, this could help me a lot as I tackle the same issue of bump steer
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99 Posts
Yeah man thanks for sharing that info. I have the Baer bump steer kit on my Falcon, and I was wondering what others were running theirs at.
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