Rear axle shift when lowering
06-12-2011, 01:03 AM
#1
2nd Gear Member
Thread Starter
Join Date: Jul 2010
Location: Louisiana
Posts: 297
Rear axle shift when lowering
So I recently put a new set of staggered wheels on, and even at stock height I can see that the axle is not centered. I do plan on lowering it soon and my question is this: When you lower the car, does the axle always shift to the same side on every car? I'm asking, because if that is the case, I wonder if it will actually shift itself more center and I might not need a panhard bar.Any help would be appreciated. Thanks!
06-12-2011, 02:25 AM
#2
4th Gear Member
Join Date: Mar 2009
Location: CA
Posts: 1,291
Yes, the axle will move whenever the ride height is changed. The axle travels in an arch with the 3 link and panhard design. The mounting point for the panhard bar is on the right for the S197 chassis; not every car is the same.
My axle wasn't centered perfectly either, and now that's lowered it still slightly off center. An adjustable panhard bar should be used, but you won't know until the car is lowered and settled on that suspension; that's where to on-car adjustable one comes in.
Best of luck. UMI makes great stuff.
My axle wasn't centered perfectly either, and now that's lowered it still slightly off center. An adjustable panhard bar should be used, but you won't know until the car is lowered and settled on that suspension; that's where to on-car adjustable one comes in.
Best of luck. UMI makes great stuff.
06-12-2011, 08:12 AM
#3
Retired Moderator
Join Date: Jun 2006
Location: SF Bay Area
Posts: 9,235
^ I agree 
If you go with UMI, or any other brand, be sure to get a PHB that has the adjustable nut at the very end of the bar and as far away from the center as possible. The bar can get quite a load, in terms of compression on a RH corner and the adjustament nut is the weakest link. The bar will bow a bit under heavy loads, so best to keep that nut right at the end.
Jazzer and $.02
EDIT: I realize the nut toward the middle is easier to adjust, but you only need to do it once
Jazzer-approved design
Jazzes non-approved design
If you go with UMI, or any other brand, be sure to get a PHB that has the adjustable nut at the very end of the bar and as far away from the center as possible. The bar can get quite a load, in terms of compression on a RH corner and the adjustament nut is the weakest link. The bar will bow a bit under heavy loads, so best to keep that nut right at the end.
Jazzer and $.02
EDIT: I realize the nut toward the middle is easier to adjust, but you only need to do it once
Jazzer-approved design
Jazzes non-approved design
Last edited by Jazzer The Cat; 06-15-2011 at 06:37 AM. Reason: Updating post with images corrected info
06-14-2011, 07:18 AM
#4
6th Gear Member
Join Date: Feb 2007
Location: state of confusion
Posts: 7,635
So I recently put a new set of staggered wheels on, and even at stock height I can see that the axle is not centered. I do plan on lowering it soon and my question is this: When you lower the car, does the axle always shift to the same side on every car? I'm asking, because if that is the case, I wonder if it will actually shift itself more center and I might not need a panhard bar.Any help would be appreciated. Thanks!
With the S197, most times lowering will push the axle toward the driver side. So if it's already "off" toward the passenger side the lowering will tend to offset this (and can end up "overdoing" it). If you're already "off" toward the driver side you could expect the off-centeredness to get worse. Depending on how fussy you are (or need to be for big tire clearance reasons), there can be more situations that might require correction than not.
But since the PHB can be done completely separately from the lowering, all you really have to do is get the lowering done and see what needs to be done at that time.
I'm in full agreement with Jazzer with respect to the adjuster location and expected use. Unless you're going to be swapping springs like most folks change underwear, PHB adjustment is not something that you'll have to be constantly fiddling with. Spend a little longer getting the structurally better PHB that's less convenient to adjust, adjusted the first time. At most, adjust it once more if the springs take an intial set, and you'll be done with it.
Norm
06-23-2011, 12:27 AM
#6
2nd Gear Member
Thread Starter
Join Date: Jul 2010
Location: Louisiana
Posts: 297
Thanks a lot for the info guys!
YEah, just wasnt sure if it tended to go to the same side every time. I'll check out the umi bars! Thanks!
Very good to know, thanks for that! So can you provide some info on the difference in these two:
http://www.umiperformance.com/catalo...roducts_id=308
http://www.umiperformance.com/catalo...roducts_id=248
Is the grease/lube they offer something to get, or is there better elsewhere?
This is what I was thinking, and it is off center toward the drivers side now, so looks like it's going to just get worse. No huge tires, just 285's out back, and when they went on I could see a little more tire on the drivers side.
http://www.umiperformance.com/catalo...roducts_id=308
http://www.umiperformance.com/catalo...roducts_id=248
Is the grease/lube they offer something to get, or is there better elsewhere?
Since you didn't mention which way the axle is off-centered in, it's kind of difficult to tell you for sure what is going to happen.
With the S197, most times lowering will push the axle toward the driver side. So if it's already "off" toward the passenger side the lowering will tend to offset this (and can end up "overdoing" it). If you're already "off" toward the driver side you could expect the off-centeredness to get worse. Depending on how fussy you are (or need to be for big tire clearance reasons), there can be more situations that might require correction than not.
Unless you're going to be swapping springs like most folks change underwear, PHB adjustment is not something that you'll have to be constantly fiddling with. Spend a little longer getting the structurally better PHB that's less convenient to adjust, adjusted the first time. At most, adjust it once more if the springs take an intial set, and you'll be done with it.
Norm
With the S197, most times lowering will push the axle toward the driver side. So if it's already "off" toward the passenger side the lowering will tend to offset this (and can end up "overdoing" it). If you're already "off" toward the driver side you could expect the off-centeredness to get worse. Depending on how fussy you are (or need to be for big tire clearance reasons), there can be more situations that might require correction than not.
Unless you're going to be swapping springs like most folks change underwear, PHB adjustment is not something that you'll have to be constantly fiddling with. Spend a little longer getting the structurally better PHB that's less convenient to adjust, adjusted the first time. At most, adjust it once more if the springs take an intial set, and you'll be done with it.
Norm
06-23-2011, 07:30 AM
#7
Retired Moderator
Join Date: Jun 2006
Location: SF Bay Area
Posts: 9,235
Of the two links for PHB's listed above, my personal preference for higher performance is the the second one. It will generate a bit more NVH, but just like to relieve bind in ALL ways possible on suspension components. In this case, there will be VERY little, but just how I approach this stuff.
If they have a tube of grease that comes with the bar, I'd recommend you get it.
Jazzer
If they have a tube of grease that comes with the bar, I'd recommend you get it.
Jazzer
06-24-2011, 04:18 AM
#10
1st Gear Member
Join Date: Jan 2011
Location: CO
Posts: 83
I would go this route if I was going to the track and wanted the BEST setup. For the street, these cars handle pretty good with a few minor tweaks (panhard, swaybar, shocks, and bushings). You will also need to look into adjustable lower or upper control arms to correct pinion angle depending on how low you go.