BMR Tech Tip: Clock those bushings after lowering your S550!

[tyguy]

correct, unless you got something like race ramps.

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[FlyBy]

correct, unless you got something like race ramps.

Nice! What's your method to get the car up on the wheel cribs? Do you use the drive-up ramps that pair with these?

 

[tyguy]

I have jacking rails to jack up each side of the car. I'll put half the blocks in the first round and then put the second blocks in.

 

[DarkestHour]

I have jacking rails to jack up each side of the car. I'll put half the blocks in the first round and then put the second blocks in.

Holy hell. How high does your jack lift the car? :eyebulge:

 

[tyguy]

I think it's 23inchez or so? If nothing else just add a block of wood once the car is up on the first set of cribs.

 

[terryz]

The RLCA front inner bushing is almost impossible to reach with a torque wrench when the car is only lifted with jackstand on the LCA. Any suggestions? Maybe ramp is better?

 

[BmacIL]

The RLCA front inner bushing is almost impossible to reach with a torque wrench when the car is only lifted with jackstand on the LCA. Any suggestions? Maybe ramp is better?

Drop the exhaust. That seems to be the common thing to do to access it.

 

[qtrracer]

So back in the day of Fox Mustangs, we had the same problem; lower the car without releasing preload on the bushings and the ride quality was in the dump and heights were uneven. Same thing with the first IRS cars.

Ford designed those rubber bushings with the rubber bonded to the shell and then placed serrated ends to dig into the chassis/suspension mounts. The bushings don't actually rotate in the shell - but twist like a spring (which they actually are in this mode). The twisting adds wheel rate resistance to the point of bind when the bushing can't twist further. Bad handling results occur suddenly.

When the springs are put in and the mounts not loosened, the new ride height is twisting the bushings as if going over a bump. So on the bump side of the suspension, there is not much twist left before bind. On the extension side, there is more movement before bind. In this case the situation often causes lopsided height as well as degraded ride quality.

The fix is similar to what BMR states, or replace the bushings with poly that rotates (generally a three-piece), delrin, or bearings. Each of these progressively creates more NVH.

I will add to all the advice given that from my experience doing this job many times, the car does not need to be level. The end you're working on needs to have the suspension loaded. If you raise the car to place on ramps, blocks, cribs, etc. you must either put a pair of greased plates under each raised tire (greased side between the plates as in a sandwich) so the wheels will move to their correct position completely loading the suspension correctly; or jounce the car on the suspension to set the wheels. Due to the IRS, this must be done on that end too. Then loosen the relevant suspension bolts and then jounce the car again to release and reset the bushings at the new position. Then torque to spec.

If there was built-in pre-load or some other assembly oddity, this process will correct it.

 

[BMR Tech]

So back in the day of Fox Mustangs, we had the same problem; lower the car without releasing preload on the bushings and the ride quality was in the dump and heights were uneven. Same thing with the first IRS cars.

Ford designed those rubber bushings with the rubber bonded to the shell and then placed serrated ends to dig into the chassis/suspension mounts. The bushings don't actually rotate in the shell - but twist like a spring (which they actually are in this mode). The twisting adds wheel rate resistance to the point of bind when the bushing can't twist further. Bad handling results occur suddenly.

When the springs are put in and the mounts not loosened, the new ride height is twisting the bushings as if going over a bump. So on the bump side of the suspension, there is not much twist left before bind. On the extension side, there is more movement before bind. In this case the situation often causes lopsided height as well as degraded ride quality.

The fix is similar to what BMR states, or replace the bushings with poly that rotates (generally a three-piece), delrin, or bearings. Each of these progressively creates more NVH.

I will add to all the advice given that from my experience doing this job many times, the car does not need to be level. The end you're working on needs to have the suspension loaded. If you raise the car to place on ramps, blocks, cribs, etc. you must either put a pair of greased plates under each raised tire (greased side between the plates as in a sandwich) so the wheels will move to their correct position completely loading the suspension correctly; or jounce the car on the suspension to set the wheels. Due to the IRS, this must be done on that end too. Then loosen the relevant suspension bolts and then jounce the car again to release and reset the bushings at the new position. Then torque to spec.

If there was built-in pre-load or some other assembly oddity, this process will correct it.

This is excellent information and I applaud you for it. :cheers:

As a chassis and suspension part manufacturer, we try to draw a line at some point on how far we go with our recommendations. You start splitting atoms and it can backfire on ya. lol

Bumping this bad boy to the top!

 

[whalesalad]

Bump!

I have seen the torque-spec thread with the photos that associate the names of various parts to what they actually look like.

Unfortunately they are referred to in many different places by many different names, so I am kinda confused!

I have a severe rake sitaution going on where the front tucks tire and the rear has a huge gap.

What specific things in the rear should I touch? The big ass nasty bolts that connect what I think is the lower control arm (the part that holds the bottom of the spring) to the subframe?

Photo:

 

[bobbyh]

Are there any photos of the bushings that need to be re-clocked?

There was mention of some photos of the parts but I did not see anything in this thread.

Thanks

 

[Coaster]

Are there any photos of the bushings that need to be re-clocked?

There was mention of some photos of the parts but I did not see anything in this thread.

Thanks

There is a pic in the first post of this thread: http://www.mustang6g.com/forums/showthread.php?t=47084

 

[BMR Tech]

Here is an updated pic that may help you guys out.

 

[BmacIL]

Anyone been successful at doing this on ramps? Seems like near impossible unless it's lifted at least 2 feet up.

 

[zuki_dan]

Anyone been successful at doing this on ramps? Seems like near impossible unless it's lifted at least 2 feet up.

[MENTION=10281]BmacIL[/MENTION]I have done it with my car on jack stands with the wheels off and sway bars disconnected. I used the jack under the brake rotor to compress the suspension until it barely lifted off the jack stand on the corner I was working on then loosened and tightened the suspension points that have rubber bushings.

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