Rear axle drop when car lifted.

[jlwdvm]

Is there any way to prevent the rear axle from sagging all the way down to the end of the shock travel when jacking up the car? I have a Ride Tech 4-link and coil overs in my 69 firebird project that is always going up and down on my 2-post lift. When the car goes up, the rear goes down until the shocks are extended all the way out and the springs unload.

[DBasher]

http://www.summitracing.com/parts/tgi-111271-kit?seid=srese1&gclid=CLbWwJSojMkCFYeCfgod1eADVg&ibanner=MobileSwitchNo. :thumbsup:

[randy]

are you trying to do something or prevent something?

[Vince@Meanstreets]

Is there any way to prevent the rear axle from sagging all the way down to the end of the shock travel when jacking up the car? I have a Ride Tech 4-link and coil overs in my 69 firebird project that is always going up and down on my 2-post lift. When the car goes up, the rear goes down until the shocks are extended all the way out and the springs unload.

what are your current spring specs? length weights

[jlwdvm]

Not sure what my spring rates are, but the coil overs are what came with my stage 2 kit from Ride Tech for a 1st gen F-body. The shocks are single adjustable. I am trying to prevent the shocks from being completely unloaded when I lift/jack up the car. When this happens, the weight of the rear end is held by the unloaded shocks. Also, since the springs are completely unloaded as well, I have to be careful that they pop back into place as I place weight back onto the suspension. Since I am still in mock up/assembly stage, I placed the rear at ride-height and then used a rope on each side to secure the rear axle to the old rear snubber bolt hole and tied tightly. This prevents the axle from being able to drop. The straps mentioned earlier might be the answer.

[dontlifttoshift]

Replace shocks with these until you are not in the mock up phase.

http://static.speedwaymotors.com/RS/SR/Product/36/91636037_L_181d4d18.jpg

http://www.speedwaymotors.com/Coil-Over-Shock-Mock-up-Tool,57416.html

FWIW, you are not hurting anything with what you are doing right now.

[dhutton]

I don't think your springs should be falling out of place at full drop. Add keeper springs that are made to prevent this.

Don

[carbuff]

I recently added the zero-pound springs to my rears. Over time, the spring started rubbing through the shock body on my Ridetech shock bodies when they unloaded, to the point that I sent them back to RT and had them rebodied. These are simple to install, although not exactly a cheap solution, and they allow full droop on my setup without unloading the spring.

https://www.pegasusautoracing.com/images/L/1876.JPG

You also need these:

https://www.pegasusautoracing.com/images/L/1877.JPG

It ends up being about $160 for a set for the 2 rears...

Here they are installed and assembled:

http://i100.photobucket.com/albums/m23/carbuff69/1971%20Firebird%20Formula%20-%20Project%20TOW/IMG_20150924_193148_zpsadd89vrs.jpg (http://s100.photobucket.com/user/carbuff69/media/1971%20Firebird%20Formula%20-%20Project%20TOW/IMG_20150924_193148_zpsadd89vrs.jpg.html)

http://i100.photobucket.com/albums/m23/carbuff69/1971%20Firebird%20Formula%20-%20Project%20TOW/IMG_20150926_194421_zpsanrthfye.jpg (http://s100.photobucket.com/user/carbuff69/media/1971%20Firebird%20Formula%20-%20Project%20TOW/IMG_20150926_194421_zpsanrthfye.jpg.html)

[dontlifttoshift]

Smh......

[dhutton]

Smh......

http://www.summitracing.com/search/product-line/eibach-ers-helper-springs

:stirthepot:

Don

[dontlifttoshift]

Why does a project car on jackstands (in this case, a lift) need tender springs?

[Build-It-Break-it]

I spy with my little eye a Ron Sutton sticker on those ride tech shocks:goggles:

[dhutton]

Why does a project car on jackstands (in this case, a lift) need tender springs?

It doesn't but assuming he has it set where he is going to drive the car I don't think he should leave it in this condition.

Don

[dontlifttoshift]

.....and I am assuming that since it is a project car, it is far below finished weight........

[jlwdvm]

Weight has nothing to do with my problem, and I will still have the problem every time I want to lift the car on my 2-post lift once the car is finished. When the car is lifted up from the frame, the rear drops until the shocks/springs are completely unloaded and the rear is hanging from the fully extended shocks....the 4-link allows for this, which is different than when the car still had leaf springs. Leaf springs will only allow for limited sag of the rear axle when the car is lifted...no where near the limit of the shock. I've had steel tubing to take the place of the shocks when mocking things up.

[marolf101x]

It's perfectly fine to hang the rear end from the shocks. They can take it.

You should not have a free spring when the car is off the ground. . .there should always be a slight bit of preload.
5.2" stroke shocks use either a 10" or 12" spring. If for whatever reason your spring is not preloaded at ride height (make sure the shock is roughly 14.5" from eye-to-eye at ride height) we have 12" springs that can be used, or we have a drop spring cap to take up some slack.

Can you tell me the measurement of the shock at ride height?
How about the spring free length?
How about the spring rate?

[TheJDMan]

I have been around and around with this discussion with my G-Link. I first installed a set of Speedway Motors take up springs similar to those listed earlier. This kept the main spring in place at full drop but once I installed the exhaust the full drop would allow the drive shaft to come in contact with the mufflers. At that point I had to install limit straps similar to the ones listed at the beginning of this thread to limit the shock extension to 14". I currently still have both devices installed in the car.

Take up spring
http://www.speedwaymotors.com/AFCO-27005-Coil-Over-Take-Up-5lb-Yellow-Spring,24622.html

[dontlifttoshift]

OP, it seems you have two concerns.

1. The rear end hanging from the extended shocks. Like Marolf said, non issue. The shocks are perfectly capable of supporting the weight and there are hundreds of OEM applications where the shock runs out of travel in extension before the spring or suspension does.

2. The spring unloading from the seat. This is common as well, see above posts.

I have no idea what state of build your car is in but I assure you, weight has everything to do with it. If you are missing glass, upholstery, fuel, etc you will not have enough weight to load the spring properly at ride height. When all of that weight is added, you will need to adjust the spanner nut to preload the spring to get ride height back. At that point, you may find that you don't have a problem at all.

[marolf101x]

^^^^ this!

[raustinss]

OP, it seems you have two concerns.

1. The rear end hanging from the extended shocks. Like Marolf said, non issue. The shocks are perfectly capable of supporting the weight and there are hundreds of OEM applications where the shock runs out of travel in extension before the spring or suspension does.

2. The spring unloading from the seat. This is common as well, see above posts.

I have no idea what state of build your car is in but I assure you, weight has everything to do with it. If you are missing glass, upholstery, fuel, etc you will not have enough weight to load the spring properly at ride height. When all of that weight is added, you will need to adjust the spanner nut to preload the spring to get ride height back. At that point, you may find that you don't have a problem at all.

Now we won't say donny is smart....he's just not stupid lol
He is right thou

[TheJDMan]

The OP is concerned about the excessive amount of rear end drop when the car is raised on the lift. His question isn't so much about being concerned over hanging the rear end from fully extended shocks but more so the fact that the springs come unseated when the car is lifted off the ground. I had the exact same issue with my G-Link and complete or incomplete when the car is raised off the ground the rear end drops too far. In my case the rear end drop was so excessive that the drive shaft came into contact with the mufflers while also unseating the springs hence the need to install the take-up springs and limit straps.

To the OP, install a pair of take-up springs and limit straps and you should be good to go.