Spring perches not level?

[Joe Blaze]

On my '71 Blazer, I just had my stock worn out front and rear springs replaced by a Tuff Country 2 inch lift kit from Suspension Connection. It seems like my rear axle spring perches are not level/horizontal now. I never looked closely at them before, so i cant be 100% sure if they are much different. The directions with the new springs say that the locating pin on the top is not exactly in the center of the spring between the shackles, and that the longer side on each one should go towards the rear.
Should the spring perches be perfectly horizontal, or is it OK that they are at a slight angle now?

[lolife99]

You might try asking in the 4x4 section.
I don't have the knowledge to help you, sorry.

[71blazerdetroit]

I must say at a glance something is wrong there,

1)did you measure from front eyelet to the center pin? make sure you follow the contour of the leaf pack.

2) mind posting a pic of your driveshaft? the pinion looks to be pointing towards the ground

3) the one pic showing your drivers side leaf looks as if its not tightened down

[71blazerdetroit]

sorry,
to at least answer your question, no the perches dont have to be level.

[72longbed]

Joe Blaze,
there's really only a couple of things that could have gone wrong here.

One is: are the springs actually installed backwards? Meaning, did you mistakenly install them with the rear eye on the front mount.

Since the center locating pin of the spring pack is closer to one end of the pack, you may have the spring turned around backwards, which would change the location and angle of your rear axle.

If the spring IS installed correctly, then what is most important is the angle of your u-joints in relation to each other. The u-joint at the front of the driveshaft needs to be at the same exact angle as the u-joint at the rear of the driveshaft. There are guys on here that know more about this than I do, but this is real important for your vehicle to drive down the road without binding and driveline vibration. I would check first to see that you have the spring pack installed correctly, then check your u-joint / pinion angles.

72longbed

[Stocker]

I checked my '72 K20 (I know, may not be the same as your Blazer) -- OEM except for rear AALs. Just crawling under it on the street, the locating pin seems awfully close to center. The spring perches angle down very slightly (your pics appear to have more of an angle) but the pumpkin (& pinion) are angle up a bit. Also, there is a spacer (about 1/2") between each perch and spring pack.

I believe lift kits 4" or greater require an angled spacer under the spring packs. I wonder if your 2" springs need them too.

[Joe Blaze]

The centering bolt on the new springs is not in the middle of the springs. See this note from the Tuff Country install instructions: Special Note: The new rear springs have an off set centering bolt, the longer end of the spring needs to be installed towards the rear of the vehicle. Here are some more photos of what's going on there. How does my driveline angle look?











While i was there, here are a few of the front driveline, how does it look?

[OLDCHEV4X4]

The rear yoke of the transfer case, and the yoke on the rear pinion have to be at the same angle. Remove drive shaft, and check with a angle finder. If the back dosent match the front, you will need a angle block between the springs and the perch to fix it.

Make sure the long side of the spring is to the rear.

[Mr. 250r]

The pictures are confusing me somehow but I know people do that on 4x4s to fix driveshaft angle because they don't want shims but it looks like that's what happened I could be wrong though
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[TheWhiteElephant]

The springs on my 4" Rough Country came with a shim. The thicker part of the shim goes toward the rear. As far as I know, and I'm no expert here, you shouldn't "need" a shim for a 2" lift.

[Joe Blaze]

I spoke to Warren at Tuff Country Tech support, and he wanted me to take photos and email them to him. He passed the photos among the crew there, and they said the pinion angle looked OK, and as long as I dont have any vibration problem, it was acceptable to have a slight tilt to the perches.

[72longbed]

Ok then. Drive it and see if you have driveline vibration, shimmy, etc. I checked mine and there is a 15 degree shim between the perch and the spring pack. I remember that I had the same issue after installing my 4" lift springs. The shim aligned the angles perfectly and the vibration went away.

Good luck with it.

72longbed

[kmk023000]

What was the final verdict on this? I am 90% done with my tuff country 4" lift and i have the same tilt issue in the back.

[72longbed]

You will have to finish the suspension and drive the truck on the road at various speeds to see if you have a driveline vibration. There is no way (that I am aware of) of predicting that you have it right until you actually drive the truck.

When these "running vibrations" show up, it is usually traced to the angles at each end of the rear drive shaft not matching. These angles are measured with the truck on the ground and with the 'load' in the truck that you will normally be carrying. I had mine checked with a full tank of gas and me sitting in the truck. Spare tires, tool boxes, ex-wives, favorite dog, etc., etc. ...., can make a difference in how the truck compresses the suspension, which in turn will change the driveshaft angles.

Good luck with it. If you know a really good truck shop that balances driveshafts on a regular basis, they will be able to help you easily if you have a driveshaft vibration. They understand pinion angles too.

72

[Joe Blaze]

I do have a noticeable noise that sounds like kind of a whir when I accelerate. Could that be a driveline angle-related noise?