Tuff country 4" lift. Pinion angles?

[Campbel45]

I'm currently installing a Tuff country 4" lift with rear springs on my 71 shortbox. Do I need to worry about front and rear pinion angles with this lift?

[Bigdav160]

My opinion is: pinion angles should be checked anytime the ride height is changed.

Correct angles are important to vibration free driving.

However, the more the lift, the shorter the life of your u-joints. They get overworked.

[Campbel45]

How should I go about finding and fixing these angles? I was hoping someone with a 4" lift would chime in if they had adjusted theirs

[LONGHAIR]

You can't do anything about the front without some fairly serious surgery.
If you put a tapered shim in there to raise the pinion, it will screw-up your caster angle. Then you will be back here asking "why does my truck wander all over the road?"

[americanmusc1e]

Originally Posted by LONGHAIR

You can't do anything about the front without some fairly serious surgery.
If you put a tapered shim in there to raise the pinion, it will screw-up your caster angle. Then you will be back here asking "why does my truck wander all over the road?"

BUT, the front driveshaft shouldn't be turning at highway speeds most of the time anyway. I'd leave the front alone unless it's really bad. The back is the main one you have to worry about.

[Campbel45]

Thanks for the info guys. How should I go about changing my pinion angle? I will google it after I post this. I know it involves using an angle finder which I have. I was thinking of finding my pinion angle before the lift and then after the lift remeasure it and whatever the difference is thats what I need in shims. Is this a logical way to go about it?

[tgh117]

I put a 4" lift on mine almost 3 years ago. On my trans crossmember there were some almost spacer looking things between the bolt head and the crossmember, so I took those and used them to space the crossmember down just a hair. I left everything else as it was, and other then needing some extensions for the emergency brake cables, and getting some new brake lines, I didn't do anything driveline angle wise.

My truck is more of a sunny day runner now, so its a rarity if I use 4x4, but everything functions as it should, and there are no vibrations.

[Bigdav160]

Yes

And tapered shims can be used to correct it.

Just be careful about the centering pin fully engaging the spring perch.

[Campbel45]

Sweet thanks!

[special-K]

I wouldn't worry about a thing with a 4" lift. I've never had any issues in any of the many 4wds I've run 4" lifts on (including shorter K/5s) that I did nothing but install and go.

['63GENIII]

Can a double card an joint be used in place of shims to help alleviate drastic front angles? I always wonder about any kind of shim or block set up on the front.
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['63GENIII]

Sorry I meant double cardan. Stupid smart phone!
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[obijuan]

pretty much all you need to know with a 4" lift.

[argonaut]

The rear wont be an issue because you are most likely running a single joint at each end. The offset provided by the lift springs will not affect relative angles much. The operating angle of the ujoints will be higher which means they wont live quite as long, but as long as they dont bind on full suspension droop you will be okay. If you do a shackle flip, then you'll end up rotating the axle.

In a 72 the front already uses a double joint at the transfer case. For this geometry the front pinion should point almost in line with the front drivshaft. So when you lift the front 4 inches it will mess up your pinion angle. You won't really know how much until you do it. On mine I was able to get away with a 4 degree shim up front to reach a compromise between the pinion angle and the caster angle.
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[obijuan]

Measure caster in its current non death wobble having state. After the lift match that measurement.
Betting you wont even touch it.

[Mr. 250r]

Im pretty sure some lift blocks are actually machined at an angle i believe both of mine are but ill double check so dont quote me and.... death wobble is so fun lol

[argonaut]

Keep caster angle at at least 4 degrees with respect to the ground and you'll be fine.
I can't say that I've ever experienced this "death wobble" personally but my assumption is that it is caused by poor suspension and steering geometry. I run 35" tires on a dana 44 front axle with a bolt in shim giving around 4-5 degrees of caster and it is smooth as silk at all speeds with no steering dampers. Also make sure you properly torque all u-bolts as non torqued bolts can add to vibration and oscillation.

Personally I only use short blocks and shims that bolt into the leaf pack. You can get angled shims at multiple angles pretty cheaply from partsmike.
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[special-K]

I've never had death wobble in any of my trucks. I've never lifted past 6" and that was on longbeds or Suburbans. I never did anything about angle adjustment on those,either,and never had an issue. Right now I am running a 4" spring lift on an '85 Jimmy w/14-bolt rear using a conversion u-joint and the transfer case is the longer slip-yoke type (NP208). I have no angle issues in that set-up. Been that way for 3 years now.

[Mr. 250r]

Both of you say you've never had death wobble so I have to ask have you ever had a dana 60? 44/10s don't seem to have an issue with death wobble now im not saying its non-existent with them im just saying compared to a dana 60 its nearly non-existent lol because they almost always seem to have them

I ran my suburban with unbalanced bias ply 38.5s super swampers up to around 70 with a 4in lift and never touched any pinion angles and never had a problem with my 10 bolt, swap in the dana 60 instant death wobble which is caused by many things but most notably the kingpin springs

[special-K]

I had an '84 K30 for about 5 years and have had trucks I installed Dana60s in. I've known of others with this problem,just been lucky with my own,I guess.

[argonaut]

As with anything, keeping your components in good condition is always the first step in having a functional machine. Then second is a properly engineered setup.
Just my humble 2 cents.
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[obijuan]

I run exclusively leaf sprung gm 60 fronts. Make your leaf spring pad parallel to the ground. Caster is set in the C. Its a no brainer to set up. Alignment is pretty large tolerance as well. Wild tires and wore out steering ends as well as wore out leaf bushings. the front upper shackle hanger is often overlooked.
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[Campbel45]

Well got the axle back in with the lift kit and its only off by 1 degree so I think I will leave it alone. But this has all been great info! Thanks guys!

[jjzepplin]

Had the death wobble on my 60- put a double stabilizer on it and those 36's stayed put. I guess a stabilizer does exactly that. I put a double cardan on the rear and pointed the dif toward the t-case and that thing has been flawless for ten years of burnouts and slammin gears towing trailers and my g80 has been hanging tough too (14bolt)

[Campbel45]

Hey guys what do you think about this shackle? Before the lift it was almost straight up and down. The directions for lift to use the longer side of the spring towards the back. I measure it out and did just that but the directions are kinda vague. Kinda scared the shackle will hit the mount. Think I'll be okay?