D1 Alignment Question

mastercamper

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Nov 18, 2006
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Erwin TN
Finally got the castor correction bushings installed and I need to have the truck aligned. Is there thing special with these trucks to align them? I've had my D2 for 17 years and never had an alignment even after dong a lift.
 

terryjm1

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Jan 23, 2011
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I just installed caster correction radius arms but haven’t finished other suspension work yet. So, I haven’t driven it to evaluate the alignment. My thought, perhaps erroneous, is if all that changed was caster going back where it should be, an alignment isn’t needed. To those that know, please educate me.

Last time I changed suspension/steering parts I aligned it myself. It took a little time but I got it.
 

Flyfish

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Oct 29, 2004
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St. Louis
That shouldn’t affect your alignment. If it was off a little, it’s possible having corrected arms make it noticeable that you couldn’t tell before but that’s pretty doubtful.

Generally changing out tie rod ends is when it gets affected. But for road tracking and manners, tire wear etc, it’s not a bad thing to have it checked.

I got the Firestone lifetime alignment deal about 15 years ago so I could check it any time I made suspension changes.
 
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mastercamper

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Nov 18, 2006
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Erwin TN
I’ve driven it about 30 mikes and have more low speed vibrations than before and some about 60 mph. It cost a fortune to get this bushings installed and had a hard time actually finding someone to do it. Just need to sort out the vibrations.
 

Jimmy

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Apr 10, 2006
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Aurora, CO
I’ve driven it about 30 mikes and have more low speed vibrations than before and some about 60 mph. It cost a fortune to get this bushings installed and had a hard time actually finding someone to do it. Just need to sort out the vibrations.
Somewhat common to change one thing, which effects everything else, and have a vibe show up.
 

mastercamper

Well-known member
Nov 18, 2006
934
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Erwin TN
Somewhat common to change one thing, which effects everything else, and have a vibe show up.
Yep, if it ever stops raining i'll get under it and check everything out. I did notice they had to replace a bolt and used one that's about 2 inches too long. That's just annoying.
 

Jimmy

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Apr 10, 2006
740
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Aurora, CO
Yep, if it ever stops raining i'll get under it and check everything out. I did notice they had to replace a bolt and used one that's about 2 inches too long. That's just annoying.
One of the overlooked sources of issues when doing a change like this is worn u-joints in the driveshaft. They get used to running at one angle, then you change the angle and they don't like it. Doesn't always happen, but when you've exhausted the normal stuff, consider this.
 

p m

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Apr 19, 2004
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I’ve driven it about 30 mikes and have more low speed vibrations than before and some about 60 mph. It cost a fortune to get this bushings installed and had a hard time actually finding someone to do it. Just need to sort out the vibrations.

Even in factory configuration, the front transfer case shaft and the front axle pinion are not aligned; a spring lift contributes to increased driveline angle, but at least the pinion remains pointed where it was, more or less towards the transfer case. A side effect of using castor correcting bushings - not "common," it is guaranteed - is that the axle pinion is pointed downward, farther from the transfer case. It is rather uncommon for this not to promote front driveline vibration.

That is on top of these bushings having much shorter lifespan than factory ones, and lack of off-the-shelf replacement availability.
 

mastercamper

Well-known member
Nov 18, 2006
934
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Erwin TN
Even in factory configuration, the front transfer case shaft and the front axle pinion are not aligned; a spring lift contributes to increased driveline angle, but at least the pinion remains pointed where it was, more or less towards the transfer case. A side effect of using castor correcting bushings - not "common," it is guaranteed - is that the axle pinion is pointed downward, farther from the transfer case. It is rather uncommon for this not to promote front driveline vibration.

That is on top of these bushings having much shorter lifespan than factory ones, and lack of off-the-shelf replacement availability.
My pinion angle was way of I could pull the plug on the diff and fluid would pour out. The bushings brought it down so I'm happy with that. The vibration I have is at 30mph. Pretty sure the one that's around 60 is in the rear its not bad neither is audible at most.
 

p m

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My pinion angle was way of I could pull the plug on the diff and fluid would pour out. The bushings brought it down so I'm happy with that. The vibration I have is at 30mph. Pretty sure the one that's around 60 is in the rear its not bad neither is audible at most.
You are happy that the bushings made your diff hold more oil? That's a noble goal.
Don't think that a driveline vibration you feel at 30 mph doesn't exist at other speeds - it is always present, and the stress it places on the U-joints increases with the square of rate of rotation (or square of vehicle speed). Body/suspension resonances amplify it at different speeds and make it more or less noticeable.

IM(v)HO, caster-correcting bushings are the worst way to reconcile lift, handling, and driveline vibrations. You will likely need a CV/double cardan front driveshaft in future.
 

DarylJ

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Apr 3, 2011
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Doylestown, PA
IM(v)HO, caster-correcting bushings are the worst way to reconcile lift, handling, and driveline vibrations. You will likely need a CV/double cardan front driveshaft in future.

As someone who is finally getting around to re-bushing a 98 D1 that I put HD springs on long ago (which has sat behind my barn rotting for 6 years up until recently) what would you suggest?

What I'm doing is just rebushing and aligning to see how it reacts. I'm assuming I'm gonna get it on the rack and find the axle isn't centered so I'll need to put on an adjustable/longer panhard. And that's okay. I was just going to drive it for a while after each change and see if it was something I'm happy with since I have access to the rack whenever.

Right now it just has awful manners. Bump steer, diving under hard braking.......but all the bushings are too junk to know what's causing it.
 

p m

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Bump steer - how much lift do you have? Over 3"? If so, you could benefit from an adjustable/longer Panhard rod. I did it in my D1, with barely noticeable effect. Stay away from open-faced heim joints.
 

terryjm1

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Jan 23, 2011
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The D1 I am working on hasn’t seen the road in 12 years.As previously mentioned, I believe it has 3 inch lift springs and spacers under them giving something more than 3 inches of lift. The work was only about half done when I purchased it. I just installed caster correction radius arms with OEM bushings. While the u-joints feel ok, I am pretty sure they are not. i put it in gear with no wheels, on my auto lift. The front driveshaft is noisey. On the road I bet there would be lot of vibration. The u-joints won’t take any grease. It’s probably nothing but dried grease inside. New u-joints going in. Hopefully, the u-joints are the problem. But, I recognize a double carden driveshaft likely will be needed.
 
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DarylJ

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Apr 3, 2011
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Doylestown, PA
Bump steer - how much lift do you have? Over 3"? If so, you could benefit from an adjustable/longer Panhard rod. I did it in my D1, with barely noticeable effect. Stay away from open-faced heim joints.
Terra Firma HD springs, which supposedly are just 2". And that's all I have to go on because they actually lifted it anywhere from 2.5" to 3.5" at each corner with how bad the old springs were :) At least it sits level now.

Sounds like I should carry on with just getting the bushings back into shape and see how it goes.
 

mastercamper

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Nov 18, 2006
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Erwin TN
Terra Firma HD springs, which supposedly are just 2". And that's all I have to go on because they actually lifted it anywhere from 2.5" to 3.5" at each corner with how bad the old springs were :) At least it sits level now.

Sounds like I should carry on with just getting the bushings back into shape and see how it goes.
That's what happened to mine. No issues with steering just my diff angel.
 

terryjm1

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Jan 23, 2011
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Terra Firma HD springs, which supposedly are just 2". And that's all I have to go on because they actually lifted it anywhere from 2.5" to 3.5" at each corner with how bad the old springs were :) At least it sits level now.

Sounds like I should carry on with just getting the bushings back into shape and see how it goes.
I installed terrafirma springs on my 300tdi. It has a too heavy brush bar / bumper and the extra TDI weight up front. I was concerned it would sag over time up front. However, just the opposite has occurred after only 10,000 miles. It’s sagging in the back. I now understand why some people complain about terrafirma,
 

DarylJ

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Apr 3, 2011
440
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Doylestown, PA
I installed terrafirma springs on my 300tdi. It has a too heavy brush bar / bumper and the extra TDI weight up front. I was concerned it would sag over time up front. However, just the opposite has occurred after only 10,000 miles. It’s sagging in the back. I now understand why some people complain about terrafirma,
Fortunately I haven't had that issue (yet). I almost welcome it because HD springs were a terrible choice. The ride quality is just awful.

All I really wanted/needed was 2" of lift. I suppose I'll be shopping for something else eventually.
 

Gordo

Well-known member
if you have bump steer you may want to check the swivel preload and get it back in spec. Been a long time ago but that was the fix for my classic. I also installed an OME stabilizer which seemed to help. For the vibes, I'd be looking at the front ds if its around 30 and the rear ds if its around 60. Sounds like you may wanna look at both in your case.