Adjustable panhard rod - educate me :)

alex

alex

Well-known member
Apr 29, 2004
2,310
0
Libertyville, IL
It is not difficult to modify the cat if you need to. The hardest part about it is removing and reinstalling the y-pipe. It helps that the stock cats have the catalyst in the forward part of the cat--the back (the part that interferes with the driveshaft) is empty.

If you want, I have a y-pipe with that has been modified to to clear a larger driveshaft sitting in my shed. The pipe is used, but the catalysts are new, less than 1000 miles on them. I had it rebuilt at a local shop. I can show you the what you need to do, or trade you for a new (or similar mileage) y-pipe.
 
alex

alex

Well-known member
Apr 29, 2004
2,310
0
Libertyville, IL
I don't know how much interference Steve has, but the issue I was having would not be fixable by a zerk. I was getting rubbing with only a couple of inches, if that, of compresing of the front suspension. Flexing out the front wanted to put the driveshaft and the cat in the same space, in a big way. The modified pipe fixed the problem, with no ill effects on the cat. After that, the DDC shaft worked great. I could drive 80mph with no driveline vibes--at the time my truck had 5" lift and 35" MTs. YMMV.
 
T

Tortuga

Member
Aug 23, 2017
11
0
Long Beach,CA
From what I have been reading you do not need an adjustable pan hard rod on a 2004 Disco. Is this correct? I know this is a really old thread. Just hoping to get some clarity. Atlantic British sells one for the 04 D2 in non adjustable. I have a 4 inch lift and I can't tell that anything is off with my axle.
 
cdansan

cdansan

Well-known member
Sep 15, 2008
537
0
Northwestern, Vermont
Measure from the opposite frame rail to something fixed like the brake rotor, you will find that axle offset to one side.
The offset just gets worse as the axle travels down from ride height.
 
p m

p m

Administrator
Staff member
Apr 19, 2004
15,627
859
58
La Jolla, CA
www.3rj.org
Tortuga said:
From what I have been reading you do not need an adjustable pan hard rod on a 2004 Disco. Is this correct? I know this is a really old thread. Just hoping to get some clarity. Atlantic British sells one for the 04 D2 in non adjustable. I have a 4 inch lift and I can't tell that anything is off with my axle.
Click to expand...
Front suspension on a D2 is no different from D1 or RRC.
Do you _have to_ have an adjustable (or correct-length) Panhard rod with 4" of lift? No.
Is your axle shifted sideways with the stock Panhard rod? You bet.

IIRC, the one I have now is a TerraFirma unit, with proper rubber bushings on both sides. Can't tell if it was worth it, but I have between 1.5 and 3 inches of lift, depending how and where one measures.
 
D

DiscoPhoto

Well-known member
Jul 23, 2012
2,581
76
Vermont
04 D2s are unique in that the distance between the panhard mount on the chassis and axle is fixed, it does not change based on lift, or articulation.
 
seventyfive

seventyfive

Well-known member
Jan 3, 2010
4,280
100
over there
facelift d2's have a longer panhard rod...don't know what zach means by what he typed.

fwiw, the additional length needed is pretty minimal. if you have access to a welder, drill press, and saw you can cut the panhard and sleeve it. the adjustable is fancy but not needed.

1) get a used panhard for a couple bucks.
2) cut it closer to the frame end.
3) take a sleeve tube and slide it over the panhard
4) wiggle the truck side to side, let it settle.
5) take a quick measurement to verify the chassis is sitting over the frame equally.
6) tack weld the sleeve. remove panhard and weld properly.
7) install panhard.
 
R

robertf

Well-known member
Jan 22, 2006
4,786
360
-
seventyfive said:
facelift d2's have a longer panhard rod...don't know what zach means by what he typed.

fwiw, the additional length needed is pretty minimal. if you have access to a welder, drill press, and saw you can cut the panhard and sleeve it. the adjustable is fancy but not needed.

1) get a used panhard for a couple bucks.
2) cut it closer to the frame end.
3) take a sleeve tube and slide it over the panhard
4) wiggle the truck side to side, let it settle.
5) take a quick measurement to verify the chassis is sitting over the frame equally.
6) tack weld the sleeve. remove panhard and weld properly.
7) install panhard.
Click to expand...


so some fact and speculation on that...

the 03/04 has a longer transmission, moving the transfer case front output further away from the front axle.

the 03/04 has a different part # for the axle housings, I suspect this is to adjust the radius arm bracket angle so the pinion is pointing at the correct spot to keep the driveshaft vibrations away.

The panhard is awfully close to the diff "cover" as is. if the cover moved up in relation to the panhard like it would have to when correcting for a longer distance to the outputshaft, it would almost certainly make contact when on the bump stops.

This is why I think the 03/04 has a longer panhard (and drag link)

I also don't know what zach typed. he described how a watts linkage works
 
seventyfive

seventyfive

Well-known member
Jan 3, 2010
4,280
100
over there
robertf said:
so some fact and speculation on that...

the 03/04 has a longer transmission, moving the transfer case front output further away from the front axle.

the 03/04 has a different part # for the axle housings, I suspect this is to adjust the radius arm bracket angle so the pinion is pointing at the correct spot to keep the driveshaft vibrations away.

The panhard is awfully close to the diff "cover" as is. if the cover moved up in relation to the panhard like it would have to when correcting for a longer distance to the outputshaft, it would almost certainly make contact when on the bump stops.

This is why I think the 03/04 has a longer panhard (and drag link)

I also don't know what zach typed. he described how a watts linkage works
Click to expand...

never really looked too hard at the reasoning...always assumed to have a longer flatter panhard for better suspension geometry.

didnt even know the difference until denny made me one of his cross steer set ups. that's when we realized the pre facelift chasis side mount hangs down lower. i had to cut that mount and drill a new hole...for the panhard.

id have to look at my '03 to see if the axle mount is higher than '99-'02.

after lengthening my panhard i realized i should have just hockey stick'd the panhard to keep the axle from shifting while articulating.
 
p m

p m

Administrator
Staff member
Apr 19, 2004
15,627
859
58
La Jolla, CA
www.3rj.org
seventyfive said:
after lengthening my panhard i realized i should have just hockey stick'd the panhard to keep the axle from shifting while articulating.
Click to expand...
You do know that the only thing that matters for geometry is the distance between the axes of panhard rod bushings, right?
In other words, lower or higher frame- or axle-side mount location cannot be substituted for by a hockey stick rod.
 
seventyfive

seventyfive

Well-known member
Jan 3, 2010
4,280
100
over there
p m said:
You do know that the only thing that matters for geometry is the distance between the axes of panhard rod bushings, right?
In other words, lower or higher frame- or axle-side mount location cannot be substituted for by a hockey stick rod.
Click to expand...

Yes I do....I was trying to get this thread going a bit... was hoping frank would've caught that and chimed in. It's been a while since we had some good hazing and shit talking.
 
D

DiscoPhoto

Well-known member
Jul 23, 2012
2,581
76
Vermont
fishEH said:
How's that?
Click to expand...

Lol. I was being facetious, pointing out how absolutely absurd the comment was. It's a fixed length rod, if you change the height of any Discovery, it's going to extend or shorten the distance between the two mounting points.
 
D

discostew

Well-known member
Sep 14, 2010
7,713
1,016
Northern Illinois
Tortuga said:
From what I have been reading you do not need an adjustable pan hard rod on a 2004 Disco. Is this correct? I know this is a really old thread. Just hoping to get some clarity. Atlantic British sells one for the 04 D2 in non adjustable. I have a 4 inch lift and I can't tell that anything is off with my axle.
Click to expand...

The panhard rods job is to keep the axle centered under the frame. To keep the axle centered under the truck, you need to compensate for the fact that you changed one side of your triangle(height) so you need to change the length of the panhard rod to keep the third side(your axle) centered under the truck.

Somebody was saying in this thread the panhard rod pushed the drive shaft into his converter. Sounds like he didn't use the adjustable panhard rod to center his axle.
 
Tugela

Tugela

Well-known member
May 21, 2007
4,756
563
Seattle
Thread Resurrection Sunday:

What are the options on the market worth looking at for an adjustable panhard rod these days? I see TerraFirma. Anything else to consider?
 
  • Like
Reactions: terryjm1
You must log in or register to reply here.
Top Bottom