Trailing arm? Center link? Track bar? Not sure

Suspension related stuff goes in here.
moses
Posts: 34
Joined: Wed Aug 24, 2016 1:42 pm
Your car is a: 1976 Fiat 124 Spider

Trailing arm? Center link? Track bar? Not sure

Postby moses » Mon Aug 29, 2016 2:41 pm

On my '76, there's a rod on the rear that runs from one side of the suspension to the other. When looking at the suspension from the rear, it is furthest back and spans the width of the rear axle, on the side closer to the rear.

At some point, a previous owner decided it would be a good decision to pull the car by this rod, using a chain or hook. It's buckled now and needs replacing, but I don't know the exact name of this part.

Looking online at various sites, there are available parts called trailing arms, center links, track bar/panhard rod, and other similar-looking parts, but I want to make sure I have the right one.

I'll add a picture when I get home today, but does anyone know the name of what I'm describing?

And please excuse my ignorance. I'm not very good with suspension.

User avatar
opus10583
Posts: 861
Joined: Tue May 03, 2011 7:13 am
Your car is a: 1978 CS1
Location: Westchester County, NY

Re: Trailing arm? Center link? Track bar? Not sure

Postby opus10583 » Mon Aug 29, 2016 3:11 pm

Hi,

It's a Panhard rod, https://en.wikipedia.org/wiki/Panhard_rod.

It's supposed to be straight in your car, "kinked" or "bent" after 1978. You may have a the newer but incorrect spec.

Ciao,
Mark

moses wrote:On my '76, there's a rod on the rear that runs from one side of the suspension to the other. When looking at the suspension from the rear, it is furthest back and spans the width of the rear axle, on the side closer to the rear.

At some point, a previous owner decided it would be a good decision to pull the car by this rod, using a chain or hook. It's buckled now and needs replacing, but I don't know the exact name of this part.

Looking online at various sites, there are available parts called trailing arms, center links, track bar/panhard rod, and other similar-looking parts, but I want to make sure I have the right one.

I'll add a picture when I get home today, but does anyone know the name of what I'm describing?

And please excuse my ignorance. I'm not very good with suspension.
...Yes; I know what it means: Fabbrica Italiana Automobili Torino.

DOLCETTO: 1978 CS1; 10:1, DMS, 4-2-1...
ANDIAMMO: 2012 500 ABARTH

Acquista il Biglietto; Prendere la Gita! - Hunter S. Thompson

moses
Posts: 34
Joined: Wed Aug 24, 2016 1:42 pm
Your car is a: 1976 Fiat 124 Spider

Re: Trailing arm? Center link? Track bar? Not sure

Postby moses » Mon Aug 29, 2016 3:34 pm

opus10583 wrote:Hi,

It's a Panhard rod, https://en.wikipedia.org/wiki/Panhard_rod.

It's supposed to be straight in your car, "kinked" or "bent" after 1978. You may have a the newer but incorrect spec.

Ciao,
Mark


Thanks, Mark. I had a strong suspicion that was it.

On mine, it's the correct spec but definitely damaged. I can see the difference between the two types. Mine has a gouge and bad bend right in the middle where it was towed from. Time for a replacement!

Thanks again.

DieselSpider
Posts: 2130
Joined: Wed Dec 24, 2014 10:21 pm
Your car is a: 1978 124 Spider with Isuzu Turbo Diesel

Re: Trailing arm? Center link? Track bar? Not sure

Postby DieselSpider » Mon Aug 29, 2016 9:21 pm

moses wrote:
opus10583 wrote:Hi,

It's a Panhard rod, https://en.wikipedia.org/wiki/Panhard_rod.

It's supposed to be straight in your car, "kinked" or "bent" after 1978. You may have a the newer but incorrect spec.

Ciao,
Mark


Thanks, Mark. I had a strong suspicion that was it.

On mine, it's the correct spec but definitely damaged. I can see the difference between the two types. Mine has a gouge and bad bend right in the middle where it was towed from. Time for a replacement!

Thanks again.


How bad does it crab walk down the road. If that panhard/track bar is bent you won't be going down the road straight and the rear end will be more likely to swing out during hard braking.

Note that the alignment specs require the trunk to be weighted so the track bar will be at its laden position when they align it. Track bars by nature cause the rear track to shift slightly to either side as the rear suspension goes through it range of motion and can have a dramatic effect on the thrust line dynamics of the car when they are not right.

moses
Posts: 34
Joined: Wed Aug 24, 2016 1:42 pm
Your car is a: 1976 Fiat 124 Spider

Re: Trailing arm? Center link? Track bar? Not sure

Postby moses » Mon Aug 29, 2016 9:25 pm

DieselSpider wrote:
How bad does it crab walk down the road. If that panhard/track bar is bent you won't be going down the road straight and the rear end will be more likely to swing out during hard braking.

Note that the alignment specs require the trunk to be weighted so the track bar will be at its laden position when they align it. Track bars by nature cause the rear track to shift slightly to either side as the rear suspension goes through it range of motion and can have a dramatic effect on the thrust line dynamics of the car when they are not right.


Just posted this: viewtopic.php?f=14&t=34139

Should have thought about how bad this would affect it. A trailing arm is bent too, making it even worse. Just ordered a replacement, hopefully it doesn't take too much elbow grease to swap out.

User avatar
njoconnor
Posts: 614
Joined: Thu Jul 05, 2012 7:06 pm
Your car is a: 1972 124 Spider

Re: Trailing arm? Center link? Track bar? Not sure

Postby njoconnor » Tue Aug 30, 2016 7:27 am

Once you have the panhard rod and one of the trailing arms off, you're 40% into the rear suspension. Take a look at the bushings, and think about replacing them on all 4 trailing arms as well as the panhard while you have the car in the air. Toughest part is pressing the old bushings out/new bushings in if you don't have a press (I used a bench vise and a collection of sockets....and lots of dish soap....). Use lots of PB blaster on the bolts before wrenching.

Neil
Neil O'Connor
Madison, WI
72 FIAT 124 Spider
12 Jeep Grand Cherokee Overland Summit
14 Ram 1500 Laramie Longhorn Eco-Diesel
ex-71 FIAT 124 Coupe
and a host of Audi's, Saabs, VW's, MOPAR's, Fords, and a Bimmer....

DustyDave
Posts: 69
Joined: Fri Oct 19, 2018 9:12 pm
Your car is a: 1978 Fiat 124 Spider
Location: Greenville, SC

Re: Trailing arm? Center link? Track bar? Not sure

Postby DustyDave » Sat Oct 26, 2019 10:03 pm

To the comment on panhard rod being bent after 1978, what drives the need for a bent one vs. straight? I have a 78 and it appears to have a bent rod, though not sure that is the right one. The bend looks rough and looks as though axle mount point is also bent. Wondering if my car uses a straight rod, but it got bent somehow and not supposed to be bent. If I knew why bent is needed, I could check. Is it a certain differential type that requires the bend to get around? If so, Any way to ID what type I have? I see good pictures in this post with bent rod. I wonder if anyone has pictures of rod and differential with a straight rod, that would be helpful. Any insight would be greatly appreciated!
P.s. my car is not running yet, so can’t comment on how it drives.
Thanks, David

DustyDave
Posts: 69
Joined: Fri Oct 19, 2018 9:12 pm
Your car is a: 1978 Fiat 124 Spider
Location: Greenville, SC

Re: Trailing arm? Center link? Track bar? Not sure

Postby DustyDave » Sun Oct 27, 2019 8:12 am

ok, a little more research and I think I answered my own question.
Appears the change from straight (earlier) to bent (later) panhard rods occurred midyear 1978, which is the year of my car :shock:
So it seems the differential type changed from "pumpkin" or "hogs head" style that comes apart (earlier) to a style with that has an inspection cover (later). The lengths of the bars are also different: straight is 40" long eye to eye, and bent is 36.5" long eye to eye. Mount points are different as well.
I will check mine today and possibly post pictures.

resources:
https://www.mirafiori.com/faq/content/s ... ndswap.htm
Info on panhard rod listings from Midwest Bayless

DustyDave
Posts: 69
Joined: Fri Oct 19, 2018 9:12 pm
Your car is a: 1978 Fiat 124 Spider
Location: Greenville, SC

Re: Trailing arm? Center link? Track bar? Not sure

Postby DustyDave » Sun Oct 27, 2019 11:30 pm

I determined I have the 40" straight panhard rod with the earlier "pumpkin" style differential. All makes sense now, the bend in the current panhard is due to mishandling, and not the intentionally bent panhard rod.

redcars
Patron 2020
Patron 2020
Posts: 487
Joined: Sat Jul 31, 2010 9:36 pm
Your car is a: 1981 Spider 2000
Location: Collinsville, IL

Re: Trailing arm? Center link? Track bar? Not sure

Postby redcars » Mon Oct 28, 2019 8:38 pm

The latter cars have a larger diff and need the bent panhand bar to clear it.
1987 Lotus Super 7 clone
1981 Fiat Spider 2000 AT
1982 Fiat Spider 2000 5sd
1970 Fiat Coupe

ward00
Patron 2018
Patron 2018
Posts: 110
Joined: Tue Jan 23, 2018 5:30 pm
Your car is a: 1975 Spider

Re: Trailing arm? Center link? Track bar? Not sure

Postby ward00 » Mon Oct 28, 2019 9:20 pm

36.5" ouch.

You might be interested in reading this discussion on the mirafiori site. Lots of talk about the effect of lowering springs and such on how much the panhard shifts the rear of the car in either direction.

https://www.mirafiori.com/forum/viewtop ... 15&t=98735
75 Spider
75 Sport Coupe restoration


Return to “Suspension Related”

Who is online

Users browsing this forum: No registered users and 22 guests