Technical Question About 4-Bar Bushings

Afternoon Folks!

New to the site here, and recently got into my first open engine hot rod (1930 Ford). I’m working on learning everything I can, and getting into the hobby.

As I was doing my crawling around the car familiarizing myself, I noticed the rear side of my 4-bar suspension bushings are completely roasted. I mean gone gone. I removed the axle side bottom link of the 4-bar, and the axle slid forward about an inch.

I backed my truck up, and hooked a heavy duty ratchet strap to the axle and pulled it back in place to reset the bolt.

I want to replace all the bushings (tops are hell to get to). Is this normal for the axle to push like that? Or should I bring it to my local hot rod shop and have some geometry measured?

Any recommended do’s and don’ts of replacing my 4-bar bushings?

Thanks again for the help all, and I’m excited to be here.


-Willy

 

Speedway sells them..easy to replace.

 

Seems like rubber just ain’t what it used to be. There have been posts where the bushings disintegrated before the build was even on the road.

 

roger that. I just haven’t messed with 4-Link before. It made me nervous when I undid the bolt, a the axle moved forward on me. Is that a normal occurrence?

i backed my truck up, wrapped a ratchet strap around the axle and pulled it forward back in place.

 

Man you’re not kidding. These bushings are completely GONE. Just disintegrated

 

Call Cory at RJs speed shop. He was able to instruct me how to measure the bushings I needed. He got them to me in less that a week.

 

Sweet! Thanks for that!

 

I can relate to exactly what you mentioned, I believe what you have experienced is the norm however it might be advisable to converse with Teflon here on the Hamb as be is a bonified ch***is builder, & yes, several sizes are available so be aware of the proper bolt & bare end diameter. I opted for the Pete & Jakes brand as the word is they offer a better grade material, additionally they are available with or without the metal bushing insert, much cheaper if your inserts are in good shape. Good luck !

 

Thanks man! I went ahead and bolted it back together after I saw that axle move forward lol. Got nervous.

my first open engine, and certainly 4 link. Let me message @teflonhjarna.

Thanks again for the advice

 

Sorry WillyCG, I sent you down the wrong road, the ch***is builder was not teflon but rather Gary Mussman from Cornhusker Rod & Custom my mistake.

 

The human condition gets us all. Thank you for the guidance none the less!

is he on here?

-Willy

 

By the way Gary's avatar is Krylon32 here on the Hamb.

 

perfect, thank you again

 

Welcome
I replaced mine on the rear in my A Roadster and had to pull the backing plates to get to the upper rear ones. It needed an axle seal too....
just one rod end at a time
looks like you have coilovers and mine was a buggy spring...don't know if there are tricks to doing with a coilover set up
I hung the rear frame off of jack stands up enough so that the tires were off the floor just a little, pulled the wheels then put a floor jack under the axle side I was working on, just lifting enough to take the weight off the spring.....
then one end at a time....
I used a really long drift punch to m***age things so the bolt would align back up .... as necessary
work slow and methodical ...don't get horsy

disclaimer; I had pretty high confidence that the axle alignment was good and rechecked afterwards
only one way to learn is to do it

 

Killer info, and thank you so much. This is what I’m working with here (photos).

It made me nervous when that axle slide forward on me like that lol. I don’t know if hooking a ratchet strap up, and pulling it back in place is the right or best way. But it did work.

However even pulled back, the only way the screw fit in there was without a bushing, and the sleeve was allllll the way forward. That got me curious on the actually geometry of these setups, and questioning if it was even correct

 

Plastic bushings have a shelf life. I had Pete & Jakes fabricate a four-bar front suspension some 25 years ago. I've still not gotten the project on the road, but about three years ago I replaced all the bushings, which had rotted away in place. I think the new Pete & Jakes bushings are improved and have not had an issue with them.

 

Well, when you put the links up to the axle brackets, with no weight on the car, you should be able to fit all bolts in without pushing the axle around. Shouldn’t be stressed one direction or another. If it is, you are already directing the parts to wear out, and you haven’t even put any weight on the car.

I’d recommend unhooking the coilovers before you take the bars loose to replace the bushings.

 

I just went through this too. all of my bushing were smoked.... my 30 has TCI 4 bar front and rear. I ordered all new bushing from TCI.

When I did the rear I put the car on jack stands on my rear cross member (maybe you could just use jacks stands on the frame rails) and placed a jack under the differential. This helped me take the load off the 4 bar and made it pretty darn easy to R&R.


If using urethane bushings, dont use anything other than polyurethane bushing lube... some companies provide the lube, a lifetime supply will cost about $20 depending where you buy it.

I was overly cautious and did 1 bar at a time plus I marked each bar to ensure I put it back in the right orientation.

All in all it is a very easy job

 

Man…. You all have been so helpful. As I was saying, I’m a new guy and just got my first open engine. I’m going to follow you alls instructions on this; hopefully get it done with no headache.

when I took one end (rear bar) down the other day? I didn’t put it on jack stands, but rather put a floor jack under the dif and lifted the car maybe an inch off the ground.

when I put the bar back up? The holes were very misaligned, and the axle had gone forward probably an inch. So I had to hook a ratchet strap to the axle, and hook it to my other truck trailer hitch to get it back in place. Something about that just didn’t seem quite…. Right?


Maybe what I was missing was the frame rail support.

 

For sure you need jack stands under the frame rails when you are working on the rear suspension.

 

Got it. I usually do atleast for safety’s sake. It started as a “I’ll have a quick look”; then I dropped a bolt out, and that axle popped forward lol.

definitely an “oh ****” moment.

 

Before installing the new bushings, you might want to inspect the bore that the missing bushing fits into. I may be hammered from being run like that.

 

I agree with Alchemy. If it’s just a four link something isn’t quite right if it moved like that. What he said remove the shock and see if it’s forcing the axle. Presumably youve got a Panhard rod too but I wouldn’t have thought that’d do it but you never know. The links are going to set the pinion angle so you don’t really want to adjust them unless that’s wrong.

 

From what I understand from your first post, you had lifted the vehicle via the rear axle housing, then removed the Link bar bolt with the weight of the vehicle still on the suspension?

If so no wonder the axle rotated, you need the weight supported by stands under the frame rails and the coilovers disconnected before removing anything from the 4 link ***embly.

 

Cars are heavy. Stop and think about how the weight of the vehicle pushes on the parts just sitting there. You need to remove that weight from the parts you're trying to work on. It's like trying to replace a floor beam under a house while the house is sitting on it.

 

Another vote for Pete & Jakes bushings. 4 bar bushings are a wear part due to the stress imposed on them during suspension articulation. Good quality bushings are a must.

 

After replacing the "rubber " bushings on my roadster several times , I had a machinist friend to set up his CNC lathe and make them out of UHMW round bar stock...

 

From your pics it looks like the upper and lower brackets on the axle the 4-link ends attach to are different widths. The lower has more bolt threads showing.

 

I made my bushings out of Acetal rod and I haven't had a problem yet. Think about getting a lathe someday, they are so handy when working on a hot rod unless you have a machinist for a friend.

 

That does look odd. The sleeve inside the bushing controls the clamped width of the bracket, as you can see in the lower connection. Maybe a poor repair of another failed bushing by the previous owner.