Rear sway bar mounting point question on a '74

[tdskip]

Great thread Chris, very well documented.

I have a 3.2 in my '74, will need to double check fuel pump location.

Is the factory early style bar likely to present fuel pump fit issues, or is that more likely with the later ones?

I'm not going to be racing her, and can/will reinforce the factory mounts to box them in. That should hold up OK, no?

Thanks guys.

[tdskip]

Originally Posted by chrismorse

If you have an 18 mm rear bar, the front bar should be 20 mm. This bar set is the "Carrera" option. If the front bar is thinner, you willlikely have a lot more oversteer.

I have a 20mm bar on the front, was going to stay with a 18mm or 15mm from factory to keep things under (to the best of my sketchy abilities) under control.

[chrismorse]

Originally Posted by tdskip

Great thread Chris, very well documented.

I have a 3.2 in my '74, will need to double check fuel pump location.

Is the factory early style bar likely to present fuel pump fit issues, or is that more likely with the later ones?

I'm not going to be racing her, and can/will reinforce the factory mounts to box them in. That should hold up OK, no?

Thanks guys.

The factory bar will fit just fine, but the fuel pump mounting bracket is kind of in the way for welding in reinforcements. You may be able to sneak in there and get enough reinforcement welded up. On the advice of Grady Clay, i moved the mump up front.
The right mount was all twisted and ripped up, the left was cut, propably with a sawzall, as you can see inthe photo.

My dad bought the car new, and ordered the carrera bars. Even though he was a very conservative driver, the bigger bars still ripped off the stock mounts, so i think anyone with an 18 rear bar would be advixed to weld in more support before the sheet metal fatigues.

[chrismorse]

Originally Posted by tdskip

I have a 20mm bar on the front, was going to stay with a 18mm or 15mm from factory to keep things under (to the best of my sketchy abilities) under control.

If my math is right, the 18 mm bar is just a touch more than twice as stiff as a 15mm bar, (bar diameter to the 4th power for comparative purposes).
, so, it might be better to stay with the factory balance.

However, i drove the car for several thousand miles with no rear bar and the 20mm front bar and street driving was just fine.

With both bars, the car was much flatter and had better balance.

dazed and confused,
chris

[bkreigsr]

Originally Posted by tdskip

Thanks guys - I do weld so I'll look at making some reinforcing plates.

Can I switch gears a bit and ask about the rear bar I bought? This was listed and confirmed over the phone as being a "drop in" for my '74. I don't have access t the car and the bar in the same place, so forgive me for not actually trying it.
This looks right as it will push on to the mounting point on my trailing arm.

These drop links will work fine. They have already been modified to work with the later style 'bolt thru' bars. (See that bronze bushing in there?)
You now have to get a matching bolt long enough to go through everything and not have any slop in the drop link bushing (diameter-wise), once hooked up.
Bill K

[tdskip]

Originally Posted by bkreigsr

These drop links will work fine. They have already been modified to work with the later style 'bolt thru' bars. (See that bronze bushing in there?)
You now have to get a matching bolt long enough to go through everything and not have any slop in the drop link bushing (diameter-wise), once hooked up.

oh, and you have not been 'shafted' by a fellow Pelican.

Bill K

Thanks for the note Bill. Very willing to admit if I'm wrong here, and I am a newbie, but I got a 20mm stock bar and not 22mm front bar I ordered and paid for.

Again, hope I'm wrong here but I don't think the later year bar I received will work with the stock mounts on a 1974, will it? Won't the rear bar that I was sent require new mounts be fabricated?

[bkreigsr]

Depending on what hardware you received with the purchase, you should be good to go. In fact, those modified drop links will accept a range of diameters, whereas the stock - unmodified - links will only accept different diameters if you swap out the rubber bushings.
If you still have the mounts on the car you showed in your first post - you should not require any fabrication.
Again, if you are running anything heavier than the stock 18mm bar - keep an eye on the factory mounts and welds - especially if you have to really tweak it to get it back to spec.
btw how are you measuring the diameter?
fwiw, I'm using a 22mm bar from an 87 on my 77 with a modified drop link - no problems.
Bill K

[tdskip]

Hi Bill - thanks for the help.

I'm using a digital caliper measuring the bar at mid-point. Is that correct?

Here are some pictures of how the bar would need to fit based on what I have;

I didn't receive any mounting brackets, and please excuse the obviously incorrect bolt, it was just there to help mock it up.

The bar will be required to be mounted at a downward angle if that matters. Totally open for other ideas / corrections if I've got this wrong.

[bkreigsr]

That's the ticket.
do yourself a favor and replace those black bushings on the chassis mount. downard angle is normal.

Here's the bolt that I used: McMaster-Carr 95430A423 M12 x 80mm, 1.75 mm pitch, 10.9 Stl, hi viz Blue Hex Cap Screw. (of course any M12 x 80mm should work)
Bill K

[tdskip]

Bill - thanks for the coaching here. Glad it looks like I can make this work, even it ir require replacing the bushings and tracking down brackets that were supposed to be included.

Chet - another PM sent.

I sent the seller a note indicated that I got the details wrong on the rear bar and apologized for that.

[tdskip]

Hi guys - anyone know off hand what the bolt pattern is for the actual sway bar bracket mounts? I thought I found M8x18 but that is a bit of an oddball thread...

[Walt Fricke]

TD

The stock bolts to hold the U shaped sway bar bushing holder to the "welded to the chassis" bracket is M8x1.25 thread. That is the standard and common thread for 8mm bolts/nuts.

There is no such thing as an "18" metric thread, at least outside maybe Swiss watches. 18 threads per mm would be mighty fine indeed.

It is just possible that a thread length of 18mm would be adequate for this job. You need enough for a washer, two bracket sheet metal thicknesses, and the nut welded on the top of the chassis bracket.

Good news is that you can use longer bolts as long as they are full thread. There is room above the bracket for a fair amount of extra. If you don't have a bucket of old 8mm bolts saved from previous projects, just go to a decent hardware store and get some. Not a critical part like, say, a rod bolt or flywheel to crank bolt.

[tdskip]

Thanks Walt

[bkreigsr]

should be a regular M8 x xx(length) x 1.25 thread. the captured nut might be a nylock, or similiar type, so you can't finger tighten the bolt all the way home. Bill K

[Walt Fricke]

In fact, you want slightly longer bolts for this application, especially since you don't have adjustable drop links. There is apt to be some preload involved, so having longer bolts will allow you to draw the bar up into place without a huge struggle.

[tdskip]

Thanks Walt.

I do have a question on installing the drop link - do I tap the "cup" part of the drop link on to the ball shaped mounting point on the trailing arm? Assuming I should put grease in the "cup" part of the drop link before installing it (and cleaning the trailing arm mounting point).
.

[bkreigsr]

I use a broom stick cut to about 15" long (so it extends past the bodywork) under the springplate and give a firm rap with a BFH. I suggest you do that part first, then do the bolt-on part - adjusting the body height with a floor jack, if you have to, to get the holes to align. Bill K

[tdskip]

Originally Posted by bkreigsr

I use a broom stick cut to about 15" long (so it extends past the bodywork) under the springplate and give a firm rap with a BFH. I suggest you do that part first, then do the bolt-on part - adjusting the body height with a floor jack, if you have to, to get the holes to align. Bill K

Got it. How much and what type of grease to use in the cup?