Rear suspension
 

Just got done with all the front suspension brakes, calipers, rotors etc. gotta say very disappointed with brake performance. No real improvement over original.

Now for the rear. Is it easier or harder to replace all the bushings than the front? Front was probably a 4, 1-10, mostly due labor time.
Thanks

I had an easy time of it and this was the first time doing any work like that. I bought a $40 impact wrench at Harbor Freight and it made life way easier. For the Watts link, just make sure you have all of the right markings on it/mark it before you take it all apart. And take pictures!

Do you have drums or disk at the rear?

The rear is less work if you are not doing the 4 links from the chassis to the axle, otherwise its a 6 or 7
due to age and getting at the bolds for the links.

When you get everything snugged up (but not tight) put t he stands under the axle to let the watts link
and other suspension bits settle, then tighten them all up. If you don't do this, it can cause the rear
to sit high or offset due to the poly bushings binding a bit when new.

impact will make things way easier, also only going to larger brakes would really increase the performance

I just put my rear end back together on my build and used new poly bushings. It took a bit of finagling to get some of the torsion bars into the slots with the new bushings. The watts links were definitely the hardest to get in there. With the grease the bushings wanted to slide back out of the ends. I found that using my floor jack and a block of wood and the occasional rubber mallet strike helped press them into place and line up the holes. Good luck!

Thanks everyone, i do have drums in the rear, but will dive in once we get to summer and don't drive the car for a month or so.

I didn't expect much from the the new brakes but since the right side pad was bent and only a quarter of it was making contact it should be better. Maybe over time it will be better.

What kind of pads,rotors..have you allowed enough time,driven enough to bed in the pads? Even hi-performance brake upgrades need to be driven gently for a bit to allow parts to break in to realize full braking potential. Did you upgrade flexible brake hoses to stainless braided? This alone gives you better pedal feel and modulation. DOT4 fluid another upgrade,raises boiling point of brake fluid to help with brake fade.

If the rear drums are worn, out of adjustment, or have air in the lines it can really make a huge difference in brake performance overall.

I just had new front rotors and Hawk HP street performance pads installed on my 85 GS (drums in rear). I also had stainless steel DOT hoses installed all around. Only about 400 miles on this upgrade. Slight improve in pedal feel. Braking and modulation is improving as the set-up beds itself in. I did not expect it to match modern car braking; but my confident is much better given this upgrade.

Should be much better on autox and track days for sure.

I love this forum always very helpful. Only driven about 30 miles and I did follow manufacturers bedding in process.

Went with oem brake lines since I saw zero improvement when I added them to my F150, I know apples and oranges but can't imagine much change on such a light car. Once I replace the rear and bleed the entire system I'm sure I'll see the full potential.

Yeah Chris, the rear drums make a huge difference. Also the SS lines do make a difference
in how direct the brakes feel. They still work about the same just a bit faster reaction due
to the lines being rigid.

When you do rears just go ahead and get new brake cylinders, they almost always leak
with age and need replacing anyways and they are so cheap. New drum brake hardware is
a wise investment as well. The old stuff will probably be all grotty and scaley.

For your car, the auto adjuster will work to some extent but I would hand
adjust them as much as possible to get good initial pad contact.

When the brakes are all dialed in they work amazing well. Just have to keep on top of
maintenance and adjustement to keep the working well over the life of the pads/shoes.

Rear bushings are not replaceable, you replace the links. Get 'em now while they are still available.

If you've only driven 30 miles, your brakes are still bedding in. Especially on a manual trans car, I have found that it can take up to 1000 miles before the brakes are working optimally.

My 2c: replace the rear bushes with poly. The watts links bushes are easy. The lower trailing arm rubber bushes are best removed by burning them out with an oxy. This is the only hard part. The poly bushes are cheap and in my experience using Super Pro brand bushes, did not increase NVH at all.

However, LEAVE the factory rubber upper trailing arm bushes in place. Yes, you can replace the links as a whole, but the shagged rubber in the upper link combined with the poly elsewhere helps delay binding up of the rear due to the uneven watts link. The more shagged the rubber the better, so you are actually better off not replacing the links at all.

Never replace the rear suspension bushings with poly, they're too stiff and don't let the suspension move.

The rear suspension has significant geomety problems and requires compliant bushings in order to articulate. This is amplified if you remove the sway bar, the suspension goes from "moving" to "locked up" very quickly.

Don't forget the side effect of tearing off mounts from the axle or body when using the poly/sold bushings.. I just can the upper links/watts and go offset(to the right on the upper link) three link with a panhard bar..

Old rubber is stiffer than new rubber. Rubber gets harder as it ages. The aging process involves the light solvents evaporating away, reducing compliance.

Links ripping off may be exacerbated by stiff bushings but it is mostly because of rust (Mazda made several dirt shelves) and the fact that the rear suspension geometry sucks.

The best thing you can do is find an 18mm rear sway bar from an SA, to save the chassis.

Speaking of the rear sway bar... I was at at track day in the rain last week. My 85 GSL is set up with UHP tires (Yokohama S.Drive), racing beat springs, racing beat front/rear sway bars, and tokico blues. Drivetrain is stock except for RB exhaust. 30psi front and rear, 55-60 degrees ambient temps and constant drizzle keeping the track wet.

Nearly every corner the rear end refused to hook up and was snapping out. My instructor was helping me find better lines to avoid it, but there was just no rear grip. After two sessions I unbolted the rear sway bar. It didn't completely solve the grip problem but it smoothed out the transition and instead of knocking us about when the rear broke loose I could slowly apply throttle until I felt it start and then hold it there. It was much more predictable without the rear sway bar. Now, that was the RB rear bar on the softest (extensions at their longest). I wish I could have swapped in the factory bar to see if that caused the problem too. I've felt the snap with both bars on dry days but the wet track really magnified it.

A 2400lb car isn't going to hook up well in the rain, especially with a limited slip diff.

S.drives are also some of the shittiest tires you can get for the rain. I used to have a set, I really don't miss them.

Loosening the rear sway probably helped because you weren't able to get the suspension to lean enough to make the geometry problems noticable.

I have a set of BFG Sport Comp2s on my Volvo. 3200lb on 195/55-15s, and I can't get the ABS to activate under hard braking even in the rain, and this car brakes harder than anything I've ever owned. To the point that I love running up to 90mph on offramps just so I can roll into the brakes and feel the Gs that much longer.

This is pertinent, because it's been raining here pretty much all week, and I finally took my dried out bald old snow tires off and stuck the summer shoes on, and I've been all HAHAHA I AM GOD HERE with the rain. I almost feel bad for the plebes who don't have good wet tires. Almost.

(And this car only has 11" rotors on it. Imagine how much of an a-hole I will be when I find my S60R, which has gigantic Brembos and only weighs a couple hundred pounds more, kind of like an STi for people with thinning hair)