Alfa Romeo Forums banner

1 - 14 of 14 Posts

·
Registered
'91 164L 3.0 V6 12V 5-speed
Joined
·
80 Posts
Discussion Starter #1
Changing shot rear bushes on my car and couldn’t find original rubber bushes for a reasonable price here so going to set up poly bushes for rear trailing arm (body and hub).

Question: those two washers that were between trailing arm and the bush and between the nut and the bush, are those needed with poly bushing? Are they affecting wheel alignment?
 

·
Premium Member
Joined
·
27,084 Posts
I would think you would want the big washer under the nut for sure for safety. Is poly bushing and/or steel bushing inside poly to wide?
 

·
Registered
'91 164L 3.0 V6 12V 5-speed
Joined
·
80 Posts
Discussion Starter #3
Yeah, under the nut makes sense and doesn't affect anything. It's not that the poly bush is too wide or anything, it flexes enough for sure, but I was wondering if the poly bush is wider than the original rubber bush and because of this it doesn't need or want the washer between bush and trailing arm. Maybe it changes camber?

Wheel alignment is due no matter what.
 

·
Premium Member
Joined
·
27,084 Posts
Yeah, under the nut makes sense and doesn't affect anything. It's not that the poly bush is too wide or anything, it flexes enough for sure, but I was wondering if the poly bush is wider than the original rubber bush and because of this it doesn't need or want the washer between bush and trailing arm. Maybe it changes camber?

Wheel alignment is due no matter what.
Lateral rods adjustable threaded ends used to set rear toe in to 4-6mm.
 

·
Registered
Joined
·
1,480 Posts
I would definitely keep those big washers, whether using poly or otherwise. Although very unlikely, the last thing you want is a bolt starting to pull through a bush.
 

·
Push hard and live
Joined
·
9,835 Posts
I’d avoid poly. Durability issues, and can add to bumpy and noisy ride.

OE style from a Classic Alfa quite reasonably priced. I’d recommend their “heavy duty” units, as the dimensions are more accurate.
 

·
Premium Member
Joined
·
14,228 Posts
I’d avoid poly. Durability issues, and can add to bumpy and noisy ride.
I have had poly bushings in the rear of my Spider for 15 years and about 75,000 miles with no problems. Richard Jemison drove it at Road Atlanta last year and posted on here about how well it handles.
 

·
Premium Member
Joined
·
2,839 Posts
The variability of experiences with poly is what always worries me.

We tried them in a racing car and they didn’t last 6 races. They may last for years in a less demanding environment.

I’ve chosen not to use them unless there isn’t an alternative.

It’s a personal preference item. Nobody is right/nobody is wrong.


Sent from my iPhone using Tapatalk
 

·
Premium Member
Joined
·
27,084 Posts
I had poly on all four corners of my 164S and they worked fine for almost 10 years still OK when I sold car this year.
 

·
Registered
Joined
·
3,057 Posts
Static toe in is set unloaded. Toe changes with compression caused by load in the rear seats and trunk. Also, toe in reduces tire wear resulting from negative camber when the rear is unloaded. Officially, camber is not adjustable.

I suspect but do not know that rear camber increases with suspension compression, a characteristic of strut suspension geometry. With fwd and a lot of negative camber at the front you want significant additional toe in as the rear suspension rises with weight transfers on lift off or braking.

Normally, toe in increases both under compression and extension of the rear suspension. This stabilizes the chassis during hard cornering and transient maneuvers. With fwd these characteristics are very important for predictable handlin. Indeed, an easy way to increase the agility of a fwd chassis for better track performance (and more, um, exhilerating street driving!) is to reduce rear toe in and possibly reduce negative camber gain. This is the "secret sauce" European chassis engineers use to create the various Renault Megane/Clio iterations with their alarming handling. Fwd touring cars used similar tricks to get their race cars to rotate through corners properly. Requires a lot of skill to survive though.

For the 164 toe at the rear changes with suspension compression because the control arm pairs are of different lengths. The forward arm tracks a shorter arc than the rear adjustable arm. The strut design will reduce toe in under initial compression and then increase it as the suspension compresses further. Extension will increase toe in as negative camber decreases
 

·
Premium Member
Joined
·
27,084 Posts
Do not use OEM for upper motor mount silent block bushing on top or rear head. Even freezing it in dry ice and heating the head bracket and having the factory install tool it is still a major disaster to try to install it. Use split poly with steel sleeve for that position. Ask me how I know!
 

·
Registered
Joined
·
1,480 Posts
With you on that one Steve. Did mine about 10 years ago with Powerflex and still perfect - took a while to chisel out old innards.
Have also had Powerflex bushes in the rear trailing arms, where mount to body and been working fine for almost as long.
In contrast, the Birth bushes put in the other end of the trailing arms a year ago already seem to have excess play.
 
1 - 14 of 14 Posts
Top