7 replies to this topic

[Chris D.]

Hi All,

 

I imagine bushings are foremost in a lot of our minds now with the recent rule change.  So, I figured I'd bring up an old topic once again since I'm on the fence and could use some advice.  Since I'm already tearing into the front suspension to install the new offset bushings on the upper A arm, do I just go ahead and replace all of my ancient rubber bushings all around?   

 

There doesn't seem to be any consensus on this.   Some feel that older bushings may be better since the rubber has hardened over time.  I am leaning towards not replacing mine.   Plus Steve's recent photos of the latest bushings from Mazdaspeed are concerning to me.   Looks like they would be more compliant.

 

The only data I've seen on this I found in this old post from the old site:

 

http://forum.specmia...29;t=000058;p=0

 

This seems to support leaving the old ones in place.

 

On the other hand, if one were to do a complete tear down of a donor and convert it to an SM, wouldn't bushing replacement be standard practice?  I can't imagine the top builders out there replacing every wear item on the car except the bushings.

 

A little background......my car is '91 with 105k on it.   I bought it bone stock at 85k and converted it myself to an SM (so I'm VERY attached to it).   Any advice from others who have been down this road?

 

Thanks!

 

[James York]

It's very expensive to replace all the rubber suspension bushings.  I think the entire set is $700 or $800.  I am guessing you will never notice a difference and probably can find a better use for that money towards something on your car, data, coaching, .....

[dc2696]

Unless they were in a state of complete distress I would opt out of replacement just for the sake of it.

[Alberto]

With such low mileage on the car, I'd leave them alone.  Replace if they show play.  Otherwise, there is little benefit in going to new.  These bushings are quite robust.

[Chris D.]

Thanks for the input so far.   I am certainly leaning towards directing my money to a shock rebuild instead.   I'm going on several years on the same set.

[Ron Alan]

Thanks for the input so far.   I am certainly leaning towards directing my money to a shock rebuild instead.   I'm going on several years on the same set.

At least in my area, a shock "rebuild" is more than a new shock!

 

I'd like to know from an expert just what happens with age on these? Short of a seal break, does something on the inside go bad? Simplified, isnt it just fluid going back and forth through a hole or holes? I sent mine in after 2 years(they definitely needed new bushings)...now its been 5 years total. They seem to have done ok the last time out!  Sorry for the thread jack...dont forget your shock bushings gentleman!

[Alberto]

As I understand it from last time I had a shock rebuilt and custom valved (at Tri Point), the principal wear component is the oil in the shock.  Racing puts a lot of heat into the oil and it breaks down.  Beyond that, there is the shock rod that can wear - especially when the oil breaks down - and the various seals that slowly wear and stop sealing or get damaged from hitting big bumps.

 

I've been on my current shocks going on 5 years now.  Been meaning to get them rebuilt but... time and money...

[Tao]

hi all,    I discovered excess play in both the left and right side rear bushing.......soooooo I decided to replace every suspention bushing on the car....

after all of the discussion of older bushings being time hardened and better, it wasn't a decision I took lightly........I will report back on how a complete set of new bushings feel/handles

 

I found this youtube video on removing and installing Miata bushings...(search  "how to change bushings Miata).......the guy uses a plumbing nipple that fits exactly on the bushing housing for easy pressing in or out........made the job of changing all of the bushings fairly easy...

IMPORTANT hints if you use his method;  the plumbing nipple he list as 1 3/4"   is really a 1 1/2" ......there is no such thing as a 1 3/4 pipe size..( the discrpency is measuring outside diameter vs. inside diameter of this nipple)

I used 5' and 5  1/2" length bolts.....the 5 1/2" came in handy b/c I would double and triple the washers.

if you can find 7/16 bolts I would try them...they should fit better and be stronger...(didn't have them at my local home depot).

 

cheers

buy extra bolts and nuts.....a few of the bushings were stuck and I stretched the threads