just replaced the trailing arms with Rotary Extreme links....nice improvement, especially off the line

however, there is still a little slop on/off the throttle at speed, which is probably the differential bushings.....at some point I'm going to throw Jim's nylon teeth shakers in there, but I'm wondering how long the stockers are usually good for? car has 65k miles

thanks

 

64.9k

 

congrats on the replacing the key big fat OEM rubber bushing in the rear trailing arm. i consider it an essential mod as the compliance toes the rear wheel in and out under braking and acceleration. very bad bad thing. i just run a nylon bushing in the stock aluminum arm but Rotary Extreme's product is excellent.

the other essential rear suspension mod is to replace the (again) big fat rubber bushings in the differential support. notice if you put a floor jack under the diff that the jack support pad moves up an inch before the car starts to raise..... not cool.

all this slop in the rear end comes to a screetching halt w a couple of nylon bushings. as to teeth shaking? you won't notice them after 5 miles of driving.

assuming you are running the right air pressure.... 30 front, 27-28 rear set cold.

good luck,

howard coleman

 

thanks Howard

 

I noticed the differential bushings for the Pettit launch kit are Delran....Jim/Howard do you have any comments on the use of this material vs. nylon?

quite a few people seem to put new stock bushings back in

 

See this is the bushing that I'm looking for. I already have the solid diff bushings. I wonder if Jim has any left?

 

Delrin is a brand of nylon made by DuPont, durometer should be about the same as the Nylon 6-6 used by Jim

 

I just replaced my diff bushings and feel I should have left the original 113k mile
bushings in.

The old ones were hard as hell and probably closer to a solid bushing than the new, and much softer bushings.

I thought I'd replace them, since I had the diff out.

 

I just swapped out my stocker diff bushings for the Mazdaspeed 40% stiffer units. The stockers had quite a bit of axial play available to them. You could stick a 1/4 inch drive extension in there and wiggle them around a bunch. The mazdaspeed are of the same design as the stockers (look identical) so are likely oil filled as well. VERY much more stiff than what I pulled out of there. The whole job took ~3 hours, pretty easy (12 ton H frame shop press helpd ). Follow Jim's directions in the suspension section. Hardest part was getting the nuts that hold the cradle to the pumpkin loose. Ended up gorrilla-ing them with a box wrench... knuckles still hurt.

The new bushings have a bit of road drone that wasn't there before. The tranny no longer hops up and down over bumps. The shifter feels like it's embedded in rock. Solid as hell. VERY glad I did this (along with the pillow *****, replacing shocks (with stockers) and spring seats, replacing inner lower spherical bushings... waiting on mazdaspeed trailing link bushings and toe link bushings from Ray Crowe). I HIGHLY recommend the mazdaspeed ones, though I have no reference on the nylon bushing noise issue...

 

nylon literally never wears out, that's the advantage....the vibration issue seems to depend on who you talk to

how much are the Mazdaspeed bushings? did you get them from Ray?

 

I got 'em from Corksport (360-260-CORK), $163.17 with tax and shipping, Their Item number 3rx-3-191, Mazdaspeed number F128-28-890. I hear you on the never wear out, especially for the diff application, guess I just don't want something that hard and buzzy. I drive on the street, not the track, so the nth level of performance is not as important to me as enjoyable ride, including not too much noise (so why am I putting up with this DAMN noisey Mazdatrix short shifter? Sigh...)...

 

thanks, the Mazdaspeed bushings sound like the best compromise for the street