how to: diff bushings
 

alright. . . i got these urethane bushings from fdnewbie as a beta test. first of all. . . thanks ramy!!!! they installed great. . . 2nd, i cant drive the car due to some exhaust issues that happened during the installation. :D it sucks. . . just make sure you dont do custom work BEFORE you make sure the engine and transmission and differential and ppf are in good straight lines. ;(

anyways, the construction is great. . . sorry, i didnt get any pictures of the bushings themselves. . . i thought i had. . . anyways, heres the deal:

first youll need to jack up the car. . . all i did was the rear. no real need for the rest of the car to be up in the air unless youre planning to do something else. . . as i will be doing. :/ take off the catback while youre doing this. . . after the cars jacked up. ;)

then, take off all the covers in the rear. this will show the braces that need to be removed in order to get the job done.

http://216.77.188.54/coDataImages/p/...528241diff.JPG
http://216.77.188.54/coDataImages/p/...528292diff.JPG
http://216.77.188.54/coDataImages/p/...528313diff.JPG
http://216.77.188.54/coDataImages/p/...528334diff.JPG
http://216.77.188.54/coDataImages/p/...528355diff.JPG

then, jack up the rear end. . . just support it. . . anyway will do fine.

once supported, loosen the bolts/nuts that hold the diff bushings to the subframe.

http://216.77.188.54/coDataImages/p/...528366diff.JPG
http://216.77.188.54/coDataImages/p/...528397diff.JPG
http://216.77.188.54/coDataImages/p/...528418diff.JPG
http://216.77.188.54/coDataImages/p/...528449diff.JPG
http://216.77.188.54/coDataImages/p/...284610diff.JPG

i found that going directly below the nuts/bolts was the best and easiest way. . . still tight. . . but the easiest none the less.

after the diff bushing bolts are out, lower the differential until it rests on the rubber stoppers that are on the subframe or something. . . youll see them. :D

now, its time to loosen the bushing bracket from the top side of the differential. i found it to be easier to do ALL of them from the passenger side. like so. . .

http://216.77.188.54/coDataImages/p/...285011diff.JPG
http://216.77.188.54/coDataImages/p/...285212diff.JPG
http://216.77.188.54/coDataImages/p/...285313diff.JPG

once you get all 4 nuts undone, take the bracket out through the passenger side. . . this is just about the ONLY side with any room. geh.

and here you have the culprit. . . the clunk maker. . . the back breaker. . . bleh. . . the diff bushing bracket. :D

http://216.77.188.54/coDataImages/p/...285514diff.JPG

notice the cracked action on my bushings. . .

http://216.77.188.54/coDataImages/p/...285715diff.JPG
http://216.77.188.54/coDataImages/p/...285916diff.JPG
http://216.77.188.54/coDataImages/p/...286017diff.JPG
http://216.77.188.54/coDataImages/p/...286218diff.JPG

now, just find someone with a press. . . that should be easy right???? hehe. . . garfinkle to the rescue. :D

http://216.77.188.54/coDataImages/p/...286719diff.JPG
http://216.77.188.54/coDataImages/p/...287020diff.JPG

heres a picture of the nasty old turd. . .

http://216.77.188.54/coDataImages/p/...287621diff.JPG

and a comparo. . .

http://216.77.188.54/coDataImages/p/...287922diff.JPG
http://216.77.188.54/coDataImages/p/...288123diff.JPG


and a picture of what your wife will do once she catches on to the fact that youve spent so much time on your car!!!!!

http://216.77.188.54/coDataImages/p/...6angrywife.JPG

alright, i hope that was a good enough write up. . . sorry if i missed anything. the installation is obviously the opposite of the removal and pretty much straight forward. i didnt think it was as hard as everyone else mentioned, but i could see how it could turn into a task. :D

once i get road worthy again, ill take the car out and let everyone know how they feel. one thing i noticed already is how STIFF the diff is. . . and should be!!! my other bushings allowed me to push on it with just my hands. . . moving it about 1/4 inches. yikes!!!

hahaha, anyways. . . i hope this helps some people out there. . .

paul

and thanks to ramy, here are some pictures of the bushings UNinstalled. ;)

http://img.villagephotos.com/p/2004-.../bushings1.jpg
http://img.villagephotos.com/p/2004-.../bushings2.jpg

of course. . . they have some pretty hefty pins in the center.

nice. this was one of my all time favorite mods. im putting on some AM trailing arms from eyecandy this week. i hope it makes it even more fun to drive.

were you able to notice any kind of a difference after you installed new or upgraded diff bushings? i cant wait to find out what its like. :D

paul

yes it cleared up almost all the drive line slop. the car also did not pull to the side in the rear on hard launchs. they make a slight whine noise, but it sounds pleasant at times.

As an aside, you CAN get to those bolts that mount the bracket to the subframe through the suspension from the side. Pull the wheel and get a nice long extension. Also allows proper torqueing.

I went with the Mazdaspeed bushings... very nice. Shifting feels like moving a lever in a rock, really solid. Good mod, though the trailing arm bushings were better (REALLY feel that clutch engaging :) )

yeah, i thought about pulling the wheels off, but decided to just leave it alone. . . haha, lazy i guess. :D

i cant wait to see what it feels like. . .

well, the bushings feel great. no more slop. everything feels nice and positive.

the FIRST thing i noticed was when i was backing out of the road that leads to my house. . . there was a definite "whine" sound. i assumed it was going to be a little more noisy. the loudest is while in reverse.

while going down the road, i no longer hear clunks or feel shimmies. the car feels a lot more solid now. there is a TINY bit of whine. kinda low pitched. . . but not too bad. if i had my radio on. . . i wouldnt notice it. OR if i still had tortoise launcher catback on there. . . i doubt id notice it.

i do understand that a major reason for this to be SUCH an upgrade for me is that my old bushings had already failed. i can say this however. . . stockers WILL fail. these. . . should last A LOT longer. . . theyre solid.

over all. . . i love em. no reason to take em out. i dont know what it feels like to have metal in there, but i can assume its not something i really care to deal with. this was nice. . .

BIG THANKS TO FDNEWBIE FOR LETTING ME TRY THESE OUT!!!!!

paul

Do you notice any vibration in the higher RPM range? (~6,000+)

i havent had any issues like that. ill run it up a few more times just to make sure, but i havent felt ANY major vibration. . . just heard the noise. thats all.

these bushings can be squeezed, they arent hard like metal or even plastic. . . just harder than the stockers. i dont know what the durometer reading is for them, so. . . :/

I NEED a set...FDnewbie, want another test subject???

Paul, whatcha smokin? Now that you've tried 'em out, take 'em out and give 'em back! :rofl :rlaugh: I had ya going there for a sec, didn't I? :p:

NP Paul. I'm glad you like them, and I was confident you'd do an excellent and fair writeup about them. You proved me right :) Thanks for the writeup and your impressions!

And the reason they're not hard is cuz they're made from made of 90A polyurethane, which is the expensive high-grade material.

Thanks for the offer, but I already sent another set to Phil (Herblenny), which is one more set than I anticipated. One of the main reasons is these bushings are a huge PIA to make, since urethane is so hard to cut accurately. These CANNOT be machined. They must be done by hand using a grinder, so they're done one set at a time.

The grinder has tolerances of 1/1000th of an inch (.001), so it's very accurate. But I think +-.005 is good enough for bushings, which is why Paul got a set with .005 difference from each other.

~Ramy

hehe, ill get em back to you ASAP. . . I PROMISE. . . ;)

i figure im good for SOMETHING on this forum. . . or maybe some of my slightly sarcastic remarks tickle someones fancy. hahahaha

eee-eee-eeee. . . . ::pulls on shirtneck::. . . . . thanks?!?!? :D

when i saw them i was pretty surprised that they were done by hand. . . very nice workmanship.

heeeeeeeeeeeeeeeeeey, why i oughtta!!!!!! :D

seriously. . . i wouldnt have known if you hadnt said that just now. they both went in just as expected and felt like they had the same fit.

GOOD WORK. lets see some more!!!

paul

Nice Write up Paul!

I'm going to pull it out soon... maybe this weekend and install the bushings.
By the way, Bushings looked great and definitely quality work.

I will also take tons of detail pics. I'm currently trying to pull an engine from another car and put my new engine in. Phew!

looks like your work is cut out for you phil!!!! have fun. . . the diff bushing replacement wasnt nearly as bad as i thought it was gonna be.

paul

To anybody in this thread who has recently replaced their bushings - I might be interested in buying your old ones -
https://www.rx7club.com/showthread.p...=1#post4747981

Will these be offered at a lower cost than rx7.com diff bushings which is at $120/set?

I freaking hope not since I got a set sitting right here.

I'd be interested in other suspension bushings. Poly don't require as much maintenance, don't they?

The rx7.com bushings are plastic; these are urethane. We're working on making a few (very very few) complete sets, as the amount of manual labor required is simply making it not very worthwhile lol. We may have a small amount of material left to make one or two more sets of diff bushings only. Price is still TBA, depending on how long the material we have left lasts.

Thanks
~Ramy

mmmmm. . . ramy. . . COMPLETE sets???? mmmmmmmmmmmmmmmmmm. . . me likey. hahaha

Pics dont work - any chance of getting them back up?
cheers

Please!

whats ppf and why dont any of the pics work?

How do you have over 1200 posts and you didn't know what PFS (PFSupercars/ AKA Peter Farrell Supercars) was and you don't know what a PPF is (Power plant frame) ?
The pics don't show up because this thread is two years old.

o haha didnt look at the date i guess some one brought it back from the dead... and i thought it was new.......sorry i am not that educated but if i had a picture and the name i would remeber it

I heard somewhere that you have to drop the PPF, rear suspension, and driveshaft to do these. It doesnt sound like the OP did all that. Is it really as simple as the OP posted? Can you get to all the bolts/nuts without having taken out the PPF, rear suspension, and driveshaft.

You do NOT have to drop the PPF, or driveshaft. Just follow Rotorbrain's directions. Hardest part for me was getting the nuts loose that hold the diff bushing carrier to the diff. It is tight getting on top of the diff to get those nuts...

Good luck.

Charlie

Thanks. I'll give it a try.

Wanted to bring this back as I'm currently in the process of doing my bushings.

Right now I'm at the above mentioned step to remove the bolts on the top of the diff that hold the bushing carrier. I have enough space to get the wrench in there for all bolts, but I don't have enough space to get any significant amount of force/torque to rotate the wrench.

Do you guys have any other tips to try and get around to making a bit more space so I can get more torque on the bolts?

One thing I did notice is my diff doesn't really drop down quite as far as the OP stated. My diff drops down and stops about 1/2 in. from the rubber stoppers on the subframe. Anyway I don't see how this would make a difference but maybe I'm not seeing something I should be.

my memory is really bad
but I think you jack up the wheels themselves and put wood blocks or books under them
and that causes the diff to lower
keep in mind- i did this 7 years ago so I could very well be wrong

Yes - you can force the wheels up a little to drop the differential a little more.

It is still a colossal pain in the ass to get these bolts off though.

Alright I was able to get it off. I didn't end up having to lower the diff any more, there was enough space with how I had it.

What I ended up doing was to use a standard open-end wrench to remove the nuts on the passengers side, and then using ratchet/socket to get the ones on the drivers side.

The way I was able to get enough leverage, was by using the chassis cross-brace that is right in front of the diff. That brace is shaped in a very good way to let you use it like a crobar. I rested it on the CV-joint socket or whatever its called and just pulled.

I realized afterwards that it would've been good to post up pictures of the process since the OP's aren't uploaded anymore. So I'm going to document it when I put it back together I post up new pics and directions of how I did it for future references.