Pettit Racing Diff bushings
 

Having some issues installing these bushings we bought; uncertain if the race around the old bushing needs to be reused or not. Right now the new bushings sit really loose in the mount as pictured you can see the gap... Did we receive the wrong bushings?

Thanks in advance
-Dan

You should not re-use the race. Looks to me like its the wrong bushings. Why don't you contact Pettit?

We were working on this Sunday and Pettit was closed. Called them this morning and turns out we had a set for the RX8. The tech that answered the phone said they would swap the part free of charge if we sent it back. Pettit Racing is a great shop with amazing customer service. I highly recommend them.

I had them in my old FD, not sure what's on mine now. But they're easy to put in. Other then the part where you need Arnold Schwarzenegger to out the pig back in.

Let me know how you like these, I was considering replacing my worn bushings with them. I'm interested to know how hard they are to swap and if you notice increased vibrations and such.
Be sure to post up!

The act of physically installing them is simple. It's dropping the diff and putting it back up that's a pain. Unless you have a nice ass garage setup. What durameter did you go with?

I have the Petitt black (street) set. There is a small, barely perceptible increase in NVH. Primarily some gear noise at low speed--and this is in a fairly quiet car.

The fitment is fine, but the install was a PITA; primarily because my big hands and arms don't fit in the allocated space.

A 17mm flex head ratcheting box wrench helps a lot.

I'm sending the bushings back today to get swapped out. Hopefully the turn around will be quick, but going from Las Vegas to West Palm Beach and back won't be speedy. I'll post some pictures of the install and a review after a few days of driving around. I got a good deal on the set which is why we were installing them. My factory bushings were perfect until we did a little "experiment" with them. Needless to say when they say liquid filled they really mean FILLED. lol But I should be able to give a good comparison over the oem bushings.

Ok, so I'm finally getting around to updating this thread. Well the install ended up taking slightly longer than expected.

When we got the bushings in they were very easy to get into the mount. The replacements were for the FD and were slightly larger. They measured just slightly larger than the diff mount holes. But after the box with the new bushings had sat in the back of the UPS truck on a 110 degree day in Vegas, the bushings felt pliable enough to get in. So being too excited to wait to get to my friend's house I installed them by hand. They slide right in with a good bit of force. I placed a cloth over them and used a mallet to get the bushing flange to sit nicely against the mount.

This is where the real fun began. Now back at the car, the mount can be maneuvered easily enough to get it mounted back on top. We fully tensioned the mount bolts on the differential before mounting the bushings back to the frame. Not the funnest angle as many already know but with a pry bar and finding the right leverage points you can get the nut torqued up.

Getting the bushings back in place was a whole other animal. The Pettit mounts use the stock rubber thrust washer that came off the stock mounts(The rubber piece with four tabs and an alignment arrow on one of them. We positioned a jack under the differential and started working it up. You can move it by hand but no one wants to hold it in place for too long. With the mounts about to slide in, position the thrust washer back on the diff mount. Then jack the diff up. The frame will hold the washer in place, you can't fit it in once the mounts are in place. We were able to work the bolts back in from the opposite side. Stock the bolts back out towards the diff but there is no way to tap them through that way unless they are perfectly aligned. So we ran the bolts in from the wheel side and placed the nuts towards the differential. I don't think that makes any difference as there is no tension in this connection, only shear.

With the rear end all bolted back up we were able to throw the wheels back on and take it for a spin... Almost.

When we took the wheels off, we found a screw in the one tire. I took it to get patched and got handed another surprise. The tires were circa 1996. Almost factory. Lol. Well the car had to sit another week waiting for the tires I ordered to get in. And another week. And a few more days until I had finally had it and had run out of stuff to clean on the car and just wanted to drive it without that awesome yellow enkei spare. So I took it over to Discount Tire and picked up some new tires on the spot. Face palm for not going there sooner.

Having finally be able to drive the car for a few weeks now I can say it is night and day. My factory bushings were not torn or broken so I believe they were operating as they should before the change. But when I would really get on it and run through the gears I would get a hard kick from the rear end when I shifted. That is gone now. Shifting is still pretty notchy but a gallon of NEO 75w90 sitting on my work bench should take care of that. I used to get a noticeable clunk from the rear end when I would be driving slow and shift up into second. That is gone now as well. The rear end feels much sturdier and far more planted. I can't really tell if it was the diff mounts or the tires or both, but I have to try quite a bit harder to break the tires free as well.

I'm still running on a stock suspension all around including sway bars and I can easily say this is a great driving mod that makes the FD that much more fun.

i recently also installed the pettit bushings, theay are night and day!

dose the lip go on the inside or outside of the mount?

I installed mine on the inside (Lip closer to the diff).

it is nice to see mention of the Diff bushings... as i mentioned in post one of my sticky suspension thread in the Suspension Section, there are two bushings that should be replaced/upgraded on the FD... the Diff bushibgs and the large rubber bushing on the front of the longitudinal lower link in the rear of the car.

don't believe me on the diff bushings?

put a floor jack under the diff and you will find the diff moves up almost an inch before the chassis moves! there should be no disconnect here. axle bounce and spider gears are a lethal combo not to mention the lack of linearity overall.

the other large rubber bushing effects toe which, especially in the rear you want solid.

all the other bushings and rod ends/spherical bearings/pillowballs just need to be in good shape. generally only the spherical bearings are a maintainence item.

and, of course, as Mario says, "Check your tires."

30 psi in the front, 27 in the rear set cold.

the FD is a one of a kind road (race) car... enjoy.

howard

I went with the whole petti race rear end kit to stiffing everything up. Also got Jim's diff cradle to go with it.

an additional chassis upgrade is...

either solid motor mounts OR a Garfinkle engine torque brace.

both take the vulnerable power plant frame out of the job of resisting torque twist and get it back to just aligning the eng and diff. both also improve shiftability.

a huge bonus w the motor mounts is engine removal goes from a bear to a pussy cat.

i bought the Himni street mounts. remove your stock mounts from the engine, deep six the rubber thingy so all you have is the steel piece. helicoil a 3/8 coarse thread in the mount, buy a couple of 2.75 inch X 3/8 bolts, drop the puck in the well and you are set. the motor will slide straight back at the proper height and onto the input shaft. place the bolt thru the subframe hole, thru the puck and thread into the mount.

if you have ever had to remove your motor w the stock setup you will appreciate the modest expense of time and $ to never have to go there again.

HC

So far got irp track engine mounts, banzi trans mount, petti rear end, toms diff cradle. Super pro bushing and plan to replace all pillows and wheel bearings.

I have these now and installed. As for the rubber thrust bushing.. I noticed that the center pin of the PR bushing is smaller then the hole inside the thrust bushing. . Is that normal? Did you center it somehow when you installed it?