DIY Differential Collars Installation & Review

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We are always looking for all sort of products for our ride. This time Rob (Rob.ok) added a set of Differential Collars to his S2000. After reading his review, I got a set of those and had the chance to share his excitement with him. We would like to thank Rob for sharing the following DIY installation and review.

Not to many people have seen these so I figured I’d do an installation write up and driving impressions. The diff collars are basically an aluminum bushing collar that is designed to limit the amount of flex / play in the OEM diff bushings. These are not solid mounts so they do allow some flex which is great for street driving as well overall wear and tear on the diff.

Typical install time should be right around 2 hours for your average Joe.

You’ll need:
5mm allen key (for the sway bar end links)
14mm socket (both short and deep)
19mm socket (short)
Socket Extension
Flexible Socket Extension
Torque Wrench
Jack & Jack Stands

You have to remove the rear sway bar in order to get access to the rear diff mounts. This my entail removing your exhaust, especially if you have a dual exhaust. I was able to work around my single exhaust my simply removing rubber exhaust hangers.

Here is the OEM set up.

I started with the rear mounts first….

Sway bar out of the way.

First you need to loosen the large (19mm) nut on the center of the bushing. Once you have all of the bolts loosened, place a jack under the diff to relieve the pressure / weight of the diff on the bushings. Once you have removed all of the bolts, slide the diff mounts out of the sub frame. At this point you have to lower the diff so that the diff mount will slide off: the trunk is way.

The diff collars are pretty much self explanatory….

Again you will need the jack under diff… just the reverse of what you had to do to get them off basically.

For the fronts, I thought it would be easier to just remove the diff mount but you may find it easier to remove the aluminum mount that is connected to the diff. I did the front mounts one at a time. It helps to keep everything a little loose when doing it this way.

You must remove the rubber exhaust hanger in order to get the diff mount out his way. Again I was able to do it without removing the exhaust system, but I did have to remove all of the hangers so that I could move the exhaust out of my way.

I’ve attached full size photo copies of the service manual so you have all the torque specs. Just click here and here! Once you got everything back together and hand tight, break out the torque wrench and then install the sway bar according to the service manual and your all done!

I’m really impressed with the quality of the product and the installation was straight forward and relatively simple. I have to tell ya… I’m really excited about this mod.

Here comes now Rob’s Differential Collars Review!

I’ve done some limited street driving and even ventured out to an SCCA autocross today to test the new differential collars. Overall I’m very happy with the design, function, & performance of the product.

For those of you that are considering these collars, go jack up your car right now! The rear diff is the an official jack point for the rear of the S2000. If you pay attention, you will see how much flex the OEM bushing have in them when you go to jack up the car and lower it. The first thing I noticed after installing the diff collars is that the diff is now solid as a rock. The is virtually zero play in the bushings at all!

I really did not know what to expect from the diff collars as I had never thought that OEM bushings were a problem. In fact, I thought that it might be rather difficult to quantify the difference with them installed. I could not have been more wrong! The difference with the diff collars was immediately noticeable through every application of the throttle. Initial delivery of torque was improved substantially and every throttle adjustment was delivered almost instantaneous to the rear wheels with a very direct feeling whether it was on, off, or part throttle. Up shifts and down shifts are noticeably firmer with a more direct feel for the road surface by suppressing the wasted motion in the OEM bushings. Heel and toe down shifts also become much more sensitive to the rpm match / wheel contact to the road surface. In other words, if your revs are too high or too low during the clutch engagement, you get a noticeably sharper impact on engagement. Getting the proper rev match gives the driver much more feedback on the rod surface. During wheel slip, again the feedback through the chassis is significantly improved allowing the driver to modulate throttle to increase traction more efferently.

These diff collars are supposed to allow for a minimal amount of deflection, and looking at the design there should be a tiny amount. However, I do not feel any, despite knowing that there has to be a minimal amount. This is 100% ideal!!! I want the diff to feel firm and direct with throttle application, and yet I want to make sure that there is some initial compliance that will help with long term reliability.
When doing normal street driving.. that tiny bit of compliance is noticeable as the diff is not transmitting all of the vibrations to the chassis like a solid mount would.

The diff collars improved feedback so much that now I’m really sensing just how much wasted motion and feedback is lost in the tranny and motor mounts. Stiffer tranny and motor mounts just quickly rose to the top of my mod list.

Key Points:
1. Improved drive feeling through torque application with a more direct initial throttle response.
2. Improved up shifts and down shifts: Up shift are direct with an improved application of torque and power. Heel and toe down shifts give the driver an improved feeling of the rev match.
3. Improved feedback when approaching & exceeding the tires traction limits (wheel slip).
4. Wasted motion / deflection through on and off throttle application of the OEM bushing is significantly stiffened.
5. Just enough compliance to eliminate unwanted vibrations during normal street driving.

I am very happy with the performance of these diff collars. I will be spending a few days on track with them shortly, but I do not expects any different results. This review is of my own opinion and based very much on “feeling” as technical data can not be provided to show “feedback”.


Here follows now my personal impressions for the Differential Collars!

I think it’s now my turn to give my feedback since I have them on the S for almost a week now. I also had the chance to go on track yesterday and I’ve got only positive things to say about this mod.

First of all, thanks Van (superslows2k) for the fast shipment which included also a tracking number. My special thanks to Rob (rob.ok) for answering couple of questions I had via PM, and for his post with the installation instructions and review.

To the point now. Installation is really straight forward and very easy. As Rob described in his post, the differential bushings play with those collars is minimized significantly and the differential becomes very solid. However, no vibration is transfered to the car body which is great. That remaining tiny amount of play would be about one millimeter, which you cannot feel it while driving, but it’s there. I will never be worried again about the wear of the differential bushings. Just get those collars and you are done, considering that your bushings are in good condition, of course.

As for performance impressions now, you get a more responsive feeling of the power delivered to the wheels when stepping on the gas pedal. Last time I got that feeling was with the installation of the J’s Racing Engine Torque Damper. However, I felt an improvement with the differential collars.

Now here comes the best part and I totally agree with Rob’s review. The handling is greatly increased, heel & toe down shifts and rev match feels excellent. Another thing I’ve noticed and I really don’t know how to describe it, is how the Torsen limited slip differential really works when cornering. You can actually feel it even better. I could go writing more and more, but as I mentioned Rob’s review covers everything.

In short words, I highly recommend them!

I would like to mention also the weight of them which are very light indeed:

eXedium Racing S2000 Differential Collars
Material: High Quality 7075 Aluminum

Set consist of 8 pieces:
– 4pcs (big) x 64gr = 256gr
– 4pcs (small) x 36gr = 144gr

Total weight of the set = 400gr


Photos courtesy of Rob.ok and energetic

Click here if you require more information and further reviews on the Differential Collars.

NOTE: S2KI welcomes the opinions of its members on the S2000 and on all topics related to the S. Should you feel the creative urge to pen a few words then by all means do so and PM Energetic, Aashish2 or Onehots2k OR send us links to what you would like us to write about and we will feature you (or your community) on the S2KI Home Page.

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