INTRODUCTION: This Article demonstrates the repacking and clamp replacement on the CV boot of a 987. Many Cayman owners who regularly track their cars have developed the issue of CV joint grease leaking from their boots. Usually, the first sign of this problem is grease splattering on the inner wheel rim as seen below:
On closer inspection, you can see evidence that the grease is leaking out from around the outer end of the CV boot, and not from any crack or split in the boot itself; there is additional grease build-up on the suspension parts:
The conventional wisdom is that this results from high heat in the rear brakes and nearby exhaust pipe which liquifies the grease, allowing it to seep out. In addition, I found that the OEM boot clamp was loose enough to rotate around the boot, so it wasn’t helping much.
When I developed this problem a couple of years ago on the driver’s side, I made the “mistake” of taking my car to the dealer, who proceeded to replace both boots on that side (which requires removing the hub and half-shaft), which was pretty expensive. Since then, several Cayman owners have described fixing this problem themselves by just repacking and re-clamping the boot in place on the car. So, when it happened on the right side, I decided I would undertake this fix myself.
1. Replacement Boot Clamps – I chose to use the ear-type CV boot clamps as replacements. There are other types of clamps that use a winding or cutting tool to tighten, however the ear-types work pretty well once you figure out how to use them. The smaller, inboard OEM replacement is p/n 996-332-257-00, and is stamped 42.5 (mm). The outboard clamp I ordered based on a PET diagram was 74mm, and was too large for the job. I had to make a quick trip to my local dealer, where they told me the techs don’t use the OEM clamps (which are not adjustable in size), but use the type shown below, with multiple holes which allow it to be adapted to a variety of diameters:
2. CV Joint grease – many people will probably prefer to replace with the OEM grease. Since I continue to use my car primarily as a track toy, I decided to switch to Redline High Performance CV-2 synthetic grease, which is designed for racing and higher temps, and hopefully, less likely to liquify and seep out again.
3. CV boot clamp crimping pliers – I picked these up at an O’Reillys Auto Parts store for about $10. After you snap your clamp into place, you use the pliers as shown below to crimp the “ear” on the clamp, which further reduces the diameter and thus tightens the clamp on the boot:
1. Jack up the car and place on jack stands – remove the wheel on the affected side.
Safety First: be sure to block your front wheels to prevent rolling, and never get under the car without using jack stands!
2. Remove the old clamps – Note, you may have to turn the brake rotor in order to get access to the clamping mechanism. My inboard clamp was of the ear-type, and easy to remove after bending up the little hook which holds the clamp closed.
The outboard clamp was a different matter – I couldn’t figure out an easy way to pop it free, so I ended up using some diagonal pliers to chew away the retaining lug and pry up the end of the clamp. Just be careful not to damage your boot in the process!
3. I cleaned the axle with some WD40 to facilitate sliding the boot back, and then pushed it back. I was surprised by how little grease was left in the hub, and how thin (i.e. liquid) it was:
4. Next, using paper towels and rags, I tried to clean out as much of the old grease as I could, rotating the hub to get access to as much of the inside as possible. This is how it looked before the new grease went in:
5. I then packed the new Redline grease in using my fingers to force it down into the innards of the hub until it was topped off. This was a bit messier than I had anticipated. Redline also sells their grease in a grease gun cartridge, which in retrospect would have been a neater way to get the grease in there. I’ll have to get a grease gun for the next time I do it . . .
6. Now it’s time to slide the boot back into place – it is much easier if you jack up the wheel hub, so that the axle is nearly horizontal:
7. I replaced the inboard clamp first, figuring that would help hold the boot snugly to the hub when I applied the outboard clamp. Using the crimping pliers I snugged the clamps up as much as I could.
Then the outboard clamp:
On a scale of 1 (easy) to 5 (very hard) I would rate this job as a 2 – it is rather messy, but not particularly difficult once you figure out how to remove and replace the clamps. Happy Driving!
This article was originally published by KS-CS on February 7, 2014 on the Planet-9 Forum. Many of the images are no longer available from that forum. You can try to contact the original author on Planet-9 or, if you have a picture that fits the description, please send it to me and I will update the article. Fortunately, my boots don’t need repacking and I’m not going to dive in there just for the photos.