Help with 930 CV joint boots

I'm working on fitting up half shafts on my RF-40. I purchased a set of 4 GKN 930 CV joints from a source on ebay and they seem to be just fine. I then ordered a set of boot flanges from another source that were listed as 930 CV flanges and they fit the CV joints perfectly. The boot seating area on these flanges is 2.970" inches in diameter. I ordered a set of boots from another source that were listed as fitting all 930 Turbo CV joints (part number 90133229312). However, the seating area diameter of these boots is about 2.190" in diameter. I don't think they are meant to stretch that much, but don't know... The seller of the boots says that I must not have 930 CV joints, however, I am pretty certain that they are (108mm OD, 94mm bolt circle, 40mm wide).

In looking for boots online it appears that you can get boots that go over the entire joint (not what I want), or boots that go on the flange. Are there multiple different flange seating diameters available? If so, does anyone know of a source for good quality boots that will fit the above flanges? I see many straight accordian pleat type of boots, but want the smaller tapered pleat type of boots.

Thanks in advance for any pointers. Bill
I have tried 3 types of boots on the 930 c/v joints in my car. First I tried the sleek,sexy "Aero" boot such as the type on Indy cars. These extremely low profile boots look great, but are made for open wheel race cars with 1.5in total suspension travel and ripped open after a short time in my tube chassis GT car.
Next up was a low profile Empi "Offroad Buggy boot" with 2 pleats to be used with a flange such as yours. They look great and are very cheap( the rubber boot costs @ $15),however I could never get them to totally seal the grease in. No matter how I clamped or glued the boots to the steel flange they would either leak out at the point where the boot mounts onto the flange,or where the flange mounts to the C/V.
So now for this season I went with stock replacement Porsche 930 boot assemblies( where the rubber is factory crimped onto the steel flange) sourced from Taylor gearbox (although should be available from others) with a little RTV on the face of the C/V to boot and C/V to drive flange and so far this season they are nice and clean with no grease leakage.

Jut my own observations,
Dave D.
Take a look online at Dorman, they offer a replacement silicone boot that is super flexible.
I think they list by diameters. They hold up very well.


What Joules says --haven't tried them yet, but they look like an excellent option to me


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Thanks for the feedback guys. I am running an Audi 016 transaxle that is mounted low, therefore the half shaft angles are pretty severe. I wanted to use the bigger diameter flanges for more axle / CV clearance. I am worried about using the Aero style boot due to the large angle, not sure they will last very long. The neoprene boots are about $7 to $10 each, so may see how they work first. Thanks again for the pointers, Bill
The axle angles in my car are around 12deg( there more in a stock 911) and have run the Aero boots( split open after a short while due to angle), off road buggy "low profile boots" ( they leaked grease and made an annoying mess no matter how I attached/sealed the boots to the flange), and recently went with the stock 930 replacement without any issues.

Dave, your comments are what made me think the Aero style boots might be a waste of money. I'll try the cheap boots and see if I have the same sealing issues (the flanges I have are very heavy duty and the sealing area seems substantial) before I try the "bonded" flange / boot assemblies. I still need to measure and order axles... Thanks, Bill
I used a very thin smear of rtv where the boot flange meets the c/v face, and the c/v face to drive flange to prevent grease from seeping through due to centrifugal force. I also tried to glue the boot to the flange with black trim cement( in addition to using a band clamp) as per Karteck Offroad's suggestion.
I bond our boots to the flanges with polyurethane adhesive, never had any trouble with them leaking grease, using about 24* of joint angle IIRC
Do you mean the poly windshield adhesive?? I thought about using that. I refer to that stuff as liquid duct tape, as I have used it for so many uses other than for windshields!!

Michael Holmes

Lifetime Supporter
I am looking at 930 boots, I believe they will fit on the Audi 016 trans, my CV joints are 4.25 which is equivalent to the 930 108mm


I had success with putting a layer of Lucas Red 'N' Tack Grease in the boot where it contacts the C/V. It seals the C/V grease in as it thins over time. I also use stainless zip ties to secure the boot to the joint.

Fran Hall RCR

GT40s Sponsor
High speed off road boots work the best but be very careful how much grease you use , no more than the manufacturers spec or the boot will tear..

On the race cars we use the same high speed style Chris showed a couple of posts back.

Contact the Driveshaftshop , Empi or Kartek

Chris Kouba


The sexy aero ones Chris posted spec 6 degrees max articulation, I am at 12 static.

I am quickly (<250 miles) going through my second set of boots from the Drivshaft Shop, and as pleasant as they are to do business with, I would prefer something more durable. A specific recommendation (brand, part number) would be greatly appreciated if you've addressed it already.


Chris Kouba

Thanks for the links Fran. I was also able to locate available items but seek an alternative known to work. Any suggestions?

Any reason why your standard issue boots would wear that quickly?

Fran Hall RCR

GT40s Sponsor
No idea as its not something we have experienced or heard about really...many other guys have run their cars on track with no issues with the same ones for a long time.

I have never had any issues with my personal cars splitting boots, I have thrown a clamp here and there but once replaced with an OEM style clamp the issue went away never to return

As I said give the Driveshaftshop a call...they supply what they deem best for the application and have more knowledge about their parts than anyone else has, that's why I let the experts supply this kind of part...