2004 V70, S60 GKN OUTER CV boot is now Plastic!

Post by **cn90** » 29 May 2019, 17:26

My 2004 V70 2.5T FWD with 110K. Getting ready to do routine maintenance for CV Boots, which are still OK.

The Outer CV boot GKN 303420 is now Plastic (the factory boot is rubber, I just checked it).

The Inner CV boot GKN 303946 is still rubber.

Is anyone here concerned about Plastic at all?
Maybe I am old-schooled but I prefer Rubber!
Is Plastic better?

: CV-Boot.jpg (344.82 KiB) Viewed 2855 times

XC70Rider · Post by **XC70Rider** » 29 May 2019, 18:11

Same here. I ordered for the GKN 31256231 rubber boot and got the GKN 303420 plastic boot?

I'll contact FCP tomorrow.

XC70Rider · Post by **XC70Rider** » 29 May 2019, 18:37

Doing a google search "GKN plastic boot" I found this Audi forum

https://www.audizine.com/forum/showthre ... astic-boot

They claim it's polyurethane and harder to clamp than rubber?

Post by **cn90** » 29 May 2019, 18:40

Alright,

I did a google search using key words "GKN CV boot plastic vs rubber". These are what I got, interesting debate in different forums (VW, Audi etc.):

https://forums.tdiclub.com/showthread.php?t=374629

https://www.audizine.com/forum/showthre ... ic-CV-Boot

https://www.audizine.com/forum/showthre ... astic-boot

Post by **cn90** » 29 May 2019, 19:09

Found this on Google Cache...

Updated 11/15/2012

Drivetrain supplier to switch to TPE for CV joint boots
Crain News Service

LOHMAR, Germany-Automotive drivetrain supplier GKN P.L.C. has set itself a tough task-converting all the constant velocity joint boots it uses to thermoplastic elastomer.

By 2005, the company wants to convert all CV joint boots to TPE, said Nader Khoshoei of GKN's research and development center in Lohmar.

In Europe, about half of outboard boots and 10 percent of inboard boots are made of TPE, he said. In the U.S. the figures are higher-90 percent of outboard and 50 percent of inboard.

As a major producer of automotive drivetrain parts, GKN has a 41-percent share of the global OEM market for CV joints, and has boots made to its specifications by a small group of preferred suppliers, the GKN official said.

Khoshoei said these protective boots represent the ``most demanding and severe use for TPEs.'' On the plunging inboard CV joint, for example, the boot is severely deformed at high temperatures-up to 120°C-but must also withstand freezing winter conditions in Arctic regions of Scandinavia at -40°C.

CV joint boots are ``there to keep dirt out and grease in, at a very low cost compared to that of the half shaft,'' Khoshoei said. But they are an important part of the joint, because if it fails, grease is lost and this leads to rapid failure, he said.

Tighter packaging requirements in future vehicles mean the boots will be even closer to parts like catalytic converters. That will bring operating temperatures to 140°C, with peak temperatures of 160°C, Khoshoei said.

GKN is looking for TPE materials to meet these needs, and Khoshoei bemoaned the high cost of conventional screening and evaluation test programs for CV joint boots-up to $13,000 for one material.

He described GKN's work on developing a correlation between material properties-in this case parameters measured by dynamic mechanical analysis/ differential scanning calorimetry-and CV joint boot performance.

High-temperature performance of TPE needs to be improved, Khoshoei said, and better prejudgment tools developed.

``I urge material suppliers to try and correctly define material characteristics appropriate for the product,'' the executive said.

Post by **cn90** » 29 May 2019, 20:45

XC70Rider wrote:...I'll contact FCP tomorrow...

FCP simply sells whatever GKN supplies them.
I'd not blame FCP at all.

But my curiosity is on this plastic thingy.
I read the reason why GKN switched to thermoplastic elastomer, but the rubber is so good for 15y/110K, why bother with thermoplastic elastomer?

XC70Rider · Post by **XC70Rider** » 29 May 2019, 21:04

cn90 wrote: ↑29 May 2019, 20:45
XC70Rider wrote:...I'll contact FCP tomorrow...
FCP simply sells whatever GKN supplies them.
I'd not blame FCP at all.

I know they just distribute what GKN manufactures. I'm going to find if the other brand outer boots they distribute are rubber.

Post by **cn90** » 29 May 2019, 21:19

Coming from 1998 S70 era, Rein boot lasted me 22K then minor cracks.
EMPI boots are made in China.

Just looked at GKN 31256231 or 303420, the dimensions are:
- Total of 6 ridges
- L = 144 mm
- Small end diameter = 30 mm
- Large end diameter = 95 mm

The plastic thingy scares me b/c the larger diameter lip (96 mm) has a little ridge, and being plastic, it can be "slippery". Now I understand that if people don't apply the Oetiker clamp tight enough, it comes out spilling grease! The jury is still out for plastic.

If you find another GKN (for another car such as VW or Audi) with similar dimensions and is rubber, please post.

Post by **cn90** » 29 May 2019, 22:08

GKN specifies a special tool for the plastic boot!
The torque on the tool is 23-30 Nm.
Please see the pdf...

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Post by **cn90** » 29 May 2019, 23:02

I was looking at 2004-2006 XC90 2.5T Outer CV Boot, from what I researched:
- It is still made from rubber.
- The dimensions for XC90 (right in the photo, dimensions are not certain, I got the dimensions from some websites...) are very close to the S60, V70 (left in the photo).
I personally think XC90 CV Rubber Boot should fit the S60/V70.

- Can someone call FCP to see if they can get one of each and physically measure them for us, and post their measurements?

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: CV-Boot.jpg (113.28 KiB) Viewed 2805 times