Volvo 850 Outer CV joint interchange data

[PeteB]

This thread is excellent, thanks very much to all contributing and doing all the work!

I'm placing an order and need boots for our 1996 NA 850 auto. Mecheng wrote:
"
I measured The inner boot and it matches what is listed for 300427 and 300597, perfectly. The outer boot has a different diameter which is why you need GKN 300439

So this begs the question, why not use 300427. Isn't that what you use for the outer cv boot for NA models? And this is why cn90 said use it for both.

Why go through all this trouble, the GKN boot is definitely better: thicker rubber and more pliable. It also comes with a new nut. I'm hoping to get this resolved before the weekend, and my head is tired sorting through all this different info, but it will be worth it for all of us."

I see a full kit by Rein but I'm more inclined to just buy 4 GKN 300427, is this currently
the best solution for 1996 NA 850 auto? It is currently on closeout at FCP by the way.
I too am on information
overload with all the data. I just reread this and it is hard to keep track if the discussion
is about turbo or NA. So now I think that the above is saying to use the NA outer for a turbo
inner but am not sure. The correct GKN inner (300497) for NA is available so I'll probably get
that but confirmation would help.

[cn90]

Pete,

1- REIN: been there done that, about 5-6 years ago, I thought it was the smart thing to do, i.e., ordered the REIN kit and done with.
Guess what, I was wrong, REIN lasted about 22K miles!
I posted the REIN boot issue in the thread below:

viewtopic.php?f=1&t=29716&start=10

2- "Use 300427 for both Inner and Outer"? That was my idea but it does not work.
This is b/c the cross-section profile of the metal part and rubber boot have to match for a good seal.
If you use OUTER boot on the INNER joint, it will fit from the diameter standpoint, but the profile is a mis-match and you will have a hard time fitting the clamp. Not to mention it may come off down the road.
---> DO NOT use OUTER for INNER!

Go back to the threads with some popcorn and your favorite drink...
- OUTER for N/A: GKN 300427 ---> about $10.
- INNER: Audi boot GKN 300597 is a perfect fit ---> about $10.

Keep life simple.

[cn90]

...The correct GKN inner (300497) for NA is available so I'll probably get that but confirmation would help.

GKN inner (300497) is not available in the USA.
As I mentioned above, stick to Audi boot if you have NA.

Turbo INNER:
- Go to dealer and cough up $30, it is still available.
- Or use other aftermarket as INNER does not flex much, so even with low-quality aftermarket stuff, it should last > 100K miles.

PS: What kills the OUTER rubber boot is the constant UP and DOWN (pot holes) and R/L turns. It flexes and bends the OUTER boot thousands of times ---> cracks. The INNER has much much less flexing/bending.

[erikv11]

northernlights figured it out and outlined it very clearly it in the very first post f this thread: GKN 300597 works great for the inner. Since that time everyone who has tried it, has had the same experience with that part. I'm not sure what you mean by "why go to all that trouble," just get the part that fits.

[PeteB]

cn90 wrote: "GKN inner (300497) is not available in the USA.
As I mentioned above, stick to Audi boot if you have NA."

I know FCP's stock changes but I found it (300497) here, or am I missing something,
is there something wrong with this part - GKN part number is right under the title:
https://www.fcpeuro.com/products/volvo- ... o-31256227

Edit: Now I notice that the FCP site says that this part 300497 is for a standard 5 speed,
no mention of automatic which is what we have. So does this not fit?

I'll use either but I'd like to buy them all from FCP.

[abscate]

Mod note.

Cut and paste first post in this thread as it really is complete in entirety. Refer to first post for images.

Locking thread for archive

I have had a torn drivers side outer CV boot on my 94 850 Turbo for longer than I care to admit. Because it wasn't makingg noise, I was originally planning on cleaning, regreasing and rebooting the axle, but as I investigated replacement parts there seemed to be confounding information on the CV axles.

Looking at interchange or aftermarket information didn't really help, because it seemed like within reason, i.e. any car with a 4spd auto, everything physically interchanged. But, I found different part numbers for outer boots based on turbo/non turbo, but no easy way of identifying what I had, or what I needed.

While the aftermarket support is pretty good for these cars, as can be seen from the no-core prices for complete CV axles, I wanted to stick with OEM if possible for quality reasons. The boots in particular seem to be a problem in that often the aftermarket stuff doesn't last. This meant I needed to find out what was really out there, and compare parts to find out what I could use. It turned into a bigger project than I expected as I tried to determine what these cars were originally supplied with.

So with this in mind, I dug around a bit, and scored some used and new CV parts, and here is what I found, or (disclaimer warning!) at least is my best guess.

Note this only applies to the FWD 4 spd auto for the 850, and probably the S70/V70/C70 with production dates as late as 12/98. I have no idea what is going on with the manual transmissions and AWD stuff other than the fact that they are different!

1) All CV axles have 26 splines at the hub. This is why they seemingly all interchange.

Here is an image of the axle I removed from my 1994 Turbo (which had been replaced about 7 years ago) next to a 1998 C70 axle which I reworked. I am pretty sure the C70 axle is OEM because it still had small bits of the Volvo sticker on it plus the inner boot was clearly marked Lobro. The compressed length was essentially the same, and it fit in the car with no problem.

Image

2) There are two different types of outer CV joints. I will refer to them as naturally aspirated (NA) and Turbo for simplicity. It appears that the OEM turbos were supplied with the larger ones, but because the axles are interchangeable as assemblies you might have either.

These are your two options. There is clearly a difference in size between the NA (left) and Turbo (right).

Image

Image

These cannot be interchanged on a given axle because the inner spline size is different. Even though they all have 26 splines at the hub, the NA CV joint has 25 splines inside while the turbo has 28 splines. This means the actual axle shafts are different from NA to turbo.

Other easy to measure differences:
The OD of the turbo unit is about 98mm while the NA is 90mm.
The CV balls in the turbo are 19 mm compared to 18 mm for the NA.
I do not know how strong either axle is, but it appears that at least you get something bigger with the OEM turbo axles.

Note that these both have a 48 tooth wheel for the ABS.

3) GKN (aka Lobro) is a good source for parts.

If you remember from the beginning of the post, this all started with boots. I found GKN outer boots with little trouble for both the turbo and NA CV joints. They are different, and this is where I think things can get confused because of the axle assembly interchangeability. For reference, these are the part numbers which I found from GKN:
OEM NA (small CV joint) outer boot kit GKN 300427
OEM Turbo (large CV joint) outer boot kit GKN 300439
The Turbo boot kit (300439) I bought included 2 80g tubes of grease.

The inner boot was a different story. I couldn't find a good GKN part number anywhere, which I found strange because (as I said earlier) I had a 1998 vintage inner boot on a Volvo axle that said Lobro.

So I started looking into interchange data in the aftermarket to see if there was anything close. It turns out that there is a bunch of overlap between a number of Audi's and Volvo as far as boots from some of the aftermarket suppliers like Raybestos. So I poked around and found A GKN part that appeared to be essentially the same inner boot, or at least close enough so that it would probably work.

Here's my slightly stretched out 16 year old original next to the new GKN part.

Image

This particular boot contained in this boot kit (GKN 300597) is OEM on a bunch of Audi's. I used a 1994 Audi 100 S Sedan as the point of reference. This kit comes with an extra clip plus 6 bolts that you don't need, but includes the correct size clamps and two 80g tubes (for 160g total) of grease.

Image

Here's the axle with the Audi spec inner GKN boot and a Volvo spec outer GKN boot. It was a little tight at the inner joint , but the inside geometry looked the same as the original so I am pretty sure it will hold up fine. Both of the boots kits were made in Italy.

Image

Image

4) The grease capacity of the joints is as follows:
OEM NA outer joint 80g
OEM Turbo outer joint 120g
Inner joint, NA or Turbo, 190g
This means if you buy the two kits from GKN you end up with 4 80g tubes, or 320 g total. You need 310g total for the turbo axles, or 270g for the NA, so the turbo kits combined provide what you need.

I had some trouble finding info on the inner joint grease capacity, but I actually came up with that number (190g) in two places, so I am pretty sure it is accurate. And yes, regreasing the joints is a very nasty job so I am trying to make sure I don't need to redo it too often.