Mark944na86

I was thinking of putting in the 968 upgraded caster blocks on my '89 S2, as per factory recommendations for 17" wheels.

refer:

http://www.btinternet.com/~dmsims/944t/wheels.htm

and

http://www.weissach.net/968_M030-Option.html

Now, Porsche also recommend upgrading to the 968 control arm eccentric stud. part#

951.341.431.02

But how necessary is this? Will the 968 caster blocks fit OK with the original 944 eccentric studs?

It's just that at about $64 each the eccentric studs are even more expensive than the caster blocks, and unless there's a compelling reason to upgrade them, I'd rather put the money (and time) into something else.

Any insights and opinions welcome.

-Mark

Luis de Prat

I did this upgrade 2 years ago and while you're at it, you might as well replace them since they're part of the M030 caster block upgrade.

Just from looking at the difference, it's my impression that the regular eccentric bolts will not work with the new M030 caster blocks. There's a lot less rubber in the M030 caster blocks. Here's what I got

Bolt (2) 900.910.115.02 - €0.61 each
Rubber Bushing (2) 951.341.023.01 - €40.20 each
Eccentric Bolt (2) 951.341.431.02 - €59.00 each

These are Euro prices before adding 16% VAT tax.

Mark944na86

hi Luis,

We've got the same part #s, although there seems to be some confusion (on my part most likely) about what they are. Here's Pelican's descriptions of the parts:

951-341-023-01 OEM Rear Mount with Bushing for Front Suspension Control Arm, 944/968 All from 2/85 $61.80

951-341-431-02 TRACK ARM ECC. STUD $64.71

900-910-115-02 LOCKING NUT $1.10

Now, if you look at the exploded parts diagram under the title "Front Castor (sic) Mounts"

http://www.weissach.net/968_M030-Opt...ntCastorMounts

it labels 951-341-431-02 as the eccentric bolt, and 951-341-023-01 as the rear rubber mount (what I referred to above as the caster block -- perhaps this is misleading).

Anyway, regardless of what we call these things, my question is: Is replacing the eccentric bolt 951-341-431-02 necessary if upgrading the rear rubber mount/rubber bushing 951-341-023-01?

-Mark

Luis de Prat

Hi Mark,

What my dealer described as "rubber bushing" is indeed the actual caster block, and the "eccentric bolt" is what Pelican calls "eccentric stud.

From reading about this upgrade over the years, I'm under the impression that the old eccentric studs will not work with the M030 caster blocks. If you look at one, you'll see what I mean: the openings have less rubber, and more metal.

At any rate, with the amount of added stress on these studs from larger wheels, I found it cheap insurance to go ahead and replace them. You want them in good shape to align the front end, too.

Riff

Mark-

FWIW when I upgraded to the 968 caster blocks, I did not upgrade the eccentrics at the same time. I am not sure what the difference between the two parts is, but my car aligns (and holds alignment) just fine. I run 17's on the street and 16's at the track.

Cheers,

aribop

Guys, I upgraded the caster blocks without changing the bolts and it works just fine. My local P'dealer told me there was no physical difference between the two bolts. I also have no problems with holding alingment with 17's.

Luis de Prat

Sounds good. Apparently, the M030 studs are serrated, to hold the caster setting better. Can't think of why else the tech bulletin would recommend replacing them together with the M030 caster blocks. Probably just overkill.