Djbrand1

I have a 88 944 Turbo S that I bought some 968 Castor blocks for from the consensus of the online forums that they will be an upgrade. Less rubber than the older style should hold alignment better on the track. Seems reasonable. The car is over at a pretty reputable shop that specializes in 944/951/968's, they told me that they actually prefer the older style which is on my car now. I value their opinion as they setup a lot of track cars and I am no expert, but it seems to contradict the overwhelming bias on the forums that the 968 blocks should be an upgrade. Any thoughts??

Darwantae951

Not 100% sure you can even buy the bushings anymore. I believe there was a TSB stating if you up the wheel diameter, to switch to the 968 unit.

Oddjob

Yeah, pretty sure the stock rubber castor block is NLA and supersedes to the 968 part number. The M030 Turbo S block is probably available, but zero reason not to use the 968 part.

mikey_audiogeek

The TSB also said to use the 968 caster pin that bolts through the arm. Significantly better and stronger than the stock 944 pin.

Mike

Darwantae951

Did not know that!

Oddjob

968 uses the same eccentric bolt part number 951 341 431 02

Dimi 944

The 968 caster blocks are considered an upgrade due to the better rubber material used and design as well.
However, if you use the housing of the older caster blocks and replace\strip the rubber with the urethane bushings from Powerflex (http://store.powerflexusa.com/porsch...ngs-p1241.aspx) you might end up with a better solution.
You can use the urethane bushings on the 968 caster blocks as well.

Djbrand1

Interesting, shop said since it's the Turbo S, it has the Turbo Cup bushings in it already. I'll try to get the part number off of them.

pettybird

it does, but that doesn't mean they're indestructible. I think they have a dab of red paint on them to identify them as the harder bushings.

mikey_audiogeek

Will take your word on that. When I replaced the stock eccentrics on my 944s2 the replacement "968" caster eccentrics from Porsche were fully machined compared to the cast/forged original item and had the serrations whereas the originals didn't.

I have some photos somewhere, if anyone is interested.

EDIT: Up until about 2001, the recommended caster eccentric was 951 341 431 01. Then changed to 951 341 431 02 Refer http://www.corlieto.ch/porsche/abe/a.../944_13_09.pdf

The 951 341 431 03 part supercedes both 951 341 431 01 and 951 341 431 02 and is listed as the replacement in current editions of PET.


Cheers,
Mike

Luis de Prat

If you ordered the new 968 M030 caster blocks and excentrics from Porsche on advice of the TSB, you probably got the newer 951 pins anyway.

Oddjob

Sure - I’d like to see a picture of the latest updated version of the eccentric castor bolt. Was the design change made on the -02 or -03 part?

I am sure there are more than a few errors in the various versions of PET, and this is apparently one of them on the 6.03 version I have. It shows the -02 eccentric as the original part number going back to 85.5 cars, and the -03 part did not exist as of the ‘03 release date. It does show the castor block was not updated to the later style -01 part until ‘93 968s.

Interesting that the factory would make any effort to update the eccentric bolt, as they are not prone to failure - never seen or heard of a break on heavily raced and wrecked cars. Other suspension parts have significantly higher catastrophic failures (like control arm balljoints and hubs) that have been known for years, and no upgraded parts have been released.

mikey_audiogeek

Indeed. It's always interesting to look at part numbers and see what revisions have happened. The last two digits give the revision number.

Sometimes revisions happen because of a change in supplier or manufacturing process, not necessarily due to an improvement or to resolve a problem.

Can't find the photos at the moment. I bought my new -03 eccentrics from Sunset Porsche in Sept 09.

Cheers,
Mike

mikey_audiogeek

Photos:
https://rennlist.com/forums/showthre...ferrerid=27835

Contadino

I have an '89 turbo S with the M030 suspension and recently upgraded to the 968 caster blocks too. I left the eccentrics where they were and just replaced the blocks. Now I am wondering if I need to have the car re-aligned. I had to move the eccentric bolts down a tad to insert them into the caster blocks. I think that increases the caster setting. Do you think it would be enough to require an alignment?