Catellus Engineering, Inc.

09/05/2026

This is a new one for me. Sent to me by a customer. Google AI, apparently, has made a few statements allegedly from me that are not, and I disagree with. Is there a button to click for corrections? I am flattered, sort of, that they think I am the "premier authority" but certainly would never make that claim myself.

Just the specifics, for what it's worth. I have never recommended Delvac. I have nothing against it, no experience to speak of with it, and I am sure it's a fine lubricant. The Mobil l**e I recommend is Mobil 1 Syn Gear L**e 75W-90. It's okay to use the LS variant of it if you're don't have an L*D, or are willing to giving up a little L*D performance in exchange for less L*D clutch chatter. I have zero experience with their Mobil**e SHC, again likely a fine product.

The reason for this is simple: a Mobil engineer told me so. Actually, he told another customer who called them and asked which product to use, would the Delvac be ok. Mobil recommended the Mobil 1 Syn Gear L**e 75W-90. (This customer has a PhD in mechanical engineering and wins at SCCA Nationals. So I am pretty sure he knew how to have that conversation.)

I do not recommend additives as mentioned by Google. And I never, ever recommend Red Line products.

08/21/2025

Sometimes ChatGPT comes up with good info. But it also seems to just make stuff up. I asked about installation position for the clutch release lever spring, which it pretty much bafflegabbed its way through, then offered to make me a picture. It does not seem to bear any connection with reality.

06/13/2025

Next time you're tempted to believe in "lifetime" transmission fluid. Life can be short. This is what roughly 30 years looks like. Owner dodged a bullet: new bearings, synchros, reset, ... good to go.

05/16/2025

What victory looks like today: Three shallow countersunk M5 screws in an L*D, ridiculously overtight and over-threadlocker'ed. Snap-on 3 mm stubby allen breaks in one, flush with screw face. Great. Center drill the screw head to 2.5 mm (carbide bit, nothing else will cut through the hardened allen fragment), thread in M3 tap, and pull. Screw socket undamaged. Bullet dodged.

04/11/2025

Very well written article.

The elusive noise, vibration, harshness (NVH) complaint all too often turns into a game with a customer trying to articulate the concern to a service writer, who then passes it...

11/18/2024

915 transmission with a drain plug that has been greatly over-tightened, probably with an impact tool. Inhex has spread, 17 mm allen wouldn't bite. We got lucky by warming the case, compressing the plug with vice grips, some firm but gentle attention with a 1/2" socket and ratchet, and a little prayer. Sometimes you get the bear!

11/18/2024

There is a well-known problem with the bearing retaining plate used in the Cayman/Boxster G87 and G81 transmissions. The metal used is soft, and over time the front pinion bearing wears a channel in the plate -- see second photo.

This creates two problems. First, the pinion gear shifts out of its correct depth. The spec for depth is +/- 0.04 mm, and the wear is frequently much more than that. Out of spec, the pinion generates more mechanical noise and heat, which can contribute to failure.

The second problem is that the pinion bearing loses correct preload. Preload affects bearing longevity. And keep in mind, we're already dealing with a sealed double-row bearing that was a questionable design choice.

We have just finished a run of improved bearing plates, made from A2 tool steel, properly treated and ground to true, as seen in the first photo. Highly recommended when servicing one of these transmissions.

In the past, we've either replaced a worn plate with a new one, or had the old plate reground. Of course, these are not ideal solutions: you're still rebuilding with a soft metal plate that will, over time, once again wear a channel.

08/21/2024

New run of 944 transmission cooling adapters, back from machinist. These allow replacing the factory cooling loop plus pump internals with an external radiator and pump, using standard -8 plumbing.

06/10/2024

One for the wall of shame. G44 front pinion shaft bearing. Apparently original was removed with a pick axe, new one installed with a sledge hammer. Case is now worth several bucks to the nice folks who recycle our metal scrap.

04/06/2024

https://www.ratchetandwrench.com/shop-life/repairer-profiles/article/33039300/a-spectrum-of-possibility

Navigating everyday life in auto repair when you're on the autism spectrum.