Hi Guys. First post, try to do my best. After almost 40 Years, we have our 5580 at home. Scale model from the tires up. Size approx like the Giant Truck but with scale tyres. Feats:

-2L motor below the inline 6-cylinder, rubber isolated. Protrudes a bit into cabin due to size.

-Uses 2 AAA batt boxes hidden as fuel tanks parallelized with Light&Sound plate for SBrick. Pulls / pushes 400gramms against scale with new AAA lithium batteries.

-Has front leaf springs like the orig, also a bit of caster, an almost precise ackermann and a sketchy but well-rolling high-degree turning front hub. A small turning radius is an important selling point for the real. It's not any sturdy and falls apart quite fast without rubber reinforcement if the servo pushes hard. The main "impossible" feature is the front hub due to inline turning pivot, only working with this stupid setup incl. 1L axles with stops (which don't exist unless some pins meet a chef's knife). There is no room for any other inline solution I could think of (Mk2 crane rims).

-The rear suspension is the "Airglide 100" using rubbers as air cushions. Also uses ball joint parts which had to be made a bit more loose by turning them in a drill for some time. Sorry for your losses, there was no other way around, lack of ball parts is just as meh as inline front hubs for this size of wheels. (one WIP picture shows an "Airglide 200" with the V shaped upper arms which was just too large. Kenworth drivers say the 100 is unbreakable but heavy, the 200 is aluminium so meh).

Speed and turning radius demo (vid):

-The cabin is empty as this got way too heavy anyway for the front leaf springs (1860ish gramms with 2 boxes).

-Fifth wheel has a strong connection to the live axles and chassis, and has realistic freedom of movement. Does not include lock pin but a 1x1 pin could slide deep into place if reversing to a trailer.

-Oh yeah. The rear differentials also needed a 2,5L axle, so it was chef's knife time again.

-No doors as we are poor but happy. A 6x8 door with stickers would fit.

-Various parts are stressed too much. If this MOC shall not be displayed here due to the above illegal moves, just let me know or remove it.

20240419_123916 by lapa leves, on Flickr

Edited July 30, 2024Jul 30 by lapaleves
people wanted more pics

Wow, this is a very cool build, well done.

Welcome to Eurobricks!

Looks like quite an in-depth modification you did! I like the idea of spinning the ball joints in a drill until they get loose! You can always argue that it's just worn out, not modified! :)  (In seriousness, though, this forum is pretty accepting of modified parts. People might respect something unmodified more, but lots of people use custom/modified parts when necessary). One tip for next time, though: We'd like to see more embedded pictures! I had a look through your flickr album you linked, but it's easier for folks if you link images for what you're talking about directly.

Anyways, I hope to see more work from you in the future! Looks like you had fun with this project!

So be it. Thanks for the feedback, edited orig post.

Thanks for the extra photos :)