The story of the Airstream 310 Jacket

[LM782]

Wow! That is a beautiful rig. Welcome back to being a MoHo owner. I'm sure you will get the mechanicals figured out soon enough. 70k is just broken in.

Luis

[PeterH-350LE]

Originally Posted by LM782

Wow! That is a beautiful rig. Welcome back to being a MoHo owner. I'm sure you will get the mechanicals figured out soon enough. 70k is just broken in.

Luis

Never say never This time a made it almost 3 years without a classic, which is a new record.

[PeterH-350LE]

Finally got the airbags and finished installing them. For those curious about the 300LE rear suspension, here is a close up. No cut leaf springs, dog bone, no possibility for the bags flip. And yes the airbag carrier beam could also be dropped, after getting those massive Nuts cracked.

[PeterH-350LE]

If you have the original air compressor (mounted in a box underneath in the early 90"s models) and you have a mystery leak, you should look at the check valve right at the compressor. Some brilliant mind thought that aluminum would make a great check valve especially for tapered Threads

I found the same cracked valve in the 92 350LE.

[PeterH-350LE]

Put up wet and no maintenance for a decade!

Fixed the trans housing output shaft seal, it was pouring out. The engine rear seal needs to be done ,too. I am having the oil tested by Blackstone Laboratories before making any major decisions about the engine.
The fuel lines crossing over from the frame rail to the engine (4th picture) were about to go up in flames. I just don't get it how folks can just ignore such severe safety issues. I sure am glad that I didn't try to drive this rig the 90 miles from San Antonio to Austin.
The excellent body and interior make up for a lot of these mechanical and safety issues. But it should serve as a warning to potential classic buyers to not jump in some unknown 30 year old rig and drive across the country

[PeterH-350LE]

The oil filter tells its own story of neglect. Fortunately there is a heat shield with a clamp, because once I removed the clamp the filter just turned out easily by hand. Any guesses how old this filter is ...20 years ?
The space in front of my shop tells the story of the battle. So the tally is it took 4 days to get this coach roadworthy and thats only with a brake inspection and not some much needed brake maintenance work. Ok, Dirk (you know who you are), do you read me? Forget the dream of jumping in one of these rigs in somewhere USA and happily driving down the road .

[Boom Sounds]

Originally Posted by PeterH-350LE

bubbles and a heavy duty rear suspension. Quite amazing and puzzling that they only used it on the 91/92 300's

Helllo - he's back. I wonder who will be the (very) lucky owner of this coach.

My 1991 250 had the standard air bag suspension set up.

If you look here: https://www.gm.com/content/dam/compa...-Motorhome.pdf
How does the 300 LE GVWR map into the chassis lengths and standard set up from Chevy when it lt left he factory. I'm curious as to why they would do that. I have a vague memory of a discussion about Airstream modifying suspensions in the hope of addressing shortfalls in the load capacity of the chassis. Something which clearly wasn't possible or strictly legit.

As a side note, my 250 (which did come out of the commercial division) had a VIN tag with a GVWR of 14500 lbs. I asked a few other 250 owners about this and everyone else had 12300 lbs. Again, very odd...Chevy did offer the higher load weighting as an option.

[PeterH-350LE]

Originally Posted by Boom Sounds

Helllo - he's back. I wonder who will be the (very) lucky owner of this coach.

My 1991 250 had the standard air bag suspension set up.

If you look here: https://www.gm.com/content/dam/compa...-Motorhome.pdf
How does the 300 LE GVWR map into the chassis lengths and standard set up from Chevy when it lt left he factory. I'm curious as to why they would do that. I have a vague memory of a discussion about Airstream modifying suspensions in the hope of addressing shortfalls in the load capacity of the chassis. Something which clearly wasn't possible or strictly legit.

As a side note, my 250 (which did come out of the commercial division) had a VIN tag with a GVWR of 14500 lbs. I asked a few other 250 owners about this and everyone else had 12300 lbs. Again, very odd...Chevy did offer the higher load weighting as an option.

Amazing info (as usual), Nick! Except all of them sport the leaf spring set-up. The 91/92 300LE doesn't even exist in that line up. It obviously was dropped by aliens to completely mess us up, after we finally thought we had figured these rigs out. The GVWR is 14500, just like your 250, haha. I have to measure the wheel base to see if that is listed in your doc.
Thanks

[Boom Sounds]

Originally Posted by PeterH-350LE

Amazing info (as usual), Nick! Except all of them sport the leaf spring set-up. The 91/92 300LE doesn't even exist in that line up. It obviously was dropped by aliens to completely mess us up, after we finally thought we had figured these rigs out. The GVWR is 14500, just like your 250, haha. I have to measure the wheel base to see if that is listed in your doc.
Thanks

Was it on the 178” chassis? Do you think it was Airstream or a prior owner modification? I would have thought it came out of GM as totally standard although there were some optional RPO codes for a heavier suspension from the factory and i’ve always pondered whether that is what happened to mine. One day, if I’m feeling flush I might pay GM for a build sheet breakdown from Website: https://www.gmheritagecenter.com to see if it tells me anything. Might be a waste of 50 bucks though

[PeterH-350LE]

Originally Posted by Boom Sounds

Was it on the 178” chassis? Do you think it was Airstream or a prior owner modification? I would have thought it came out of GM as totally standard although there were some optional RPO codes for a heavier suspension from the factory and i’ve always pondered whether that is what happened to mine. One day, if I’m feeling flush I might pay GM for a build sheet breakdown from Website: https://www.gmheritagecenter.com to see if it tells me anything. Might be a waste of 50 bucks though

Its the 208" chassis. I have seen pictures of 2 other 300's with the same Airbag setup. So its not some prior owner modifications, it came like that from GMC.

[Boom Sounds]

Originally Posted by PeterH-350LE

Its the 208" chassis. I have seen pictures of 2 other 300's with the same Airbag setup. So its not some prior owner modifications, it came like that from GMC.

You can spend 5 bucks with Northstar Performance and get a RPO build sheet. I suspect it’s the same as GM. It would be interesting to see the build sheet and might inform what they used put together at the factory.

[PeterH-350LE]

Originally Posted by Boom Sounds

You can spend 5 bucks with Northstar Performance and get a RPO build sheet. I suspect it’s the same as GM. It would be interesting to see the build sheet and might inform what they used put together at the factory.

Nick, I went to their site, but did not see any link for that kind of info. Can you enlighten me?

[PeterH-350LE]

In the meantime, I wrote Airstream about the 300LE models and the lack of info and the crossed out 350 Model number on the cover of the manual.


They were kind enough to reply right away with not much info, but here it is:

Dan Maul (Airstream)
May 21, 2025, 8:11 AM EDT
Hello,

Thank you for reaching out. That's a great find. I'm really not sure why the manual, the previous or original Owner may have lost of throw out the orig manual and picked up a 350 which would be almost identical.
The suspension may have been changed due to parts shortage, vendor changes, or testing different suspension. There's really no way to tell. We may have a few people that were here when it was built, but I'm sure they won't remember those kinds of details.
As far as production records, we would probably have the records of what and when a VIN was built, but not the details of what was in each unit other than what you've found on the website in archives. It may list out what was installed, but not why the change.

Dan
Dan Maul
Visitor Experience Coordinator
AIRSTREAM®

[Boom Sounds]

Here you go Peter https://store.northstarperformance.c...rpo-codes.html


For info, I’ve spoken to many 250 owners over the years and there was no specific manual for that unit either. We got a 350 series manual with a few extra loose pages from technical design which were 250 specific and set out the electrics and plumbing set up. The manual number was also crossed out and 250 added. That was it.

[PeterH-350LE]

Originally Posted by Boom Sounds

Here you go Peter https://store.northstarperformance.c...rpo-codes.html


For info, I’ve spoken to many 250 owners over the years and there was no specific manual for that unit either. We got a 350 series manual with a few extra loose pages from technical design which were 250 specific and set out the electrics and plumbing set up. The manual number was also crossed out and 250 added. That was it.

A lot of items are 100 % transferable, but having a diagram of a completely different Airbag system is a bit over the top. Thanks for the link!
Cmadmaxman has pretty much convinced me that the Air systems on all classics are an aftermarket job. Who did the 300 version is still a mystery.

[Boom Sounds]

Originally Posted by PeterH-350LE

A lot of items are 100 % transferable, but having a diagram of a completely different Airbag system is a bit over the top. Thanks for the link!
Cmadmaxman has pretty much convinced me that the Air systems on all classics are an aftermarket job. Who did the 300 version is still a mystery.

I agree, that matches my understanding as well. My hunch—especially since you’ve seen the same setup on other 300s—is that this was an Airstream modification specific to the 300 series. As for why they did it, that’s probably a detail lost to time.

The 250 is a bit of an oddball. There’s hardly any documentation aside from those loose pages I mentioned, a single A4 sheet listing options from Toscano RV, and a German-language promotional poster I picked up years ago—likely from the failed attempt to export diesel 250s to Europe.

From what I’ve been told by Airstream, many of the 250s were built by their commercial division, including models like the Aircoach shells and ambulances. The archivist confirmed that mine came through the commercial side of the factory, and I’ve always wondered if that explains its supposedly higher load rating.

I could be mistaken, but I don’t recall seeing much promotional material for the 300s either. It makes me think that both the 250 and 300 might have been special-order models, and perhaps your unusual setup is a result of it coming through the commercial division as well. You might want to reach out to Sam Martin, the archivist—she’s been very helpful in the past.

Either way, I think that’s a fantastic coach—great size, and I imagine it would do really well over here, especially with an LPG conversion. Propane is still much cheaper than petrol in most parts of Europe.

[PeterH-350LE]

a little generator maintenance. Thanks to Cmadmaxman for talking me into de carbonizing the heads/cylinders whilst I had it out and for guidance and specs!!
One of the head bolts was barely finger tight. Those OEM Onan parts sure are pricey, $420 for an OEM carb versus $60 for the knock-offs. I went with OEM on most parts.

[PeterH-350LE]

Generator all back together, the replacement made in china metal filter at the carb leaked, had to get rid of it. Did a test run, fired right up and its running smooth. Will install tomorrow

[PeterH-350LE]

Rear Centramatics arrived! 400-417 ready for the new Goodyear tires coming soon. Only the best!

[cmadmaxman]

Looking good Peter, glad it all worked out. Nice to have a good running Genset!