1999 Freightliner XC Chassis front air spring replacement

[mhowie969]

Greetings All

I know that this thread is old, but just in case that there are still RV'rs still needing front air springs for the older XC chassis. I recently replaced the front air springs on my 1999 Winnebago Adventurer 34V. The OEM part number for the original air front air spring was W01-358-9586. Average price for the OEM bag is $300 per air spring.

With the OEM replacement air springs being so expensive compared to other comparable sized air springs. I decided to do some research, I found that the OEM air springs required about 95 psi to support the weight on the front axle. While this is within the capability of the air spring it is very much on the high end of the bags capability. I up-sized my replacement air springs to Firestone W01-358-8204. These springs are slightly larger, still have the internal bumper stop. The price is $150 a pair, which is half the cost of one OEM air spring. The calculated air pressure to support the front end is now 75 psi. This is right in the middle of the design range for an air spring

These new air springs ride so much better then the OEMs that I replaced. Much smoother going over road expansion joints and small pavement defects, I live in Michigan so there is no shortage of road defects.
Any Questions feel free to IM me.
Mike

[JNSNWT]

Welcome to the group and thanks for sharing your information.

[Patrick 8200]

Great info. I have a 2002 Fleetwood Expedition on an XC chassis that also utilize the W01-358-9586 front air bags. Did you install these yourself or have a shop do it. Did the 8204's bolt right into place without having to mod anything?

[greystroke]

Great info. Just checked my PN on DTNA connect. It is 90557221 which is equal to Firestone ..9586.


Would like to know more about installation. DTNA has a replacement procedure but would like to hear it firsthand from someone that has done it.


Welcome to the Forum.

[JNSNWT]

It’s been a couple of years since I replaced the front bags on my 2001 Freightliner XC but I don’t remember anything out of the ordinary. Just soak everything in your favorite penetrating oil the day before you attack it.

My bags were still working but the 20 year old rubber had severe cracking and I’d rather replace them at my leisure in my driveway than pay someone on the side of the road.

[greystroke]

Originally Posted by JNSNWT

It’s been a couple of years since I replaced the front bags on my 2001 Freightliner XC but I don’t remember anything out of the ordinary. Just soak everything in your favorite penetrating oil the day before you attack it.

My bags were still working but the 20 year old rubber had severe cracking and I’d rather replace them at my leisure in my driveway than pay someone on the side of the road.

Good info. If I replace mine I will start by using the DTNA procedure. Did you have to do anything different? Anything to watch out for?

[mhowie969]

Yes. I did the work myself. Direct fit no mods. Lower air bag mounting bolt is 1/2 inch instead of 3/4 inch like the original, so you will need a good hardened 1/2 inch washer.

Jack the front jaacks all the way up, remove wheel and disconnect level control valve linkage on the side your working on. You do not need to disconnect shock. JPut jack stand or block the chassis so that you are save. You will need to drop the front axle, (one side at a time) to access the bottom mounting bolt.
You will need a good breaker bar 3 foot plus. To break the axle mounting bolts loose.
All in all if you have the tools and some mechanical skills it takes about 1 hour per bag.
While your there and the wheels are off, don't forget to check out your front brakes. And check that the clevis pins on the S cam slack adjusters are free, they like to rust from sitting.

Good luck and don't forget to re-tighten the wheel lug nuts and the front I beam mounting nuts after 100 miles or so.
Mike

[greystroke]

Originally Posted by mhowie969

Yes. I did the work myself. Direct fit no mods. Lower air bag mounting bolt is 1/2 inch instead of 3/4 inch like the original, so you will need a good hardened 1/2 inch washer.

Jack the front jaacks all the way up, remove wheel and disconnect level control valve linkage on the side your working on. You do not need to disconnect shock. JPut jack stand or block the chassis so that you are save. You will need to drop the front axle, (one side at a time) to access the bottom mounting bolt.
You will need a good breaker bar 3 foot plus. To break the axle mounting bolts loose.
All in all if you have the tools and some mechanical skills it takes about 1 hour per bag.
While your there and the wheels are off, don't forget to check out your front brakes. And check that the clevis pins on the S cam slack adjusters are free, they like to rust from sitting.

Good luck and don't forget to re-tighten the wheel lug nuts and the front I beam mounting nuts after 100 miles or so.
Mike

Thank you!

[00Weasel]

Mike,


This is absolutely great information. Thanks for sharing. I am prepping to replace my front airbags in my 2000 model year, 1999 Freightliner XC Chassis. Like you, I found the price of the Firestone 9586 airbags quite elevated. I did have a couple questions for you (or anybody else).



In all of my research, I have not been able to find any load chart or weight capacity for any of the Firestone Airbags; where did you find the numbers to calculate that the front axle load would be at 75psi for the 8204 vs 90 for the 9586?


Where did you source your new bags? I have come across several sources, but none were $150 for the pair. I typically see them for around $100 each, which is still much better than the OEM, but if I can save a buck......


The parts diagrams that I have seen for the 9586 bags have the air inlet as a 1/2" NPT Female fitting, while the 8204 bags have a "combo stud", which from what I can tell is a 3/4" bolt with a 1/4" air inlet through the middle of the bolt. Did you have to modify the incoming air line/fittings to get this to fit?


Also, from what I can tell, the 9586 base plate is Aluminum while the 8204 is composite. I don't think that this will be a problem, as long as I can see that the load capacity is the same or more.



Also, I scoured the Firestone Airbag replacement guide to cross reference part numbers, and made the attached picture. I found that the 9584 and the 5776 bags are extremely close in dimensions, but are more expensive than the 9586 bags and are harder to find.



Anyhow, I really appreciate the amount of research you put into this.


Happy New Year!
Gabe

[bpu699]

Subscribed. I just ordered a front air bag and stock was $300 each with a 2 month wait to get…

[bpu699]

Subscribed. I just ordered a front air bag and stock was $300 each with a 2 month wait to get…

Are the prices you found for actual Goodyear products, or knock offs?

[00Weasel]

The ones I have found appear to be genuine Firestone parts. I have had the best luck searching for "Firestone 8402" and combing through the search results. There are bags on Amazon from "Torque" that appear to be decent quality. Allegedly they come with a lifetime warranty, and are priced reasonably. I have zero first hand experience with them, so I don't know anything aside from what is in the Amazon listing.

[mhowie969]

Greetings all
The airbags Are Torque, lifetime warranty. Now $190. on Ebay.

https://www.ebay.com/itm/11430425251...IAAOSwGZlhUioX


I installed new nuts and connectors from Amazon

• 
  
  1/2-13 Nylon Insert Hex Lock Nuts, Stainless Steel 18-8 (304), Bright Finish (304), 10 PCS
  4.7 out of
  
  $8.49
• 
  Hard-to-Find Fastener 014973242183 Fine Finished Hex Nuts, 3/4-16, Piece-3
  
  1. 4.7 out of 5 stars
     
     $7.34
• New air connectors
  PneumaticPlus PN15 Series Push to Connect Tube Fitting, Male Elbow (1/2" Tube X 1/4"…
  
  4.8 out of
  
  $34.99

Note: do not use plastic or composite fittings for the air line, you can't afford to loose the front suspension going down the highway due to a cheap fitting.


You will also need two hardened, thick washers, grade 5 is fine.


I did go out for a test run after installing the air bags, 10 miles down a rough 2 lane at 55 and 10 miles back on Michigan freeway at 65-70. I normally travel 62-65 but this was a test for ride comfort and control, not MPG.

These air bags are much better then the original bag springs, both for handling and comfort.
Whatever air spring you get, make sure that it has the internal snubber, and close to the same min and max height and similar piston diameter

Mike

[00Weasel]

Mike,


Once again, thanks for the great information, especially about the air fittings.



One last question, where did you find the load capacity information for the different air bags? I have just not been able to find them, and my google-fu is usually pretty good.



Gabe