Search | Statistics | User Listing | Member Roster | Coach DB Forums | Albums
FMC Owner's Forum
Home -> FMC Owner's Forum ->  General Discussion -> Mechanic's Corner -> View Thread

You are logged in as a guest. ( logon | register )

Rear Torsion bar height adjustment
Jump to page : 1
Now viewing page 1 [25 messages per page]
View previous thread :: View next thread
   General Discussion -> Mechanic's CornerMessage format
 
woodlandfarms
Posted 2020-04-10 8:46 PM (#7201)
Subject: Rear Torsion bar height adjustment


Regular

252525
I have looked at the service manual, and have seen only one conversation in the group which was more air bag oriented. While I have the back end torn apart for the brake job, there is no way to adjust the torsion bar to increase ride height is there? I have 40 year old sag and probably shouldn't fight the fight on air bags but have to ask.
Top of the page Bottom of the page
andy1canada
Posted 2020-04-10 10:37 PM (#7204 - in reply to #7201)
Subject: Re: Rear Torsion bar height adjustment


Elite Veteran

500100100
Location: Victoria, BC. Canada
Fight-the-fight!

Terry
#846
Top of the page Bottom of the page
LCAC_Man
Posted 2020-04-11 8:35 AM (#7205 - in reply to #7204)
Subject: Re: Rear Torsion bar height adjustment


Elite Veteran

5001001001002525
Location: Oceanside, CA
The "group 7" steering section of the manual has something in the "coach leveling" that speaks to it. I didn't even bother with it, I knew I was going to have all kinds of differing loads/tongue weights so airbags just made more sense for me.
Top of the page Bottom of the page
hemi354az
Posted 2020-04-11 11:58 AM (#7206 - in reply to #7201)
Subject: RE: Rear Torsion bar height adjustment


Extreme Veteran

50025
Location: Scottsdale, Aridzona
Too bad you did not WEIGH the front and rear of FMC #86 before you started your brake and now rear suspension project.
Too bad you did not measure the ground to jack location Frame HEIGHT at the front/rear, and left/right before you started your brake and now rear suspension project.
Those numbers would show just how much things are out of "position" and perhaps overloaded.
Remember never add any weight behind the rear axle of a FMC. This includes Bumper Stickers !
If you have a rear mounted spare tire . . . move it to the FRONT !
If you are going to carry Coal to Newcastle in a trailer with a lot of Tongue Weight . . . you should have bought a Peterbuilt or Kenworth or Freightliner.

Below, and scattered thru this Website, is the often used improvement to FMC Rear Suspension.

http://www.fmcowners.com/mbbs22/forums/thread-view.asp?tid=273&post...

http://www.fmcowners.com/mbbs22/photos/photo-thumbnails.asp?albumid...

Do NOT use either of the stock FMC rubber rebound bumper mount holes.
Put a NEW hole for the Timbren mount 3/4 inch (center to center) INWARD in line with the REAR stock hole, as shown in picture 17.
That position allows the compression of the Timbren to expand WITHOUT touching the inner reel or rim, as shown in pictures 19 and 20 from another FMC.
I prefer the "Single Convolute" Timbren over the "Double Convolute" as short/fat is more stable than the figure 8 shape shown in pictures 19 and 20.

Pictures 13, 14, and 15 show where the upper edge of the Timbren has to be filed off to fit snugly right against the stock FMC bracket.

Search the word "Timbren" to see more.
Bounce ON ! Lou #120



Edited by hemi354az 2020-04-11 12:00 PM
Top of the page Bottom of the page
hemi354az
Posted 2020-04-11 2:19 PM (#7208 - in reply to #7206)
Subject: Re: Rear Torsion bar height adjustment


Extreme Veteran

50025
Location: Scottsdale, Aridzona
Please see http://www.fmcowners.com/mbbs22/forums/thread-view.asp?tid=273&post...
Posted 4-11-20.
Lou #120
Top of the page Bottom of the page
woodlandfarms
Posted 2020-04-12 12:16 AM (#7209 - in reply to #7201)
Subject: Re: Rear Torsion bar height adjustment


Regular

252525
Wow Lou... Good stuff. A lot less pricey and complicated than the air bags. I am a bit confused, does the timbren kick in under "normal" conditions? Does it provide improvement on the sagging? It looks like it does but I can't fully tell.

Well, I am going to button up the Moho tomorrow, start / finish my alcohol flush and then DOT5...
Top of the page Bottom of the page
andy1canada
Posted 2020-04-12 10:05 AM (#7210 - in reply to #7209)
Subject: Re: Rear Torsion bar height adjustment


Elite Veteran

500100100
Location: Victoria, BC. Canada
After reading what I could find on the Timbren spring application to our coaches, I decided that any tangible benefit justifying using them remained unclear.

IF they could be pre-loaded with a verifiable load of a few hundred pounds shared between them, I concede they could help slightly in terms of displacing very small portion of the load - normally bore by the torsion bar alone - slightly rearward, a foot or so, which should benefit handling by shifting a bit more of the coaches weight onto the front suspension.

How's the alignment, ball-joints, shocks etc?

On a cautionary note: I think the Timbren's could prove useless if there are other reasons your coach is not tracking/steering right. They might mitigate worn torsion-bar bushings partially but it would make sense to make certain all other suspension - front & rear - parameters are in 'in-spec' first and if that don't solve your handling issue, go forward from there.

Moving the spare tire out to the front bumper is also a great suggestion. Also, if the budget permits and you're still running the OEM Onan genny back there, consider replacing that, too. The options to shed 150 - 200 lbs off the arse-end with a lighter genny are many.

Those old Onan's are a - 360 lb blight upon our asses!

When they are set up right these coaches are a joy to drive so stay at it and you'll soon be flying around corners - pedal to the metal - like you used to in your Chevy van when you were a kid!

Keep the questions coming. You'll get lots of good help here, same as I did.

Peace & Good Health to All!

Terry
#846

Top of the page Bottom of the page
woodlandfarms
Posted 2020-04-12 11:30 AM (#7214 - in reply to #7201)
Subject: Re: Rear Torsion bar height adjustment


Regular

252525
Terry. I can't thank you enough for the response. Did you go with the Timbren or did you go with Airbags? Or are you just riding the Torsion Bar?

As for my machine, it is in amazing shape considering I think it has sat since 2008. Almost all of the upgrades that FM whatever in California suggested the PO paid for and had done. So I have upgraded wiring, shocks, windows, added front torsion bar. The PO also kept immaculate records (far far better than me so far). Everything he did is on a printout which is now in PDF. Happy to share if anyone cares. The big thing is that it just sat, and that is no good for a machine, especially when along the coast in the PNW. The Transmission might as well have a hole drilled through the case as it leaks like a syve. The tires are too old to be safe (although brand new in terms of wear). The plumbing froze up, and all the copper was ruined, including the shower valves that ruptured. Brakes are rusted over, but now I hope fixed. I know the AC is in trouble, and I have an odd electrical issue that none of the center counsel guages work. I have to sort that short out. But it is pristine on the inside, nothing a little elbow grease and some sewing won't fix. I am excited about it. And glad I have people here willing to give advice so freely.
Top of the page Bottom of the page
andy1canada
Posted 2020-04-12 1:47 PM (#7216 - in reply to #7214)
Subject: Re: Rear Torsion bar height adjustment


Elite Veteran

500100100
Location: Victoria, BC. Canada
You're welcome.

What little I know about these coaches I learned from the owners manuals, reading most all of the more than 10,000 posts on the now defunct Yahoo FMC site, digging-in and fiddling with stuff; as well as advice from all the good-people on here.

Not sure what you meant by, "...added front torsion bar."? Could be interesting.

This is the direction I've decided to go in with air-bags to mitigate the extra 400 lbs my Cummins swap will bring to the ass-end of #846.

Plywood mock-up: http://www.fmcowners.com/mbbs22/photos/show-album.asp?albumid=191&p...

http://www.fmcowners.com/mbbs22/photos/show-album.asp?albumid=191&p...

Rough sketch: http://www.fmcowners.com/mbbs22/photos/show-album.asp?albumid=191&p...

Actually got off my duff during this Covid downtime to get my mig welder (Miller 211) set up and try it out. Took me all 15 mins to realize I weld like - shite! Going to try to get the gas system working with it today and see if that helps me any. Won't attempt to weld up these trailing arm air-bag mounts till I'm competent enough to weld them strong enough. Pretty comes later, with a grinder and some Tremclad.

Living... learning.

Terry
#846
Top of the page Bottom of the page
woodlandfarms
Posted 2020-04-12 2:13 PM (#7217 - in reply to #7201)
Subject: Re: Rear Torsion bar height adjustment


Regular

252525
HA. No, Jeez. Added front windshield fix. I have Torsion bars on the brain. The welding thing has taken me a while to get the hang of. That Miller 211 is a sweet and very forgiving machine. Gas will help a lot, but remember it only works when it isn't windy. I learned on stick, and let me tell you I am the worst welder there is. I cannot weld upright to save myself. But if you can fined a friend who knows the basics, after half an hour you can weld most everything you need... My hope is to learn tig, I have a poor mans setup that I am starting on until the purse strings loosen enough for a real tig welder.

Thanks again for all the advice.
Top of the page Bottom of the page
andy1canada
Posted 2020-04-12 3:15 PM (#7218 - in reply to #7217)
Subject: Re: Rear Torsion bar height adjustment


Elite Veteran

500100100
Location: Victoria, BC. Canada
No sweat... giv'er!

Terry
#846
Top of the page Bottom of the page
Jump to page : 1
Now viewing page 1 [25 messages per page]
Jump to forum :
Search this forum
Printer friendly version
E-mail a link to this thread

Go to FMCowners.com HomeRunning MegaBBS ASP Forum Software
© 2002-2024 PD9 Software
(Delete all cookies set by this site)