86 Sunrader 21' Leaf Springs & Suspension question

[tbluge]

Greetings everyone, I just purchased a 86 Sunrader (21')  and the front suspension is completely flat.  I purchased a new prothane bushing (full) kit and new Blistein shocks for both front and back.  But i can't seem to find anything about the actual springs.  Can you purchase them?  are they a complete pain to replace?   I have heard people of taking them to a shop to be rearched / put in helper springs but i guess i'd rather have new ones put in if possible.  I'm not above bringing it in but if i can do it myself i'd much rather do that. 

Thanks in advance!

 

[WME]

An 86 should have front torsion bars not springs. There are some adjustments that you can do to raise the front.

HD bars are hard to find. New stock bars are easy.

Edited February 26, 2016 by WME

[jmowrey]

We had ours rearched and the helper springs added. The way it was explained to me by my mechanic (who did the replacing but not the rearching) is that this process is more an art than a science. He sent the springs out to someplace that has expertise in doing this. The result was fantastic. Our rig rides higher and is far more stable than it was. It was money well spent.

Hope this helps in your decision.  

[Bob C]

jmowrey--You must be talking about the rear springs.  The original post was referring to the front suspension being "totally flat."  The torsion bars may be adjusted (a little) or replaced.  The front springs are a straight shaft and can't be re-arched.

[zero]

On 2/27/2016 at 10:04 AM, jmowrey said:

We had ours rearched and the helper springs added. The way it was explained to me by my mechanic (who did the replacing but not the rearching) is that this process is more an art than a science. He sent the springs out to someplace that has expertise in doing this. The result was fantastic. Our rig rides higher and is far more stable than it was. It was money well spent.

Hope this helps in your decision.  

I worked in a shop that re-arched springs 40 years ago.  May be more then a "lost art."   The only right way to restore a spring is to re-bend it and then use the correct heat and quench process to re-temper it.  Many shops now adays just rebend the spring to get it back to the original arch profile but do not retemper.    Regardless - seems kind of useless on a Toyota RV unless there are leaves added to each pack.  Toyota never made springs that were meant for the full-time weight of an RV.  So if they are Toyota original - seems to me restoring them "back to original" is kind of a waste of time. They will just squat and sit on the 2nd stage as they are designed to do.  And yes, I realize the original post is about front torsion bars.   I guess if there was such a thing as a "repair" for a torsion bar - it too would involve a retemper process.  Not much sense since a torsion bar is not an expensive part.  Probably cost more for the labor to get one in and out then the part itself.

[Totem]

Since the topic header is leaf springs but the OP mentioned also front springs in opening salvo, I'm going to go on the idea that I wont get admin banishment if I suggest Air springs/Air Bags to raise the height and ride quality improvement a bit.

Agree with JDE ; if the springs bent once they will again. Air bags push the springs out and keep them in arch.

[payaso del mar]

I was going to start a new thread, but this seems like as good a place as any to ask.  I recall Linda mentioning that trying to raise the front by jacking up the preload adjusters on the torsion bars would result in a very stiff ride.  the torsion bars just float freely in the splines once you unbolt the ends.  anyone have any thoughts on whether raising the front end by moving the torsion bars a spline or so in the housing would be feasible?  would it also result in a hideously stiff legged ride?  other negative effects?

 

thanks!

[linda s]

I don't believe I ever said it was a stiff ride. I just said you can get a little lift from it. Not much though.

Linda S

[OlympicMtnBoy]

I do believe you can also reindex the front torsion bars, but you can only get so much out of them either way.  Check out some of the 4x4 Toyota truck forums for lots of DIY write ups on that.  You can get new spring packs custom made for the rear.  I was quoted over $1000 to get new spring packs for my Nissan Sunrader though, I just ended up going with airbags since I didn't have them.

[zero]

It is fairly easy to just add a few leaves to the back and beef up the spring packs.  I've done it to every Toyota RV I've owned.  You basically have to unless some other remedy has been added like air-bags or Hellwig helpers.  Toyota's heaviest spring packs made for the 1 ton duallies are not designed to ride fully loaded all the time. That is the issue.  The people who built these RVs should of added to the springs to get them off the 2nd stage.  Only slight catch with these Toyotas is the odd-ball spring width.  As I recall, no body else uses it except for a few Mazdas.  2 3/8" instead of the more standard 2 1/2".   Plenty of places sell special extra leaves with the correct arch and width to bolt right in.  

On the subject of torsion bars. Seems turning them only increases ride-height. It does not change their "spring rate" and if anything  - helps them to break. That because once you increase the ride-height, you also increase the travel and that leads to earlier failure.  Especially in a tired piece of spring-steel.  

[payaso del mar]

Linda, didn't mean to mischaracterize your comments.  maybe I misread you but I thought you said your 4WDYota expert buds told you jacking up the preload adjusters would make the ride stiff legged.

JD, increasing the ride height was the idea.  i don't want something that will loosen all the cabinet screws on every expansion strip.   you're right on it increasing the failure risk, but have you ever heard of torsion bars snapping?  I suspect it's more likely they would just sag a bit faster as the metal fatigues.  either way, might be good to start with new ones if doing this.