Rear Suspension Issues - Need Help! (1 Viewer)

[Sputnik40]

Ok - Looking from help from the more experienced.

I have a 76 FJ40 that I did a SOA on using very soft stock springs. I run a center ladder bar (actually an FJ80 front torsion beam) that prevents axle wrap - springs are flipped, 1" over stock shackles, running 39" Krawlers. Rancho 9000's inboarded.

I've seen a lot of comment on how you get rear end squat with this set up - especially on steep unhill climbs. I can deal with this when crawling on dry rock or other good traction surfaces (have around 65:1 crawl ratio) - but am not wheeling the way I want to when on slippery stuff and more skinny pedal is needed to get up and over obstacles on really steep inclines. If I'm not making it up I get axle hop (not wrap) due to the soft springs, tires aired down and maybe too soft a shock. Due to past pinion breakage episodes - I just tone it down and/or take a winch (rare) - I figure this out so I can hammer it like I used to .

Would higher end shocks help out here, I really don't want to stiffen the spring packs up (I mean heck - those who run 55 springs have to have similar issues) - any ideas appreciated.

 

[lowtideride]

A wrap bar will cause wheel hop if not set up with the correct angles...

I am sure Mace will chime in with the answer...


See you on the trails in a few days!!!

 

[lowtideride]

P.S. after you broke your last pinion up on slick rock I was wondering if the 80 series bushings where still allowing axle wrap. I doubt it would have flexed enough to have bound a u-joint though... Hell I don't know.

 

[bustanutley]

Got any pictures of your wrap bar? Wrap bar design is similar to link design, you want your bar long and flat, also if you are useing a shackle at the end, it is important for it to be perpendicular with the tangent of the arc the bar swings.

 

[Mace]

Pics please..

 

[Sputnik40]

Al - that last pinion on slick rock was pure overzealous skinny pedal and Krawler traction - I can't fault anything else...especially seeing as how I walked Gaurdrail, Skoolbus, Helicopter (twice on the steeper line), Lower 2 (except for Jaws) and Upper 2 that same week - all taking it easy and playing nice. Same for my August trip - I just wanna get back on the gas and have more fun.

If it's the bushings in the 80 arm - I can just replace with a 2" x 2" square tube or what have ye.

I have the 40 in storage at my parents due to bitch neighbor complaining about my vehicles - left her a nice note and parked my beat up 88" Series III in front of one of her yuppy vacation properties so she can see it from her house everyday. Yuppie scum are invading my downtown historic neighborhood - and while I've got an equally nice house I'm in the group that's more concerned with the neighborhood - not making money - whew, rant off...of course with the temps starting to dip welding season if here .

I'll dig out pics or have Al take some on 11/10 (most likely in action and breaking something else) .

 

[lowtideride]

Al - that last pinion on slick rock was pure overzealous skinny pedal and Krawler traction - I can't fault anything else...especially seeing as how I walked Gaurdrail, Skoolbus, Helicopter (twice on the steeper line), Lower 2 (except for Jaws) and Upper 2 that same week - all taking it easy and playing nice. Same for my August trip - I just wanna get back on the gas and have more fun.

If it's the bushings in the 80 arm - I can just replace with a 2" x 2" square tube or what have ye.

I have the 40 in storage at my parents due to bitch neighbor complaining about my vehicles - left her a nice note and parked my beat up 88" Series III in front of one of her yuppy vacation properties so she can see it from her house everyday. Yuppie scum are invading my downtown historic neighborhood - and while I've got an equally nice house I'm in the group that's more concerned with the neighborhood - not making money - whew, rant off...of course with the temps starting to dip welding season if here .

I'll dig out pics or have Al take some on 11/10 (most likely in action and breaking something else) .

I sure will take some pics home boy...


I still don't believe that you broke your pinion just because of the skinny pedal. You were getting on it but I dint think you were too bad into the throttle.

 

[Eskimo]

I haven't really seen any rigs with an anti-wrap bar like yours (and mine) that didn't have tons of anti-squat and bounce like crazy.

2 friends have switched to Alcans with the anti-wrap leaf and I've seen 'em in action, and they work pretty darn well.

I had the same hop problem, so I went from a soft shock (Doetsch 3000, angled inward) to a Bilstein 5125 mounted straight up and down, dropped a few hundred pounds from the back by losing the body tub, and it still hopped like mad.

I know you're not airing down too low, after all, they are Krawlers, don't they spontaneously burp the inner bead below 8 psi?

 

[Sputnik40]

Here's a few pics. First shows how arm is mounted solidly to rear axle - that's beefy plate - so except for the flex in stock bushings it's pretty stout. The second shows the results of trying to make a standard sized item fit a previously designed skid plate - the angle is all wrong and I recollect I got feedback here to change it! The third shows the change to a standard shackle from a different angle - it might still be that this angle is wrong.... I can do neutral drops with either shackle arrangement and not get any axle wrap - but obviously with the super soft springs it's a different story when going vertical and putting more weight on the rear suspension.....

Cost for those alcans - I'm mega busted on other projects (two 88" rovers, a boat and taking my son to along on the guys only Costa trip this year - my 11th). That and I'm craving the Orion HD with twin stick - need a simple solution .

Yeah Al - with or without this problem, I'm sure you'll be egging me on . Nice article by the by - just a shame you have to inlcude pics where we're both busted!

 

[Sputnik40]

Couple of different angles...

Al - surf is head high and barreling down here, but fickle due to all teh backwash from the winds - we're up at 5:45 and hitting it at daylight - what's going on in St. Auggie? Duane sent pics of madness raking the pier - and I noticed that the beach renourishment is goooooone!

 

[Sputnik40]

Yeah - I've definitely got em angled in pretty steep to get the max size shock in there - your reply helps big time though showing that the stiffer shocks don't help - and I've watched your build here and there and you've got a tough rig.

Hmmmmm, yeah - have to add air once in a while mysteriously - but not so bad that I ever get 4 lbs or lower - give or take .

Alcan prices with anti wrap and how close to flat can you run them - I'm just sitting here (the lady friend has left so the mushy movies are swapped out) and watching Pirates II and see how those waggy springs are just soft as heck - but then again slow and in the traction is never problem - slick, slippery or loose traction (e.g. anything but dry rock) and damn, just can't get it going....

I haven't really seen any rigs with an anti-wrap bar like yours (and mine) that didn't have tons of anti-squat and bounce like crazy.

2 friends have switched to Alcans with the anti-wrap leaf and I've seen 'em in action, and they work pretty darn well.

I had the same hop problem, so I went from a soft shock (Doetsch 3000, angled inward) to a Bilstein 5125 mounted straight up and down, dropped a few hundred pounds from the back by losing the body tub, and it still hopped like mad.

I know you're not airing down too low, after all, they are Krawlers, don't they spontaneously burp the inner bead below 8 psi?

 

[Sputnik40]

Always happy to oblige the camera - so long as another ex-girlfriend doesn't end up on the cover of another DVD .

I sure will take some pics home boy...


I still don't believe that you broke your pinion just because of the skinny pedal. You were getting on it but I dint think you were too bad into the throttle.

 

[lowtideride]

Couple of different angles...

Al - surf is head high and barreling down here, but fickle due to all teh backwash from the winds - we're up at 5:45 and hitting it at daylight - what's going on in St. Auggie? Duane sent pics of madness raking the pier - and I noticed that the beach renourishment is goooooone!

We are hitting it now...


Winds are offshore...and its semi glassy.

The beach is gone.

 

[too tall]

The angle on your track bar is creating too much antisquat (causing you to bounce) Also your shocks could be a little more vertical ( more effective ) Wasn't there a thread on this same setup before? Lower the front end of your wrap bar and you'll keep alot more traction.

 

[Wildman]

The angle on your track bar is creating too much antisquat (causing you to bounce) Also your shocks could be a little more vertical ( more effective ) Wasn't there a thread on this same setup before? Lower the front end of your wrap bar and you'll keep alot more traction.

Yea, I agree, also try a good quailty shock, those RS9000 suck. I cant even begin to explain the difrence between my old RS's and the Bilstens that I went to. WORLDS of difrence.

 

[Eskimo]

Yea, I agree, also try a good quailty shock, those RS9000 suck. I cant even begin to explain the difrence between my old RS's and the Bilstens that I went to. WORLDS of difrence.

I'll agree that the control overthe body was worlds better with the Bil's, but they didn't help control the axle hop.

 

[Sputnik40]

Will look into re-engineering the angle - kinda tough as I'm trying to keep it above the skid plate. While I agree the angle isn't perfect - be careful how you look at it - it is definitely higher than the front spring hanger - but it's also misleading how high it goes due to the curve in the FJ80 arm - it doesn't shoot as high up as that curve makes it look.

I had excellent traction this past weekend - and only minor wheel hop on longer skinny pedal climbs - just dropped the clutch whenever it started hopping and took another try slower - no problems. Also - since it's settled so much, am going to put back in the set of mild add a leafs - this should help with the pinion angle that's come up a tad since the springs settled....

I did however have a minor roll on a big rock that you had to take at a steep angle due to trees - made it the first time nose to the sky, the second time - well - see pic below. After that I broke a Poly Performance long side rear axle - pissed - but I had some sick traction and was just krawling and kabing! Gonna call today - hoping I'll get a discount or something on another set? I'm known for being overly optimistic.

Heck of a lot of fun - I'll let Al post up on that one.

 

[lowtideride]

I was impressed by you breaking the poly. You were the first person I have seen break one of those rear axles. Next time you make your way up here we will have to head straight for the bigger rocks...It will be a broken parts winch fest but thats what it seems we do when we team up

 

[Tapage]

How much power you have in your skiny pedal ? n just to broke a poly axle ..

 

[Sputnik40]

Not really a power issue - but bored out 2F, fuel injected with a DUI distributer into an SM420 and 4-speed case with 3 speed gears. I was just pushing (hard) a funky line that the axle either didn't like - or it's defective.....damn good time thought .