Leaf Spring Droop

tim_krueger

Well-Known Member
Posts
728
Reaction
28
Sunday afternoon my friend Matt and I went out to Wild Wash to test his Toyota. Matt built new steering components and changed the front shock configuration. We wanted to work out the bugs before running at the ROR next Saturday. The front end handled so much better than before that we noticed a shortcoming in the rear. The rear is set up 2.5 SAW’s, (factory valveing less 1 bleeder screw) air bumps, and a Deaver Ranger Prerunner pack. The rear measures 15+ inches of wheel travel when jacked up, but uses only about 11” jumping and 8”-9” in the whoops. Basically it doesn’t droop out all the way, for instance off a big jump the springs droop to the point that the arch is the same as when the springs are off the truck. The shackles are about 6” long (I think), they sit 5 degrees back of vertical at full droop and 10 degrees down of horizontal at full bump. The tires don’t fill the holes going through the whoops so it tends to bottem and kick alot. I think easing up on the rebound valveing will help a lot but Matt’s sure it’s the springs and shackles that don't work right. If we change the valving to let the shock extend faster will that make the truck kick. What exactly causes kick, a bump taller than the compession allowed by the travel or the springs extending off of full bump??? If anyone has any suggestions please let us know.
Thanks
Tim
 

havahockey

Flipper
Posts
3,146
Reaction
725
When you droop out the rear with a jack do the leafs seperate at any point? I was told by Deaver that once your leafs start seperating that isn't "usable" travel, so that might be the case. If not, it could be your valving.
 

drtdevil93

Well-Known Member
Posts
1,769
Reaction
11
rebound valving needs to be very fast (.008 shims usually). slow rebound makes it kick, fast rebound keeps it planted.

the spring should droop to the same arch as when they are out of the truck real quick, if it doesnt you have a shock valving problem.

erik
 

J_Dog

Well-Known Member
Posts
610
Reaction
3
In our 7S truck, "kick" seems to be more noticeable when bottoming out. When the suspension is fully compressed up against the bumpstops, the only thing left for the force to do is push the rear of the truck up. Loosen the rebound, so it extends faster, and keep track of what you do, in case it doesn't work or gets worse. We run King 2.5" prerunners w/ bypass valves. According to King, you want to keep the rear wheels on the ground as much as possible. If the rear wheels get off the ground, this is when the truck will start to bounce side to side. The rear wheels on the ground keep things going in the right direction.
 

tim_krueger

Well-Known Member
Posts
728
Reaction
28
Well we finally got to go back out and test the valveing changes that Matt made. Matt lowered the rebound to .008 front and rear and raised the compression to .015 front and .010 rear. In matt’s words “it’s a whole new truck”. It worked so much better, through the same whoop section the truck was in 3rd, up from 2nd last time. The truck only kicked big once on 8 passes, and that was on a 3 foot whoop with a face like a wall. The truck was able to be controlled so much better that compared to last time it was like riding in a caddy on the freeway. The rear seemed to be in almost constant contact with the dirt and never started swapping. We had lots of fun Sunday thanks for posting advice it sure helped. THANKS MATT FOR LETTING ME RIDE!
 

matt_helton

Racer
Posts
3,876
Reaction
300
wanger, yep he is right. it is a whole new truck. it would have been a perfect day if not for the damn right side upper control arm twisting into a pretzel. i guess its too fast now for some of the suspension components. no worries, i can build new stuff. anyways, thanks to eric from deaver for recomending the .008 shims on the rear rebound. that made all the difference. i can actually feel the rear end falling into the wholes instead of packing up and kicking off the tops of the whoops. i think also that changing the front compression shims to .015 from .008 also helped in the way the rear now reacts. i was hitting things that i had hit before and the rear kicked, and now the truck launches a bit nose high. perfect in my opinion. and the new lower gear ratio also lets me go a bit faster cus now im in 3rd gear alot. 5.67 ratio now, had a 5.43 prior. anyways, thanks again to the guys that replied to the this thread. your tips helped ALOT!!! see you all at the ROR on the 18th.
 

drtdevil93

Well-Known Member
Posts
1,769
Reaction
11
you can thank pete albano and greg gagnon, they are my shock teachers


erik
 

havahockey

Flipper
Posts
3,146
Reaction
725
www.arto-motive.com/lucernewhoops2.wmv

I'm pretty sure I know that i need to get the rear to rebound faster but wanted to see what you guys think about the valving from this little video. Its about 1:30mins with the second half slowed down so you can see what its doing. The terrian are whoops from 1 foot to a few 3 footer deep going about 55mph.

Any info/opinions would be cool!
 

J_Dog

Well-Known Member
Posts
610
Reaction
3
havahockey,
MORE rebound. The slow-mo was very good to watch. The front looks like it works very well. You can definitely tell the differecne from the front to the rear. The rear wheels look to be staying up way to long (not dropping fast enough in the troughs). It looked like the truck stayed pretty straight, but with the rear wheels staying in the air I would think it would start to get a little hard to handle (rear end would start kicking left to right) or you would need to slow down. Looked like it got a litle "kick" up a couple of times as well. With faster rebound it would probably handle better. As always, keep notes and don't be afraid to make changes. With notes, you can always get back to what you had.
 

Eric_M

Well-Known Member
Posts
189
Reaction
1
jason,

to me the rear does seem to be rebounding slower than before. what did you do to chage the rear?
 

havahockey

Flipper
Posts
3,146
Reaction
725
Thanks for the input, that seems to be the general thought, the rear needs to droop out faster. Jerry at Camburg valved the front a few times and it seems to be real close to being dialed in, now its time to dial in the back.

Eric, Erik over at Deaver reworked the springs for me and made them softer, so I think thats why they don't droop down as fast.
 

tedmales

Well-Known Member
Posts
541
Reaction
10
i do not know what to do about valving, but i looks like it works pretty darn good.
 

drtdevil93

Well-Known Member
Posts
1,769
Reaction
11
shouldnt droop out any slower from the spring being softer. i made the spring taller, so it should be drooping out faster than before. just speed up that rebound. it makes a huge difference.

i remember your passenger side shock seeming wrong to me. might be something wrong inside. i had a dead shock on my truck for a while, and wasnt hugely noticeable, it just didnt work great. it took a while to droop out, and the rear would start bouncing side to side in the deep stuff.

erik
 

tim_krueger

Well-Known Member
Posts
728
Reaction
28
the front looks good and i agree that the rear seem to droop out a little slow. the stuff matt and i were hitting was alot bigger though. another thing i learned was that the valving on the front of the truck has alot to do with how the rear works and vice versa. so maybe just adjust the rear and see what it does to the front and rear then adjust again if you have to. by the way can you post a little more info about your truck front and rear suspension, shocks, etc. anyways im still new at this "high tech" tooning stuff and still learing. back when i had my blue toyota the only big shocks were kusters lol
good luck and keep us posted on what happens
 

havahockey

Flipper
Posts
3,146
Reaction
725
Ya when we take them apart to valve them hopfully all is good inside.

As far as my truck, it has Camburg LT up front, Swayaway 2.5" coilover and airbump. In the back 62" Deavers, Swayaway 2.5" triple bypasses, 32 gal fuel cell, dual spares, etc.
 

matt_helton

Racer
Posts
3,876
Reaction
300
wow, its so cool that this old thread has come back to life. thanks guys. anyways, just as a side note. i wanted to give a special thanks to Kartek for royaly reeming me on valving shims. 2 dollars a piece, not 2 dollars for a stack(5), but 2 dollars EACH!!!!!!!!! even though they gave em to me for a buck fifty each cus i complained. its still highway robbery. the tool at the counter rattled off some schpeel about the ultra high strength special material and the extensive manufacturing process that goes into making them and thats why they cost so much. WHATEVER!!! so in the "immortal" words of the Fishd00d.............WHAT A JOKE. ok, im off my soap box now. sorry.
 

CRAIG_HALL

Well-Known Member
Posts
2,527
Reaction
575
What type of shocks are they? King shims cost even more.
 

matt_helton

Racer
Posts
3,876
Reaction
300
they are Leak-A-Way shocks. just seems pretty crazy to me to charge that much. but maybe im an idiot, who knows. its the first time ive ever re-valved any 2.5 shocks. i used to have 2.0 fox shocks on my old yota and i re-valved those. it was along time ago but it seems those were real cheap. and i realize they are smaller but still. seems crazy to pay that much.
 

RacerX

Well-Known Member
Posts
1,093
Reaction
55
King shims run about $5 a shim, maybe more. FOX's are great, $1 a shim
 

J_Dog

Well-Known Member
Posts
610
Reaction
3
BHTool is absolutely right about the front and rear working together. We had a problem with the rear end kicking up on jumps, but in reality it was more the front not lifting up enough. We loosened the rebound (made it faster) on the front and the problem was solved. So, don't forget the overall picture when dealing with one end of the truck. What you do to the rear will affect the front.
 
Top