Torque Steer / Bump Steer after lift???
- Thread starter jgolden
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More then most
Not to much trouble topping out running dirt roads at speed
All your issues could be 17" rims.
I would remove them send them to me to eliminate a possible problem.
PM me with payment method?
FWIW: I was getting bump steer that actually emanated from the rear. It was especially noticeable when I drove over speed bumps. I installed Slee's adjustable pan-hard rod and eliminated 90% of the problem. I imagine I could get it back to stock if I relocated one of the pan-hard mounts so that the rod sits more or less horizontal ala stock lift.
Don't know if that is what you are feeling with your "bump" steer or not...
Don't know if that is what you are feeling with your "bump" steer or not...
I agree. I've driven a lot of lifted vehicles. Lifting a coil sprung rear without extending links causes issues with geometry. These changes typically result in squirelly behavior. On one of my troopers (similar suspension design) with 4-5" of lift, I had to lengthen links and fabricate a panhard drop bracket. This cured 100% of my compression steer issues.
Does anyone know what the recommended difference of height is between the front and rear of the 100 series?
I'm referring to the measurement from the HUB CENTER to the BOTTOM of the FENDER LIP. I think I'm have a little bit of torque steer but I'm trying to keep my rig level and not have that "stink but" stance.
Also, what is the recommended droop for the front? I believe it should be 50mm or about 2 inches, correct?
Thanks for input.
I'm referring to the measurement from the HUB CENTER to the BOTTOM of the FENDER LIP. I think I'm have a little bit of torque steer but I'm trying to keep my rig level and not have that "stink but" stance.
Also, what is the recommended droop for the front? I believe it should be 50mm or about 2 inches, correct?
Thanks for input.
^^^been doing a lot of research here lately on this very topic. Best I can tell is ideal rake (difference in height from rear to front) is 1 inch. I was running level for a few months after my lift install and noticed the vehicle tracking towards any uneven surface on the road. Just didn't feel right, so I lowered the front to allow for a 1 inch rake. Haven't driven yet but looking forward to see if there is any improvement.
When you do get out for a drive, keep me posted, would ya?
I'll be checking this post the next couple of days.
Thanks,
Agreed. 3/4 to 1 inch rake is the sweet spot for handling. I tried to go for the "level stance" but even with a 1.5" lift and diff drop I still had torque steer. It was pretty much eliminated after dropping the front 3/4"
Caster is casing tracking problems
When you change the rake of truck you are changing the caster of the front end.
If you like the flat look you could have it and have no tracking issues if you can get the front end caster back to specs with alignment.
I do not know how far caster can be adjusted on 100s, but a good alignment shop can give you an answer.
When you change the rake of truck you are changing the caster of the front end.
If you like the flat look you could have it and have no tracking issues if you can get the front end caster back to specs with alignment.
I do not know how far caster can be adjusted on 100s, but a good alignment shop can give you an answer.
Anybody know enough about front end alignment on the 100's that can shed some light on this?
As noted by tmils470, could this be a caster problem?
If so, is it correctable?
I really don't like the "stink bug" look...
As noted by tmils470, could this be a caster problem?
If so, is it correctable?
I really don't like the "stink bug" look...
I'm 21 5/8" hub center to fender on my 100... I have about 2.5* front caster and I'm using TC upper control arms. About 70mm droop.
If you cannot achieve something in that caster range or better you are in for torque steer. The factory upper arms won't let you get back to that caster if the lift is too large.
The rake is really academic - rear springs play a big part of this visual equation... put 863's on the back in an empty truck and you're never getting 1". It will be ass up. You need to match your rear to the load you are running in conjunction with the spring height.
If you cannot achieve something in that caster range or better you are in for torque steer. The factory upper arms won't let you get back to that caster if the lift is too large.
The rake is really academic - rear springs play a big part of this visual equation... put 863's on the back in an empty truck and you're never getting 1". It will be ass up. You need to match your rear to the load you are running in conjunction with the spring height.
I am sitting right at 20.75" upfront with ProFender shocks, TC UCA's and have no torque steer or wandering. I used to run my front end near 22" and it was terrible.
I have OME 866 Heavy coils with OEM torsion bars. The springs give me 1.5" in the rear and have a ~.75" lift upfront (never measured before lift)
This is the only picture I can find sitting on level ground.
I have OME 866 Heavy coils with OEM torsion bars. The springs give me 1.5" in the rear and have a ~.75" lift upfront (never measured before lift)
This is the only picture I can find sitting on level ground.
I have 2.2* caster on stock UCAs with 21" front hub center to fender. Firestone completely got my alignment adjusted per my request as I was previously out of spec. Basically, it can be done with stock UCAs.
RobRed, how did you measure your caster? Didn't know you could...
Via alignment rack.
As mentioned above you can get that range stock it just depends on lift and how much adjustment on other specs you can live with. Front Droop is a key factor as well... If you have no / less than 50mm the front end will hop all over. More droop is better.
I'm keeping my droop more than 50mm (not much more though...).
FYI my dimensions for the front end are 24.25" from hub center to bottom of fender lip.
What's been done: the entire 2.5" suspension lift kit from Just Diff's including UCA's, diff drop kit from BIO, 1.75" body lift (and 35" BFG M/T, although that makes no difference in the measurements we're discussing).
Note: My dimensions may be as much as a 1/4" off because: When I measure this, my tape measure has to bend out over the side wall of the tire a wee bit because I have slightly offset wheels. BUT, that should not matter as long as I'm adjusting the TB's to be exactly the same measurement on each side with the same distortion on each side when measuring.
FYI my dimensions for the front end are 24.25" from hub center to bottom of fender lip.
What's been done: the entire 2.5" suspension lift kit from Just Diff's including UCA's, diff drop kit from BIO, 1.75" body lift (and 35" BFG M/T, although that makes no difference in the measurements we're discussing).
Note: My dimensions may be as much as a 1/4" off because: When I measure this, my tape measure has to bend out over the side wall of the tire a wee bit because I have slightly offset wheels. BUT, that should not matter as long as I'm adjusting the TB's to be exactly the same measurement on each side with the same distortion on each side when measuring.
Off topic. But can you post a pic of that BL? And did you have a build thread? Would love to know what you have on your truck and where you got it. Thx
Raising the rear of the truck will affect caster, however rake will not affect how the truck handle. A truck with 3 degrees of caster with 0 rake and one with 1" rake is going to drive the same, if the caster is the same. If you are experiencing better driveability after lowering the front, it is because you are changing the alignment, not because you are changing the rake.
Unless you drive that fast that the downforce on the roof is better with rake vs without rake!
Unless you drive that fast that the downforce on the roof is better with rake vs without rake!