Performance and control issues with lifts what should I beware of?

[upda...@hotmail.com]

Yes, a inexperienced peson wanting a toy... I recently purchased a jeep
with a 2.5" skyjacker suspension lift 0.5" shackle lift and a 1" body
lift. My question is control and safety on highway driving. Someone had
told me that a shackle lift makes control an issue with a short base
vehicle. being that I would use this vehicle in the summer to drive on
a major hwy 40mi one way to work, would it be recomended to scale down
the lifts and which would be best. I'm assuming that some of the drive
train has been modified to accomodate the lifting, so what should i
look for in reversing those issues? I'll do some off roading but it is
also a time to time work vehicle.

Wazz00

[HarryS]

If the suspension and body lift was done properly with the correct tire off
set there should not be a problem. If you are just going to be on the
highway and you have off road tires change them out for a tire that is
mainly for the highway. Remember GOOGLE is your friend.

--
HarryS My 2˘
<upda...@hotmail.com> wrote in message
news:1111207146.7...@g14g2000cwa.googlegroups.com...

[upda...@hotmail.com]

Hi - what is ment by "correct tire off" - thanks

[upda...@hotmail.com]

Hi - what is ment by "correct tire off" - thanks

[Cherokee-Ltd]

"correct tire off-set" This refers to the backspacing of the rim and
controls how far in/out your tires are in relation to your fenders.
-Brian

<upda...@hotmail.com> wrote in message
news:1111240825.9...@l41g2000cwc.googlegroups.com...

[upda...@hotmail.com]

Oh- I see... that is to adjust the wheelbase wider for compensation of
the taller vehicle?

Just one more quick quick question...

With the suspension lift, what modifications may have been done to the
drive shaft ect.. to compensate for the greater angle between ends of
the drive shaft?

thanks for the jeep 101 tutorials

[Cherokee-Ltd]

<upda...@hotmail.com> wrote in message
news:1111246906.1...@o13g2000cwo.googlegroups.com...

Oh- I see... that is to adjust the wheelbase wider for compensation of
the taller vehicle?

*******No, although that would be benficial. Wheel offset is to correct
interference issues and is usually more critical for the steering axle. The
correct offset, even a 1/4" may make the difference in rubbing a control arm
when turning or ripping a fender flare off when the suspension is fully
compressed.

Just one more quick quick question...

With the suspension lift, what modifications may have been done to the
drive shaft ect.. to compensate for the greater angle between ends of
the drive shaft?

*******The driveshaft angle must be correct or the result is vibration. This
occurs when the universal joints have different angles. When the driveshaft
spins on an angle, the bottom of the joint is actually turning at a
different speed than the top of the joint. When the output shaft (transfer
case) and input shaft (rear end) are aligned correctly, they off-set
eachother and eliminate vibration. With a regular driveshaft, you DO NOT
want the ends pointing at eachother, you want them parallel to eachother.

At extreme angles like those found on a lifted TJ, not only do you need a
way to compensate for high angle, you need a longer driveshaft and a method
for preventing the driveshaft from disconnecting at the slip yoke on the
transfercase due to increased suspension travel. This is when you install a
"slip yoke eliminator" (SYE) and a "double cardon" or "constant velocity"
(CV) driveshaft.

By eliminating the slip yoke from the transfer case, you need an extendable
driveshaft. The driveshaft must extend when suspension extends and contract
when the suspension compresses. The slip yoke is built into the driveshaft.

A double cardon or CV joint on the driveshaft solves the angle issue. When
you install it, you aim the rear end yoke at the transfer case yoke. To
visualize, the front of the driveshaft bends down from the transfer case
yoke via 2 universal joints that compensate for eachother and runs inline
the rest of the way into the rear end.
See here: http://tinyurl.com/5x9yo

-Brian

[Jumpin' Jiminy]

Any lift raises your center of gravity. With a total of 4" lift, I
would avoid sudden swerves as you are more likely to roll a lifted
vehicle then an unlifted vehicle.
Be aware of this when you drive and you will be fine.

A 1" body lift does not create any real problems.
It is not high enough to force you to bend the shift levers or
relocate the radiator. It does allow more crap to enter your engine
compartment since there is now a gap between rail & fender.
Some gas tank upgrades use this added space to give you a larger tank
or your tank is also raised to make room for a rockshield
Your fuel mileage will take a hit. Probably from the increased
turbulence.

A 0.5" shackle lift is not enough to cause any problems and is a very
safe upgrade.
A 2.5" suspension lift is the best & safest way to get the height but
with comes a much stiffer ride.
It's a sweet but hard riding combination to get you 3" of 'safe' lift.
In either event, your fuel mileage also takes a hit.

Drive-train Modifications:
Problem here is that with a 3" lift, your axle's pinion yoke no longer
points at the transfer case and has to be adjusted by adding shims to
where the spring is clamped to the axle. With the wrong angle, you
will go through lots of U-joints. Sometimes the transfer case is
shimmed as well.

If you are looking to reverse your suspension lift, you will have to
reshim your axles. It's probably not necessary if you are only
reversing the {small) shackle lift and not at all for reversing your
body lift. This is pretty cheap if you have the tools.
You may also have to replace all your flexible brake lines as they
will now be too long. You will probably also have to change some
steering components such as the pinion arm.

Another drive-train modification that I would assume was done to your
jeep to enable it to run the 35" tires that your lift allows, was to
change the ratio in your axles.
What this means is that when you go back to smaller tires (as you must
after dropping it) you will find your engine running at a much higher
rpm to keep your speed up.
This is big bucks and involves regearing your axles.

Your speedometer will also read that you are going too fast and will
need a new gear. This is real cheap. (relatively speaking)

My suggestion to you is rather then dropping your jeep, is to leave
the lift alone and invest in a cheap set of rims & tires, more on the
original size, to get you through the summer & live with the higher
rpm's and incorrect speedometer.
If you think that small tires on a lifted vehicle are unacceptable,
then consider getting as narrow a tire as you can while keeping the
height. e.g. BFG 33 x 9" AT

An alternative solution might be to just get rid of the body lift and
run 32 or 33's. Your mileage will go up and you won't have to change
much more then a speedo gear.

Big tires are expensive to buy, they wear fast and your gas mileage
takes a hit from the larger profile. Steering components wear faster
from their heavier weight. Best to avoid commuting on them.

Have you considered parking the jeep & buying an old Geo for the
commute? It'll probably work out cheaper and you can sell it after.

JJ