This buildup runs
in chronographic order, the earliest mods at the top and the latest mods
at the end.
Our green K5 has
been getting a little bit biased toward trail use, so when it came time
to pick up a general purpose traveling, camping, fourwheeling truck, we
ended up with this '88 Suburban. Now that 3 kids are part of the general
traveling package, the full size rear doors are great to have and the
cavernous interior means we can carry all the people and gear we need,
and sleep in the truck too.
The overall goal is to leave it low enough to get decent gas mileage, add
a little lift and a little bigger tire to help with the offroad use, and
not spend a bunch to do it.
Here's what we started with:
Here's what it looked
like a day and a half later with what we're now calling the "Stage
It started out with
stock suspension, a fuel injected 350 motor, TH700 trans, 208 t-case,
10 bolts front and rear and 235/75 tires. We added what is now the
core of our
complete 3-inch lift system
(minus the steering box brace and drop pitman arm which we added later,
and we use different shocks now): Click
HERE to see the current
3" Tuff Country
EZRide front springs
Semi-custom rear springs that were left over from my K5. (stock 52"
pack with 4 added leaves and no overload)
#GU38010 4" shackle flip in the rear
#GU37011 HD Greasable front shackles
#GU37012 Greasable front main eye kit
#GU38003 Greasable rear suspension bushing kit for 1 3/8" shackles
New U-bolts front and rear
#GU0010 Braided Stainless Brakeline Kit
4 new TCI-SX8000 shocks for 4" lift
#GU37001 Swaybar Disconnect Kit
We also added
#BU09009 4.5" Bumpstops and a set of new 33x12.50R15 Goodyear ATS tires on 15x8 military surplus
Total cost for the
suspension upgrades was $1003.00 and the tires ran about $600 mounted
and balanced. The rear springs and the wheels were left over from previous
projects but neither are real high dollar items.
Then we loaded up
and went to Moab for some Memorial Day ('02) fourwheeling with the family. We ran a tiptoe through Hell's Revenge, Kane Creek, and part of Steel
Bender. The 'Burb performed quite capably, we never had to be winched
or strapped, and only needed extra rocks in a couple of spots. Not bad
for a truck the size of a whale with open diffs. And the best part was
that it did it all with the AC running and got 11-12 mpg on the road trip
down there. Overall pretty nice. Here are some trail shots from that weekend:
We had a few minor
tuning changes to make after running the 'Burb for a while:
The 3" front lift and 4" rear lift was intended to set the typically
saggy suburban level or a bit high in the rear and measurements indicate
that it sits exactly level, so a set of our Zero Rate Add a Leaves may
find their way into the rear suspension in the future to make sure it
stays up where it belongs.
We ran the stock
steering setup for a couple months and while its function was fine, it
had a small bit of bumpsteer so we added a 2" drop pitman arm and
now the truck drives as good or better than it did to start with. Part
# is SKYCA50 for $95.00.
The rear driveshaft
geometry worked out OK with no changes after the lift but when the truck
was loaded we were picking up a vibration so before the last road trip
we dropped the transfer case 3/4" and shimmed the axle up about 6
degrees to get it all lined up perfect and now it runs nice and smooth
all the time. Axle shims are #U8004 and cost $25.00 for the pair.
At this piont, (Fall
'02)This truck is pretty capable as is, but since no truck is ever "done"
we do have some future plans to upgrade it for on and offroad use:
Add a 4.56 geared
14 bolt FF and gear the front axle to match, in addition to adding 8 lug
hubs to the front. This will make the overdrive a much more useful gear,
give us better braking ability, and let us run a set of 34-35" tires
that we have kicking around here.
We plan to add our
bolt in steering box brace to make sure the box stays attached to the
frame. This truck has a factory engine oil cooler so the box brace install
will take a little more than on most trucks.
We need bumpers and nerf bars, no question. Proper body protection will
allow us to do trails we wouldn't attempt otherwise. Or just allow us
to get out of some trails with doors that still open. They might help
fend off some parking lot dings too.
Maybe, in the rear only. If the front gets a locker it will have to be
selectable so we can still run in 4wd on snowy and icy roads.
for the "Stage 2" modifications
We had run some decent
trails with the 'burb through the summer and used it for a few camping
trips and started itching for a bit more durability and off road ability,
along with some deeper axle gears so we could run our transmission in
overdrive again. So before a Thankgiving '02 trip to Moab, we decided
to make some more changes. I don't really recommend wrestling with a 14FF
axle with a belly full of turkey, but it's done now.
While the 3.73 geared
28 spline Corporate 10 bolt rear had been an adequate performer for us,
we were a little nervous about locking the rear up and running bigger
tires. So we started looking into a 3/4T axle swap. What we happened to
have around was a 14 bolt FF rear axle from a military CUCV truck with
the standard issue Detroit Locker and 4.56 gears. So we cut the spring
perches and shock mounts off, put them on in the proper locations for
a 1/2T or 3/4T truck and bolted it up. We went the cheap and easy way
on the driveshaft and used a NAPA conversion ujoint at the pinion and
used our 3/4T ubolt conversion kit to bolt it up. We also added a set
of our Zero Rate Add-a-leaves to the bring the rear up a little more at
the same time.
The front 10 bolt
was re-geared to 4.56 and fit with 3/4T 8 lug wheel bearing hubs and rotors
to match the rear. We also added the proper 3/4T caliper mounting brackets
but used the original '88 calipers. We were tempted to drop in the Lock-Rite
we have left over from the K5 but resisted since we know how they handle
on icy roads. It'll stay open for now and be just fine.
tires are actually a set of 315/75 Procomp All Terrains on our old Stockton
16x8 steel wheels. These tires have made the rounds on several different
vehicles so they're new to the 'burb and that's about it.
After this swap,
we're pretty sure all subs should have come as locked 3/4T trucks. The
bigger brakes are great, it's nice not having to worry at all about the
rear axle strength or durability, and the Detroit locker is almost invisible
except when you want the traction. The 4.56's work out fairly well for
overall use but the motor could use a bit more power. 4.88 gears would
be OK but we'll be looking into some motor mods to get the power to run
in overdrive up moderate hills or with a headwind.
We did a bit of grinding on the bottom of the 14FF to smooth it up and
get better ground clearance and it's definitely paid off. More than once
it's slid it's way over a rock instead of hanging up on the stock diff's
The 35" tires
required some more fender trimming, partly due to the size, partly due
to the width of the new front axle configuration and the steel wheels.
The trim job is not really obtrusive but was definitely necessary. A 1"
body lift may be in the future to give them a bit more room but it definitely
works now in all but the twistiest situations.
Here's a list of
the parts added this time:
4.56 gear set for
the 10 bolt front axle
8 lug hubs, rotors and brake backing plates
3/4-T u-bolt reversal kit
14 bolt full floating axle with 4.56's and Detroit locker
1" Zero Rate Add-A-Leaf kit
After taking us on
a few winter camping trips and some snowmobile towing through the winter,
it came time for a trip to Canyonlands NP for Mother's day and luckily
the radiator started leaking before we left instead of after. We replaced
the radiator with a new stock replacement and did a minor motor tuneup
at the same time. After adding plugs and a cap and rotor, we had a noticeable
increase in power and mileage. It's easy to forget all the regular maintenance
that has to be done when we're busy doing performance upgrades, but it
never goes away.
The camping trip was great, we had a comfortable vehicle to ride in on
the way down, we did Elephant Hill (a 3 or 3+ rated trail) with no difficulty
and drove home. Overall the truck did just what it should do, everything
we asked with no problems.
As of August '03
the 'Burb has been a daily driver for about 2 months and is doing great. Mileage is about 13 mpg on 55-65 mph roads and it just keeps doing it's
job with no major problems. It's been on a few easier 4wd trips up here
in the mountains showing off the views for the relatives and it works
great for these milder trips.
OCTOBER '03 Time
for a few changes.
Through a summer
trade deal, we came across a set of 16x10 Weld aluminum wheels with some
MT Baja Claw tires on them so we made the best of the situation and put
a set of 315/75-16 BFG All Terrains on the wheels and slapped them on
the 'Burb. We've used the BFG AT's before and been extremely impressed
with the overall road manners and offroad traction so they were a pretty
easy choice. The Weld wheels? We do like them but they don't exactly fit
the "budget" part of this buildup. A set of black steel wheels
would do the same job for a fraction of the cost. Since we have them,
they'll probably stay for a while.
We also had our old K5 bumper sitting around so we went mounted it up
for a little rock and deer protection. The Hellas come in pretty handy
Here's a "beauty
shot" with the new wheels and tires and the mods mentioned below. The ride is pretty level and this is with most of a full tank and a load
of camping gear.
We have been planning
a return trip to the Hole in the Rock trail in SE Utah for about a year
now and having been there before we knew some more changes were in order. This is a somewhat demanding trip in that it involves a LOT of time in
the truck. You start and finish with a 6 hour drive on the asphalt, over
everything from 75+ mph interstate to some slower speed twisty canyon
roads. Then you hit the dirt (and rocks) for about 90 miles of rough offroad
driving with a little bit of medium grade rock crawling mixed in. We definitely
wanted premium shocks and this is where the thought process gets a bit
strange. We decided to add the standard Ford shock towers to the front
to allow us to mount longer shocks but with the short suspension lift
(3"), the towers would hit the floorboards, so a 1" body lift
became a natural thing to add. This also gave us a bit more tire clearance
which we needed with the 35's and provided us with a good excuse to replace
the body mounts with some of our urethane mounts. Some of the factory
rubber mounts were totally gone so it was really time for new mounts.
True to the nature of such processes, we just did get the body mounts
and body lift installed in time to pack up and leave for the trip so instead
of using the extended shock mounts, we had to bolt a set of ProComp MX6's
into the factory mounts. Luckily the shocks intended for a 4" lift
worked as well as can be with the 3" springs we have on the 'Burb
so it wasn't too big a deal.
This is from the
lower section of the Hole in the Rock trail:
Once again, we were really happy we made these changes before the trip. Apparently the body mounts being blown out had been creating some body
creaks and groans because with the new mounts the truck is a lot quiter
in twisty situations. The 1" body lift gained the tires a bit more
room and helped with clearance between all the chassis parts and the body,
and last but definitely not least, the shocks.... High pressure gas shocks
are the hot ticket for keeping good ride quality on rough roads and the ProComps did their job well. The adjustment feature let us control the
body roll in the more rugged sections and still turn the damping down
for running over washboards, and the high pressure gas monotube design
did just what it's meant to, provide quality fade-free damping despite
being hammered by a heavy truck. The shocks were hot enough to be uncomfortable
to touch 3 separate times and never showed any sign of excess fade. We've
run lesser shocks in similar situations and been totally without damping
after 15 minutes of run time. We still have plans to re-mount longer shocks
but even in the stock mounts, the MX6's did a good job.
Here's another shot from the trail, this makes me glad we didn't do this
in a wagon like the guys that cut this trail out.