Author Topic: My '81 Suburban C20  (Read 8720 times)

Offline paniolo

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My '81 Suburban C20
« on: August 14, 2011, 11:16:13 pm »
Don't see a ton of burb threads so thought I would throw mine up.  Give me a good place to document some things and work out what next step should be.

First, some history.  1981 C20 Suburban Silverado with factory towing pkg, 454, TH400 and 14bolt rear end.  I picked it up about '04 down in Austin when I needed a tow vehicle to get my 4x4 to and from the trails.   I bought it from a drag racer that used to tow his Camero up to Dallas.  He got a new 2500 from work so this became surplus.  It was basically ready to roll.  He said he put an early '90s 454 in it and had the Turbo 400 built for towing.  Judging by the paint and condition on both that seemed reasonable.  Only system not working was the cruise that wasn't hooked up after the engine transplant and the a/c that had been converted to r134, but slowly leaks out.  Interior was adequate.

I didn't do anything to it but fluids and filters and use it to tow my junk around 1-2x a month.  It towed like a monster, pulling my 6,000# with ease at 70 and was able to pull up long grades right with my bud's Cummins.  Then my son got in over his head in traffic and ran the drivers front into a concrete wall.  Pushed the fender and bumper back into the tire and bent the radiator support.  Luckily the hood was fine.  Was able to hook the bumper and front end up to the back of my 4x4 and pull it out enough to be drivable.  

Then lost my job when the company went bankrupt, and moved up to Dallas for new job.  Parked the burb in the driveway and it seemed like a good opportunity for my son to learn how to work on cars with the damage he caused.  But I was working 6 days a week and not able to supervise much, he got everything off, but didn't do a good job of keeping track of where things came from.  Then he moved off to college.  So it sat in the drive way for 4 years.  I knew I could put everything back, but also knew it would be a big jigsaw puzzle.   Well finally got off my rear this spring and got a junk yard fender/inner, radiator support, bumpers installed.  Then continued and got it in running condition again.  The master cylinder had failed and a wheel cylinder seized.  Changed flushed all the fluids including the gas tank.  So it's running good again and I'm working on the list of improvements I had meant to get to years ago.  

Here are some pics after fixing the damage, but nothings clean on it.

That is a weird reflection by front bumper.


It came with the cowl induction hood.  Original paint was Dark Chestnut and was repainted a brown metallic at some time.  But it matches real close to the inner doors/ interior.


All the windows are tinted and I picked up some chrome steelies with 90% tires.


Didn't get any pics of the accident damage, here is a shot after I got the fender and radiator support on before grill/bumper.  I did some work cleaning up the po install of the tranny cooler and oil cooler.


Front end after repair.  Used radiator support, valence and bumper/mounts.  The drivers side bumper end was almost touching the front wheel.  New grill and drivers side headlight bezel/ light buckets.  Not real happy with the hood gap, it bows a bit.  The replacement fender had a ding from a bumper just above the marker light, you can see in this pic.  I was able to push most of it out.



Side shot after primer.  It is a little tight to the door, but I couldn't get it any farther forward.  Just enough to clear.


Since it had been sitting so long I proceeded to change coolant (duh), oil, flush break fluid, tranny fluid and filter and diff fluid.  Found the master cyl was bad after sitting so long.  Replaced that and found one of the rear wheel cylinders was frozen too.  Nice thing I found the brakes looked like new!  Greased all the joints.  Then since I mainly tow, wanted to install the a/t filter/ temp gauge I had bought years ago.  For some reason the po had routed the lines just to the aux cooler and the hard lines were all bent up.  Took those out straighted them out, rerouted the outflow to the a/t filter then the a/t radiator cooler then to the aus cooler.  Figure the additional routing added 2 qts of fluid.  Fabbed up a mount for the a/t cooler.  was hoping to get by without bracing it ... but it was like a diving board!  :D  oh well.


« Last Edit: August 15, 2011, 01:06:12 am by paniolo »
David M.
'81 C20 Suburban, tow pkg, 454, TH400, 14bb

Offline paniolo

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Re: My '81 Suburban C20
« Reply #1 on: August 14, 2011, 11:45:56 pm »
Next project: the fire hazard wiring the po put in!  There were all sorts of circuits; brake controller, driving lights, alarm, work lights, aux cooling fan, stereo feeds, aux gauge feeds coming off the battery.  It was like spaghetti and even worse the majority were unfused!  Some of the wiring seemed to be from old household extension cords.  Something I should have done when I first got the truck, but really didn't comprehend how really bad a lot of it was.  Lots of stuff tucked way up in the dash, so pulled the dash pad and instrument panel to ease getting to everything.  One good thing, is very little of the original harness was hacked into.  Just poorly designed new circuits.  When I was done there were yards and yards of wire laying all around the truck!  I ran a 12 gauge wire with a 30 amp circuit breaker to an aux fuse panel that I mounted behind the e-brake pedal.  Then rewired the 3 panel AutoMeter gauges and Sun tach.  I joined the lighting for those gauges into the harness so they are controlled with the dash lighting.  Also ran a circuit for the brake controller. 

While the instrument panel was out I went ahead and cleaned it up, filled some old holes and hit it with some paint.  Looks a lot better.
In process:


I decided to add the a/t temp gauge into the clock spot.  Fabbed up a mounting bracket out of some sheet metal.  Not the prettiest, but with the bezel on it looks fine.


The old dials were so brittle that the speedo one disintegrated when I touched it.  Followed by the temp gauge.  Finding needles was impossible.  So I got a cluster from a '79.  But when it came in the needles on that one had a different pin size.  sheesh.  Thought about just using the '79 cluster, it had a tach but that means the fuel gauge was in the spot I was planning on for the a/t gauge.  Also the oil pressure was mechanical.  So I swapped in the speedo (100mph) and temp gauge.  The fonts are different, but it will be hard to notice.  Thought about white faces to get consistency, but then the a/t temp would be black still.  meh ... good enough!


Also gave some attention to the dash vents.  Cleaned crud out of ducting, repainted the vents, added some rubber o-rings to the mounting posts to tighten up the movement so they don't just flop down now.

Put the dash back together, broke one of the cluster mounting tabs.  sigh.  Looks good but even with cleaning all contacts and replacing some dead bulbs the dash lighting is marginal.  May go to higher watt bulbs or LED.  Maybe if I do the whitefaces to make the gauges consistant (if I figure out how to get the a/t temp) I'll go with amber led's.

OK, next project.



David M.
'81 C20 Suburban, tow pkg, 454, TH400, 14bb

Offline paniolo

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Re: My '81 Suburban C20
« Reply #2 on: August 15, 2011, 12:12:14 am »
Door work.  All 4 door panels were replacement and the color the po sprayed on had been flaking.  Sitting in the Tx sun the last few years made that worse.  Also some of the elec window/door lock switches were loose, worked intermittently or slowly if at all.  Plus the po had cut a speaker hole in the front door panels but taken them all out before selling.

Front passenger with speaker hole.


Back panel:


I decided to fiberglass the speaker holes from the back, then bondo to fill even from the front.  The bondo is going to be smooth after sanding while the rest of the panel is textured ... but it's a lot better than a freakin hole in the door!  Pic of the fiberglass work on the drivers panel.  Also fiberglassed in the window/door switches that the po cut oversized holes for.


Then on to paint.  po had given me a couple of cans of CRC? color.  I debated using them ... as obviously he did and it all peeled!  But that paint is not cheap, so I went with hoping his prep work was lacking and maybe he didn't use adhesion promoter.  After doing some after the fact searching I see this is a common problem with that paint, so I will probably redo it sometime.  I did learn and tracked down SEM for the back doors when the old paint ran out.  Too bad I didn't use the SEM on the front and the bad stuff on the rear.

While the panels were off lubed up all the lock linkages and pulled out the lock actuators.  Disassembled, cleaned and lubed.  Also cleaned all electric connections and reinstalled with dielectric grease.  The glass channels and inner and outer window scrapers were terrible on the drivers and passenger side.  Lightbulb!  didn't I buy some of that back in Austin before I moved?  Dug around and Eurika!  I did ... and I bought it for all 4 doors!  New rubber window channels, and inner/outer scrapers for all 4 doors!  It was like Christmas in July.

Front door finished.

Just need some covers for the straps and it will look great.

Rear door finished.


The dash cover the po had put in had totally faded out in the sun.  So I used SEM on that too.  Worked well and stayed soft.


New window seals ... sweet.


All the windows operate great now.  The intermittent operation from the drivers side switch was fixed.  The door actuators are all slamming into place with authority now.

On to the next project!
David M.
'81 C20 Suburban, tow pkg, 454, TH400, 14bb

Offline paniolo

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Re: My '81 Suburban C20
« Reply #3 on: August 15, 2011, 12:41:44 am »
Opps, forgot some engine pics.  The po said this was an early 90's engine.  I keep meaning to get underneath and get the codes to find out exactly what it was from.  But it looked well cared for, and since he was a drag racer he put an Eldebrock manifold and Holley double pumper on.  Also a set of AutoMeter gauges and Sun tach.



You can see my a/t filter on the left side by the a/c.  I wanted the mount to be as vertical as possible so all the filter would get used.  The cruise control actuator is on the drivers side, but don't have the servo for the carb.  Would like to get that working.  The a/c has a leak, you might be able to make out some greasy areas on the line by the compressor.  I'm guessing o-rings so I will give that a go first.  But surprise there is still some pressure in the system after sitting for years.  So I'll get it evacuated first.  The a/c project is probably next in line.

Right behind lighting.  The stock sealed beams are marginal and dim.  After research I decided to go with e-code H4 conversions.  I don't think HID is a good choice for these lamps ... no housings are truely designed for HID combined with the height of the lamps means you really have to angle them down not to blind other drivers.  Then the foreground would be so bright it would impact your distance vision.  So the plan is install a relay harness, which I got from Daniel Stern Lighting  He added in some extra relays so I can run either both or just a single high beam and also to control some work lamps I have on the back.  He just sends heavy gauge terminals, high temp light sockets and nice dual 87 relays with ganged connectors so it all fits together as a tight group. You supply your own wire.


I was going to get the Hella Free Form conversion housings and run 80/70w Osram bulbs, then 100w bulbs in the upper high beam only.  But to save some money I saw some Hella Free Form 500 driving lights with 100w bulbs for less than half what I would spend on the high beam conversion.  So now I plan to leave the dedicated sealed high beam and add on the driving lights.  So on full high beam in the country I will have the 80w H4 bulb, the 60w sealed beam and the 100w driving lamp.  All individually controllable, but all shut off by the single high beam switch.

Then I saw some Cibie conversion H4 lamps on ebay.  These are the highest quality lamps made ... but they were used.  For the price I bit.  The reflectors look great, but they do have some pitting.  Foolishly, I thought I could grind them out with some 3m Trizact discs.  They did take off a layer of glass, but after going through series of 5 grits and finishing off with Cerium Oxide polish and a few hours of time the difference is hardly noticeable.  These would work great on hard glass water spots or a scratch from a metal wiper blade.  But if you can feel the scratch with your fingernail it is probably too much.  Hope to save some body the money and time to not try this!  :D

The cibies:


I've probably been penny wise and pound foolish with these.  I'm sure they will still be an upgrade on low beam and I KNOW they will be a major improvement on high beams with the Hella driving lights added in.
« Last Edit: August 15, 2011, 12:46:01 am by paniolo »
David M.
'81 C20 Suburban, tow pkg, 454, TH400, 14bb

Offline paniolo

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Re: My '81 Suburban C20
« Reply #4 on: August 15, 2011, 01:02:33 am »
Future projects:

Get A/C operational.  Evacuate and flush, install o-rings.  Need to fix rear a/c blower and also high blower speed in front (resistor's?)

Replace headliner.  It was in nice shape but has basically fallen apart from sun damage.  I think the po installed an after market, but the fabric was really thin.  Looks like a cat got to it!


Replace front seats.  Not sure if I will go with the 60/40 bench or buckets with the counsel.  I do like the armrests in the buckets.  My existing bench is torn and there is a crater on the drivers side that makes you sit crooked and gives you a back ache after a hundred miles or so.

Starter solinoid, I seem to get some heat sink issues... so thinking about an external solinoid.  I am seeing about a 700ma battery drain on the battery cable to the starter that needs to be tracked down too.

The only issue I have ever had with the engine is throwing alternator belts.  I've tried a few times to realign, but it never seems to work.  Originally the top bolt was missing.  Soon after I replaced that, the lower long bolt sheared off.  I now wonder if the bracket is tweaked.  Replacement steel ones are pretty cheap.  I also know the po put in a high output alternator so I am also considering if it really should have a double pulley.  A serpentine setup would be nice.  I'll keep my eyes open at the junk yards.

Install A-pillar Unity spotlight I have.  Will make finding camping spots, way around campground easier.

Color match the replacement front fender

Repair cruise control system.

Install Deep Cycle auxiliary battery to power stereo, internal car camping accessories and a power inverter mounted in back.

Thats it for now.

« Last Edit: August 15, 2011, 01:22:40 am by paniolo »
David M.
'81 C20 Suburban, tow pkg, 454, TH400, 14bb

Offline bake74

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Re: My '81 Suburban C20
« Reply #5 on: August 15, 2011, 07:54:22 am »
     Looks good after the fix, as far as the fender aligning back up, it might not have gotten pulled all the way back out.  It seems as though you are determined to get all the things done, keep up the good work and keep up informed.
#1: The easiest and most obvious solution to any problem is 99% of the time correct.
#2: There is no such thing as impossible, it just takes longer.
  74 k10, 77k10    Tom

Offline big bear

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Re: My '81 Suburban C20
« Reply #6 on: August 15, 2011, 04:20:17 pm »
love the burb.

Offline Engineer

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Re: My '81 Suburban C20
« Reply #7 on: August 15, 2011, 06:27:06 pm »
Somebody makes those 9/16" lugs nuts that have the external thread for the chrome OE GM hubcaps.

My oldest son just bought a set for his '79 K-30 so that he can use the factory hubcaps that came with his factory '01+ aluminum wheels.
2002 Chevy 2500HD 4x4 8.1/ZF6sp RC/LB
2001 Chevy 2500HD 4x4 6.0/4L85E EC/SB
1997 Chevy Blazer 4x4
1994 Chevy K-2500 4x4 C6P 5.7/4L80E
1979 Chevy K-30 4x4 4sp 4.10
1977 Chevy K-30 4x4 4sp 4.10 454

Dad of an Eagle Scout, and a Life Scout

Offline paniolo

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Re: My '81 Suburban C20
« Reply #8 on: August 15, 2011, 07:18:24 pm »
Somebody makes those 9/16" lugs nuts that have the external thread for the chrome OE GM hubcaps.

My oldest son just bought a set for his '79 K-30 so that he can use the factory hubcaps that came with his factory '01+ aluminum wheels.

I thought I was getting the alloy wheels, but the kid I was getting them from didn't know what he was talking about.  The primary thing I needed was new tires, the old ones were dangerous.  Ended up getting a good deal though. 

I've seen those external threaded lugs.  It was about $45 shipped for a set of 32.  My other problem is the covers I have are GMC.  I should get on the ball and do an ebay sell, then buy the Chevy ones.  Just got an email from ebay today offering a free sale.
David M.
'81 C20 Suburban, tow pkg, 454, TH400, 14bb