What do I do with my 2003 Z71 Suburban?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

homesick

Full Access Member
Joined
Sep 19, 2018
Posts
1,505
Reaction score
3,956
Exactly why I have a 2005 Tahoe Z71 and a 2004 Silverado K2500HD. Great trucks. Just turned 168k miles on the Tahoe and has 118k miles on the truck. Gobs of miles and time left in both.

Not that it's really relevant, but I've always really liked the dash layout and looks of them too. Hell, the exterior styling looks good too. Still.

joe
 

Matthew Jeschke

Full Access Member
Joined
Dec 28, 2017
Posts
2,070
Reaction score
1,455
Location
Sahuarita, Arizona
My rig is same miles, although most all rebuilt. That said most of what I did wasn't necessary. Do some larger maintenance...

FYI ~ At approx 240k miles I blew up my 5.3L tinkering in my garage. Tore it down, aside from what I broke engine was like new inside! I'm not a fan of the plastic lifter trays nor the press fit rocker arm needle bearings... but other than those two weak links the engine should run almost forever. That said, wouldn't hurt to compression test it before you invest too much time and money. Otherwise, it's still got decent power and gets similar mileage as always then maybe forego compression test.

Clean up weak points in transmission accessible via service pan and dropping valve body such as changing the steel check balls with the plastic ones. You'll likely have to buy a new separator plate as I'm not sure where to source the paper gaskets otherwise. Total cost maybe $40 although bit intimidating. That said is much easier than you'd think.

Make sure ALL fluids are replaced. Coolant (flush), front diff, rear diff, flush crankcase (do you have any sticky lifters?). Leave AC alone if works fine.

Do a seafoam intake clean, heck maybe do two. Can borescope cylinders after if you're adventurous.

May consider flushing cats. I just did this... worked like magic. Used powder drain cleaner / Sodium Hydroxide

Replace brake hoses if you haven't already. Classic tube has a reasonable deal on direct fitment steel braided for not much more than rubber.

Check fuel pressures to see if pump is holding up. Bosch makes a really sweet drop in pump for cheap that's higher flow, E85 compatible, and really inexpensive if you're feeling adventurous and up to swapping the pump out of the housing, which isn't too hard. I swapped in a AEM one but Bosh is cheaper for similar spec. https://www.ebay.com/p/849307292

Go through your front end / steering. Check for loose idler or pitman arms. Replace as needed. Same goes for tie rods. FYI Had BAD luck with moog. I like Mevotech TTX stuff. Been off road and ZERO issues with it. Moog lasted for 10k miles and bit the dust.

3M makes a GREAT spray on protectant for frame. I forget name of it, comes in a spray can. I keep handy and spray my frame ANYTIME I'm doing maintenance under the truck. You'll want to get it, and spray up your frame anywhere it's bare.

Do you have 4wd w/ Auto/AWD feature? That's the NP246 TX case. The other cases may have similar issue. But I know the NP246 AWD TX case chews up the rear housing. Get a case saver and or new rear half of the housing and rebuild the case. It's MUCH easier than it sounds. I have a post on it on the forum here.

Run Lucas Injector Cleaner through the fuel system on next four or five tanks consecutively.

Do you have any engine codes? If so list them and would be worth tackling them.

Any quirks with the truck (hard start, steering pulls, squeaks, etc?)

Truth is, if you take care of some of the larger maintenance, the truck will go until you're tired of it or wreck it.
 
Last edited:

OR VietVet

GMT800 SUV/Trucks
Supporting Member
Military
Joined
Oct 8, 2014
Posts
21,346
Reaction score
38,337
Location
Willamette Valley
Since I have a transmission temp gauge on my Tahoe cluster and crew cab truck has rear heat and air, I have the exact same dash layout and steering wheel controls.
 

S33k3r

Full Access Member
Joined
Aug 14, 2017
Posts
2,619
Reaction score
3,666
Location
Dallas, Texas
I routinely find myself driving one of our suburbans, the escalade, the Sierra, but mostly my Duramax. Sometimes I forget which vehicle I'm in!
 
OP
OP
Jocko PDX

Jocko PDX

Full Access Member
Joined
Oct 12, 2023
Posts
182
Reaction score
127
Location
Portland OR
So last week the suburban started making some grinding or rubbing noise. I took it down to Valvoline and it was out of transfer case fluid.. Empty.. Apparently there is a small crack down by the drain plug. In any event I had it filled for $30 and it sounds great again. I thought it was going to be a gonner.. Nope you just can't kill this bad boy. Its awesome. I still drive it most days over my new Denali.
 

OR VietVet

GMT800 SUV/Trucks
Supporting Member
Military
Joined
Oct 8, 2014
Posts
21,346
Reaction score
38,337
Location
Willamette Valley
So last week the suburban started making some grinding or rubbing noise. I took it down to Valvoline and it was out of transfer case fluid.. Empty.. Apparently there is a small crack down by the drain plug. In any event I had it filled for $30 and it sounds great again. I thought it was going to be a gonner.. Nope you just can't kill this bad boy. Its awesome. I still drive it most days over my new Denali.
It will leak out again. It likely has done some internal damage. You need another transfer case.
 

Fless

Staff member
Super Moderator
Joined
Apr 2, 2017
Posts
12,678
Reaction score
25,875
Location
Elev 5,280
So last week the suburban started making some grinding or rubbing noise. I took it down to Valvoline and it was out of transfer case fluid.. Empty.. Apparently there is a small crack down by the drain plug. In any event I had it filled for $30 and it sounds great again. I thought it was going to be a gonner.. Nope you just can't kill this bad boy. Its awesome. I still drive it most days over my new Denali.

If it's the 2-speed transfer case I hope they used Auto Trak II blue fluid. Those cases also get what's called "pump rub" where the pump rubs through the case and the fluid drains out that hole.
 

PPV_2018

Senior Member
Joined
Oct 22, 2024
Posts
171
Reaction score
296
Location
U.S.A.
Sell it & regret it forever.

Insurance should not be a factor in your decision. Ditch the full coverage and just keep liability on it. If something goes wrong with it and it needs to sit for a while, drop the coverage until you get it road worthy again.
 

Forum statistics

Threads
133,619
Posts
1,888,356
Members
98,846
Latest member
lenma
Top