Questions about GMT800 2000+ Silverados

Dexcool: That's a 90s onward thing. It's not a problem if cared for and silicated coolant doesn't touch it (old school "green conventional" or Zerex G-05). If it bothers you, you could just start doing annual radiator drains and topping it off with a "all makes all models" coolant, those are chemically very similar to Dex, Peak Global Lifetime is supposed to be the best, but anything will do if you're draining half of it annually.

Trans fluid: If it's still in good shape (red, smells ok), just drop the pan, change filter, and fill it back up with fresh fluid. If it has 170k on the trans, I'd go with Valvoline Maxlife.

amg_rx7 wrote: Alright, bought a new-to-me truck yesterday. Figured I'd update this thread and continue to ask some maintenance related questions. Specs: - 2001 - 5.3 - 170k miles - RWD The truck is very clean. Especially the interior. Drives nicely but front shocks are a little worn and a fresh alignment would help a bit. The PO is a "chevy guy" and did a lot of maintenance. After I paid him and signed paperwork, I went through the maintenance list one more time and asked what coolant he used. Learned he used Dex Cool. Questions: Is Dex Cool specified for this engine / truck? I thought that was an 1980s thing... Anyone have a link to a good how to procedure for flushing / changing transmission oil? Doesn't need it right now but I'd like to read up on it. Is there a good Chevy truck forum where I can find other good troubleshooting procedures and How-Tos? Thanks.

Another question in addition to the above - Is the stock exhaust efficient? PO added a Flow Master muffler and I'm not liking the drone. I must be getting old...

Stock muffler is restrictive. I like dynomax. I had a super turbo, after that rusted out I installed an ultro flow. The ultro flow is a little louder but doesn't drone like a flowmaster. Otherwise, you can go cheap with a glass pack. The ultra flow is built more sound - the super turbo's last a few years and are toast.

On the subject of GM truck exhaust systems: do they still have that awful Y pipe thats more of a T pipe?

Those are good, honest trucks. The Chevy independent front suspension is the nicest to drive of the big 3 during that era, but also requires replacing occasionally. Shocks are cheap and easy.

4L60 is the question mark in the whole thing, similar to other full size 1/2ton trucks. Take care of it and reserve some mental funds for an overhaul. 120k-150k seems to be the magic number, although if they make it past that some live forever.

I personally think anyone with high mileage domestic vehicles needs to find a good transmission guy on retainer.

Congrats on your purchase. I went from a pimpy 04 F-150 to an much more basic GMC "SLE" trim 05 2500HD and I don't regret it at all.

When it comes to having to work on it yourself, the Chevy really shines.

amg_rx7 wrote:

amg_rx7 wrote: Alright, bought a new-to-me truck yesterday. Figured I'd update this thread and continue to ask some maintenance related questions. Specs: - 2001 - 5.3 - 170k miles - RWD The truck is very clean. Especially the interior. Drives nicely but front shocks are a little worn and a fresh alignment would help a bit. The PO is a "chevy guy" and did a lot of maintenance. After I paid him and signed paperwork, I went through the maintenance list one more time and asked what coolant he used. Learned he used Dex Cool. Questions: Is Dex Cool specified for this engine / truck? I thought that was an 1980s thing... Anyone have a link to a good how to procedure for flushing / changing transmission oil? Doesn't need it right now but I'd like to read up on it. Is there a good Chevy truck forum where I can find other good troubleshooting procedures and How-Tos? Thanks.

Another question in addition to the above - Is the stock exhaust efficient? PO added a Flow Master muffler and I'm not liking the drone. I must be getting old...

Stock, it's meh. At least you didn't have to drive 14hrs back from FL listneing to the V4/AFM/DoD drone in my Suburban. Maddening and vomit inducing.... It's the stock system. I personally, would just pony up a decent stock replacement, but performance oriented cat back from Dynomax. They tend to be under $400 for everything.

Just flush out the coolant and replace with something similar. What I have witnessed seems to be caused by electrolysis. The engines just don't seem to be grounded "enough", which causes the buildup of crap in the system. I have no real hard data to back it up, but whenever I had to work on a cooling system, I always felt like the coolant had an electrical charge to it.

There are forums out there, and I can't seem to recall them off the top of my head, but these trucks are still caveman easy to work on. I would just ask here first anyways.

Tyler H wrote: Those are good, honest trucks. The Chevy independent front suspension is the nicest to drive of the big 3 during that era, but also requires replacing occasionally. Shocks are cheap and easy. 4L60 is the question mark in the whole thing, similar to other full size 1/2ton trucks. Take care of it and reserve some mental funds for an overhaul. 120k-150k seems to be the magic number, although if they make it past that some live forever. I personally think anyone with high mileage domestic vehicles needs to find a good transmission guy on retainer.

I agree on the easiest to soak up the bumps, but damn they suck when the crap breaks. The whole front end was engineered to be used on something at least 2k#'s lighter, that is across spectrum of 1/2 to 1-ton's. Flexible and spindly come to my mind after working on them.

As to the transmission, I have to disagree only because about 5% of the driving population does the required maintenance to any vehicle out there. It doesn't help that the big 3 have a big tendency to engineer it "strong" to be cut down by the accountants to just be asked if it will do "X" on the already diminished "performance". So it's any wonder they last as long as they do.

amg_rx7, if you can pass the sniff and color test on the fluid and you do go ahead and change it, I would put in 4 qts of "wet clutch" tractor fluid and top off the rest with ATF. I did that with my last high mileage 4l60, because of the known issues: stripped sun shells, broken sprags, or "welded up" OD clutches from baked/hardened seals. Never had an issue with it even towing well over 10k pounds with it once. Eventually, I traded it in with 177k on it and still working great.

I used to hang out on http://www.fullsizechevy.com/forum/forum.php occasionally. They were pretty good for the most part, but its been while.

In reply to SilverFleet :

Sorry to revive an old thread but I googled GMT 800 rust and this was the first or second result.

Just helped dad replace brake lines on his ‘00 Z71 yesterday.  Man.  I can’t believe this thing.  The body is cherry but all the important stuff looks like it’s been resting with the Titanic for the past 100 years.  I looked at the A-arms and told him that even after we fix the brakes he can’t safely drive it.  And the disconcerting thing is...they only treat the roads 3 or 4 times a year here.  And if I compare it to my 1 year older and double the miles Ford Super Duty, the difference is dramatic.  SD has almost no rust.  While we didn’t buy the Z71 new, we know who did and we know it didn’t spend its winters in Maine.  Widow down the street practically gave the truck to my dad.  He paid too much!

what is up with this?  Dad’s previous truck was a 2000 S10 that had the exact same issue.  We didn’t know its history and chalked it up to a saltwater flood.  Now we know that was unlikely.  That little truck was a peach...or so we thought...until the differential cover rusted through.  Then we noticed all the other stuff.  Unsafe at any speed doesn’t only apply to Corvairs.  

The only silver lining here is that we have a sub 50,000 mile 5.3 awaiting snails.