Buying an avalanche....

Hey guys,
i went through few Silverado trucks in my business, and i need to buy a versatile truck like an avalanche is. My question is, im looking at 2002-4 models, i know that v6 engines are strong and last forever, but would you think an avalanche would be underpowered with one?
currently i drive a 4.8 silvy 2wd with 8ft box, and its ok, but 5.3 on my other one is nicer.
Is 5.3 a good choice for avalanche? also anyh problems with 2-4 model years? what should i be looking for?when buying one?

just saw that hypertech is available for these trucks, what does it do? any gains and pluses from using it? or just B/S?
Thanks!!!

Hey guys,
i went through few Silverado trucks in my business, and i need to buy a versatile truck like an avalanche is. My question is, im looking at 2002-4 models, i know that v6 engines are strong and last forever, but would you think an avalanche would be underpowered with one?
currently i drive a 4.8 silvy 2wd with 8ft box, and its ok, but 5.3 on my other one is nicer.
Is 5.3 a good choice for avalanche? also anyh problems with 2-4 model years? what should i be looking for?when buying one?

just saw that hypertech is available for these trucks, what does it do? any gains and pluses from using it? or just B/S?
Thanks!!!


I did not think you could even get an Avalanche with a 6 cylinder. I could be wrong though. Mine is an 02 4x4 with the 5.3 litre. It rocks! Plenty of power for what I need. It is really versatile. Bed sits up a little high, but you don't have wheel wells to fool around with, that doesn't bother me too much. The things that went wrong with mine (which were fixed by the dealer, even though I bought it used) were the blower motor resistor would not allow the blower to work on setting #1, and the parking brake did not work. Other than that, it is great. Examine the rear of the cab for evidence of water leaking into the cab. I have heard of people complaining about the rear glass being cracked. My plastic around the rear glass has a little piece missing on the corner, but it does not effect the performance any. Also make sure the tailgate cables look and feel secure. I heard there was a recall on these. Mine seem fine. Get one of these, you won't be sorry.

Hey guys,
i went through few Silverado trucks in my business, and i need to buy a versatile truck like an avalanche is. My question is, im looking at 2002-4 models, i know that v6 engines are strong and last forever, but would you think an avalanche would be underpowered with one?
currently i drive a 4.8 silvy 2wd with 8ft box, and its ok, but 5.3 on my other one is nicer.
Is 5.3 a good choice for avalanche? also anyh problems with 2-4 model years? what should i be looking for?when buying one?

just saw that hypertech is available for these trucks, what does it do? any gains and pluses from using it? or just B/S?
Thanks!!!
First off there are no engine options with the Avalanche. All 1500 (1/2 ton) Avalanches come with the 5.3l V8 and all 2500 (3/4 ton) Avalanches come with the 8.1l V8.

The biggest thing that you will notice while looking at Avalanches is that there is a difference in gear ratios for the rear end. In the years you are looking at they came in a 3.73 and a 4.10. The 4.10 is much better for towing and is less of a dog. The 3.73 gets slightly better fuel economy on the highway. Some people have reported better fuel economy with the 4.10 in the city but they are with in 1-2 mpg of each other. If I could pick a rear end all over again I would go for the 4.10 as would most people once they drive these trucks for a while.

With all Avalanches no matter what year do this. Ask to go on a test drive and take it to a car wash. The best kind is one of them that is the self service pressure washers and spray around the back window and midgate. Then get in the back of the truck and fold the seats and look for signs of water in the cab. The 03+ has a redesigned seal in the midgate as an improvement over the 02 which was the first year it was out. Other things to look at is take out the back window and inspect the plastic trim around the glass on the inside and out. Many people have had problems with the plastic around the glass cracking. Check the plastic cladding on the truck even if you get one with out the plastic sides (Available 03+) you still have the plastic on the sail panels and the saddle bag lids. You are looking for fading. This is just a cosmetic issue and shouldn't rule out a potential vehicle but if it is fading then get the dealer (if Chevy) to apply a Gatorback treatment to it. They should know what you are talking about as there is a service bulletin out on it from GM. It is free even out of warranty but it will take some fighting if out of warranty so get it done before you agree to buy. Other than that nothing special other than what you would look out for in any used truck.

As for the Hypertech. Yes, it is available. There are many people that have them and use them to change timing advance, shift points, speed limiter and recalibrate the speedometer for larger tires. The will boost performance but it is nothing like a tune like this in a Turbo engine such as a Duramax. The changes are very slight but when added along with other modifications such as headders, cat back exhaust, intake and then you will notice it. The only real draw back is that some of the tunes say they require super premium. I don't know how much I buy that but I don't have a Hypertech and don't plan on getting one. But that is just me.

The Avalanche is actually built on a Suburban frame and shares many parts with this vehicle so even though it looks more like a Silverado it is more of a Suburban than a pickup. It actually is heavier than a Suburban by 400 lbs and 2" longer than one as well. People are shocked by that fact.


Hope this helps

and the parking brake did not work.

Yeah I forgot that one. The Parking Brake is completely worthless on these trucks but it is not just the Avalanche it is any GMT800 with this rear brake set up. So I'm talking about the Silverado, Tahoe, Suburban, Avalanche and thier GMC cousins. They have this stupid little drum brake inside the rear rotors. Yes, you read that right. There are drum brakes and disc brakes on the rear axle. We would have been better off had GM left the drums alone from the 80s or gone to straight disc brakes. I would have prefered straight disc but I don't understand this combo setup they have. I was servicing my rear brakes and snapped a little bolt off that holds a spring clip on the drum's shoe. The only way to extract it would be to pull the rear axle. I pissed and gutted my rear drum brakes so I don't have parking brakes now. No loss in my book. I never used it. 99% of them on the road can't hold the vehicle properly and they would be worthless in an emergency situation if they can't even hold the vehicle at a stop in gear at idle. To go to the dealer for a brake job on the rear axel will run you around $600-1000. If you don't have problems like I did you can do it yourself for about $200. Oh and because GM set the brake bias so goofy on these trucks you will burn through 2-3 sets of rear pads before needing fronts. Many people complain that the Avalanche doesn't stop as well as thier old Silverados. So keep that in mind. I would say ti could be explained by the brake bias and my comment before about the weight of the Avalanche. It is way heavier than the Silverados you have been driving for work.

The biggest difference you will find in model years will be options. The 02s had the light grey cladding and the older interior that was used in the pickup & tahoe/suburban line from 1999-2002. Then the new interior came out which all 03+ Avalanches would have. The 03+ also has a darker grey cladding. GM started taking away features on us for some reason so I will post a link at the end to another forum that I belong to that has a great resource section. There you can go into each year and see what changed from the previous year. Things like the under hood light and cabin filter were left out of the 03 when it came out. Then the dual visors were taken out of the 04s and one of the side bed lights. There are other things but those are the things that were dropped from year to year. Oh and nothing was really added to make up for the loss. In my opinion the 03 was the best year as far as what came with it and is what I have. How ever if you find a great 04 go for it. The things taken away can easily be added if you want. The bed light being the most difficult but it has been done by many people.
I know of many 02 owners that wish they had an 03+ because there are more aftermarket items available for it. The biggest one is the backup camera that has a small 3.5" LCD that replaces the cubby hole to the right of the HVAC controls. I love mine and it isn't available for the 02.

Here is that link

http://www.chevyavalanchefanclub.com/resources/index.html

i had in mind a 02 one, that my friendly dealer has (i purchased few silverados from him) but, what you have written about the seal and rear window changed my mind. I grew up driving yj's tj's and lately an xj. all of these vehicles were lifted and went through a lot of mud. I just got a little bit tired of seeing water and mud in the cabin, and if i know it leaks, or there is a chance it will-I dont want it:) I assume 4.11 came with Towing option? Are trannies in avalanches same as in silverados? will fail sooner or later, or different model? i assume the fuel pump is probably the same, as it is built on a suburban frame. Had few of these fail on the trucks i owned.
I would like to thank you for writing all this to steer im in right direction:) that is a lot of info, and time you took:) Thanks:)
I have one question, how is the stereo in these trucks? is it same as in 2003 silverados and requires a special adapter to install an aftermarket unit?

i had in mind a 02 one, that my friendly dealer has (i purchased few silverados from him) but, what you have written about the seal and rear window changed my mind. I grew up driving yj's tj's and lately an xj. all of these vehicles were lifted and went through a lot of mud. I just got a little bit tired of seeing water and mud in the cabin, and if i know it leaks, or there is a chance it will-I dont want it:) I assume 4.11 came with Towing option? Are trannies in avalanches same as in silverados? will fail sooner or later, or different model? i assume the fuel pump is probably the same, as it is built on a suburban frame. Had few of these fail on the trucks i owned.
I would like to thank you for writing all this to steer im in right direction:) that is a lot of info, and time you took:) Thanks:)
I have one question, how is the stereo in these trucks? is it same as in 2003 silverados and requires a special adapter to install an aftermarket unit?

I just want to first say I am a very happy owner of an Avalanche and through other forums I know of thousands of other happy owners that do not have any of the above listed problems. You did ask for what to look for so these are areas to check as problems have come up there. The biggest thing that you can do to prevent water leaks is to take care of the seals. I protect them with a silicon rubber treatment as I do all the door seals. Also I woudl recomend every 6 months or so to clean out all the drains. There is info as to where they are located in the owners manual. The bed area is not water proof. There are a series of drains that route water away from the seals to help prevent water intrusion into the cab in the event that one of your seals are comprimised.

As for the crack in the trim of the back window. Mine has a hairline crack as well as most of them do. This does not cause an air leak or water to get in the truck. In fact mine is cracked on the inside. I'm really not worried about it.

As for the gear ratios. To tell what rear end you have in the truck look in the glove box. There will be a huge list of codes that tell you everything about the truck from paint color to what radio you have. The 4.10 has nothing to do with if a vehicle has a towing package. The 4.10 ratio was a factory option and for the most part is only found on custom ordered trucks. Some dealers out there ordered 4.10s but most do not. It is luck to find one as the vast majority were 3.73. I really wanted a 4.10 but couldn't find one. I wanted other options more than that so I settled for the 3.73. The codes that you are looking for is going to be either a GT4 or GT5.

GT4 = 3.73
GT5 = 4.10

For the 02-04 rear range those were the only ratios available. Another code to look for is G80. This indicates that the truck has the Eaton G80 Locker. The G80 Locker will be standard in all Z71 and Z66 trucks and optional in all others. Contrary to popular belief there was never a limited slip rear diff offered in the Avalanche. This is also a fact for all the Silverados, Tahoes, Suburbans and thier GMC cousins of in the same year range. The G80 is a locker and operates very differently than a limited slip. For more info on the Eaton Locker go to thier web site. They have a ton of good info on it and how it works. We have this arguement every few months on the other sites with new people.

Tranny would be the same as you would find in the Suburban and I would also assume the same as the Silverado. GM likes to use the same components in as many vehicles as possible as it is cheaper for them. Over all they are pretty good. That said I know of people that have blown trannys. Check to make sure that your truck has a tranny cooler. Even though you may get one with a towing package they didn't come with an aux tranny cooler. I think they are around $75-100 at the dealer and pretty easy to install.

You are right the fuel pump is the same as the Suburban. The biggest trick to keeping them going is to keep your truck full. Most of the people that have them die also are the type of people that like to see the fuel warning come on before running to the gas station and then they only throw in a few gallons and take off again. The problem is that the fuel pump is cooled by the gas. So as it runs low on fuel it gets hot and it is hard on it. It can also suck up sediment that is in the tank and shorten its life.

As for the radio... I have an 03 with the 6-disc changer and Bose system. I like it but many do not. I have pretty bad hearing loss from my time in the US Army and am deaf in my left ear from a blast injury. So I probably am the worst person to ask about quality. I would say that if you didn't thing the stereo in your Silverado was up to par then you will say the same thing about the one in the Avalanche. Personally I pretty much had to have an 03+ because I wanted the steering wheel controls. Your 03+ Avalanche will have the exact same radio system as a Silverado. Remember I said GM likes to use components in as many vehicles as possible. That said the 02 Avalanche is totally different when it comes to the interior. That was why I didn't want an 02. The radio in an 02 is a 1.5 DIN the layout of the dash is different and steering wheel controls for the radio was not an option. The 03+ has a double DIN radio size so it is much larger just like the Silverado line. This is one of the things that changed from 02 to 03. There are also a lot more computers in the 03. Basically in an 02 if you are in the driver's seat and roll down a back window there are a set or wires that go from the switch to the back window motor and operate the motor. That isn't how the 03 works. The switch talks to a computer in the front of the truck. That talks to another computer in the back of the truck through a BUS system (think computer network) Then the back seat computer sends a signal to the window motor. That is a dumbed down explination. Oh and incase you didn't know the 03 Silverado has just as many computers. Don't be afraid though. GM did a really good job with these computers and it is very rare to have one fail.

I hope this helps and good luck in your search.

i went out and test drove 2002 one today, with leather. It was one of the first ones i wanted to see. the odometer read 160 000 Km. Im not sure how the avalanche would feel comparing to a silverado, but this one felt like it had 360 000kms not 160. The engine was a littlebit underpowered(tired because of the milage?), the truck felt loose, as if the shocks were shot, and the brakes felt weird-soft-not enought braking power. Other than that the other the only other thing that bothered me, was the zebra look on the plastic.
Other thatn that, i loved it, the size of it inside, the seats, etc. Very nicely engineered vehicle. I have to buy one within next two weeks, im pretty sure i will get a 2003 model now, z71 with 4.10 ration:) will keep you posted.
Thanks again;)

i went out and test drove 2002 one today, with leather. It was one of the first ones i wanted to see. the odometer read 160 000 Km. Im not sure how the avalanche would feel comparing to a silverado, but this one felt like it had 360 000kms not 160. The engine was a littlebit underpowered(tired because of the milage?), the truck felt loose, as if the shocks were shot, and the brakes felt weird-soft-not enought braking power. Other than that the other the only other thing that bothered me, was the zebra look on the plastic.
Other thatn that, i loved it, the size of it inside, the seats, etc. Very nicely engineered vehicle. I have to buy one within next two weeks, im pretty sure i will get a 2003 model now, z71 with 4.10 ration:) will keep you posted.
Thanks again;)

Many of the trucks with the 3.73 rear end feel under powered. Heck all of them do that is why we mod them. As for the ride it will be different than a Silverado. If you want to do a comparison and the dealer only has one Avalanche see if they have any Suburbans. Because they share suspension and all other chassis components the ride would be very close. The brakes are going to feel soft. They are all like that. From year to year there were some changes to the braking system but still is a common complaint. It gets worse if you were thinking of going with 20" rims or bigger. The Zebra look of the cladding is correctable with a product called Gatorback. If you are dealing with a GM dealer they should know what it is. It is the approved solution put out by GM. Dealers are to apply the treatment to all Avalanches even those out of warranty. Some dealers are better than others so get it done as part of the deal. It will save you a trip. Here is more info on Gatorback

http://www.gatorbackcoatings.com/

Good luck on the search for a 4.10. If you can find one verify it by the codes that I gave you before. It is possible to find one but they are out numbered by far with the 3.73 models.