I am in the process of buying a 2003 Chevy 3/4 CC SB with the Dmax LB7. I have done a Vin check and came back clean and it has not had the injectors changed under warranty and has had only a few recalls done. The guy I am buying from is an aquaintance of mine and he did all his own maitenance.

Now to the questions:
1. This truck is getting ready to pop out of warranty soon and what are things I should be looking for to possibly have covered under warranty before it runs out? Being new to the diesel world I wont know what to look for so can you guys help me out here.

2. What are things that you would typically due maintanance wise after purchasing the truck? IE changing fluids, fuel filter, tranny, transfer case etc. I will read on what kind of fluids to use so just the basics are appreciated.

3. What are things that I should expect that I might not be used to doing coming from a gasser? YES VIRGIN DIESEL OWNER...:D

I am sure I will have numerous other questions and looking forward to racking up some posts on this site.. Thanks..

how many miles?? still under the 36k? make sure all of the computer updates are up to date. make sure there are no major leaks, squeeks etc. make sure all the windows work, radio, ac etc.
i would change all the fluids and then start your own records. change the ally filter and fluid inside. engine oil and filter. you know the drill
what to expect??? make sure you add anti gel when its going toget cold out. carry a spare fuel filter in case yours plugs while you drive. i would recomend installing the high idle kit (look in the do it yourself section). also look into a secondary fuel filtration system ex. nicktane. thats about all i can think of right now

No its getting ready to go out of 100k warranty.. I noticed the tach doesnt work and they are fixing that. If I have the dealer do all the fluids do they typically use quality fluids and filters? or should I look into changing all this myself. I have done differentials on other trucks but never changed oil or fuel filters on a diesel. If they are similar I will try to tackle it. If you think I would be better off letting someone else look at it the first time I might let them or another qualified mechanic look at it..

It is easy to change all the fluids, look in the DIY section, thee is TONS of information in there. Look close at the transfer case, and keep an eye on it, if you see alot of fluid coating the bottom of your truck, on the muffler and right side of the diff, then the old dreaded hole in transfer case has showed up, there are folks here with that at 80 thousand miles, that is IF you have the 4WD. Fill out a sig, showing us what you bought, it will help in the future when you ask questions.

dealer will moer than likely use penziol with an ac delco filter. i would change the fluids yourself. very simple

oh another thing is look to see if the speedometer flickers when you accelerate. 03's have problems with gauge clusters. when i got mine my speedo would flicker and then i also noticed my oil pressure pegging out in the monring.

Jeremy you should easily be able to change all the fluids and filters on that truck. Might take a little time the first time out, but after that you'll be a pro. Plus it lets you get familiar with the truck. I've already changed all mine on my 07 just for the pure fact I want synthetic in mine rather than conventional oil. The tranny was the worse plan on getting covered in oil when you pull the pan to change the internal filter. Also make sure you spin off the external filter and change it. I change mine every 5k miles just preventative maintenance for the pure fact you'll be pulling a heavier load with it. Other than that I only know minimal regarding the LB7 and there's TONS of info to read about on this site. Alot of helpful people here just like the other sites we are on. Just don't forget to run anti gel in the winter basically anything below 30 degrees a gelled up diesel is nothing fun to deal with and that will be your hardest transition from gas to diesel. The other one will be trying to remember your not driving a gas engine anymore. Also from experience in both my BIG rig as well as truck DON'T run it out of fuel you'll be cussing when you do. My practice is always keep it above 1/4 tank for reasons of not running out as well as not sucking all the crap from the bottom of the tank. From what we've talked about sounds like the truck will work out perfect for you and if you have any diesel questions I'll help you the best I can.

I noticed you mentioned gauge cluster.. The tach in this truck was not working and they are looking into it as we speak. Sounds like it might be the cluster. I didnt notice the oil pressure flickering but I will make sure I look for that... Thanks.

oh another thing is look to see if the speedometer flickers when you accelerate. 03's have problems with gauge clusters. when i got mine my speedo would flicker and then i also noticed my oil pressure pegging out in the monring.

I noticed you mentioned gauge cluster.. The tach in this truck was not working and they are looking into it as we speak. Sounds like it might be the cluster. I didnt notice the oil pressure flickering but I will make sure I look for that... Thanks.

if the tach doesnt work they will change the cluster and all will be fine. all fluids are changed like any other vehicle. oil filter is very easy to get to. allison spin on is easy to get to. make sure to change it at 5000miles or so. my truck usually starts shifting weird around that point to thats what reminds me to change it.

The gauge clusters have a stepper motor in them that kinda goes hairy, my speedo sometimes quits, but then starts again, for a few months then does it again, the stepper motor is the problem.

This probably a stupid question and I am still trying to read in the maintenance section on this but you have a spin on filter on the tranny in addition to the filter inside the pan? Does it do any good to change one without doing the other?


if the tach doesnt work they will change the cluster and all will be fine. all fluids are changed like any other vehicle. oil filter is very easy to get to. allison spin on is easy to get to. make sure to change it at 5000miles or so. my truck usually starts shifting weird around that point to thats what reminds me to change it.

So changing the cluster wont fix this or is the stepper motor part of the problem if the tach isnt working. I will find out what the problem was from the dealer and let you guys know..


The gauge clusters have a stepper motor in them that kinda goes hairy, my speedo sometimes quits, but then starts again, for a few months then does it again, the stepper motor is the problem.

The allison site says that you only need to change the internal filter on overhaul, BUT like me I changed my internal filter just so I know all is clean, change the spin on every 5-8 thousand miles, that is what I do, set up your own timeline, and everyone has their own as well.

The stepper motor, there is one for each gauge I think, is what drives the needle, the 03's were the one's that showed the problem the most I think, but the dealer just changes out the cluster.
There is a guy on Ebay who fixes them with a fast turnaround time, for like 120 bucks, or you can swap him your cluster for one of his for alot more money, but either way the dealer should fix it if you are buying from them.

Good luck.

So I will plan on changing both filters now so I know they are clean and then change the spin on every oil change or so. I am going to have to make a list here.. :eek:

Allison (check their website or go to the OEM Allison section on this site) recommends the internal filter be changed if your tranny is overhauled. Otherwise, just change the spin on. Up to you though. Just a tip...don't buy your spin on filters from GM but find an Allison dealership instead - filter is the same but your wallet will thank you ($6 vs $46). Also, there should be a round magnet on the spin on that you'll have to transfer over to the new filter.

Thanks for all the advice guys.. Im sure I will have more questions as I start digging into things the next week or so.. Here is a stock picture of the truck and hopefully alot of upgrades coming soon... Oh by the way.. The dealer said they will have to replace the instrument cluster and hopefully that will fix a few other lights that are out on the steering wheel controls and the radio. If not, Im sure there is something rolling around this site about that..

Oh yea, look in the DIY section, it even covers the instrument lights replacement, knobs with the paint rubed off, you name it, it is just about in there.

Soon to have the Transfer case pump upgrade in there as well,

have em look into the injectors

if you change your one oils dont forget the magnet in the spinon tranie filter

I like running Lucas fuel treatment in every tank whether its cold or not just to keep the pump and injectors lub'ed. As far as the internal tranny filter, I try to change it about every 50k miles unless I'm doing a lot of towing. One hint on your fuel filter is to prefill it, that saves you a lot on the priming, also pull the inner fender skirt on the passengers side. And there are places to get that filter cheaper than $40. And DON"T run it out of fuel, it's a b**** to prime then.