Transmission Oil Change

[2500HD 8.1]

The maintenance schedule recommends changing the transmission fluid and filter either at 50,000 or 100,000 miles. I have always changed it every 30,000 miles or so. My Denali has 29,000 miles now, and I will probably change it soon. How often do you guys change your transmission fluid??? Is it as important to change the trans fluid often to protect your trans like changing engine oil every 3,000 miles to protect your engine??? Or is this today's trans fluid and transmission designed to go many miles (100,000) without service???

 

Anyone have any parts #'s, GM or aftermarket, for a trans filter for a 2005 Denali. I believe there is only one transmission available, but in the past I had problems getting the right part # from the local auto parts store with my 2001 Suburban.

[C & A s Dad]

I believe I am right when saying a Denali was only avail in a 1500 series?? Your name 2500HD 8.1 has me questioning myself.

 

If it is a 1500 with a 4L60 and you have a CARQUEST store nearby, you will need a 96080. The catalog list a first and second design but it is noted that the second design will replace the early design. This is the # I have provided. Our filters are supplied to us by SPX Filtran who supplies all major companies. They are excellent quality.

 

As far as when to service the trans. I tow some with mine and will service it at 30K. I also use Amsoil syn fluid and run an oversize trans cooler to keep things nice and cool while towing. If you are not towing, 30K may be a little overkill. I would suggest a good syn fluid and you can even use the new Dexron VI as it is a syn and will retro to earlier GM vehicles that did not come with VI.

 

Amsoil offers some great instructions to help you do a complete fluid exchange at home. It is very easy and will add only about 30 mins to your trans service and will replace all the fluid instead of 4 to 6 qts. If you cannot find the instructions PM me and I can step you through it.

 

One last thing. I do not think you have a drain plug but if you do, it will be installed very tight from the factory with a med. stregth thread locker. Use a premium quality black impact 6 pt socket in a 1/2" drive and get under the pan where you can apply good upwards presure on the plug while turning it. If you feel any slip, stop and get a small propane torch to apply just a little heat to the plug. The heat will melt the threadlocker and let the plug come right out. If you use a cheap 12 pt socket, it will round the head of the plug.

[Bill55AZ]

I just moved from AZ to Utah, and towed a lot of stuff up here in a utility trailer over the last 3 years.

We had a 1600 sq. ft. shop on the lot before the house got built and used it as a warehouse to store our stuff in the interim. With the AZ heat and climbing mountains with extra weight in the bed, and towing, I did the tranny service early. Otherwise, I would have left it alone til the 100K mark.

[2500HD 8.1]

I believe I am right when saying a Denali was only avail in a 1500 series?? Your name 2500HD 8.1 has me questioning myself.

 

C&As Dad, thanks for your informative response. First, if you read my signature, you will see that I previously owned two 2500 8.1 Suburbans. Now, I have a Denali, but I didn't think I needed to change my user name?

 

I don't have a drain plug in my trans pan. I found the part #'s for the filter kit, but there is a shallow and deep pan. I probably have the deep pan, but I hope the deep pan is obvious to tell because the part stores are not very helpful. I'm going to refill with syn trans fluid. I will probably try Amsoil. I tow once in a while, but do mostly city driving. I think I will change it around 30K just to be safe.

[asepgrad98]

the deep pan has two sections, a deep part and a shallow part

[2500HD 8.1]

the deep pan has two sections, a deep part and a shallow part

 

Thanks, I might just have the shallow pan then. I'll have to inspect it again.

[04silverado1500]

i am also currently in the same position. i own a truck with 53k on it and i am planning on changing it at 100k my grandpa is a former GM mechanic and actually the most trusted tranny guy from the mid 50s all the way to the mid 80s he told me even with the towing i do 3 times a month in the summer once every month in the winter and the towing the truck has been through in its earlier days i dont even have to consider the 50k mile change. now this is his opinion but an opinion that i value. i dont think its bad to change your tranny fluid earlier but in the maunual it even says for harsh driving conditions change it at 50k. 30k seems a little to soon. i mean maybe if you use your vehicle to tow every day but other wise 50k or 100k will do. but hey this is just our opinions we also never let a vehicle go over 3k with regular oil and 5k with synthetic and i even change my synthetic every 3k

[svensk]

IMO GM's new Dexron tranny fluid is AMAZING...my in-law just had it put in his G6 and even I could tell the difference in how well it shifts now.

Another thing...trannies are the one thing on a vehicle I will NOT touch. I absolutely despise draining that fluid, and how it dumps everywhere...it sux. I'm taking mine to the dealer for my next flush.

[ZZ327]

I have my own changed at around 100K.

 

I just took the work truck in to have it flushed @ 150k miles. They said it was like mud!

[plainvanilla]

I believe I am right when saying a Denali was only avail in a 1500 series?? Your name 2500HD 8.1 has me questioning myself.

 

C&As Dad, thanks for your informative response. First, if you read my signature, you will see that I previously owned two 2500 8.1 Suburbans. Now, I have a Denali, but I didn't think I needed to change my user name?

 

I don't have a drain plug in my trans pan. I found the part #'s for the filter kit, but there is a shallow and deep pan. I probably have the deep pan, but I hope the deep pan is obvious to tell because the part stores are not very helpful. I'm going to refill with syn trans fluid. I will probably try Amsoil. I tow once in a while, but do mostly city driving. I think I will change it around 30K just to be safe.

 

 

 

hey if you have a transmission shop there that does the BG trans service its a good deal.

When you change the fluid yourself you usually get less than half of it out, the torque converter and cooling lines hold about 6 quarts. If you take it to a shop with a BG machine, they hook up the the cooling lines and install a cleaner conditioner and circulate the system, then flush it out totally and refill with new fluid. it cost about $99 but if you do it BEFORE your factory warranty expires, BG will extend your transmission warranty to I think 100,000 or more if you have it done every 40K or so. I'm a little sketchy on the details, but I got the basics down. I always hated doing the tranny, got oil everywhere no matter how hard I tried not to.

 

When mine comes do, thats what I'm gonna do for sure.

[C & A s Dad]

IMO GM's new Dexron tranny fluid is AMAZING...my in-law just had it put in his G6 and even I could tell the difference in how well it shifts now.

Another thing...trannies are the one thing on a vehicle I will NOT touch. I absolutely despise draining that fluid, and how it dumps everywhere...it sux. I'm taking mine to the dealer for my next flush.

 

Man, you do this and when you get through it is in your hair, under arm pit, behind your ears. You would not want to miss all that fun would you?

 

2500HD1 Now I see in your sig where the HD is gone. Sorry. My guess is you have the deep pan. Mine did on my 02 Yuk XL.

[2500HD 8.1]

Yea, I looked at it. There is a deeper section to the pan, but it is only about a 1/2 inch deeper than the rest of the pan. I assume the shallow pan is completely flat.

 

I'm guessing that only GM dealers sell the new Dextron VI trans fluid???

[C & A s Dad]

The new Dex VI is on the market. Valvoline has already made it avail to us and we have it in the CARQUEST Brand as well. I do not have the Valvoline # with me but the CQ # is CQ 426.

[Black02Silverado]

C & A s Dad has it. Easy to do the change out, especially if you have a helper. Here is the procedure for a full transmission fluid exchange. I just helped my supervisor exchange out all the ATF in his daughters 03 Honda Civic. Not bad for him since it only took 7qts. Your truck will take 16qts to get a full exchange of fluid.

 

Changing it out at 30k is about right for average use with regular ATF fluid. If you ran synthetic you could go longer. AMSOIL severe service change of ATF is 50k and normal service is 100k miles.

 

The Carquest here had Dexron VI.

[C & A s Dad]

I found the Valvloine #. It is VV370 in case you do not want our CQ Brand. Valvoline packages our oil but another company does our Trans fluids. It is great quality but I know some people look for that "Name Brand" on the bottle.