Jump to content

Recommended Posts

Posted

I have a 17 Silverado 1500 z71 that I bought used with 89k miles on it. Around 93k or so, the transmission had to be replaced. It now has almost 100k on it. I know the transfer case fluid is supposed to be changed around this time. 

 

My question is, what are the odds that they changed the transfer case fluid when they replaced the transmission? Or would it not be standard procedure to drop both at the same time. I've searched and have seen mixed opinions. The paperwork did not specify if it was done or not. 

Posted

Well,

I think if the trans had been serviced BEFORE the owners manual recommends(I do more fluid changes) you wouldn't have needed to replace it. So I bet the transfer case was never touched.

Posted

I agree as far as the trans goes. It was a risk of buying a used vehicle. Fortunately I had an extended warranty that covered it, otherwise I would have been real upset. 

 

Just trying to stay up to date with the maintenance now since I can only assume it wasn't fully taken care of before I bought it. 

Posted

If it were me, I'd go ahead & change it as it only holds about a quart or 2. Easy job.

  • Like 1
Posted (edited)

I would change it out. I would never trust the shop to be proactive, they likely did only what was necessary and used the lowest cost products in their repair. If you are of the believe all lubes are the same, then drive with confidence. 

Edited by elcamino
Posted
On 7/17/2023 at 1:57 PM, Jeff Newell said:

I have a 17 Silverado 1500 z71 that I bought used with 89k miles on it. Around 93k or so, the transmission had to be replaced. It now has almost 100k on it. I know the transfer case fluid is supposed to be changed around this time. 

 

My question is, what are the odds that they changed the transfer case fluid when they replaced the transmission? Or would it not be standard procedure to drop both at the same time. I've searched and have seen mixed opinions. The paperwork did not specify if it was done or not. 

 

 

Unlikely.  Transfer case was probably removed with the fluid in it.  Its only 2 quarts in there so not a whole lot of extra weight.  

 

No more than ever 45k miles IMO for transfer case.  The book shows 97,500mi for "normal use" which is insane because the 2500/3500 chart shows every 45,000mi or for severe use every 22,500mi.  

  • Like 3
Posted

Yeah. Definitely going to change it. Just hoping no damage has been done. No idea how well it was maintained before I bought it. 

Posted

For good measure, I would suggest replacing Front and rear diff as well as the transfer case. You will already be under the truck with the tools out, so what is an extra 30-45 min of time to have fresh fluid in everything?

  • Like 4
  • Thanks 1
Posted

What’s the best fluid for front, rear differential and for transfer case? For 2015 Sierra 4x4

weight, brand etc..

I don’t get under the truck anymore so what’s a fair shop price for all?

thanks in advance 

Posted

I use a synthetic 75W90 limited slip GL5 gear oil in front & rear.  Walmart Super tech works & is a good cost effective  GL5.

Transfer case takes Dexron 6. I use AC Delco  for it but any Dexron 6 meets the spec.

  • Like 1
  • Thanks 1
Posted

I used Mobil 1 Delvac 75W90 in my diffs because it doesn’t contain limited slip additive. The additive isn’t recommended for the G80 locker. It took 4qts 12oz for both diffs. 
 

B1ABF76B-EA38-4C0A-93CB-5F44EF90C147.webp.09a714491c9d0182df317c0ceb4656f5.webp

  • Like 2
  • Thanks 1
Posted
On 7/21/2023 at 7:11 PM, Wyatt1963 said:

What’s the best fluid for front, rear differential and for transfer case? For 2015 Sierra 4x4

weight, brand etc..

I don’t get under the truck anymore so what’s a fair shop price for all?

thanks in advance 

I used Amsoil Severe Gear 75W90 for the Front and rear Diffs in my 2014 and Amsoil Synthetic Trans oil for the transfer case.

  • Like 1
Posted
5 hours ago, BigBlue2014 said:

I used Amsoil Severe Gear 75W90 for the Front and rear Diffs in my 2014 and Amsoil Synthetic Trans oil for the transfer case.

 

Same here

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Latest Articles

  • Posts

    • I tried tapping it.  This might sound like a dumb question, you should feel vibration or some type of noise when it turns on? Can someone please verify? Thank you all!
    • I feel better now for my own view point and actions or lack there of towards the dealership service theme reading your post and others. GM corporate is who offers the two free oil changes on the HD trucks and I bought my truck in Feb of 2025 and those oil change offers run out within 2 years I believe and I highly doubt I will be using either one of them. I had asked if I could officially give those free services to another customer ( a friend ) and they said no, its all a GM corporate thing based on the vehicle in question. What that service advisor did however was go into a little story about how such and such customer was denied engine warranty because he had done his own oil changes because then they are not documented ... you see where that goes and so an employee playing the game of scaring the customer into having the service work done there most certainly triggered my thought process. At a later date I did talk to the person who handles warranty claims at the dealership and she said to be sure to document the oil changes and keep receipts for the oil and filter ( coped the receipts from cases of Mobil oil and case of filters I bought from them ) and the vehicles VIN, the date of service, mileage etc and staple that together as a record I would give them if that was ever needed and I keep my own log book for services for each vehicle as well. Oh and about 8 months after I bought the truck the dealer starts calling me to offer a maintenance service since they haven't seen my vehicle show up on their system ... for the mere fee of 300.00 Canadian to change the oil and rotate the tires and a few other minor checks and I declined the offer, I get the call again a couple of months later for the same thing and she could tell I was not interested and she asked if they should take my name off the call list and I said yes, do that !.    By the way did you happen to keep your factory oil filter to open it up and see the surprises inside as I expect some will show up as per the odd little sliver of metal shaving and particles that the filter does trap along with bits of grey silicone sealer that come off of the inside edge of mating surfaces. I have cut open every filter so far on my truck although few miles but have changed the oil often and the second filter was vastly better with very little of anything, that first filter was the unsettling one as I expected it would be. 
    • I get why they do this…but man…not ideal. I only extract on inboard boat engines because the drains are buried and even then I hate it because it’s easy to leave a quart behind with that method.   They should market it as an “oil refresh” not oil change!
    • I only get oil changed where I can watch. Valvoline pulls through the dipstick into a see thru glass. When done they show me the dipstick. About the only way they can mess up is using the wrong oil. But that secret wouldn’t stay secret long. Honda uses TQ wrenches on everything. You can watch through a plate glass window. Discount tires does that with tires. Trust but verify. 
    • I would not argue that with you. It would be pointless to argue against the truth and you speak the truth.    My question and in fact the entire point of this thread is an exploration into the levers of wear which happens no matter how well we maintain our powertrains.    Some of these levers we exert a good deal of influence over which can and do result is lower wear, longer powertrain life. Some others we are sort of stuck with.    An engine is typically done when the ring to bore seal no longer is able to do the job effectively. Normally the first thing to go in a engine otherwise well maintained and adult driven is this seal.    Looking into the means, methods, products and attitudes that influence the rate of wear seems a worthwhile inquiry to me.     
  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...