Chevy Colorado Curious for Advice/Opnions

[A1BadPizzaGuy]

The vehicle is my '04 Chevy Colorado 5cyl 5-speed. It now has roughly 154k miles, and I acquired it used with 135k or so. I drive it very easily, but I drive 1000mi in about a week and a half. I'm fairly confident the rear differential fluid has never been changed, and also that the manual transmission hasn't been touched.

I mean to change the fluid in the differential as per the owner's manual which says it needs to be done every 50k miles. This may not be sound reasoning, but I'm reluctant to open it up and change it after so long because I haven't observed any problems with the differential. Basically, I'm worried that since it performs perfectly after this long that something might go wrong if I mess with it.

Do you think I'm onto something, or what the heck am I waiting for? haha

 

[LeakySeals]

The test of your reasoning. Are you reluctant to change your engine oil because its been a while and everything runs good? Or do you change your oil before the engine starts to run bad?

 

[simple_gifts]

IMHO, the myth of not changing diff, MTF or ATF if "it has been in there a long time" is propagated by people (mechanics) who don't want to do the work, and rightly so. An AT failure somehow is linked to the changing of the fluid, not the 13 years it was neglected, for example.

You should change the fluids. JMO

 

[daves87rs]

I'd change them...

 

[A1BadPizzaGuy]

Good point on the engine oil haha. That has occurred to me throughout my thinking on this. And yes, it's a stretch for me to see how changing the fluid could cause a problem. The only reason I waited so long is that I wanted to do it around 150k miles to give it a good benchmark. But it seems I reached that mark a while before time would allow I actually do the work.
I was made more concerned when I read on a colorado forum that someone's differential started clicking after he changed it.

Anyway, thank you guys very much for the replies.

 

[LeakySeals]

The reason is usually the part left out of the thread - used the wrong fluid, fulled it wrong... or what it sounds like is waited too long, changed it when it was too late and blamed it on the change rather than being a procrastinator.

 

[LeakySeals]

that camry in my signature..i change all the fluids in that old thing constantly. All of them, including brake fluid. It hasn't been apart for anything, thermostats, transmission filter, all original. Just drains and fills every 20k or so.

 

[Gene K]

Change the rear axle lube and trans lube. Make sure the new lubes meet spec IE dont put GL5 in the trans unless it calls for it.

 

[A1BadPizzaGuy]

Originally Posted By: Gene K
Change the rear axle lube and trans lube. Make sure the new lubes meet spec IE dont put GL5 in the trans unless it calls for it.


I'll check the manual again to be sure, but as far as I know, the differential and trans call for synthetic 75w-90. "75w90 GL-3" is stamped on the side of the transmission, but any other place I look says the fluid is "GM part no. *something*". So, I would need to find a GL-3 instead of putting a new GL-5 fluid in it?

 

[artificialist]

Originally Posted By: A1BadPizzaGuy
Originally Posted By: Gene K
Change the rear axle lube and trans lube. Make sure the new lubes meet spec IE dont put GL5 in the trans unless it calls for it.


I'll check the manual again to be sure, but as far as I know, the differential and trans call for synthetic 75w-90. "75w90 GL-3" is stamped on the side of the transmission, but any other place I look says the fluid is "GM part no. *something*". So, I would need to find a GL-3 instead of putting a new GL-5 fluid in it?

GL-4 is often used to replace GL-3. Amsoil and Redline make a 75w90 GL-4 for this purpose.

 

[JTK]

I know the rear diff oil was black and ugly looking on my 2005 Trailblazer when I changed it at ~36Kmi. The magnet strip on the inside of the cover looked like a dirty Hedge Hog too. The gasket was a nice metal/rubber reusable deal, which was nice.

Joel