90K miles. Should i change the trans oil ?
Mar 22, 2013 | 09:51 AM
#11
Teching In
Joined: Apr 2012
Posts: 28
Likes: 0
From: The woodlands, texas
My trans fluid was like that around 75k and i lost 3rd 4th and overdrive at 80k. Lol
Hope you have better luck than i did. But id agree and not change it, always been told "if its never been changed before then dont change it"
Hope you have better luck than i did. But id agree and not change it, always been told "if its never been changed before then dont change it"
Mar 22, 2013 | 11:06 AM
#12
Just to add to this, same story with my brother. He was an original owner of a 02 Suburban 8.1 w/ 4l80e. He drove it 100k never towed, just drove the kids around in it. He was going to sell it, so decided to do a flush for when he sold it. After that it wouldn't lock up in OD. Had to have the tranny rebuilt.
Mar 23, 2013 | 12:14 PM
#13
Staging Lane
Joined: May 2009
Posts: 98
Likes: 0
NO. Don't change it.
If you change it at this point you will likely remove what's holding the clutches together. Many many many transmissions that were not properly maintained worked right up until someone decided that changing the fluid 50,000 miles past it's expiration date would be a good idea.
Pretty much the old fluid has developed a friction material suspension and this keeps the clutches biting when applied. New fluid doesn't have this.
If you change it at this point you will likely remove what's holding the clutches together. Many many many transmissions that were not properly maintained worked right up until someone decided that changing the fluid 50,000 miles past it's expiration date would be a good idea.
Pretty much the old fluid has developed a friction material suspension and this keeps the clutches biting when applied. New fluid doesn't have this.
It really is a crap shoot to change the fluid in a transmission that has not been regularly maintained if it has some miles on it. Here's why... in the normal process of aging, the soft parts wear. Those are the clutch plates, the band/s, converter clutch and so on. So, if they've worn there is more clearance in the given clutch pack. Plus the clutches will be somewhat glazed, or surface hardened so to speak.
Now, the existing / old fluid has super fine debris floating in it... hence the dark color. That debris adds a certain amount of friction to the clutch's ability to grab the steel plates. The new fluid has no fine debris in it, plus it has fresh lubricants.
So add the fresh lubricants, add the wear and tear on the clutches, and take away the fine debris that was circulating in the old fluid and yeah it can begin to slip.
That's something I've seen many countless times in the past. I tell my customers to think in terms of the old fluid being like your blood. There are anti bodies in our blood that keep us from getting sick right?
I would recommend a fluid and filter change, but do not flush all of the old fluid out.
Hope that helps!
g
Mar 23, 2013 | 12:31 PM
#14
Staging Lane
Joined: May 2007
Posts: 75
Likes: 0
For what's its worth I drive a nbs 07 silverado 4.3 4l60e rcsb. The trans was never serviced since new, I know the original owner. I bought the truck with 284k, at 286k or so I did a pan drop and added 5qts of fresh fluid. Then at 312k I did a full flush with 16qts of dexron 6. Trans shifts better than before also runs cooler.
Thread
Thread Starter
Forum
Replies
Last Post
D1SCSS
GM Parts Classifieds
44
Jan 25, 2016 10:14 PM
Noah Burns
GMT K2xx Trucks General Discussion
5
Sep 7, 2015 05:50 PM
thewrx
Cars and Motorcycle Classifieds
1
Aug 12, 2015 08:28 PM
