Tranny/ Rear Diff fluid
Senior User
Joined: Aug 2003
Posts: 438
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From: Colorado Springs
I added a mag-hytec cover and the following:
20K - rear and Amsoil 75W-140
50K - front and Amsoil 75W-90.
I'll most likely change them again at 100k, and then every 100k after that.
Auto tranny, I drain and replace the fluid/filter every 30k. I don't do the flush as I feel the filter keeps the fluid pretty clean.
Mark
20K - rear and Amsoil 75W-140
50K - front and Amsoil 75W-90.
I'll most likely change them again at 100k, and then every 100k after that.
Auto tranny, I drain and replace the fluid/filter every 30k. I don't do the flush as I feel the filter keeps the fluid pretty clean.
Mark
Senior User
Joined: Nov 2005
Posts: 382
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From: Big Red country
There is plenty of research, including by GM, that shows there is a definite advantage to changing the diff fluid by 10K. So if you haven't already, I would change that for sure. The Torqueshift is another matter. I have OA's that show it is capable of going longer than 30K. The tranny has a bypass filter that does a great job, coupled with a cooler and great design and this tranny is awesome. None the less, for about $20-25 you can drain the pan and replace only that fluid and be set for another 25-30K. Its your dime and your truck.
Fleet Owner
Joined: Nov 2003
Posts: 27,881
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Originally Posted by scafes
There is plenty of research, including by GM, that shows there is a definite advantage to changing the diff fluid by 10K. So if you haven't already, I would change that for sure.
Senior User
Joined: Nov 2005
Posts: 382
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From: Big Red country
The studies (GM and LockheedMartin) showed that removing the break in particles that are present in the fluid greatly increased the life of the diff. Since the fluid isn't filtered, it makes alot of sense. Those metal particles are flowing around the gears getting mashed into the bearing surfaces.
My first thought though when I read the article was, who cares anyway, diffs last a long time! I have only had one fail and that was in a 3/4 ton van, Dodge BTW, loaded heavy most of the time. The side gears had severe galling and wear, but the van had about 120K on it. Who knows if it ever had a change of fluid since new.
Thing to remember though is that todays diffs operate in a harsher environment than they used to, yet they really haven't changed much over the years. More powerful engines, less cooling via air flow, bigger stock tires, etc.
I will look around and see if I can find the article lying around here, has to be somewhere, I don't throw things away.
My first thought though when I read the article was, who cares anyway, diffs last a long time! I have only had one fail and that was in a 3/4 ton van, Dodge BTW, loaded heavy most of the time. The side gears had severe galling and wear, but the van had about 120K on it. Who knows if it ever had a change of fluid since new.
Thing to remember though is that todays diffs operate in a harsher environment than they used to, yet they really haven't changed much over the years. More powerful engines, less cooling via air flow, bigger stock tires, etc.
I will look around and see if I can find the article lying around here, has to be somewhere, I don't throw things away.
