Originally Posted by millco
What is the NVH? How many miles do you have on your trans and how hard do you work it? Typically the most junk you will find in the pan on an oil change is at the first change. Did you get yours new?
NVH = noise, vibration and harshness initiatives to make th etrucks more like a car. In the process of making the trans shift like a car its killing it at every shift point because it slips more than it should. Load it down and the situation is aggravated. Address those items and a 90% of the observed problems disappear.
I have 160k on my truck, had since new. Smarty has been on and turned up since about 40k. Burned the direct clutches out of it with too much TQ at 105k. Its used for playing, DD, and 5-15k trailer pulling.
The first change to clean out the junk is normal. These units are not flushed and cleaned before assembled so there always seem to be small filings that end up in the pan after the a bit of driving. The shops I have worked at would rebuild a unit, put about 10 miles in test drive on it then drop the pan and fluid to clean an residual junk and make sure there is not any major issues. The factory doesn't do that so we have to.
Originally Posted by millco
I am convinced that if you install a large enough filter head and filter you will not restrict the flow of oil in there enough to measure the difference (And this is what you want so you don't shorten the life of the trans.).
Oh, and for me; the reason for installing a remote filter is to catch much more of the particles in the oil than what the OEM filter can. Have you ever seen what is inside the OEM filter. It isn't much of a filter at all! (I have changed lots of filters in other autos that actually only a had screen in there for a filter!) The filter I will use will be around 10 micron. This OEM filter should be able to catch stuff at least as small as bugs (Or what: 150 micron! The junk that will cause wear in there is around 20 micron and larger
Any time you try to filter down to 10 micron the filter is going to add restriction, the feasibility of adding large enough ports and enough surface area to minimize the flow restriction is where things get iffy. Even if you have a 30 psi bypass on the filter you still will negatively affect the flow by the design physics of the fliter and bypass, you can't get away from that. The question becomes how much restriction is too much and that info is hard to come by.
The OE filter is about 40 micron IIRC, adequate to keep larges pieces out of the system but not so much it restricts the ability to draw fluid from the sump, key point as to why the filter is the way it is. Given that the heavier materials will settle to the bottom on the pan and the large stuff won't get thru, its a pretty good system is the trans works as it hsould with minimal slipping and friction degradation. Like I said, if you see evidence you need to filter more the OE will do the filter is not going to address the problem.
Can a better filter help overall life expectancy? Yes it can, but, at what cost by putting it inline?
Consider using a shift kit to boost pressures, add better servos with better sealing capability to stop the slipping on shifts. A shift that happens firmly and quickly will generate little wear particles. The fluid acts as a buffer so frictions and steels meet rotational speeds about the time the the lubricating oil is squeezed from between them. Very few wear particles are generated. The downside to the OE is a firm quick shift that is not as smooth as they like, plus they can't sell rebuilds and parts later either.
Under the stock pressures and typical leaky sealing rings on servos the rotational diffrential is too great to match the frictions and steels as the oil is squeezed. This generates a lot more wear particles and potential grit to run thru the trans.
OE parts on a 48RE are high energy clutches, the stock steels tend to wear faster than say a Kolene steel but thats by design. With the previously mentioned fixes, I have noticed a definite difference in the amount of the black film one sees in a typical stock trans. That film is wear form the steels. When I rebuilt the trans we used new OE clutches and steels, they are wearing much better than they did on the stock system.
Extra filtering is not a bad idea, but, on a stock trans and inline its not something that I believe will increase trans life. Too many other things are more effective. Fix the issues that cause the need for extra filtering and it negates the need for the filter.