Hey if your doing tranny coolers, get one more and I will come over... I do drive a mobile workshop.... that needs a cooler. I am a little younger and can get dirty. Greg has my number.

 

ya know, that is a very good point. According to the lab I use, they say that the method for taking samples is actually quite important. In a perfect world, they prefer that samples be taken 'live'. Meaning, a fitting gets installed directly into a port that receives fluid pressure when the engine/transmission is running. Here is a link to the fitting I am talking about.
http://www.jsgindustrial.com/pdfs/oilsampling.pdf
The procedure is to get the device up to operating temperature and take the sample while in operation. I think the fittings have some sort of orifice restriction that keeps the fluid from coming out at high pressures...

So far to date, I have yet to purchase and install said fittings because I am using my one pressure port for a trans temp sensor. So, my sample was taken by simply pulling the drain plug on the pan, catching the fluid as quickly as possible and then re-installing the plug. It's a little messy but it seems to work OK...it takes about 1/3 qt to top back up again.

I just spoke with the lab a moment ago and they said the method I used will show a higher concentration of wear metals compared to a live sample from a warmed up transmission.

At this point I have a hard time believing that adding an external filter could cause higher wear metals readings. Maybe the difference between my lab reports and Pop's is the fluid brand or possibly even different materials inside the transmission itself. My trans was rebuilt using the Transgo Tugger Overhaul kit back in 2006 (which was over 150k miles ago) so perhaps they use different clutch materials compared to an OEM trans. (I am not sure if Pop has an OEM trans though....)

My lab said I should sample again in another 15k miles and that should be a better comparison to Pop's report since there will be the same amount of time on both fluids. They also said that I shouldn't get too hung up on the wear metal PPM numbers since neither the OEM or an aftermarket filtration system will have much effect on those figures. They said the viscosity at 100c and the Acid number are the real tell tale figures to look at when considering the health of the fluid. Unfortunately I don't see that information on Pop's report though...

My lab said that based on the trends witnessed so far, it appears the fluid could easily make it to 70k miles before they might recommend that it be changed based on acid index alone. At that point, the acid number should be about 1.75. They almost always recommend that ATF be changed when the acid number exceeds 2.0.

They also keep an eye on the viscosity reading because that usually begins to suffer first. The next sample will provide a little more info but his gut feeling is that I should be able to safely go 60-65k miles on this fluid before they will recommend that it be changed out. If solids (insolubles) begin to show up, then that will also prompt a recommendation for a fluid change as well...

Of course this led me to my next question which was to ask the lab about the value of adding an external filtration system to my truck. In his opinion, he felt that it was not necessary for my application. Based on my recent history of use for this vehicle, it will take 3-4 years to accumulate 60k miles on the fluid. By that time the viscosity will have sheared down enough to require a fluid change irregardless of how good the filtration system is.

If I was putting 60-100k miles on per year, then that would be a different story. In those cases, the external filters can help stretch the ATF to about 75k miles between changes and maybe even a little longer if checked more often.

I think I'll send Marv a note and see if he has the viscosity and acid numbers from his 45k report. That might be the smoking gun that I am looking for...


At this point I am on the fence still about adding supplemental filtration...
The trans coolers are still on the agenda though...I am not sure about Robin but I already picked up a TruCool max for the F450, just haven't installed it yet...
But you are welcome to come over when we are doing the cooler install, should be pretty easy. I'll give you a buzz when the time comes.