Wulfman, it's my understanding that the external filter does less than 10% of filtration when the temperature is above 160-165 anyhow. I'm after better filtration for a better peace of mind. :-) Living in the desert, towing in this dry heat is killer.

 

The factory external filter on the 5 speed TorqShift trucks filters 10% of the fluid going through the cooler lines. When the trans is below 165°F the flow to the cooler is cut by 90%, and then the filter is only filtering 10% of that flow.

The improved internal filter will filter 100% of the fluid all the time. That's why one would delete the external filter and replace it with the new internal one.

 

This ^^^.


Three weeks ago O'Reilly still had Mercon SP available for next day pickup here in the MidWest at about $4.50/quart.

 

But there's no reason you would actually need to delete the inline filter, correct? I can't see that the extra filtration would hurt anything. The only disadvantage would be that you would still want to change the inline filter periodically, although probably less often than normal due to the improved internal filter.

As I understand it, the OP of this thread installed the newer internal filter, but he did not delete the inline filter. He replaced the inline filter with a new one.

 

Re-read what Mark said there. The inline filter only filters 10% of the fluid that goes to the cooler. When the thermostat is closed, only 10% of the fluid goes to the cooler. This means only 1% of the fluid is being filtered when the thermostat is closed.

 

I also think the OP did this on a 2006 which does have a frame mounted inline filter vs the 08 that has the external filter. Not sure how much operational difference there is between the two but it sounds like the external is almost useless IMO. Again, when it's 105 outside, my tranny has no problem heating up to temp.

At this point I am leaning heavily to do the modification. However the one piece I am unsure what to do with the external filter. If i leave it, will it cause pressure problems and hinder the operation? Or is it a non issue if I leave it?

 

It is a non-issue to leave the external filter with the new internal filter. No problem at all.

 

Perfect, thank you Mark. I've think i've researched this thing to death and am just ready to do it. Looks like its time to track down a pan. Local dealerships don't have any in stock.

 

Mark's post wasn't there when I began to reply. Had I read it I would not have posted my less informed description of the transmission thermostat function.
On topic, I didn't know that the coolers return line filter housing bypassed to only run 10% through the filter. This has me considering the upgrade to the new style pan with improved internal filter on my 05. Live and Learn.
To Mark Kovlasky directly: I'd like to know if you ever came up with, or approved of, a complete transmission fluid flush? If upgrading the pan and internal filter I would like to start from scratch with all new fluid.

MOJoWales

 

The only way to flush the trans is with a heated flush machine.

 

I too had an 05 and ended up with this 08 when i apparently found the defective transmission at 20K after towing my fifth wheel for the first time. There was a known issue but it was only discussed if you had the issue. Either way this upgrade can't do anything but help to provide some reassurance.

How do you feel about the swap from Mercon SP? I'm going to O'Reillys to buy 18 qts of SP before it runs out. Don't think I'll need that much to do this swap. I'm also throwing around adding a couple qts of Valvoline Maxlife Dex/Merc.

 

any suggestions on where to find a new tranny pan? Local dealers are at zero bench stock and I'm sure i can save a buck or two.

 

Well, I took the part number from the pic in the OP (8C3Z-7A194-B) and typed it in to Google and came up with this:

8C3Z-7A194-B - Ford Pan Assy - Transmission Oil

Not sure if this is a reputable place to buy from though.

 

I have also been thinking about this upgrade. You can get additional info from these links here and here. This should give you the part numbers. You can get the parts from Tousley Parts onlne at a discount.

Mark we can't thank you enough for all that you do for this forum.

 

Regarding the swap to Mercon LV for Torqshift transmissions originally requiring Mercon SP, I decided to use SP while it is still available. While the relevant Ford TSB allows for mixing of LV and SP I saw no risk by waiting to see if there are any reported issues between now and my next fluid change. If the price or availability were a problem I would have switched to LV now. Later model 5R110W were specd with LV and there is likely no benefit to staying with SP. I just played it safe because it was the same cost and I would want to have a service center with a hot flush machine purge all the old SP out versus being able to do my own regular partial fluid and filter change. I choose to run the same fluid, all SP or all LV, if possible. Maybe Mark (thank you for your earlier reply) or another expert could point out the justification, or lack of it, for doing this but I doubt there is any real advantage one way or the other.
After digesting more of the information here I'll be changing my pan to get the new internal filter at my next service interval. When I do this I plan on retaining the external in-line filter because it is already in place.
08F250SD, were you referring to the forward-reverse failure associated with snow plow operation or some other issue? I'd like to keep my 05 on the road as long as possible.

MOJoWales