Aux filter vs frequent ATF changes?

[Runnin'OnEmpty]

Hey guys. I'm considering adding an aux spin-on filter to the trans, but can't decide if they're worth it. If the ATF's filtered when being sucked up from the pan, it seems like the aux filter would be redundant and would be filtering 'clean' fluid?

An aux filter would certainly be worthwhile if an old type screen filter was used, but the 5R55e uses a micro-media type filter that really does clean the fluid, and not simply screen out the big chunks.

So is it better to install an aux filter, or simply suction out the pan and refill with fresh MercV every summer?

Thanks for your opinions,
ROE


BTW, 24K trouble-free miles on the 2-3 flare fix.
Keeping fingers crossed and knocking on wood.

 

[bluestream1]

I agree with you that the filter in the 5R55 transmission is perfectly adequate. An external filter is going to add a restriction into the system, and is bound to slow the fluid flow especially when cold. My tranny at 155KM was perfectly clean inside, and I don't know what an extra filter would do. Frequent fluid changes are the preferred route to take in my opinion. Even with an external, you still have to go in now and then to change the internal filter.

 

[bp1506]

I would think it will filter the what the internal transmission fliter misses. I think its sounds like a good idea. I ordered a kit from summit racing and i am getting my transmission fluid changed this weekend. And i will install the kit as soon as it arrives.

 

[Jefe]

Regardless of filtering, replacing the ATF often (30k miles) is a good idea, as its more than getting the crap out, its replacing ATF that could be working less than optimally.

As for the Aux filter, I'm still on the fence on that one. I had one at one time, but took it out of the loop when I installed the 700R4, and just run a microfelt(?) filter. If the Aux filter was the last thing in line and filtered out the friction media I could see it being good, but obviously the fluid has gone a hundred directions by then.

 

[aldive]

If in doubt about the quality of the ATF, do a UOA on it; chemistry never lies.

I highly recommend the additional filter. Not only does if filter much better than the internal one, it also adds an additional quart of ATF. Flow restriction has not been an issue.

Further, the use of full synthetic ATF is a bonus.

 

[Glacier991]

One thing to remember.... the ability of the transmission to stop a rotating part is dependent on friction material and pressure. The abilityto hold a part that wants to rotate stopped once you have stopped it, is a function more of fluid properties in the friction interface, and pressure. Once my A4LD got old and started slipping, I started changing the fluid every 10,000-15,000 miles (Mercon III) and I now have 222K on a tranny I thought might die on me 40,000 miles ago.

 

[bluestream1]

If the fluid is changed every 25-30K I don't think the ext filter is needed, as that is far more than most people ever do. I took my first two internal filters apart, and they seemed to be doing a good job of keeping things clean. My VB was spotless inside after 150K. There is also a magnet in the pan to catch any metallic filings. If the internal filter was getting plugged, then I would agree with the need for the extra filter. I am sure that we won't get complete agreement on this issue.

 

[BrooklynBay]

The OEM designs of transmissions haven't changed much regarding the filter designs. It is a messy job to remove the pan, and gasket every time the filter has to be replaced. They should redesign this set up, and start to use screw on filters like engines have been using for years. This would make things a lot easier. Does anybody know if Saturn once did this on some models? Somebody once told me that they had this, but I've never worked on one to verify this concept. I wonder if an external filter (or possibly a dual external filter) could be used instead of a screen? I'm just thinking out loud, and not recommending anybody experiment on their transmissions to see how well this would work.

 

[Wrench]

Aside from having a chemical analysis done on the particulate matter on an oil sample from the trans you will probably have to rely on the filtration system to do its intended job. Does anyone have any hard data on the micron rating of either the Micro felt internal or after-market external spin-on canister oil filter used for the 5R55E? I see no point in adding an external oil flter if it is the same rating or worse. Would rather spend my money on a bigger oil cooler and carry out 30k oil/filter changes. As we all know, a regular trans oil pan inspection can help detect a possible problem and save a roadside breakdown or major hard parts failure.