Clutch/friction material suspended in old transmission fluid

[octanejunkie]

Based on this thread re Drain and Fill vs. Flush, the concept of clutch material in suspension being lost in a flush, allowing an old, or ill-maintained transmission to start slipping begs a question:

If you add an inline filter, like a Magnafine, that has finer filter media than the bug screen stock trans filter, won't you filter the suspended clutch/friction material out of the fluid?

Assuming the filter has a bypass function, some material would be filtered out, wouldn't it?

 

[LittleCaesar]

Yes, that is the idea but shavings usually stay in the pan.

In fact you can take the filter apart and see what is attached to the magnet. I saw little on mine, but only after 19k miles.

If the IAC is good, then how is the ECU 60a fuse, in relation to the stalling?

 

[octanejunkie]

Yes, that is the idea but shavings usually stay in the pan.

In fact you can take the filter apart and see what is attached to the magnet. I saw little on mine, but only after 19k miles.

If the IAC is good, then how is the ECU 60a fuse, in relation to the stalling?

I assume the clutch/friction material that has sluffed off is non-ferrous and doesn't get stuck to a magnet - there are a few in the pan already

HAHAHA - cross-post reply, re ECU and stalling, but that 60A fuse is fine. IAC was replaced several months ago, truck starts fine - just seldom, random stalls when within 30 mins of startup always standing in gear at a traffic light, never any other time.

 

[TechWrench]

Based on this thread re Drain and Fill vs. Flush, the concept of clutch material in suspension being lost in a flush, allowing an old, or ill-maintained transmission to start slipping begs a question:

If you add an inline filter, like a Magnafine, that has finer filter media than the bug screen stock trans filter, won't you filter the suspended clutch/friction material out of the fluid?

Assuming the filter has a bypass function, some material would be filtered out, wouldn't it?

If you do in fact have clutch friction material suspended in the trans fluid, that material will/can not be used by the transmission in its operation. The material has already become separated from the friction disks in the clutch packs, and the only time that material will work is when it is still attached to the disk. The only damage the loose friction material can cause is to clog the internal filter screen. Removing this material by either filtering, or flushing it out, in of itself, will not cause a trans to fail. The real problem is why this material has become detached from the friction disks in the first place. In most cases, this material has become detached because the internal seals in the clutch packs are worn or torn, which reduces the amount of hydraulic pressure that is applied to the clutch pack when it is engaged. This loss of pressure will, over time, cause the clutch pack to slip when engaged. It is this slippage that causes the friction material to break away from the friction disks. Once this material has started to separate from the disks, the only fix is to overhaul the transmission, replacing the internal seals and worn friction disks.

 

[octanejunkie]

If you do in fact have clutch friction material suspended in the trans fluid, that material will/can not be used by the transmission in its operation. The material has already become separated from the friction disks in the clutch packs, and the only time that material will work is when it is still attached to the disk. The only damage the loose friction material can cause is to clog the internal filter screen. Removing this material by either filtering, or flushing it out, in of itself, will not cause a trans to fail. The real problem is why this material has become detached from the friction disks in the first place. In most cases, this material has become detached because the internal seals in the clutch packs are worn or torn, which reduces the amount of hydraulic pressure that is applied to the clutch pack when it is engaged. This loss of pressure will, over time, cause the clutch pack to slip when engaged. It is this slippage that causes the friction material to break away from the friction disks. Once this material has started to separate from the disks, the only fix is to overhaul the transmission, replacing the internal seals and worn friction disks.

Thanks for the detailed reply!

So a complete fluid flush/exchange won't alter transmission performance for the worse?

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[TechWrench]

Thanks for the detailed reply!

So a complete fluid flush/exchange won't alter transmission performance for the worse?

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If the transmission is functioning normally, with no pre-existing internal damage/wear, a fluid change should not negatively effect the transmission function. That is assuming, the fluid used in the exchange is compatible for the transmission. In most cases I have heard of, the only time a fluid change has resulted in a decrease in function is when there was a pre-existing internal condition, which the owner was not aware of, or the fluid had been overheated to the point of failure which often results in internal seal damage and eventual failure. Especially in cases where the burnt fluid has left varnish deposits on the internal surfaces of the transmission. These varnish deposits may become loosened by the detergent action of the new fluid, and create problems. If there is a problem with a correctly done fluid change, most likely the transmission was already on its way to a failure.

 

[octanejunkie]

If the transmission is functioning normally, with no pre-existing internal damage/wear, a fluid change should not negatively effect the transmission function. That is assuming, the fluid used in the exchange is compatible for the transmission. In most cases I have heard of, the only time a fluid change has resulted in a decrease in function is when there was a pre-existing internal condition, which the owner was not aware of, or the fluid had been overheated to the point of failure which often results in internal seal damage and eventual failure. Especially in cases where the burnt fluid has left varnish deposits on the internal surfaces of the transmission. These varnish deposits may become loosened by the detergent action of the new fluid, and create problems. If there is a problem with a correctly done fluid change, most likely the transmission was already on its way to a failure.

Understood and appreciated, again thanks [MENTION=937]TechWrench[/MENTION]

The fluid in my A340E transmission is dark, but as far as I am aware has not been overheated and does not smell burnt.

The fluids I am considering for an exchange, are:
Castrol Transmax Import Multi-Vehicle ATF
or
Valvoline MaxLife Multi-Vehicle Automatic Transmission Fluid

I can do a progressive drain and fill using either fluid before, or in lieu of a full flush/exchange.

I have yet to drop my pan or inspect the stock filter, and was considering adding an inline magnafine-type filter, but my understanding of the stock filter is that it is no finer than a mesh screen and is not super prone to clogging like a paper/fiber element filter would be.

Thoughts on how to proceed?

 

[TechWrench]

Understood and appreciated, again thanks [MENTION=937]TechWrench[/MENTION]

The fluid in my A340E transmission is dark, but as far as I am aware has not been overheated and does not smell burnt.

The fluids I am considering for an exchange, are:
Castrol Transmax Import Multi-Vehicle ATF
or
Valvoline MaxLife Multi-Vehicle Automatic Transmission Fluid

I can do a progressive drain and fill using either fluid before, or in lieu of a full flush/exchange.

I have yet to drop my pan or inspect the stock filter, and was considering adding an inline magnafine-type filter, but my understanding of the stock filter is that it is no finer than a mesh screen and is not super prone to clogging like a paper/fiber element filter would be.

Thoughts on how to proceed?

Ok, lets start with your last question 1st. I, IMHO, would not recommend an external filter for the transmission. This is not to say that I am against extra filtering, when it serves a purpose, but with a normal transmission, it does not generate any particulate mater, that would need to be filtered, like an engine does. If the transmission is generating particulate matter, then it is already headed for an eventual failure, and no amount of filtering is going to fix that. This is why the normal transmission only has a screen, which is more than adequate for normal circumstances. The metal that one will find attached to the magnet in most transmission pans is usually generated during the first months of its life, and is normal break in wear. I have found, that it is very rare to find any substantial metal during subsequent transmission servicing, unless of course there is a serious metal on metal failure in progress. With my own vehicles, I have found it sufficient to do 3-4 drain and fills, with in a 2-3 month period. This will get most of the old oil out, and the new oil, with the fresh additives it contains will maintain a normally functioning trans just fine. I have nothing against someone doing a complete flush, but IMHO, it is not necessary most of the time. The only time I would consider a complete flush and replacement, would be if I knew that the fluid had been recently stressed or overheated and needed immediate replacement.

As for the two replacement fluids you are considering, as long as they meet Toyota's standards for your year vehicle, I would not be against using them.

 

[octanejunkie]

Again, many thanks. A drain and fill seems reasonable and progressive.

Based on the 2-3 month timeline you mentioned, what sort of mileage is assumed in that timespan?

Afaik, both the fluids link meet the OEM requirement, the Valvoline, however is full synthetic. My dipstick calls for Dex II or Dexron[emoji768] II, III

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[TechWrench]

Again, many thanks. A drain and fill seems reasonable and progressive.

Based on the 2-3 month timeline you mentioned, what sort of mileage is assumed in that timespan?

Afaik, both the fluids link meet the OEM requirement, the Valvoline, however is full synthetic. My dipstick calls for Dex II or Dexron[emoji768] II, III

Sent from my Pixel XL using Tapatalk

I would guess that it would be about 1,000 miles or so between each drain/refill, but I do it more on a time available to me time frame rather than any specific mileage number.

As for the fluids, because of the year of the vehicle, I, again IMHO, would probably go with the standard fluid instead of the full synthetic. The synthetic fluid may be fine, I just don't know given the age of the vehicle.

 

[octanejunkie]

I would guess that it would be about 1,000 miles or so between each drain/refill, but I do it more on a time available to me time frame rather than any specific mileage number.

As for the fluids, because of the year of the vehicle, I, again IMHO, would probably go with the standard fluid instead of the full synthetic. The synthetic fluid may be fine, I just don't know given the age of the vehicle.

I drove 1K miles last weekend, Lol
Guess I'm ready for another drain and fill

I concur with your on conventional fluid given the age of the trans and unknown overall condition.

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