Transmission Filter Inspection Finding

[Keith Knight]

For reference I just changed my old ATF fluid and filters. It’s been about 8 years and 30,000 miles on that fluid and filter. And the fluid and filters were super clean, barely anything on the drain plug magnets and like mentioned earlier only the finest of particles could be seen in just the right light. Compared to the axle drain plug magnets the transmission was spotless.
Installed Transynd 668. It has drain intervals of 300,000 miles in general duty and 150,000 in server duty transmissions.

 

[Skyhawk13205]

Took apart my PTO today found some wear on the clutch housing input gear, also found some endplay on the clutch housing. I cannot find a spec for endplay or if that is normal.

 

[aw113sgte]

Took apart my PTO today found some wear on the clutch housing input gear, also found some endplay on the clutch housing. I cannot find a spec for endplay or if that is normal.View attachment 931651View attachment 931652

That may not be wear, could just be chamfering of the gear teeth (although look a bit rough).

 

[GeneralDisorder]

That looks to my eye like they ran the edge of the gear against the hobbing cutter with the spindle speed turned up to chamfer it. I don't see how you get a radial pattern on a spinning spur gear inside that PTO. Unless there's some mechanism I'm not envisioning at work here. It's looks too uniform and the wrong orientation for a spinning gear rubbing against something. Also not shiny enough. Looks like it's been through some post machine processing - tumbling or coating or?

 

[hike]

That looks to my eye like they ran the edge of the gear against the hobbing cutter with the spindle speed turned up to chamfer it. I don't see how you get a radial pattern on a spinning spur gear inside that PTO. Unless there's some mechanism I'm not envisioning at work here. It's looks too uniform and the wrong orientation for a spinning gear rubbing against something. Also not shiny enough. Looks like it's been through some post machine processing - tumbling or coating or?

I am no machinist, though it struck me the same way. The gouges are running perpendicular to the rotation, not with it. Those didn't happen inside a spinning PTO–

 

[Skyhawk13205]

Thanks for everyone’s input, it has been hard to find a culprit, I need to take the clutch housing off to see if there is any wear there. When I took apart the PTO the same contaminates I found in the filter were in the housing. Brass shavings, ferrous flakes, and brass particles suspended in the oil. Looking how the system works it gets lubed from the transmission lube filter and returns to the sump. I have been using this manual (see attached)for reference, I found it easier to follow than the TM.

 

[Skyhawk13205]

Took the clutch housing apart, all I could really find was oxidation, there were numerous rust spots throughout the main shaft and clutch housing, the only thing I can think of is there was corrosion that broke free and caused some abrasive wear in the clutch housing.

 

[cdub0451]

What do you guys think of TES 668?

It's what I use in my '04 A1 trans. We have a fleet of 55 trucks with MD3060 transmissions using it as well. We have virtually 0 transmission issues with hundreds of thousands of hours combined, all while pulling around shipping containers. If they have 2 max gross weight 20' containers on their trailer, which is not uncommon, the gross combined weight of truck, trailer, and containers can be as much as 150,000 lbs. Normal gross weights are in the 80,000 lbs range. TES-668 is an extreme duty version of TES-295 and are interchangeable. I have the spec sheet at work and I'll try to remember to post tomorrow.

 

[Keith Knight]

Wow that’s amazing to here!

 

[cdub0451]

We use the Shell manufactured version but it should be virtually identical chemistry wise compared to the Castrol/Allison packaged TES-668.

Pro Tip: TES-295 & 668 are essentially a high grade DEX III. I mention this because good DEX III (NOT DEX VI. The specs are different even though it is "interchangeable") is getting harder to find.

 

[Keith Knight]

So using the 668, it says up 300,000 miles in normal and 150,000 in severe duty.
in you fleet what’s your filter and fluid change mileage?

 

[cdub0451]

So using the 668, it says up 300,000 miles in normal and 150,000 in severe duty.
in you fleet what’s your filter and fluid change mileage?

We change trans fluid every 6,000 hours which translates to roughly 120,000 miles and filters at 3,000 hours. It takes us about 18 months to reach the 6k hrs interval. I wish I could tell you what our oil analysis looks like in those transmissions, but we experience failures so infrequently that it doesn't meet our requirements to justify spending the money. The Chinese manufactured Cummins L9 engines in our container handlers are a different story...

Furthermore, I'm genuinely surprised at the issues people have with these transmissions. I've started to ponder how much of an effect running the 10W-30 contributes to the issues, not to mention the drivetrain speeds in stock configuration. It's probably a combination of those two things along with how hard Pvt Schmucatelli raw dogged the truck through who knows what.

FWIW, I'm using genuine filters and seals from my Allison vendor, TES-668, and Eco Hubs.

 

[Skyhawk13205]

We change trans fluid every 6,000 hours which translates to roughly 120,000 miles and filters at 3,000 hours. It takes us about 18 months to reach the 6k hrs interval. I wish I could tell you what our oil analysis looks like in those transmissions, but we experience failures so infrequently that it doesn't meet our requirements to justify spending the money. The Chinese manufactured Cummins L9 engines in our container handlers are a different story...

Furthermore, I'm genuinely surprised at the issues people have with these transmissions. I've started to ponder how much of an effect running the 10W-30 contributes to the issues, not to mention the drivetrain speeds in stock configuration. It's probably a combination of those two things along with how hard Pvt Schmucatelli raw dogged the truck through who knows what.

FWIW, I'm using genuine filters and seals from my Allison vendor, TES-668, and Eco Hubs.

I think most of the tranmission issues are from vibrations, heat exchanger failures, wiring problems, running max governed speed, and low use. One member here says “that no use is abuse.” I think the gear-train module which is about same as the 3060 is prob the most reliable part of the transmission.

Also it seems a lot of the tranmission replacments are from the transfer case failures specifically the C6 thrust bearing. The hard to source items are in the transfer case and the special 7” sump.

I think the conventional oil 15w-40 is less stable than a synthetic ATF, also the additive package is prob tailored for a different environment/application than an ATF. I think 15w-40 is prob fine but needs to be changed frequently.

Thanks for sharing, I have heard really good things about the Allison transmission line, I watched a training seminar on YouTube and one of the claims he makes is the transmission should outlast the truck chassis.

 

[Ronmar]

I think probaby the biggest issue we have is spinning the shafts way into the red zone. Longitudinal vibration is a characteristic of transitioning from one angle to another in a different plane with 4-point u-joints. The steeper the angle the worse it gets, hence the rpm vs angle limit chart, which someone at S&S probably used to wipe their ass with on drivetrain design day The only way to mitigate it is to reduce the shaft transition angle or reduce the RPM…

 

[cdub0451]

I think most of the tranmission issues are from vibrations, heat exchanger failures, wiring problems, running max governed speed, and low use. One member here says “that no use is abuse.” I think the gear-train module which is about same as the 3060 is prob the most reliable part of the transmission.

The "no use is abuse" is accurate. I've seen 10yo HMMWVs with less than 7k miles leaking at damn near every seal. The trucks look brand new until you pop the hood or look underneath it. Gotta use 'em.

I looked through our Allison publications to try to determine the difference between the MD3060 and the MD3070PT and as far as I can tell, torque converter notwithstanding, the output and sump are the only differences to the main body of the trans. We have a deeper sump pan and a TCase at the output. My fleet's 3060's have the shallow sump and regular output w/ yoke. There might be some other minor differences, but I couldn't find any in the pub.

I did find this nugget of knowledge, though. This should help provide some clarity on drain/fill volumes if it hasn't already been posted before.