Heavy duty automatic tranny lube...

[fuel tanker man]

Hey guys...

We've got a problem at work. About four of our Kenworth road tractors are beginning to have trouble with the Meritor (formerly Rockwell) 12 speed "Freedomline" automatic transmissions. These are straight 12 speed automatics, with no clutch pedal at all. (Pain in the arse on a hill at a red light, but that's another story).

The problem we're seeing is that a bushing that surrounds the shifting fork is galling and sticking on the fork rod. This causes the tranny to BANG into and out of gear, and sometimes it won't go into gear at all.

Meritor hasn't been of much help at this point. They have a "new and improved" bushing but supply is WAY behind demand.

I was wondering if there might be some kind of additive we might try in one of the trucks that is giving trouble. The current lube in the transmissions is a factory fill synthetic of some kind--not sure what. I was wondering if there might be something that we might add to the gear oil which could provide some sort of barrier lubrication to prevent the sticking of that bushing/fork.

Any ideas?

Not concerned about warranty issues at this time. The factory warranty doesn't specify that additives not be used. I've even thought of thinning the transmission oil a bit for winter use (maybe with a gallon of 15W40 engine oil or such) but am at a total loss for expertise at this point.

Dan

 

[msparks]

Don't know if I can be of much help. If there is a design/manufacturing flaw with the transmission, no lube will cure it.

If you try a higher quality lube, it might help. Or it might not.

Factory Fill syns are usually made from the lowest bidder, reason being they have to have room to mark the prices up through the supply chain. Which usually has to go through 3-4 different channels before it gets to the end user.

Amsoil makes a SAE 50 powershift trans fluid that would meet your needs. Though like I said I don't know if it would help or not.

For 12- and 16-speed transmissions, SAE 50 synthetic base lubricant,
which conforms to ZF Meritor Spec 0-81.

quote:

---

AMSOIL Synthetic Powershift Transmission Fluids are
specifically designed for heavy-duty powershift transmissions.
Formulated for extended drain intervals,
AMSOIL Synthetic Powershift Transmission Fluids contain
top-quality synthetic basestocks and a high level of
top-quality additives selected specifically for powershift
transmission performance. They offer unmatched transmission
friction performance, smooth brake operation,
reduced gear and bearing wear and increased equipment
life. AMSOIL Synthetic Powershift Transmission Fluids
extend time between overhauls.
AMSOIL Synthetic SAE 50 Powershift Transmission Fluid
exceeds Fuller CD-50 performance specification and is
ideal for use in Fuller, Rockwell, Spicer, Fabco, Warner and
other large truck manual transmissions

---

Best thing too is you can usually get it at better prices than the OEM.
877-464-8798
[email protected]

 

[Ray]

This product may be worth a try. I have never used it, but I can understand your frustration with the manufacturer not having an answer.

http://www.lucasoil.com/products/display_products.sd?iid=49&catid=2&loc=show

 

[salesrep]

http://www.schaefferoil.com/datapdf/239S.pdf
Great lube.

 

[brian fix]

MS Sparks is right in this app,, the Amsoil is used by many in comercial trans, in trucking,and IF there is a flaw in the design/operation of this no lube will help,,, check out Amsoil and change run for 25K or so drain and refill with the same,,, Sparks can get you the correct fluid and advise.........BL

 

[fuel tanker man]

Thanks guys. I found out that it's got Mobil Synthetic straight 50 weight oil in there...

I guess it's a design flaw in the tranny--otherwise Meritor wouldn't be churning out replacement bushings as fast as they can. (Still not fast enough, though...)

Anyway, Meritor says the transmissions can go 500,000 miles on the factory fill of lube (the 50 weight Mobil syn). That sounds optimistic to me, and if there are conditions inside that are causing excess heat and shearing, I'm doubting that 500K mile figure...

I'm thinking of changing out some of that oil and having it analyzed. Will post results if I decide to swap out the oil. The trannys which are giving trouble have between 300K and 325K miles on them.

Dan

 

[fuel tanker man]

UOA on this one came back pretty bad. 102 ppm of Aluminum, and 516 ppm of iron. ANA laboratories recommends draining oil immediately (we just took a sample from the tranny). Have contacted tranny manufacturer and put in a warranty claim to have the grease/oil changed. It takes about 300 to 350 dollars worth of oil, so we're hoping Meritor will warranty the change since they claim 500K miles is the distance which the factor fill should go...

The viscosity at 100 C. is 14.14 . I don't know how good or bad that is, but this is supposed to be a straight 50 weight synthetic.

I can't decipher ANA's additive numbers. Looks like 5 ppm Zinc (not much!), 964 ppm Phosphorous, 4800 ppm Barium (does that sound right? 4800 barium?) and 857 calcium.

FWIW,

Dan

 

[fuel tanker man]

Update, and a correction...

Meritor wouldn't warranty an oil change for this transmission. They only said they "noted" the bad UOA.

Anyway, I was wrong about the actual cost of the oil change. The tranny holds 11 quarts of 50 weight synthetic. We went on and had the oil changed out at our expense. Even though the transmission was under warranty, I didn't feel right leaving that obviously contaminated oil in there. Sure Meritor would have honored their warranty if the transmission had failed, but the tow bill would have been on us, as well as rental for another road tractor while this one was being fixed.

The oil change ended up costing about 80 dollars, and I felt that was the best thing to do.

Dan

 

[MolaKule]

quote:

---

I can't decipher ANA's additive numbers. Looks like 5 ppm Zinc (not much!), 964 ppm Phosphorous, 4800 ppm Barium (does that sound right? 4800 barium?) and 857 calcium.

---

Fuel Tanker Man,

Can you post the UOA? Weird numbers especially the Barium. The AW/EP additive pack just doesn't sound reasonable for an HD tanny. The Mobil stuff sounds like a Diesel Marine oil. You might be better off with the Scheaffer's stuff, at least it has good levels of EP additives.

I would recommend you establish some of kind of baseline for changing out those fluids using UOA's. For example, when the Fe gets to say 200 or so, the aluminum gets to 100, etc. What about the copper levels if the bearings are having problems.

I never appreciated the Manf. specs for mileage on a single fluid with no drain interval less than 100,000 on OTR or heavy duty trannies.

 

[fuel tanker man]

Here is a scanned image of the page.

 

[fuel tanker man]

Surprise, surprise...

The subject transmission pretty much self destructed yesterday.

An earlier UOA might have saved this one, but Meritor didn't recommend or even authorize one.

The UOA shown above was taken at way too late a stage--obviously.

Truck is in the shop, for presumed warranty repair.

Oh well.

Dan