TRANSMISSION LUBRICATION

Extended warranties and extended transmission drains are a win-win for any fleet. Uptime is enhanced — especially since the initial drain is also eliminated — and maintenance expense is down. That’s providing you follow the rules.

In the early ’90s, Eaton and Rockwell swept the customer along as they attempted to outdo each other, offering longer warranties to drive the market for each company’s axles and transmissions. These were matched by extended drains with qualifying lubes that saw the competitors eventually calling a halt for line-haul warranty at 750,000 miles/5 years with a single oil drain at 500,000 miles.

That’s a remarkable achievement, but it lays some responsibility on the user, not the least of which is the lubricant at first fill, then at that half-million-mile change.

The recommended lubes are spelled out in the Roadranger Lubricant Manual TCMT-0020. We have reproduced the list here, but there is a lot more about the lubes and the somewhat complex warranty on the company’s www.roadranger.com web site.

It’s worth noting that that the same list of approved extended-drain lubes that qualify for the 750,000-mile Eaton Fuller transmission warranty apply to the Meritor transmissions offering.

In all, there are 55 different brands listed — and all are synthetic oils. Synthetics are required because of their ability to withstand heat without oxidation and the subsequent thickening. They are also less volatile than straight mineral oils.

In reality, most — if not all — are supplied either by Cognis North America or by ExxonMobil, so within the list there are many private labels.

These lubes all qualify for the Eaton E500 extended drain, which says that no “initial drain” is required and the lubes can stay in place for 500,000 miles. It does not say that the lube is “fit-and-forget,” though. There is an obligation to check levels and top-up when necessary. Although the latest seals are excellent at keeping the lube inside the transmission, even with synthetics there is some evaporation at elevated temperatures.

The amount varies with the amount of heat seen by the transmission. The industry guideline says transmissions should not run over 250 degrees (Eaton) or 225 degrees (Meritor), though the latter does allow for excursions above this for brief operations, such as on a steep grade. If higher temperatures are a norm, then oil coolers should be specified.

The newest addition to the Eaton Fuller lineup is the Lightning transmission, which has its own built-in cooler. Spicer says the Opti-Lube system drops lube temperatures 30 degrees, so these transmissions shouldn’t need a cooler.

Spicer parent, TTC, says that continued operation at 230 degrees and above, and applications at 400 hp and up also require synthetics. And to be able to drain at 500,000 miles, synthetics are required, though there’s not a recommended list, but a specification.

The stand out is Mack, which, for line-haul operations, offers the same 500,000-mile drains and generous 750,000-mile coverage, albeit with a 60-month cutoff. It is a tribute to the robustness of the triple-countershaft design of the T300 transmission that this doesn’t require synthetics — mineral-based lubes are quite satisfactory.

As with all the other transmission manufacturers, the warranty changes with application, and Mack’s vocational users get a 300,000/36-month warranty.

Warranties drive the oil change intervals. Meritor and Spicer warranties are pretty straightforward, but there’s a complex matrix for the Eaton Fuller transmission line-up. For the most part, line-haul gets the extended warranty/extended drain package, but there are more than a few categories for different applications and the more unusual transmissions. The Roadranger warranty guide is TCWY-0900 and can be accessed and downloaded from the www.Roadranger.com web site.

Eaton has one further wrinkle in its transmission lube line-up. There’s the E250 synthetic, which is the Chevron Delo extended-service transmission lube. This is based on a different chemistry than the other synthetics, and while Chevron says it is good for the same drain period as the others, to maintain the 750,000-mile warranty, this lube needs to be dropped at 250,000 miles.

There is a cost-saving associated with this, says Chevron, even though it adds to maintenance cost. Perhaps the biggest saving might be at the 500,000-mile drain. Since the warranty only extends out another 250,000 miles, maybe a fleet is best served to use the Delo product at the drain point. And for many fleets, the five-year cutoff may well have been passed even before the 500,000-mile point. However, since warranty is past, if a fleet intends to keep the truck out to a million miles, perhaps an approved synthetic would be additional “insurance.”

Such mileages are generally not experienced by applications that use Allison torque-converter automatics, but there is good news from synthetics there as well. TranSyn is a new synthetic automatic transmission fluid developed by Castrol and specially engineered for Allison Transmission. It’s specifically designed to make Allison Automatic-equipped vehicles more productive by extending drain intervals 300%.

Extended oil change guidelines for TranSynd include 50,000 miles/24 months for severe duty and 100,000 miles/48 months for general duty, once a 90%+ fill of the synthetic has been reached. Recommended changes for conventional transmission fluid are 12,000 miles/6 months for severe duty and 25,000 miles/12 months for general duty.


Have your say


This is a moderated forum. Comments will no longer be published unless they are accompanied by a first and last name and a verifiable email address. (Today's Trucking will not publish or share the email address.) Profane language and content deemed to be libelous, racist, or threatening in nature will not be published under any circumstances.

*