Foolish Lubricant Question

[DickS]

I own a diesel pickup truck with an Allison automatic transmission. Allison is recommending Transynd (synthetic) as a replacement fluid for longer service life. What is the basic difference between ATF and HST fluid? Can the two be used interchangeably? Transynd is pretty expensive stuff but I would consider buying it if I could use it for my truck transmission as well as my Kubota BX-24.

 

[DieselPower]

No lubricant's question is foolish. The only foolish question is the one not asked.

Transynd ATF (the spec is TES-295) is a ATF (automatic transmission fluid) and should be used as such. It does share many of the characteristics of a UTF (universal tractor fluid) as far as the additive package is concerned. There are some differences however with the greatly increased EP (extreme preasure) additive package of the UTF being one of the big diferences. UTF's not only act as a hydraulic fluid but as a gear lubricant and in some applications a wet clutch and wet brake lubricant. ATF's may not have the proper formulation of anti-chatter additives needed in a tractor as the friction materials are different and the extreme preasure loads in tractor gear sets is much higher than that found in the planatery gearsets of a automatic transmission. On the flip side ATF's are better suited to handle the higher operating temperatures found in automatic transmissions along with their special additive package to deal with other automatic transmission specefic lubrication needs.

ATF is best used in automatic transmissions and UTF's in tractors. That's what they are designed and blended for.

 

[mrutkaus]

Mr. D. Power, what would you think of adding some 1-2 micron moly (TS Moly's Guard Dog 451) to the hydraulic fluid of a CK30HST at the first change, which I am doing as I type?

If so, how much?

Mike

 

[DieselPower]

I wouldn't use a 1-2 micron Moly additive. At that size it stands a very good chance of being filtered out. If your going to use a Moly additive it should be in the sub-micron size range. Either something in the .33 micron range or a completly organic oil soluable moly.

 

[DickS]

This is the response I received from an inquiry to Castrol, the people who make Transynd ATF for Allison Transmission:

Dear Sir:

Allison Transynd is suitable for use in "hydrostatic" or hydraulic transmission applications, which are commonly used in smaller (lawn & garden) tractors. These hydrostatic drive systems are comprised of a engine-driven variable displacement hydraulic pump transmitting power via the pressurized hydraulic fluid to a hydraulic motor which drives the wheels. Transynd is a heavy-duty automatic transmission fluid and it is common for ATF's to be used in hydraulic applications.

However, the Transynd fluid is not suitable for use in medium to large tractors which employ a common sump shared by a powershift transmission, hydraulic system, and final drive with wet brakes. Equipment of this type requires a friction surprised (sp?) universal tractor fluid such as Castrol UTF .

Transynd can be used for Hydrostatic applications but not for Powershift applications.

Please let me know if you have any other questions.
Regards,

 

[DieselPower]

Kind of along the lines of what I said. It does not have the additive package to handle common sump systems found in tractors.

 

[workinallthetime]

back in 01 when i went through the allison class they were using the stuff on all the big rig over the road trucks. After a few years the stuff started turning up in production trucks
we were initally told to under no circumstance mix the regular fluid with the syn fluid. then we were told it was ok then not again. lol
we put whatever is in it back in it.

speaking of your trans, i hope you changed your spin on at 3k miles and transfered the magnet to the new filter.
allison told us that you should do a spin on at 3k
and leave it alone till 100k under normal driving conditions
under not so normal
3k spin on
25k spin on
50k pan drop new filter and spin on
75k spin on
100k pan drop new filter and spin on
but you wont find that in your owners manual.
if its a 4x4 check your x-fer case everytime you change your oil, ive seen a bunch which lost all their fluid by about 50k

 

[KICK]

I work in a fleet that has 1000 vehicles equipped with either Allison B300, allison b400's or 2000 models.

We use Transynd, change it at a 72k mile interval

we run severe service, all stop and go, average miles per hours of about 10, run 20 hours a day, 7 days a week, 365 days a year.

most of our trannies last at least 300,000 miles before failure.

not so whe we used straight conventional Dexron, we had to change fluid and filters at a 12k interval or the oil would turn to mud and the trannies would generally develop issues around the 100k mile mark.

I'd swear by the brand, its factory fill on our new stuff.

As someone else said, its not universal tractor fluid.
we use it in our hydraulic systems but it is OK'ed by the factory for ATF.

 

[workinallthetime]

I work in a fleet that has 1000 vehicles equipped with either Allison B300, allison b400's or 2000 models.

We use Transynd, change it at a 72k mile interval

we run severe service, all stop and go, average miles per hours of about 10, run 20 hours a day, 7 days a week, 365 days a year.

most of our trannies last at least 300,000 miles before failure.

not so whe we used straight conventional Dexron, we had to change fluid and filters at a 12k interval or the oil would turn to mud and the trannies would generally develop issues around the 100k mile mark.

I'd swear by the brand, its factory fill on our new stuff.

As someone else said, its not universal tractor fluid.
we use it in our hydraulic systems but it is OK'ed by the factory for ATF.

was it the old at540's that had the black mud? the lct1000 in the the d-max 01-02 models had some pretty nasty fluid after about 70k

 

[KICK]

was it the old at540's that had the black mud? the lct1000 in the the d-max 01-02 models had some pretty nasty fluid after about 70k

no it was on our large buses, they have the B300. they also have a retarder, which causes higher sump temps.

only vehilces we still have with an AT 540 are Bluebirds. those dont hold up. I dont think the At 540 in our vehicle has a torque converter clutch or ever run the speed where it applies, engine cooling fan only kicks in at 200 degrees so we french fry At 540's regularly,

We got some other mini buses with the Allsion 2000, which is similar to the tranny in the GM pickups. those trannies have held up excellently. In fact I haven't seen one replaced yet and they have 4 years of service now.