ATF for Differentials?

[Tommy]

Compared with gear lube, ATF is typically lower in viscosity and has less EP additives - correct?

How then does ATF properly lubricate the differential in an automatic transaxle? Would it be O.K. to run ATF in the differential of a rear wheel drive vehicle?

 

[SteveD2]

quote:

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Originally posted by Tommy:
Would it be O.K. to run ATF in the differential of a rear wheel drive vehicle?

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Absolutely not. ATF is WAY thinner and less...sticky. I don't know why it works in a transmission, but I'm sure they're designed with that in mind.

 

[Grossomotto]

Red Line D4 ATF is API GL-4 certified for gear oils, according to the bottle. I've just become a Red Line Gear Oil nut. I use the D4 ATF in the power steering. MTL/MT-90 in the trans. 75W90 in the diffs/tcase.

I'm sure others can chime in and give a better explanation than me!

 

[MolaKule]

quote:

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How then does ATF properly lubricate the differential in an automatic transaxle? Would it be O.K. to run ATF in the differential of a rear wheel drive vehicle?

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In a transaxle you have spur gears instead of hypoid-cut gears. Rear drive vehicles with hypoid differentials create higher contact pressures, hence the requirement for GL5 lubes with high levels of EP additives.

The ATF in an automatic transaxle is a hydraulic fluid that is used to shift gears. The metallurgy, bearing types, and gear types in the transaxle is what allows ATF to be used.

 

[T-Keith]

It doesn't plain and simple. One wheel burnouts are very harmful to FWD transmissions, because they can't get as much protection. Also clutch type limited slip differentials are rare because of this.

For the most part FWD cars aren't powerful enough to have any problems, those that do have lots of problems with differentials.

-T

 

[The Critic]

Bump.

Someone just brought up this question on AcuraZine. The new 2005+ RL with the SH-AWD system has a rear differential only, even though it is an AWD system. Surprisingly, the specified fluid is Honda ATF Z-1 and not the VTM-4 fluid!

 

[oil pan 4]

If you use a ZexalTorsen diff it can use gear oil or ATF. But the rest of the rear end is another story. The zexelTorsen will hold up in a rear end filled with ATF but the rest of the rear might not do as well.

 

[lewk]

this link http://www.lubrizol.com/AutomotiveGearOil/j306_spec.asp details the new j306 standard for gear oil. sure, it simplifies selection for those in the industry, but what confusion it can create for non bitogers.this should/could be a gvwr standard that possibly would make selection easier.my suggestion;
sae 90 for passenger cars
sae 110 for gasoline trks/suvs
sae 140 lt/med duty trks
sae 140 hvy duty
this is dated material and the search funtion returned very little information. soon I'll be changing my gear oil and have a problem "trusting" bottle labeling.
signed,
catharsis

 

[MolaKule]

I guess we at SF were ahead of time by intoducing HDS-R last year, an SAE 110 in the 22 cSt category.

 

[Ken2]

quote:

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ATF for Differentials?

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Maybe in Fairbanks in the middle of winter.


Ken

 

[unDummy]

Its not a normal diff:
http://www.motorage.com/motorage/article/articleDetail.jsp?id=170450

 

[MolaKule]

quote:

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Instead there is another planetary gear set with two electromagnetic clutch packs to control torque split side-to-side, and it can be continuously varied between zero and 100 percent.

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Right, and thanks undummy. Those clutchpacks are sitting in ATF. Also look at the fins on the axle shaft areas. They are expecting things to get hot.

Now, wonder if these guys are going to specify a specially friction modified ATF?