ATF in Getrag

[dusthomps]

Guys...



I checked the fluid level on my transmission today and I noticed that the previous owner had it filled with ATF. It's been doing great so far, smooth shifting and very little noise. He must have had it overfilled because I loosened the fill plug and fluid began running out immediately. Transmission records he gave me show it was serviced at the same place for over 5 years. My question is this, I'm due for a lube change and I was wondering if I should continue running with the ATF or go to Mobil 1 5-30??? Thanks in advance.



Dustin

 

[BushWakr - RIP]

Keep in mind that I do NOT have a stick transmission, but my younger brother does... just like yours.

I'd use something other than ATF.



The recommended lube is SAE 5W-30 engine oil. The oil should meet API service classifications SG or SG-CD.



bob.

 

[Underdog]

If that's the original Getrag and it has,207,000 miles on it,if

it were me,I would keep on doing whatever you're doing.

My Getrag didn't last much over 70,000 miles. I had the

5w-30 dino in it and I didn't know about overfilling it.

I do pull heavy,almost always in the mountains. I usually

have a GCW around 19,650# so,I wasn't surprised when

my Getrag fell apart.

 

[bgilbert]

What I dont understand is my owners manual says the getrag is factory filled with ATF. Was this a bad idea for the manufacturer? Did it lead to problems for those who continued to use ATF?

I use Mobil 1 synthetic 5W30. Overfilled by one quart as everyone suggests.

 

[AlK]

The following two quotes are taken from 92 owners manual



1) "During cold weather, etc…. . You may improve shift performance by changing to a lighter lubricant, such as Mopar ATF (Type 7176). "



2) "This transmission is filled with SAE 5W-30 engine oil at the factory. "

 

[pkennedy]

These transmissioms were prone to failure for a couple of reasons and after many expensive rebuilds some solutions were recommended. The extra quart of oil solution by putting a 90 into the filler hole with a 1" nipple and cap, this allowed the oil level to come up high enough to lubricate the conical input shaft bearing. When idling this bearing would not be turning in the oil bath and would fail. This bearing also was prone to failure from wear and losing the preload (shims) and then excessive wear in the pilot bushing, under heavy load would torque up (2-3gear) and break the input shaft. DC recommended 5-30,10-30 motor oil which is not good for the synchromesh, switch to a syntec 30 or 50w manual trans oil and shifting should smooth out and supply higher load protection. I had several flywheels machined to accept the roller pilot bearing and I understand there is a Teflon/nylon material now available. The transmission was only rated at 380 ft lbs torque and when cranked up under heavier loads without the upgrades had high failure rates. DC and many individuals upgraded to the NV4500,hope this helps. PK

 

[JLEONARD]

ATF vs motor oil...

I had a 70 Dart manual that used ATF... . it wouldn't shift in the fall or winter if it had regular oil in it... clearances were too tight.

But... since I work for a bearing manufacturer I can tell you that ATF a poor choice for lubrication, pretty low on the scale... . 5-30 is much, much better. Don't know how the Gutbag made it so long if it spent it's life in ATF.

I would opt for the synthetic 5-30.

 

[dusthomps]

Well guys, after sorting through all the maintence records this is indeed the original transmission, and it's been running on ATF since 32,000 miles which is longer than I originally thought. Currently at 203,000 and rising. I'm still not exactly sure what to do, as Underdog said, it's made it this long with no problems on ATF. Decisions, decisions.....

 

[Midnite]

Aren't there lighter weight synthetic motor oils available that would provide better lube characteristics than ATF, but just as good shift quality? Maybe something like 0w30?



Mike

 

[bgilbert]

Dusthomps, well I'm sure I'll be the only one to say this, but if the transmission has gone nearly 200,000 miles with no failures and doesnt howl and make noise I would stick with the ATF, overfilled by one quart. Fifth gear in mine howls at the moon. I use Mobil 1syn 5w30. Im giving some serious thought to trying some good ATF for a few months. I think ATF is essentially 10 weight or 10W, with detergents so I've heard. Might just clean the ol' Getrag up a bit. .



If it aint broke, dont fix it... .

 

[dusthomps]

Well, I decided to refill the ol' Getrag with ATF again and overfilled by a quart. Don't worry, if it fails I'll make sure you guys will be the first to know.



bgilbert... . I checked my 89 owners manual and it does say it's factory filled with ATF. Maybe 89 was the only year they did that???



Dustin