Getrag lube

[bgilbert]

I just bought a 89 D250 4wd with getrag 5sp. Owners manual says the transmission is factory filled w/ATF. The info I've seen on here everyone is using 5w-30 motor oil. I'd like to know what the best lube to use is and why. Only problem I've noticed with it is, 5th gear is noisy and makes a high pitch chatter. 1-4 is fine. ATF or 5W-30?? thanks

 

[AlK]

bgilbert,

It would appear that most first gen owners are running SAE 5-30 (SG or SG/CD) engine oil. However, quite a few of us have added one extra litre of oil to improve the lubrication of the transmission and thereby to increase the longevity. My manual also says (page 40) "You may improve shift performance by changing to a lighter lubricant, such as Mopar ATF Plus (Type 7176). " The noise that you hear is a fairly common with these transmissions.

---

Al

 

[quikshft]

Along these same lines, what about synthetic fluids? Anybody using these and have a recommendation?

 

[Nordby]

Yep, use a 5W-30 synthetic, and add the extra quart. Lots of first gens doing that here - a couple with 100K on their units with this setup, lots of towing miles as well.



I've got about 20K on 5W-30 Havoline Synthetic, 1 extra quart, and my transmission seems to be quite stable. 4 gear growl for sure, but no change after switching.



I'm not particular about the brand - get some Amsoil or other high-end synthetic for piece of mind.



jon

 

[McGivern]

I have run Dyson supshift synthetic ATF in my truck since day 1. It was still working great at 130K mile when I towed it without shifting the transfer case into neutral and ruined it. I have been running the same fluid since rebuild (currently have 167K). I added the extra quart about 10K ago and all I notice is that it makes my trans leak a little bit. I also installed the Gomer's filter kit about 5 years ago.



Mark

 

[rwinslow]

My Getrag went 275,000 before rebuild for bearings and synchro's. Overfill by one quart and change the lube at least annually if not more often. I used Mobil 1 5W-30 for most of that time. I prefer the PAO base stock for this type of lubrication service.



See my earlier post re Getrag Failure for additional information.



The reason Getrag recommends the lighter viscosity lubes is that the input shaft has a small internal bearing (from what I can gather it is used for input shaft alignment and positioning) at the front of the shaft. Lubrication to this very small tapered roller bearing is through a 1 mm hole in the shaft. Since this gearbox does not have a pressure lube system (i. e. an oil pump) a fairly light weight viscosity oil (i. e. a 5W-30) is needed to ensure that this bearing is lubed. The Getrag does not use any hypoid cut gearing so an EP additive lube is not required - never use a gear lube with a sulfur based EP additive.



The idler shaft provides the splash lubrication for this transmission. The idler shaft is always turning if the clutch is engaged (i. e. clutch pedal out) and the engine is running.



PM if you have any additional questions.

 

[bgilbert]

I appreciate all the responses to my inquiry on getrag lube. I have put in Mobil 1 synthetic 5W30, overfilled by one qt thru top bolt on pto cover. Previous pig farmer (no offense) owner had gear oil in transmission. I havent noticed much difference in shifting, maybe a little more noise in 5th. I'm like everyone else I'd like every component in this 89 trk to last forever. I think this old trk hasnt seen as much TLC that ive been giving it since it left the factory.