Getrag 360 lubricant re-visited

[LDyck]

I am just putting together a Getrag 360 and I've read the manual and lots of posts, and it seems everyone agrees that 5W30 motor oil - better if synthetic - is the lubricant to use for this unit. Yesterday, I dropped into a transmission rebuild shop in Winnipeg to get a couple of small parts. The guy there asked me what oil I would be using, and then said that they use only full synthetic 75W90 gear oil and will not warranty a rebuild if it is not used. His point was that under heavy hauling, the other is too light.



Does anyone else have any info or opinions on this? We do get a fair amount of cold weather here and a working truck has to work. I would like to use the best lubricant for this transmission, especially considering the expense and work to rebuild it

 

[steveinaz]

I've used 15W40 For 100,000 miles. Same as the engine. SteveinAZ

 

[1stgen4evr]

The absolutely most important thing is that you ALWAYS have the transmission over filled by about one quart. You will experience a (very) few minutes of stiff shifting if you use heavier lubricant. I have run a Getrag for a half million miles with lube heavier than motor oil. If you wonder about the lubricity of what you are using, draw out a small amount after you have worked the snot out of the truck for 8 or 9 hours. Even 85AW is thin as water. If you are actually working the truck, a lighter lube that will work perfectly well for someone else who only drives to the office will not provide sufficient protection for your application.



In my opinion there isn't a single lube that will cover the range of applications that we put these trucks to. Match your lube to your application.



James

 

[JLEONARD]

In my opinion there isn't a single lube that will cover the range of applications that we put these trucks to. Match your lube to your application.

I agree. This makes the most sense to me. Here in New England I would not want to use 75/90 because I think it would be hard to shift on cold days until the oil warmed up. I've gone thru this before with other trannys.

I'm not towing so I'm satisfied that the 5-30 synthetic I am using is ok.

Of course oil does not have to be "thick" to lubricate and cool.

 

[GHarman]

lube for Getrag

I seem to always be the last to know. When I bought my 91. 5 rig I dumped the factory transmission oil and installed 4Q of Amsoil 5W-30 synthetic. I ran this until about 160,000 miles. I was then informed that the trans really needed 5Q of oil. I havent pulled much with the truck but bust a lot of winter snow in 4X4 and rough country 4X4 with commuting and occasional hauling. Now, the transmission occasionally makes noise when shifting, so I topped it off with a Q of synthetic 80W-90 and It quieted down. I am about to do an oil change with Amsoil 5w-30 syncro tran oil (5Q). If there is already damage to the syncros because of inadequate oil level this is certainly not a miracle cure. Will post results for those interested. I will drive this rig until it turns to dust. Entropy works!

 

[1stgen4evr]

The syncros in the Getrag are bronze and are the least of your concern. In the NV4500 on the other hand are composit and I am told MUST have synthetic.



Poor lubrication at the pocket bearing is the greatest vulnerability. If your transmission is making noise EVER, the translation on the noise is HELP!!!! You must repair it before you run it to failure. This is especiallly true for the 4X4. At that point, you will have little/no choice on what to do. (NV4500)



You will get a close up and personal view of "turn to dust".



If you lose power in all but 4th gear, stop in your tracks and disconnect the drive line. Tow/haul the truck to a shop and get started. You will have lost the front bearing on the counter shaft. Sometimes this is not the end of the transmission. If you knock a tooth of the cluster gear, you just blew the budget.



James

 

[bgilbert]

Sounds like you must run 75-90 to keep your warranty. Once out of warranty, 12months? Then if you didn't care for the feel of the heavy gear oil, drain and use 5-30 engine oil. As said above, whatever lube you use, make sure you overfill by one quart. Factory fill is 3. 5qt.

 

[GHarman]

Thanks for your input James. There is no one in the Denver area that I would trust with a transmission repair. Greg

 

[Hahns]

I have read conflicting data on the factory fill qty of the getrag. Is it 3. 5 or 4. 5 ? Anyone know what would happen if you overfilled by more than 1 Quart? Thanks all in advance.

 

[1stgen4evr]

if you overfilled by more than 1 Quart?



There is definitely enough space in the case for more than one extra qt. At some point (of wear and age), I expect that you would start to seep lube toward the clutch direction which would not be good for the clutch. A leak at the rear would just go into the transfer case or the ground.



Collective experience from the TDR group indicates that the one extra is good enough. Pick your application on the viscosity.



James

 

[Hahns]

if you overfilled by more than 1 Quart?



There is definitely enough space in the case for more than one extra qt. At some point (of wear and age), I expect that you would start to seep lube toward the clutch direction which would not be good for the clutch. A leak at the rear would just go into the transfer case or the ground.



Collective experience from the TDR group indicates that the one extra is good enough. Pick your application on the viscosity.



James

James

Thanks for the feedback.



Exactly how much oil is "overfilled by one quart" ???

 

[1stgen4evr]

Well I never have had a book on the transmission but if you fill the transmission (in the truck) till it is at the bottom of the fill plug, then add one qt more, you can't be wrong. I mention 'in the truck' since the rather extreme tail low mounting caused by the fact that Dodge didn't reengineer anything about the frame cross member or engine oil pan or height of the hump for the cummins install.



Consequently the engine sits at a rear low angle which in turn defines the mounting for the transmission. The problems of early failure were not all limited to pocket bearing failure from low oil at the front of the transmission but that condition was without a doubt part of the problem. Adding the extra oil brings the oil level at the FRONT of the transmission to what it should be if the transmission were mounted level.



I would also restate (from an earlier post) that I ran my 93 truck from about 1995 till 2003 (when I stunbled on TDR and discovered the info on extra lube) with the 85aw and only filled to the level of the fill plug, (some two hundred fifty thousand + miles). That is the reason I lean toward the higher viscosity lube for my application.



James

 

[Hahns]

Well I never have had a book on the transmission but if you fill the transmission (in the truck) till it is at the bottom of the fill plug, then add one qt more, you can't be wrong. I mention 'in the truck' since the rather extreme tail low mounting caused by the fact that Dodge didn't reengineer anything about the frame cross member or engine oil pan or height of the hump for the cummins install.



Consequently the engine sits at a rear low angle which in turn defines the mounting for the transmission. The problems of early failure were not all limited to pocket bearing failure from low oil at the front of the transmission but that condition was without a doubt part of the problem. Adding the extra oil brings the oil level at the FRONT of the transmission to what it should be if the transmission were mounted level.



I would also restate (from an earlier post) that I ran my 93 truck from about 1995 till 2003 (when I stunbled on TDR and discovered the info on extra lube) with the 85aw and only filled to the level of the fill plug, (some two hundred fifty thousand + miles). That is the reason I lean toward the higher viscosity lube for my application.



James

Thanks again James



I understand filling to fill hole then adding one additional court. But I added a 90 degree elbow and a 2" lenght of straight pipe to the fill hole opening. I then filled with 6 quarts (thinking a I had read that 5 quarts was the"normal" fill). When the truck sits for a few days I get clutch chatter for the first few miles (it then goses away) Based on your information I think I have too much oil in it. Hence the reason I was trying to find out the exact amount of "overfilled by one court" I think I'm gonna drain a quart out - don't want to mess up the clutch!!!!!!!!!!!

 

[dpuckett]

Sounds like you may have already done damage to the clutch. FSM from both 1990 and 1993 say 3. 5qts is the "correct" fill amount.



-DP

 

[Hahns]

I drained the trans and put 4. 5 quarts back in. I had the 6 quarts in there for only one week and drove mabe 35 miles. Clutch seems fine. So I guess I dodged the bullet!! Thanks for the help



Scott Hahn