Poll: What lube are you guys running in your Getrags?

[Niki]

I think we all agree on overfilling Getrags, putting 5 qts total in them, but what is everyone running, and with what results? The service manual calls for 5W30, but I know people are running different lubes.

 

[OKish]

i use redline mtl, or syncromesh. i have no clue on thier viscosities.

 

[CSchafer]

I used a 5w-30 and didnt like the feel of it. I've heard that people that run 90w have some trouble shifting them when it cold. I used a 50w synthetic from lucas made for transmissions, it claimed it was the **** on the bottle and honestly it worked very well. Had smooth shifts no noise and was still pretty easy to shift this winter.

 

[KOG]

One intersting little bit of information. I used to sell for Lubrication Engineers who make some very good stuff. The sales manager got a new BMW 735 in the early '90s. He immediately had all of the oils in the car changed to LE stuff with a full synthetic in the transmission. The synchros stopped working. The LE synthetic gear lube was so slick that the synchro rings couldn't generate enough friction to work! Back to conventional gear oil for that one and the synchros began to work again. And some full synthetics used to not work in motorcycles with wet clutches for the same reason - clutch slip because the lube was just too good at preventing friction contact.

The point is that a superior product isn't always great for every application. I'd certainly suggest full synthetics for almost every heavily loaded application, but you have to be aware of sometimes bizarre results. And be aware that all "synthetic" products aren't the same nor will they produce the same results. So just taking a poll asking if people are using a 5W-30 synthetic doesn't indicate that they are using similar products. It's a start in the right direction though.

 

[Niki]

One intersting little bit of information. I used to sell for Lubrication Engineers who make some very good stuff. The sales manager got a new BMW 735 in the early '90s. He immediately had all of the oils in the car changed to LE stuff with a full synthetic in the transmission. The synchros stopped working. The LE synthetic gear lube was so slick that the synchro rings couldn't generate enough friction to work! Back to conventional gear oil for that one and the synchros began to work again. And some full synthetics used to not work in motorcycles with wet clutches for the same reason - clutch slip because the lube was just too good at preventing friction contact.



The point is that a superior product isn't always great for every application. I'd certainly suggest full synthetics for almost every heavily loaded application, but you have to be aware of sometimes bizarre results. And be aware that all "synthetic" products aren't the same nor will they produce the same results. So just taking a poll asking if people are using a 5W-30 synthetic doesn't indicate that they are using similar products. It's a start in the right direction though.

I've heard that before, but not specifically related to the Getrag. I've heard of people putting anything thats slippery in a getrag, I just want to see who has good luck with what. I also realize that the lube one guy uses to tow a 20K# stock trailer in California may not be the best choice for someone driving an empty truck in the winter in Alaska. I find it odd that for every other lubricant that goes in the truck, they have a temperature chart in the service manual. FWIW, when I did maintnence on Internationals w/ 5 sp's and DT466's at a beer distributorship, we ran 15W40 rotella in the trans and changed it every time the oil was changed. We weren't concerned w/ bearing wear from lubrication though, no one knew how to drive and chipped a lot of gear teeth. Broke a lot of 2 speed axles too...

 

[dpuckett]

I have run the gammot of oils in Getrags through the years. I am currently running 15w40 (I think) in my Getrag. The one I just sold got 80w90, cause that's what I had at the time. First Getrag I bought got Castrol Syntec 5w50, and I had good results with it. When I rebuild the current one, I think I will try the Synchromax or MTL. Gotta get seals in it that work, though. :-laf



Daniel

 

[NIsaacs]

I use 15/40 Rotella with 296,000 miles on the original transmission, standard fill, not over full.





"NICK"

 

[Texas Ted]

I use a combination of 80-90 and 5-30 motor oil in mine. The shop where i had clutch work done said it was ok to do that but be sure to add the extra qt. It is a little stiff when the temps drop but it seems to work well. IT REALLY MAKES A DIFFERENCE IN THE TRANS NOISE. I could not keep the 5-30 in the trans. , even with new seals. The light oil seeps through the rear tailhousing bolts. This truck spends a lot of time fully loaded and on the road. Ted

 

[dpuckett]

Put some silicone on the threads of the bolts before you install them (be sure to take them out when the transmission is empty), as they go all the way through the case and into the gearbox. I had to do that with the one I just sold. I need to do it to mine, along with some bearings and synchros.



DP

 

[glhs]

10W/30 Mobil 1 synthetic.

 

[WJune]

Great thread, be interesting to watch. Thanks to ' Kog ' for info on too slippery of a lube. I have been running Amsoil 90 or similiar weight since installing new brass sync's an bearings. I have had trouble with 3rd gear sync an sometimes those below. Worse when first start out in cool weather. I figured clutch wasn't releasing 100%. Now I will try motor oil again. Hard to keep Amsoil from leaking also.

 

[BHiggins]

Straight 30 weight Mobil 1 synthetic.

 

[bgilbert]

One of my early 89 factory manuals said factory fill was ATF, which is basically 10wt. I have access to free ATF, so I tried it. Didn't care for the feel, was too notchy, especially when warm. Went back to 5w30 mobil synthetic + 1 quart. I now have access to 15w40 Mobil Delvac, might give that a try next time.

 

[Texas Ted]

Thanks for the tip on the silicone, DP. I was't sure if any silicone would pass through to the internals of the trans. I'll do it next time I change the lube oil.

Ted

 

[Niki]

Put some silicone on the threads of the bolts before you install them (be sure to take them out when the transmission is empty), as they go all the way through the case and into the gearbox. I had to do that with the one I just sold. I need to do it to mine, along with some bearings and synchros.



DP

You can use silicone, but it gets kind of messy when you take it apart next time. I prefer to use thread sealer when I need to put something on bolt threads protruding into lubricant/coolant.