Best oil for Getrag trans
#11
20 year old info or not, I don't believe that anything of a thicker viscosity than Synthetic 5-W30 will do it any good.
The lube has to have a GL-5 rating.
If it doesn't at least say that on the bottle, throw it away.
The "next best" stuff to run in the getrag would be the stuff they put in the NV4500, Castrol Syntorque, but it's still noticeably thicker.
Mark.
The lube has to have a GL-5 rating.
If it doesn't at least say that on the bottle, throw it away.
The "next best" stuff to run in the getrag would be the stuff they put in the NV4500, Castrol Syntorque, but it's still noticeably thicker.
Mark.
#12
It's not "tolerances" that are close in a Getrag, they are a rattly beast, even newly rebuilt, it's the oil passages that are smaller.
The biggest 2 killers is the lube slots on the input, which lubricate the bearing for the mainshaft and the lube holes for the cluster (called "counter shaft") bearings that support the cluster through pin.
Combine those smaller passages with the invariable over-use of silicone sealers, along with overloading and/or underfilling and a formula for "Filings-'O'-Getrag" can result in short order.
Mark.
#13
On the Contrary...
Heavy gear oil is about the worst thing you could put in a Getrag, and the biggest culprit in their bearing failures. It's too heavy to effectively reach the bearings and will make cold shifting way more difficult than it needs to be. GL4 is the preferred rating for an MTL. GL5 is the the diff/hypoid gear stuff:
http://stuff.is-a-geek.net/OnlineDocs/Vehicles/MTLs
http://stuff.is-a-geek.net/OnlineDocs/Vehicles/MTLs
#15
#17
I used 80w90 in mine for over 10 years until I found out different. I tore it down for for a perceived bearing noise. new rollers and needles later, it was a rear end. Point is, 10 plus years with 80w90 and now bad bearings. Right now I'm running 20w50 with some stp in it. I'm also now running a quart over, as I also only filled to the plug. Damn that was a great tranny. I love my 1st gen.
#18
#19
i saw that you have a recent post on youur tansmission is dying so we obviously shouldnt try the 5-30 weight hahaha just saying
#20
For what it's worth: I have a '92 Dodge Ram D350 in my shop with a 5.9L Cummins backed up with Getrag G360 5 spd. M/T. It came in with what sounded like bearing noise in the transmission. After all the inspecting I could do with it in the truck, I drained the oil to see what it looked like. It was fairly dirty and looked a little thin, and it was only about half full to the oil level plug. I refilled it with everyday 85W140. When I drove it the noise was gone. After doing some research I see the manufacturer calls for 5W30. In a truck gearbox?! Please! No wonder it made noise.