Drill Rig

[barkly59]

A mate owns and operates an Ingersol Rand T4W drill rig and noticed a fair bit of wear in the rotary head gearbox. He is currently using a 680 grade mineral oil
and would like to know if there is a better lubricant he can try. The rig is working in some very harsh conditions in the Northern Territory of Australia where the outside air temperature can be 110 degrees F . Or as the old people used to say in Aust “ it’s 110 in the water bag “ and that’s bloomin hot . Any info would be gladly appreciated. I have used this forum before and can’t get over the amount of knowledge there is out from many contributors. Thanks.

 

[Nige]

IMHO 680 oil is too heavy for something like a rotary head, even in ambient temperatures like you refer to. It could be that the lubricant film between gear teeth is actually breaking down because it's so heavy and that's what is causing the wear.

We had good results on I-R blasthole drill rotary heads using SAE50 TO-4 oil, or even an SAE60 FD-1 spec oil. These drills were much bigger than your mate's T4W.
Our issue most often revolved around keeping water out of the rotary head when wet drilling.

 

[barkly59]

Thanks for that Nige , he was suspecting that the 680 was a bit heavy . Will pass on your thoughts. Below are a couple of shots of his rig.

 

[Nige]

If he looks for an industrial gear oil of a similar viscosity to what I mentioned above, then it would be somewhere between a 220 and a 320.
However my preference is for a power train oil so that would be a 50 (equivalent to 220) or 60 (equivalent to 320) in the SAE scale. Any decent TO-4 specification oil should do a far better job than an industrial gear oil in that application.

 

[Cmark]

How hot is the head running? If he's getting anywhere up near 200F he may want to try a synthetic oil. In the past, I've done some fairly extensive testing in a similar situation and had excellent results with a Mobil SHC600 series.

It's not cheap but the extended drain intervals we achieved, along with reduction in failure rate made it worthwhile.

 

[barkly59]

It is running at about 140-160F . We replaced the bearings and the worm drive and bull gear. The bullgear is made of brass was very worn , would you recommend a heavy duty oil stabiliser?

 

[Cmark]

I wouldn't recommend rolling your own lube except in dire straits.
What does the manufacturer recommend? Your remark about the worm wheel being worn rings alarm bells. Some gear oils contain sulphur as an EP additive which can chemically attack bronze and other yellow metals.

 

[barkly59]

I am not sure what the manufacturers recommendation is as I cannot find any literature on it. We have just rebuilt the drive head and would like to start off with the correct or best lube . I will let my mate know about the helpful advice Cmark . Thanks to you and Nige .

 

[Cmark]

Also consider the maintenance history of the unit before failure. Has it failed despite regular oil changes or has it been sat there for 10 years with no lovin'?