Brake bands and EP lubricants

[Terry Welshans]

Greetings.

In addition to an Oliver OC-3, I own a Studebaker M29 Weasel. These two vehicles share one thing:  A brake band controlled steering differential with a planetary gear system.  The unit in the weasel is made by Clark, and looks very much like the Cletrac patented unit.

Here are a couple of images, one in the weasel, the other on the shop floor:

In the weasel

On the floor

My service manual for the weasel says very clearly to never use any lubricant other than non-detergent 30wt motor oil, as it impregnates the brake linings with the EP additive, which is most likely a form of Molly-disulfide, causing a loss of steering friction.

In fact, that is what has happened to my unit some time ago.  It steers very poorly no matter where the brake is adjusted or how hard I pull the steering lever.  The linings are almost 100% original thickness, too.

So my question is this:

Are we doing harm to the brake linings on the Cletrac/Oliver steering differential brake linings when we use newer lubricants designed to reduce friction in automotive differentials?

Has anyone noticed reduced steering after using the newer EP oils in their differentials?

[Blake Malkamaki]

The recommended oil for the transmission, lower track wheels, and idlers on the Cletracs is 50 wt non-detergent.

See this post for an indepth discussion from the past: //http://www.cletrac.org/newbb/viewtopic.php?t=422&highlight=oil+transmission

Blake

[Terry Welshans]

Thanks, Blake.

I see in that thread a number of questions about the use of EP type oils, as well as the discussion about detergent vs non-detergent oils.

There was a question in thread similar to what my weasel manual has - that is that EP oils cause a reduction in friction (which is good in hypoid gears) which makes steering difficult if not impossible.

I was thinking that I had read that the recommended oil was not an EP type, but a straight mineral oil.  

Ace hardware has a non-detergent 30wt at this link

And Phillips has a similar oil at this link

[Blake Malkamaki]

I was thinking that I had read that the recommended oil was not an EP type, but a straight mineral oil.  

Ace hardware has a non-detergent 30wt at this link

And Phillips has a similar oil at this link

I think 30wt would be too light. Get 50wt non-detergent engine oil or the straight - non-EP - gear oil as Ray recommends. You may have to go to an oil supply place to get these.

Blake

[farmerphil]

I am running 40 wt non detergent motor oil in my AD. have had no problums and works for most of the temps I run in.  You can pick up this oil at any tractor supply.   If it is rally hot out I will run a 50 wt oil.  Stay away from the GL-5 rating oils they can cause problums with the bands and the bronz bushings.  my opinion.  Hope this helps.  Phil

[Mike Shanley]

I heard of a solvent type additive that defeats residual EP in break linings.  I believe TISCO carries it.  I'll be out of town until friday, but I'll see if I can find it then and report back.  The additive is only for those who made a mistake and used an EP type lube in tractors that have wet brakes.

As Blake always says, your best bet is 50 SAE non-detergent motor oil.  Be sure it is SAE, ISO numbers ar not compatable.  Mike Shanley, Woodbury MN

[Eric Carlson]

I'd be really interested in that additive... mine came with 90w gear oil in it.
Eric

[Mike Shanley]

I talked with the guy who told me about the Tisco product.  He had a wet clutch problem from EP gear lube in a tractor.  He replaced the gear lube with non-detegent but the clutch still slipped.  He then added a gallon of Tisco hydraulic oil conditioner and the clutch worked fine.  He said it was $22.00 or $23.00 for the gallon of conditioner two years ago.

I have had a Cletrac and an OC3 with EP lubes in the differentials.  I put new bands and linings in the OC3.  I used a spray can of Brake Clean solvent on the BDH bands and they work fine.  Mike Shanley, Woodbury MN

[Eric Carlson]

Thanks Mike, I'll look into finding some.
Eric