Geoff Weeks

No KW sold to Unit Rig.

Really not enough to ID on. Cab may be a KW or Chicago Mfg cab. Unit Rig, KW, Dart, Pacific or even IHC (Payloader). IF forced at gun point, I'd go with KW on the cab shape alone.

Ok, then it sounds like one valve is either defective or out of adjustment with the other. The correct way to set them up is to block the frame up to the correct ride height. with the valves not connected to air or the bags, Lock the valves in the neutral position (how you do this depends on the valve) the Neway one pictured has a hole with a little dowel through it, you use to set it. The you adjust the linkage so it just slips on the arm with the truck at the right height. Do this on both sides then remove the dowels and connect the lines, air the truck up, removing the blocks and re checking the height on both sides. Twin valves are more difficult to set up then single, but provide side to side stability for loads that may be top heavy, it prevents the air from going to the side that is less loaded going around a corner with a high CG load. Most don't bother with a twin and just use a single valve, but on a dumper, or a tractor that hauls a dump trailer or OD loads that have a high CG it can be a good thing.

Did you check for two valves? Did you check the pressure at right and left bags and confirm they are different?

not that I'm aware of. Take a picture of the valve in question. The ones I'm talking about have only 3 ports, inlet, outlet and exhaust.

Some trucks have left and right level valves. The heavy haul tractors one place I worked had their tractors set up like that. You had to make sure they both set exactly the same. This assumes that you have actually measured the pressure at the bags on left and right. Trucks with only one valve, well you only have one source feeding so they can't be getting different pressure from the valve.

Larry, SAE 50 (synthetic or mineral) has the same viscosity range as 90 GL. 40 SAE is close to 80 GL so no change in "thickness". Gear lube and engine oil are "rated" on different scales. EP additive package in GL increases "tackyness" in the lube so it tends to stay on the gears (and syncro) better, not an advantage with syncro's. An important thing in hypoid and amboid gearing. SAE 50 or 40 are approved by Eaton and I have used both. SAE oils have better heat tolerance then gear lube and are preferred for that reason. Synthetic oil has better heat tolerance than mineral based SAE oil. If you look though what Eaton has put out about lube for their heavy manuals, all three types of oil are approved depending on market. When run in the highest heat load conditions, over 1950 ft/lbs and/or extended drain, Eaton says that the top tier of oil has to be used if you want them to warranty it. You also have to keep the oil temp below their limit with and oil cooler. If you are running below those limits and follow "std" oil change protocol, they will warranty with mineral oil as well. In third world regions they still allow gear lube to be used. Every step up in oil is better but not required for proper operation as long as oil temp is kept below X (I'd have to go back and re read to find the limit). In short, the syncro still works with all three types of oil.

Bolton, Manchester area.

"bleeding, bloody, etc" was an expletive descriptor, "the bleeding nut was so tight, I had to get the smoke wrench".

You sound like an Englishman I used to work with!😀

It is hard to know which way to turn, when only one set of eyes are on the truck, and we only "see" what is written. This isn't a knock on the poster, just if a clue isn't passed on, we will not know. @fjh said long ago that oil sample analysis would be prudent at this point, and I 100% agree, it will show what is in the pan even if no moisture/antifreeze is "seen" in the oil.

Eaton calls for many choices, it is right there in their manual. I am not recommending something that Eaton does not. Larry wasn't happy about paying the expense for synthetic and according to Eaton it isn't required. I found no info saying flushing was required at any point in the manuals I read when changing lube, if it isn't there (it may be and I missed it?) I can't point to it. If you can point to where it is required, I will accept that. When you made the the statement that syn was required it was something I had not heard or read, so I went to the source to see if my understanding was incorrect, it was not. So I linked the source material for all to read. IF you want extended drain intervals and you want Eaton to warranty it, then and only then does Eaton require its use for warranty purposes. On a used transmission none of those apply. All the oil I listed are approved by Eaton for their HD manual transmissions. By your reasoning deleting the oil cooler would also void any factory warranty. But they are not required below 350hp, although you pointed him to the delete plate. By the title of this thread, he is well below that. Transmission lube has an easy job compared to other boxes, no combustion gases, no hypoid or amboid gearing, little chance of moisture accumulating, just spur gearing, roller bearings and one double ended syncro.

I wouldn't give SAE 50 a minute of thought before filling the trans with it. Your call. SAE 50 is listed as approved. Any used transmission syncro is going to "be saturated" with what ever was run before, It will not make a difference, but as I say, your money, your call.

You can disagree with Eaton, that is fine, I went to the source to make sure I gave the correct info. further more it is a used box, so you have no idea what it was filled with. Eaton doesn't mention a need to "flush" if a different or unknown lubricant is being replaced by something else. Synthetic has better heat qualities than SAE 50 which has better than GL-1. Each is a step up. In this application, which is so far down the scale from the transmissions rating, SAE 50 would be fine. Even GL according to Eaton would be ok, but I would not recommend it. They list it as acceptable in other parts of the world (in the same transmissions)!

What is missing from that list over the "old days" is 80w90 GL-1 which is not approved any more. GL was not preferred lube since SAE 50 became common. Higher GL (2 and up) were never recommened due to their friction (EP) additive package. Here is a link to the manual you can read it yourself. I doubt that engine will exceed 1850 ft/lbs! Eaton Lube requirements. Eaton lube spec's Edit: looks like they approve GL-4 in Asia?? I guess I was wrong about that!