C7T Treefarmer ?

[Autocar]

I cut the filter open this afternoon and the paper was a light brown but there wasn't anything, small particals or any other debris. This filter was installed November of 2008. I am starting to lean towards a pressure releif valve that sticks now and then. Probably crazy thinking on my part but I am wondering about installing a pre-set pressure relief valve and installing it on the [ in ] and [out ] side of the filter line . So when the pressure hits 300 it opens and blows into a portable tank that I can put in the belly pan. Probably by now half you guys are shacking your heards When it only happens once a year or so its a hard problem to solve, at least for me. The mess it makes in a split second is unbeliveable,I always load or unload on the road and I can just see it blowing when a car comes along side or covering the road with oil. I did talk to the Franklin dealed last week about having someone coming over and just pick his brain for a few hours. They get $68.00 a hour and there three and half hours east of me I can't afford five hundred dollars travel time right now. It has warmed up enough that it is to soft to work so I am pulling the sheet metal off it and having the guy come and put new injectors and set the rack , life is good !

 

[oldseabee]

Just a quick story on the C270 Clark torque converter and trans.
The small alum pump on the converter is the charge pump. It feeds from the transmission case to the clutch pressure regulater valve on the converter which in turn first feeds The tranmission control valve.
When the proper clutch pressure is attained, the clutch pressure regulater valve shifts and starts to dump oil into the torque converter. The poppit under the clutch pressure regulater valve is a safety valve for the converter. If there is a blockage down steam from the converter and the internal pressure gets above 70 PSI the poppit opens and dumps the oil into the converter and out through the bottom drain line which goes back to the transmission case. There is lube oil fed through orfices to lube the bearings in the converter, this oil also goes into the case and drains back to the transmission. If the drain line back to the transmission gets plugged, oil will build up in the converter case and blow out the breather and or lower the oil level in the trans. case to the point that the charge pump starts to starve for oil and can't maintain clutch pressure, at that point the Clutch pressure regulater valve will close off the converter . The same thing can happen if the oil cooler or the lines to and from it get plugged. (I have seen the inside lining of the hoses break loose under flow and plug the line. when you pull the hose, it will look OK). The way to check this is to measure pressure at the port on the clutch pressure regulating valve, this is "Converter in pressure". with hot oil at 2000 rpm in neutral the pressure should read 40-80 PSI. If the poppit safety valve is leaking or stuck open too much oil will dump into the converter case and since the drain is just gravity feed too much oil will build up in the case, all this oil is not getting to the cooler so it just gets hotter as it recirculates. To check the cooler for restriction measure pressure in and pressure out In pressure should be 25-60 PSI at 2000 RPM with oil temp at least 180 F. The out pressure should be 5-10 PSI. THESE PRESSURES ARE FOR A CLARK SKIDDER WITH THE SAME CONVERTER AND TRANMISSION. They may be a little different on the C7.

 

[Autocar]

Oldseabee thanks for your information, every time someone tells something about it I pick up more understanding knowledge. Your talking about a hydraulic gage arn't you to check the pressure. The pressures you talk about seems low to me can you tell me what the one is for on the dash,it reads around 249 when the machine is running and dosen't change when your in gear and moving.

 

[lpnt65]

I would check the type of oil you have in the convertor may need diffrent brand or grade also check that your hoses have not decided to seperate in side causing them to block as thwe pressure rises

 

[oldseabee]

The 249 PSI pressure is clutch pressure inside the transmission clutch drums which is controled by the valve on the converter, that is why the small hose goes from the guage in the dash to the clutch pressure regulater valve on the converter housing. The pressures I mentioned are internal pressures inside the converter members which are limited by the poppit and spring under the control valve and are caused by restriction of flow through the converter, line to the oil cooler, the oil cooler itself, and the line back to the transmission case where the oil resevoir is located. The hard part to get your head around is the fact that the transmission and converter are seperate physically but are interconnected hydraulically.

 

[oldseabee]

Another thing that I forgot to mention is that the breather on the converter housing is really a one way check valve, lets air in but should not let oil splash out. These have a history of losing the poppit and the result is oil all over the place.

 

[Autocar]

Thanks for all the info Oldseabee I have been trucking logs for the last two weeks and waiting on it to warm up, before the mechanic will finish the work on my 4/53 . You have gave me alot of things to check out thanks again