I have a 1994 cat d5h lgp after it runs and warms up it does not want to shift from fwd to reverse without having some rpm During shift. It also seems sluggish/ and weak. The trans also seems to get warm if I push for long periods of time. I have tried changing the filter under the floor pan, checked the screen in the trans and changed the oil. No difference. I am thinking low pressure form the torque converter, or restriction in cooler or other line. Can someone please tell me where to start to diagnose this.
Have you throughly externally cleaned the radiator and transmission oil cooler package recently..? What type and grade of oil are you using..?
After you have followed Niges advice and checked your cooling system and oil type. there are a few things to do post the serial number!!!!!! supply any history or relevant information recent repairs, sudden happening etc check all the connections between the transmission pump inlet and pickup for air entering the system check that the valve spool adjustments are correct pressure check the transmission check the drive shaft rotation between the t/converter and transmission (stall test) if you are not sure how to do these tests help is available mark
This is a dozer I purchased about 2 1/2 years ago. Have been fixing small things along the way as you will with any older equipment. Most major thing that I've done so far is replacement of the steel hydraulic pressure line, it wore completely thru. . I have thoroughly washed the radiator from front side and back. Have changed trans fluids twice since I have had it went with book spec. Seems like power is continually decreasing. I have also had to change the trans filter ( under foot pan) several times after I first got it. Kept setting off idiot light on dash. The fluid I initially changed out of it seemed extremely thick also like it had skipped several services. However it hasn't had much trouble till about he last 200 hrs. What are the valve spool adjustments and procedure for adjusting. I am a mechanic for cars and trucks, so I am mechanically inclined, just do not have the knowledge or rss pertaining to anything this size.
You say you have thoroughly washed the radiator from the front side as well as from the back. The problem with the transmission cooler mounted on the fan side of the radiator is that it's almost impossible to "deep clean" both the cooler and the radiator. If the tractor was mine I would seriously contemplate pulling the cooling package from the machine and splitting the cooler off it, then pressure washing everything. At the same time the condition of the baffles, ducting, etc, etc, can be assessed and sorted if necessary. Not having 100% of the air from the fan actually going through the cooling package can have a major effect. When you last removed the transmission suction screen did it have any material in it whatsoever..? Please confirm you are using a TO-4 specification oil and what viscosity..? Something I didn't think to ask before - what type of coolant are you using..? Also another comment. Your tractor was actually manufactured in May 1993.
I will split it as soon as possible. Definitely won't hurt to double check. The screen I checked was at the bottom of the transmission on the right side of the tractor. At the first oil change when I checked it there was nothing in it. Very surprisingly clean. Coolant and oil are cat spec directly from local dealer. Coolant is due to be serviced.
I would certainly do the radiator/cooler cleaning first before proceding any further. It's a low-cost item that once it's been ticked off you know it's right. Also good to hear that you are using a good-quality coolant in the engine. If the transmission screen was clean every time you removed it then that would seem to rule out a failing transmission clutch because that's where all the burnt friction material generally ends up. When the machine is suffering from low power are the symptoms the same in every gear, forward & reverse..? I'm kind of thinking torque converter at the moment but it would need to be proved by testing before yanking it. Can you get hold of an infra-red thermometer..? That would be useful to shoot temperatures of the various components when you get into the diagnostics.
you said you checked the suction screen did you also check the torque convertor scavenge screen in bottom of T/convertor Mark
Yes, I did check screen on bottom left side below the torque converter. Clean there as well
I have access to infrared thermometer, I will have to wait till things dry up a bit to check it, has been raining for about a week. What is the process to check torque converter?
IMO don't bother with the converter at this stage. Get the radiator/cooler cleaned first then see what the result of that is before proceding further.