1979 D3 moves when it wants to

[Brandx]

New to me and I need recommendations as to what manual to order. But I would also like to get working on it. It runs and all the hydraulics work. It got it cheep because they could not get it to drive onto a trailer. I lifted it off from the ground with the stabilizers and blade, put it in gear and the tracks did not move until my son pushed and released the center pedal several times. We put it back on the ground and it moves when it wants to but with very low power. We was able to get it up onto a equipment trailer with some assistance from a winch. When it doesn't move the drive shaft stops. I checked both dipsticks and it seems they have over filled the transmission to try and get it to go. the filter cover does not look like it's been off in a very long time I cleaned the area and that is this afternoons project. I am looking for what else I can check to maybe diagnose the problem while waiting on a manual. Thanks for the help George oh serial number is 79u6056

 

[old-iron-habit]

Change the transmission filter for starters. They don't pull decent unless you have the governor speed up to high idle either.

 

[Brandx]

I cleaned the filter that is in the torque converter housing, It operates as it should with good power. I am going to drain and check the sump screen. Still looking for a manual without paying dealer prices.

 

[kshansen]

I cleaned the filter that is in the torque converter housing, It operates as it should with good power. I am going to drain and check the sump screen. Still looking for a manual without paying dealer prices.

The bare minimum I would want is the operation and maintenance manual and that can be had on CD for $49.00 from here:
https://www.servicemanualpro.com/?page=Products&searchbox=79U6056

And depending on how important this machine is to you parts and service manuals are not that bad if you go the CD format.

Nice thing about the CD format is you can print out pages for what you are working on that day and have them on the job and not have to be worried about dropping them in to the drain bucket, just print new ones next time!

 

[AllDodge]

When it doesn't move the drive shaft stops

That sounds like a transmission or torque converter issue.
Need to find my post about checking trans pressures or if Nige can repost

 

[AllDodge]

Found the document