D8N transmission problem

[muller]

hello i need help, i pull out a transmission out because the machine didnt move forward, i replace all the forward friction discs, and reseal all the trans, a week after all the clutch discs again were worn out, the same problem happened again but with less work only 4 hours. i cleaned the screen that gos on the bottom of the trans and the one that goes on converter after i put the tranny on what can i do
thanks

 

[JeremiahSr]

You need to run pressures. I don't kn ow the serial number to your machine but this is what you need to check.....A. Torque Converter Inlet B. Speed ClutchesP1 C. Direction ClutchesP2 D. Transmission lubrication F. Priority valve
Wrong pressures will burn up a pack quick.

 

[muller]

hello jeremihaSr, and thanks for the tips, look the 1 speed and the 2nd speed look fine also the reverse the only one that burned out is the forward i will check all that you told me, the only thing is that it is a lot of cluth paste that got stock on the screen tat is on the bottom of the trans, from the outside. i will try to post some pics later of the clutches. the first time the discs were OEM the second one i put some good aftermarket parts that i bought on the us.
thanks

 

[JeremiahSr]

I think both the forward and the reverse have 5 friction discs and 4 steels. After you rebuild make sure you air test packs before installing the control valve. This lets you know the piston seals installed good and the housing/piston isn't cracked or any thing. Keep an eye and an ear out for air leakage while holding air pressure on pack. Them frictions are that hard rubber/teflon material. Have to make sure you are getting good pressure to that pack. Should be at least 300 psi. If the pressure is low and air test checks out good....check your linkage adjustment really good. Make sure forward spool is fully going in dedent. That cable not adjusted properly will allow one gear good but rob from the other not allowing full pressure to pack.

 

[AmerIndependent]

Good advice from JeremiahSr!

Here’s our two cents worth:

It is important you understand that in this model, the transmission is only part of the power train, which includes the torque converter, transmission pump, brakes, cooler and differential steering. Since they all share the same oil, it's no surprise the forward clutch would be the first to suffer in the event of pressure loss or contamination since it's the most commonly and heavily used part of the power train.

Sorry to sound like a broken record but our advice is always the same- the first order of business is to inspect all three power train screens, and the filter for signs of identifiable debris that might give a clue as to the root cause of the problem. My suspicion is that the repeated clutch failure is the victim of, rather than the cause of your problem.

If we could get a look at what you find, we might be able to head you in the right direction. Some pictures would be appreciated.

Good luck! :usa

 

[muller]

here is a pic of what i found before disasemling the trans clutch on the forward pack.

 

[AmerIndependent]

Yep, you've definitely got a wasted clutch on your hands. Could we get some pics of the three power train screens and filter?

 

[muller]

i only know the screen that goes on the bottom of the trans and the trans filter, and the one that goes on the converter am i missing one?
thanks

 

[AmerIndependent]

Yes, one more screen where the main transmission pump suction line attaches to the front side of the sump.