904 no direct

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geo21

geo21

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Newfane Vt
Hi everyone . I have a 72 904 behind a /6 .Trans works fine except ,, no 3rd . If there is no load ( down hill or level cruise ) it will atempt to go in . Step on throttle and it free wheels . TP pressure has been adjusted correctly , fluid is perfect .Any ideas ? Thanks
George
 
Drop the pan to see if there is metal or clutch pieces in the filter or bottom of the pan?
 
Fluid level is perfect ? or fluid colour and smell are perfect ? The second one is way more important than the first !
 
Does reverse work ok?
THe hi clutch is common to both Drive and Reverse. If reverse will take throttle and not slip, then the hi clutch is Ok.
All forward gears also use the forward clutch, So if second gear does not slip during a Wot run, then the forward clutch is also good.
So that leaves wrong fluid level, the rear sprag,the pump, or the VB.
Low fluid you know how to check for, in Neutral, on level ground and oil warmed up.Too high a level is not good either, and will show up as foamy fluid.
The sprag you can check by mashing the gaspedal in Drive from a standing start. No slip means the sprag is holding.
That leaves the pump and the VB.
At this point it's time for an oil pressure test.Test the reverse pressure first, cuz in reverse the gauge will read maximum pump pressure, which IIRC is around 230psi.
I doubt its a VB issue.

There is one wildcard; if the governor weight retaining clip has slipped off, then the 1-2 shift will occur very very early, and I suppose if oil pressure was spewing out of that circuit, there might not be enough pressure/flo, to engage a direct clutch with a tired lip seal.
 
cannucky said:
Fluid level is perfect ? or fluid colour and smell are perfect ? The second one is way more important than the first !
Click to expand...
The level , smell and color all good , and yes I did check it in neutral
 
AJ/FormS said:
Does reverse work ok?
THe hi clutch is common to both Drive and Reverse. If reverse will take throttle and not slip, then the hi clutch is Ok.
All forward gears also use the forward clutch, So if second gear does not slip during a Wot run, then the forward clutch is also good.
So that leaves wrong fluid level, the rear sprag,the pump, or the VB.
Low fluid you know how to check for, in Neutral, on level ground and oil warmed up.Too high a level is not good either, and will show up as foamy fluid.
The sprag you can check by mashing the gaspedal in Drive from a standing start. No slip means the sprag is holding.
That leaves the pump and the VB.uch guys
At this point it's time for an oil pressure test.Test the reverse pressure first, cuz in reverse the gauge will read maximum pump pressure, which IIRC is around 230psi.
I doubt its a VB issue.

There is one wildcard; if the governor weight retaining clip has slipped off, then the 1-2 shift will occur very very early, and I suppose if oil pressure was spewing out of that circuit, there might not be enough pressure/flo, to engage a direct clutch with a tired lip seal.
Click to expand...
Everything else works as it should .I'm just going to pull it and go thru it . Thank you soo much guys . Have a great day
 
Please let us know your findings.It's a big help for us down the road..
 
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