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*gmachinz* · 10-17-2012, 04:34 PM

If it's sat a lot of the time with a fairly fresh trans overhaul to begin with-it may be youhave some debris or some dry spots in the housing of the modulator valve. If reverse is ok chances are it's not a worn 1st gear synchro set since on TH400's 1st and reverse share the same ones, you might want to pull the cover off the modulator valve and pull it out-take a lint free cloth soaked in transmission fluid and completely wipe the interior of the housing out and re-install the modulator valve-that might help...if that doesn't make a difference, try adjusting (if it's an adjustable type) the vacuum modulator itself-clockwise lowers the shift point and counterclockwise raises/delays the shift point.

10-17-2012, 04:34 PM	#4
gmachinz Account Suspended Join Date: Jun 2011 Location: Des Moines, IA. Posts: 4,143	Re: tranny issues If it's sat a lot of the time with a fairly fresh trans overhaul to begin with-it may be youhave some debris or some dry spots in the housing of the modulator valve. If reverse is ok chances are it's not a worn 1st gear synchro set since on TH400's 1st and reverse share the same ones, you might want to pull the cover off the modulator valve and pull it out-take a lint free cloth soaked in transmission fluid and completely wipe the interior of the housing out and re-install the modulator valve-that might help...if that doesn't make a difference, try adjusting (if it's an adjustable type) the vacuum modulator itself-clockwise lowers the shift point and counterclockwise raises/delays the shift point.