twalls Posted December 29, 2010 Report Share Posted December 29, 2010 Hoping their is some one out there that is very fimilar with our auto trannies. What started off as a simple engine swap has grown into tranny issues. After swaping the engine I initially had no OD. Pulled the tranny and went through it and rebuilt it with new friction discs and plates also a few new bearings. After reinstalling th tranny still had no OD. Thinking it may be the valve body I swaped in a different valve body and everything seemed to be working fine for two days, then yesterday no overdrive again. Is there something stupid I am overlooking? Any Ideas? Link to comment Share on other sites More sharing options...
natallica Posted December 29, 2010 Report Share Posted December 29, 2010 I've read somewhere that if the vacuum modulator (located on the drivers side of the tranny) is not hooked up or needs replaced, this can happen... also if the switch in the shifter handle is faulty, same thing. Could it perhaps be one of these items? Link to comment Share on other sites More sharing options...
scott87star Posted December 29, 2010 Report Share Posted December 29, 2010 Use the FSM to solve your problem, download one from www.starquestgarage.com if you don't have one. It's got an extensive section on the operation of the OD. Scott Link to comment Share on other sites More sharing options...
Alan Posted December 29, 2010 Report Share Posted December 29, 2010 Get the FSM and go thru the auto transmisson section. Lots of OD posts there. During the rebuild if the OD drum and Band was good that would leave the one way sprag in the Direct clutch(OD drum buildup). That topic came up the other day on a post from Rabbit1. OD is turned off electically and it won't engage until the engine is warmed up. Link to comment Share on other sites More sharing options...
Shelby Posted January 1, 2011 Report Share Posted January 1, 2011 you had books to do a rebuild on the tranny but not show the OD system , default on our tranny is OD on , most are OD off that means if you unplug'd both solonids on the drivers side of the trans it should go straight from 3'd to OD on the up shift Link to comment Share on other sites More sharing options...
ColdScrip Posted January 1, 2011 Report Share Posted January 1, 2011 Bit off topic but if you swapped a G54B in from a manual car you must place the bushing on the crank that our auto cars came with. Link to comment Share on other sites More sharing options...
twalls Posted January 1, 2011 Author Report Share Posted January 1, 2011 Pulled vacuum line off of modulator value and had ATF fluid on vacuum side of valve. Replaced and seems to be working now. Thanks for all the help. Link to comment Share on other sites More sharing options...
twalls Posted January 1, 2011 Author Report Share Posted January 1, 2011 Pretty meticulous on the swap, did get the bushing in the crank. Only thing that I forgot was where the rubber vent line off the top of the tranny goes. Hopefully I will eventually figure it out. Link to comment Share on other sites More sharing options...
Shelby Posted January 2, 2011 Report Share Posted January 2, 2011 Pretty meticulous on the swap, did get the bushing in the crank. Only thing that I forgot was where the rubber vent line off the top of the tranny goes. Hopefully I will eventually figure it out. it's just that a vent line, goes toward the top of the trans houseing near the block , then open , if your in florida, bugs will plug it up every week or so Link to comment Share on other sites More sharing options...
twalls Posted January 2, 2011 Author Report Share Posted January 2, 2011 Thanks Shelby that is what I had done with the line. Had thought it might plug into a canister somewhere but couldn't locate it, so that is reassuring that it is open ended. Link to comment Share on other sites More sharing options...
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