dieseldoc Posted February 20, 2012 Share Posted February 20, 2012 Got problem child guys an looking for a few ideas. Workin on a 94 F-250 7.3 powerstroke and 5 spd manual. Trans jumps out of 4th gear on coast and wont go back into gear until you stop completely. original customer complaint of hopping or jerking when letting clutch out in reverse and four wheel drive not working right. Has a luk single mass converison already. I found the chain stretched in the transfer case and bad bearing. I rebuilt the transfer case, and four wheel drive working great. However still occasionally jumping out of 4th gear on coast, and happening more frequently. Trans has 270,000 mi on it, and was grinding into several gears. Suggested trans rebuild figuring synchros worn and possibly finding a worn sliding collar. Customer sent trans to standard transmission and gear for rebuild. they replaced a sliding collar, 2 shift forks and reverse gear as well as bearings, seals, and synchros. I figured for sure we had it because worn sliding collar has been the cause of this on the few trans have worked on before. put trans in and still jumps out of 4th gear on coast. Not sure where to go from here. . . all u-joints ok, motor and trans mounts ok. once the trans pops out of gear you can push the clutch in and you still can not put back into any gear until vehicle comes to a complete stop. Have checked clutch operation and all appears to be working ok. Going to call the rebuild company and talk to them tomorrow. wondering if I am missing something obvious here or maybe something still isnt right in the trans. could a worn shift tower cause this type of symptom? thanks for the help guys I am an engine man and not so much a gear guy. Quote Link to comment Share on other sites More sharing options...
Buddy_M Posted February 20, 2012 Share Posted February 20, 2012 Did you check the pilot bearing when everything was apart? That will cause the input to move around, and could cause the clutch chatter and for it to pop out of 4th gear. Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted February 21, 2012 Author Share Posted February 21, 2012 The truck is actually my brothers truck and he r&i the trans himself. I talked to standard trans and gear this morning and they to said the pilot bearing is most likely the cause as well. I didnt tell him to replace the pilot and throw out bearings(i sort of figured that was standard practice), guess I should have told him. I talked him into bringing it in to me to do the job this time. He is a great tractor technician but doesnt always pay attention to the details. will replace the pilot bearing and check things out. will let you guys know what happens from there. I didnt figure a pilot bearing would cause it to pop out of gear i could see the hard shifts thoug, but like I said I am more an engine guy than gear guy. thanks for the input. Quote Link to comment Share on other sites More sharing options...
cbriggs Posted February 21, 2012 Share Posted February 21, 2012 4th gear is direct, couples the input shaft to the main shaft right at the front of the trans, if input shaft moves around at all, it will pop the shift collar back. Make sure it hasnt damaged the input shaft bearing on the new trans, also there is a small pilot bearing between the input shaft and mainshaft. Quote Link to comment Share on other sites More sharing options...
Jim Warman Posted February 21, 2012 Share Posted February 21, 2012 The truck is actually my brothers truck and he r&i the trans himself. I talked to standard trans and gear this morning and they to said the pilot bearing is most likely the cause as well. I didnt tell him to replace the pilot and throw out bearings(i sort of figured that was standard practice), guess I should have told him. I talked him into bringing it in to me to do the job this time. He is a great tractor technician but doesnt always pay attention to the details. will replace the pilot bearing and check things out. will let you guys know what happens from there. I didnt figure a pilot bearing would cause it to pop out of gear i could see the hard shifts thoug, but like I said I am more an engine guy than gear guy. thanks for the input. I often (quite wrongly) lose patience with civilians that aren't well versed in "machine shit". I don't think I have any special knowledge, knowledge that isn't anything more than simple logic, but it is stuff most people don't know all the same. Never assume that "the little things" were checked. Part of my job is fixing things that have been "fixed" several times already. I'm not "good"... I'm "fussy". Having said that.... dowel pins is yet one more consideration. Quote Link to comment Share on other sites More sharing options...
ktmlew Posted February 22, 2012 Share Posted February 22, 2012 also there is a small pilot bearing between the input shaft and mainshaft. Yep. I've heard it refered to as a pocket bearing. Usually a set of 10-12 uncaged roller bearings. Kinda like a u-joint cap. If the pilot bearing is binding I suppose the torsional vibtration of the crankshaft could shake it out of gear? Don't have to jump out many times to kill the input shaft and sliding collar... Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted February 23, 2012 Author Share Posted February 23, 2012 I too jim am with you I am not good I am fussy, I told my boss the other day that I am not slow I am picky and watch for the details. He said I know thats why you get the rework jobs because it most likely wont be back. I got him to haul it in for me work on. He wanted to bring it in friday night and take it home sunday. I told him not happening drop it friday night and I will bring it back when I am satisfied it is fixed and as correct as it can be. He only made it into 4th gear one time when it popped out of gear he turned around and parked it, so hopefully it hasnt done any damage to the new trans. Will see what I find saturday morning. Will keep you up to date. Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted February 27, 2012 Author Share Posted February 27, 2012 Got the trans out friday night and found the dowel pins are there. however I have always had to pry the trans back off the dowels and really push to get it on the dowels, this truck however the trans just pulled right back like they arent even there. I found the pilot bearing very loose on the input shaft as compared to the new one. I also found the release arm was half worn through from the throw-out bearing. The clutch fingers too are worn considerably. I am thinking the slave cylinder is not retracting completely and keeping pressure on the throw-out bearing to the clutch all the time. I got the flywheel cut and ordered a new release arm and hydraulic set-up. Not sure however what to do about the dowel pins.....I am thinking of ordering new ones to see if they fit tighter. Anybody else run into this before? Quote Link to comment Share on other sites More sharing options...
Keith Browning Posted March 1, 2012 Share Posted March 1, 2012 I am of the opinion that the dowels should not really "stick" to the trans at all. It is when we get rust and corrosion buildup that they become hard to separate. If this trans was out recently I would not expect it to be stuck Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted March 3, 2012 Author Share Posted March 3, 2012 Thanks for the input keith. I finally got the parts to put it back together today. Will assemble tomorrow and see what happens. I sure hope it works this time. I really dont want to pull this trans again. I have never seen this issue before so want to make sure it is all correct before assembly Quote Link to comment Share on other sites More sharing options...
dieseldoc Posted March 4, 2012 Author Share Posted March 4, 2012 Alright guys I finally found the culprit. . . .Lesson learned about not test driving before starting on an issue like this.I get it all back together and my brother takes it for a drive and says it does the same thing. I take it for a test drive and it did it to me right away. Feel the levers when it does it and it's damn transfer case jumping out of gear not the transmission. I removed the linkage for the case and pushed the lever on the case to the 2wd position and test drove again with same result. So I am pulling the case tomorrow to see what is wrong in there. I am thinkg the shift fork in the t-case is not located correctly on the shaft, after rebuilding it. Thanks for the help guys. will let you know what I find in there Quote Link to comment Share on other sites More sharing options...
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