Hope someone can give me a suggestion or two as to what might be causing this problem. I have a 1951 1/2 ton with 'three on the tree' - sometimes, I can't get the shifter to move into 3rd gear. The shifter feels like something is preventing it from sliding into 3rd gear. I can stop the truck and after shifing into 1st and 2nd, it will then shift into 3rd with no problems. This does not happen all the time, might be many shifts until it happens again. My first guess is there is somehting amiss with the linkage. Would appreciate any suggestions. Penniwinkle
Your first guess would probably be right on the money. Had the same roblem with my 58 so I opted to put in an auto trans. Doc
You might pop the cap off the top of the shifter box(at the bottom of the column) and see if the knotches for 1st/reverse and 2nd/3rd are aligned when the shifter is in the neutral position. I don't think this is your problem because this shows up in the 1st to second shift but why not check all bases. Next the external linkage to make sure there's no binding but I don't think this will be the culprit either. What I do think is the flange on the syncro drum inside the trans is worn along with the slot in the shift fork or even the clutch ring in the syncro drum. If so, it's way cheaper to pick up a good used unit than to buy the parts to repair. With all the V8 swaps they're easy to find and cheap. Be sure to pull the side cover and make sure your not getting one that's as worn as yours. If you lived near my shop you would be welcome to pick one up and try it ( I have about 10). If it worked pay for it and if it didn't--can it, no cost.
Evan is right on here but it's wise to adjust the worn & floppy shift linkage before touching the tranny . put the gear lever in the cab @ 3:00 and wedge it there as it'll droop on it's own , now go look under the hood at the two little levers on the steering column ~ they should be paralell , if not you'll beed to take the shift box apart and scrape out all the old , rock hard grease and shim & adjust , re-lube with good chassis grease (white Lithium grease is best here) , and then replace the bushings where the rods go through the arms as once those bushings are shot , poor shifting results . use PVC or whatever you can find , I dunno if the re-pop bushings are any good , hard plastic is best , the original ones were soft rubber to be quieter , not a good plan . I've seen very good homemade aluminum ones too . Next , go underneath the truck (parking brake set and wheels _chocked_ !) with the tranny in neutral , remove the little cotter pins holding the levers to the tranny arms and shim them up using thin flat washers untill the pins just fit snugly on the arms , no droop but NO drag either , then adjust the pins so they fit in the holes on the arms dead center when the shift lever is dead nutz @ 3:00 ~ this will " time " the linkage and usually correct 90 % of poor shifting . To recap : remove all play and floppyness in the shifter rods then lube & adjust . Drain and re-fill the tranny with 90W gear oil or 85W-90 if that's what your FLAPS has , remove the fill plug BEFORE you drain it and re-fill to the edge of the filler hole , truck on a level surface ~ this is very important ! these old trannies leak no matter what and should be topped up at least 2X / year regardless of miles travelled . -Nate
Nate, I have made some progress with not being able to shift into 3rd gear. The steering box was dry - filled it and tried to fix the sloopy linkage - bushing worn very bad. I found that a 'brass compression ring' fits on the linkage arm (at least a temp fix) (and I added several washers as you suggested). Also, the gear box was loose, sliding around the steering shaft. After all this, the shifter is much tighter, no sloop, but even tho it shifts into 3rd all the time now, it doesn't seem to slide into 3rd enough, seems the linkage on the 2nd and 3rd gear needs to adjusted so there is more 'downward' movement into 3rd gear (it does not fly out of 3rd but would feel much better if the shifter moved the linkage 'a little further downward). I was going to adjust at the gear box - lengthen the arm or at the tranny end. Any suggestions? Thanks. Penniwinkle
If I understand your question , it is normal for the shift lever to have less travel into 3rd. gear than it does for all the other gears , just the way they are made . when the tranny is in neutral , look at the short levers sticking out of the shift box on the column ~ they _must_ be paralell ~ if not , disconnect the shift rods , align the shift arms and adjust the rods to they slip in their holes dead center with the shift arms on both shift box and tranny aligned . It sounds to me like you've done well , get the truck up to it's sweet spot in third gear (usually around 40 MPH) and rapidly stamp on the gas then release it to see if it'll pop out ~ if it doesn't , you're now good to go . Remember : this is a 40 year old machine so expect some anomolies .
Nate, I have checked the items you suggested. Thanks for the post. I think that I have resolved the problem and the shifting is great...and does not fly out of 3rd. I fabricated a plastic bushing for the upper linkage arm (on the 2nd and 3rd gear linkage arm). The bushing only took about 30 minutes to fabricate....made it out of a small plastic cap that was off something...just laying in my tool box. The bushing fits tightly on the arm and the outside diameter just fits the busining hole on the arm. Thanks for all the suggestions. Penniwinkle
Sense of achevement eh penniwinkle, dont it feel good when you make something work with a totally unrelated item, ________ Honda airport
Simple Repairs 4 Simple Trucks I keep trying to get fellas to try repairing the odd stuff before ripping the whole vehicle apart , I am glad this worked out for you . many gearchange problems can be easily fixed by some serious fiddling to linkages and clutch release .
