54 truck 3 spd. lost my third gear, grinds trying to go in. i guess maybe the syncronizer went out. so trying to find another, question is going to do the clutch, pressure plate, t/o bearing and ujoint anything thoughts or suggestions of what else while trans is out?
About a 99% chance the clutch ring (synchronizer) in the front of the synchro drum is worn to the point it doesn't work--a very common shortcoming with these old boxes. I may have another one in my storage shed but try this first. Are you familiar with double clutching? If not here's what you do: drive at a normal speed as you go through the gears and as you take it out of second stop the lever in the neutral position, let the clutch out for just a moment then push it back down and complete the shift into high. If no grinding then the clutch ring (synchronizer) is shot. It may take a bit of practice to do smoothly but it's the only way we old farts could change gears in the old trucks we grew up with. They had spur (straight cut rather than helical) gears and you HAD to double clutch them to shift up or down. Don't miss them a damn bit.
I agree 100% but... Let's adjust the linkage too before we tear the tranny apart. Look in the shop manual and do everything it says before you start tearing it down. Double clutching and straight "H" shifting is always a good thing too. These things will work forever as long as they are not hot rodded!
Lastly ; Let's do a posative clutch test before you yank the tranny out : Engine idling , depress the clutch to the floor and engauge first gear ~ now , keeping the clutch depressed , shift it from first into reverse ~ if it grinds , the clutch and prolly also the pilot bearing are bad and need replacing or the new synchro will be chewed to junk in short order . Be sure the check and adjust the shimming of the tranny's cluster gear and to inspect the cluster gear's shaft for any wear however slight , if there's a ridge where the needle bearings or bushings ride , it is JUNK and must needs replacing before it ruins the rest of the tranny .
thanx ! Ken i had previously adjusted all linkage and was shifting smooth.when i get back to the truck i will try Evan's and Nate's tests to see what's up or down. any way to check a tranny in a PAP if worth trying ? also shifter would pop out of third going down the road when you let off gas.
Slipping Out Of 3rd. Gear One other thing : the central shaft is made up of pieces , the input shaft/gear (" Clutch gear ") has roller bearings inside it and they can wear out as well as the inside diameter where they roll , as well as the male front portion of the output shaft ~ is these two parts & rollers are worn , it causes mis-alignment of the various gears when they're engauged , causing them to slip . It's all very simple once you have it out and torn apart over some towels (so as to not loose the roller bearings) , if you spot any wear in the bearing surfaces , those parts are shot and cannot be re-used . This is why it's so important to keep re-filling those leaky old gearboxes....
One more wear spot to add to Nate's list is the slot in the 2nd/3rd shift fork and the ring the fork fits over--very bad wear points.
Thank you ! Evan is correct . My point is : these trannies are super simple , tear it down and look at it , piece by piece ~ you don't need any special tools here , not even to shim the cluster gear (an important usually skipped step BTW) , if a part LOOKS worn , it IS ~ go find another one new or good used and all will be well .
