Hoping the title will catch the eye of someone with experience with these cone type transmissions. I have a 1GM, it operated fine for years and then slowly developed this issue. It will not go into gear
unless revved over 1K at which time it slams into gear
with a big clunk. This is true in both forward and reverse.
This issue started slowly and progressed from a clunk that got worse into needing a slight rev to clunk into gear but I was cruising and didn't have the tools to work
on it so I just tried to use it as little as possible and figured I would fix it when I got home. Not ideal, I know but I'm due for a repower
It is not a cable issue - this also happens when manually shifting with cable removed. Shifter feels like it moves and engages smoothly.
Once in gear I can throttle back with no issues, the problem is when going from neutral into gear.
is a dark amber but smells fine and doesn't appear burnt. It does seem to be overfilled but it is it has been like that since before the issue started.
(Side note, can anyone tell me whether the dipstick is read by resting it on the end of the threads or threading it completely into the housing?)
It happens in both fwd and reverse which has me confused. The service
manual has instructions for making slight adjustments to the shift mechanism by loosening the case bolts and moving it either forward or backwards to correct for incorrect engagement of the cone in one direction or the other but says nothing about when the issue is in both directions. It seems to me that if it was wear on the drive cone it's unlikely to be nearly identical symptoms in both forward and reverse.
I'm going to start by draining and refilling the trans but not very optimistic.
I have great access to the shift mechanism on the side of the trans housing but pulling the trans completely is going to be a miserable job, hoping I might have some luck working on it in place.
A couple questions:
-To my untrained eye it looks like the manual says that the drive cone is actually engaged by spring pressure on the 'notch' as it lands on a taper cut into the body of the shifter - ie the shift lever takes you part of the way to engaging the drive cone and then there is a spring exerting pressure on a tapered pin which clicks into place in the shifter and finishes the rotation that engages the cone. Is it possible that my issue is worn out 'notch springs'?
-The manual gives a procedure for lateral adjustment of the shift mechanism (to correct an error where it doesn't fully engage either forward or reverse, which I suspect isn't the issue anyway) using a SST 'locating jig' which basically tells you whether the shift lever is moving through the correct arc
. I don't need this tool do I? Seems like the important thing is just that the movement from neutral to forward is the same distance as neutral to reverse so I could take my own measurements without the tool, right?