Reproduction Parts for 1916-1964 Chevrolet Passenger Cars & 1918-1987 Chevrolet & GMC Trucks
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I am really struggling to tracking down the cause of an issue and would love some input into what you think would be the cause of the following.
1931 Chevrolet Independence. Used to shift smoothly through all gears but recently it has become a struggle to get it in and out of 2nd and 3rd. No problems with 1st gear. When shifting normally while driving (double clutching of course) you have to sometime push it into 2nd with a bit of a clunk and then struggle to get it to release from second when trying to shift into 3rd.
Seemed at first to get worse when the car is hot or it is exceedingly warm out but now it seems to happen no matter what the temp is.
Nothing has been mechanically changed from when it was working smoothly and without issue. I have changed the transmission oil but that seems to have no effect on it.
The clutch seems to be working as it should and I don't feel any change in the pedal from when it was shifting smoothly and without issue. Pedal has perhaps 1.5" of play when pressed down and completely disengages when pushed down.
So what in your opinion would make the gear, specifically 2nd gear, become difficult to put in or take out of gear?
I have been struggling to find a cause for some time now and can't seem to find the reason for the fault.
I suspect the bushings on the gears or shaft wear is the problem. Pull off the top and manually check for wear between gears and shafts.
How sweet the roar of a Chevy four
Participant on Chatter since 11/22/2001
19758 posts on the former Chatter site
@chip Could you be a bit more specific of what I should be looking for? I am not green to car repair but have never dealt with this old of a transmission before and would likely not see the issue if I am not aware of what it 'should' look like when it is in fine fiddle.
The gears should not be loose or wiggly on the shafts or the shafts in the housing. Also look at the wear pattern on the gears. The gear teeth should be worn equally across the surface without any noticeable taper. The edges should be flat without any missing metal. The mesh side of the gears will have a little taper so the align easier that straight sided gears. Also look at the bottom side of the shift cover. There are two shift arms. One for first/reverse and the other for second/third. They should not be too loose and the rectangular end on the shift lever fit into the slot fairly tightly. Too much slop can make gear changes more difficult. I have had to weld or braze the end of a few shift rods and file them flat so they engage the arms firmly.
How sweet the roar of a Chevy four
Participant on Chatter since 11/22/2001
19758 posts on the former Chatter site
Dana here is the diagram from the 30 manual found on the chevy.oldcarmanualproject.com
Hopefully it helps give you some insight. Transmissions are super simple inside and it sounds like you would have no problem if you cracked it open.
I'm no expert, but if I had to poke a guess I would guess the main shaft bushing is wore the worst. The main shaft is two pieces with the splined part slipping into a bushing right behind the main shaft gear. All things mesh downward from there when shifting. I would think if that main shaft bushing were wore and the two piece main shaft were "sagging" (not spinning true) your meshing is going to be a problem.
All the gears below have bushings in them where they slide on the shafts, (counter shaft and reverse idler)
If gears look ok new bushings can be made at a machine shop of bought from the Filling station, or recently I talked to the guy at http://www.billypossum.com/
He had the bushings as well as replacement counter shaft and reverse idler shafts. Good transmission rebuild post from bearsfan on the old site.
1929 Transmission Check/Rebuild - Vintage Chevrolet Club - Discussion Forum (vccachat.org)
David
I guess my post came up as anonymous because I wasn't logged in.
I guess my post came up as anonymous because I wasn't logged in.
That was a quirk of the forum software. Hopefully that (allowing posts when not log logged in) has been fixed and the whole anonymous thing will stop.
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