wallifishrmn

Occassionally if you don't hold the shifter in first gear--when you go to release the clutch it's like it's forced out of gear. The car shifts great, had the clutch rebuilt. Like I said it does it maybe once out of ten times but sounds horrible and you feel like an idiot when it pops out. Any suggestions.

GTR1999

Check the shifter adjustment otherwise it may be in the Muncie. Usually happens with 2nd gear from being pounded.
If you have to go into the Munice I recommend getting Paul C's book and/or cd on them, will walk you through the job. www.5speeds.com

Wrencher

Pretty unusual for first gear, but it's typically caused by a worn gear set, meaning istead of a nice, straight profile across the helical cut, it becomes rounded or 'crowned' on either the gear itself and/or the cluster gear. Gear wear is most common in 2nd and 3rd, the most heavily used sets. I agree that it's probably an adjustment or something limiting the linkage travel. Don't overlook the shift lever itself! I have found that an improperly mounted console limits the lever travel.

How many miles on the trans? Going thru a 4 speed is pretty straight forward and a great improvement over a well worn unit, or you can upgrade to a modern overdrive unit with the added benefits those provide

Hans

...Roger...

Probably not going all the way into first gear.As Gary said check shifter adjustment.I see many that the shifter is just loose.

wallifishrmn

Shifter adjustment---does that mean shift linkage adjustments? Service manual says place trans in neutal; hold 1st/2nd rod and lever against locating gauge (whatever that is); tighten forward nut against the swivel and then the aft. Repeat 3rd/4th. Is this what you are talking about. Sorry I have never done anything on the transmission.

...Roger...

Yes thats it.But you will have to make a locating gauge.You said you had the clutch done....if it was recent I would have the guys that did it look at it.Other wise the first thing is if the shifter or linkage is loose you might only have to tighten it up...chances are that the adjustments on the rods are OK.I've seen lots of shifters loosen up.
edit-here is a pic of the gauge.

BarryK

in the first pic here you can see the alignment "tool" (thin metal plate) inserted into the shifter. This keeps the shifter in the correct position so that you can accurately adjust the shifter rods



this pic shows the shifter and shifter rods connected to the tranny. one rods controls the 1-2 shift, the other rods controls the 3-4 shift and the short third rod is for reverse.
The reason everyone is saying to first check the shift linkage is because when you move the shifter it moves the rod which is connected to the shift lever on the tranny to move the tranny into gear. The rod must push or pull (in the case of first gear "pull") the lever all the way for the tranny to "lock" it into the selected gear. There is a detent when it's all the way into position to help hold it. If the linkage is misadjusted it may not be going all the way in far enough and it can pop out of gear.


As mentioned, it's strange to have this happen in 1st gear, it's common to happen to 2nd gear since that gear gets the most abuse. In fact my '65 is having this problem and the tranny needs a rebuild.
If the issue isn't the linkage adjustment you will need a tranny rebuild as the synco's are probably worn and very possibly the actual 1st gear itself. Most likey if it's not the linkage you will need a rebuild kit, plus slider and fork, and maybe 1st gear.

wallifishrmn

The clutch was replaced 5K miles ago and also resurfaced flywheel, new clutch fork, pivot ball, tail shaft bushing, and yoke. Order says R & R transmission and replace clutch. This was done before I purchased the car but I have the work orders from the Transmission shop. The shifter does not feel loose and shifts very smoothly. It's like it doesn't go all the way into first gear sometimes and then if you don't hold it that time it might pop out. I really appreciate the help.

5speeds

Everyone always says.... "Check shifter adjustment" It seems like no one these days actually has an understanding anymore about what shifter adjustment can and cannot do.

If you have a good neutral gate,, you shifter is adjusted. PERIOD.

You can't make any of these transmissions "bite" into gear more by "adjusting" the shifter. There are detents in these transmissions that fix shift shaft travel.

A loose shifter HOWEVER can be the culprit, but then again you will not have a good neutral gate. It will come and go and be a variable neutral gate. So if you have a good neutral gate.... forget about shifter adjustment.

A hurst shifter has stops. If you have stops misadjusted or in to far, then it will not go in gear. Try removing the stops.

Sometimes bad mounts can cause the trans to pull out of gear with factory shifters that are frame mounted.

The most common cause of jumping out of gear are worn sliders, shift forks, and engagement teeth of the gear, not the actual helical gear teeth and Not worn synchros!! The problem is not being able to hold itself in gear. Synchros when they don't work.... GRIND

If you have had a newly rebuild unit with new gears, I have seen a great deal of these Chinese gear sets ( the ones on Ebay) put in boxes with sliders that will just not work correctly with them. Nothing is wrong with the quality of these gears, its just that they are not machined to GM specs and the engagement tooth profile demands a matching torque lock slider to go with it.

Paul
http://www.5speeds.com

...Roger...

Feeling loose and being loose are 2 different things.The 1971 Muncie shifter has 2 bolts holding it to the mounting bracket(mounting bracket mounting is another story)if these 2 bolts become loose the shifter is not held solid and it cant fully stroke the shifter rods especially if your shifter rods are in the long stroke position .The shifter becomes loose over time and you dont notice the difference.So the shifter still feels "pretty good".Because of the length of the shifter lever it has a lever advantage over the part of the shifter that mounts to the trans. and this will allow the neutral gate to "self align" and give the impression of a "good neutral gate" when actually it should be defined as a "variable gate".(defining different neutral gates will vary from person to person depending on how familiar the person is with the particular shifter type)You can have a perfect trans. and mate it with a sloppy or loose shifter and end up with the condition you are describing.Please believe me.Check or have checked all of your linkage and mounting before condemning your trans.

FB007

There is nothing wrong with checking the shifter. When loose, it can cause problems. The adjustment, as stated, is mainly to acquire nuetral.
If he wants, the side cover could be pulled in the car, the shifter forks inspected, and the shifter seals renewed while off. A badly worn fork will not allow the full throw of the gears.

jim2527

It can? If you can 100% conform this I'd appreciate it. My side cover seals are leaking big time.



95% of my shifter problems were caused by:

1. Loose mounting plate to crossmember. If the plate is loose your shifter will not be rigidly mounted
2. Loose shifter to mounting plate. Mine wasssingo ne of the 2 bolts and the other was loose.
3. Sloppy shifter. I picked up and installed a major rebuilt kit.
4. Missing linkage washer/spring clips. Mine was missing both. i replaced them as needed according to the AIM.

Other shifter issues could be:

1. Bad motor mounts. C3 shifters mount to the frame not the transmission. Excessive engine movement will mess up shifter performance
2. Bad tranny mount. Same as #1.

FB007

[QUOTE=jim2527;1566378403]It can? If you can 100% conform this I'd appreciate it. My side cover seals are leaking big time.Yep. Been there, done that.
If you need a little more clearance, just remove the tranny mount bolts, jack up the bell housing a tad, remove the tranny bolts to bell housing, and gently rotate the tranny down towards you. Simple, eh?