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I’m experiencing a notchy 1st gear. Car will shift into 1st just fine approximately 90% to 95% of the time. But sometimes 1st does not completely engage. Grinding will occur, and the shifter will pop out of gear. Clutch fluid and differential fluid have been recently changed. That seems to have helped slightly but problem still exists. I’m next going to remove the shifter, replace the bushing and lubricate. Anything else to inspect or other recommendations?
I just finished completely rebuilding my transmission and it’s flawless.
I say that only to give a little weight to what I’m about to say.
The same issue is something I responded to with someone having the same issue except with reverse.
Originally Posted by ~Josh
One of the plastic pads that are on your reverse shift fork have split or broken off so the shift fork isn’t getting that last little bit of distance on both sides needed to get locked fully onto the reverse gear’s dog teeth.
Originally Posted by ~Josh
When you have it almost all the way and let the clutch out slightly, the gear moves and because the dog teeth are coffin shaped and are almost engaged on the collar, it rotates with some force and hitting the receiving angles in the collar, makes the collar get drawn onto the teeth and fully “click” home (what you hear and feel) and then you’re able to reverse as at that point you’re locked in until you shift out of reverse.
The only fix for this is internal. Luckily you can just remove the rear transmission cover to access the reverse fork (compared to being in the main case) but the bad news is it’s still a ton of work to get to it.
The bad news is unlike being in the back box (5th,6th,reverse) your issue is in the main case which means a little more work.
Do you still have the OEM shifter? I’d suggest realigning the lower shift box before doing anything crazy. The OEM unit has a small pin attached to the housing that you are supposed to use. If not, a small Allen wrench or screw driver will suffice. You should be able to find the DIY on how to do the realignment with a forum search.
Do you still have the OEM shifter? I’d suggest realigning the lower shift box before doing anything crazy. The OEM unit has a small pin attached to the housing that you are supposed to use. If not, a small Allen wrench or screw driver will suffice. You should be able to find the DIY on how to do the realignment with a forum search.
Was just going to post this. Realign the shifter box. I did when installing the TMOD rebuilt box and 99% of my shifting issues have been resolved.
If you know how the c5/6/7 system works, there’s practically 0% adjustment available. The shifter alignment isn’t what you think. That’s only so in neutral 3rd/4th gear is in line.
If you’re already in the gate of 1st gear (or any other gear) all you can do is move the shifter all the way home. If it doesn’t engage the gear properly or pops out, there’s ZERO external of the transmission you can adjust to make the collar (internal to the transmission) fully engage the dog teeth other than address the issue with the fork controlling it, and most likely with that symptom you described it’s the plastic pads. Much less likely (very unlikely) the 1/2 shift fork is bent but I wouldn’t bet $1 on that.
Dont waste your time and money chasing crap. Plan on having the transmission rebuilt, add the rebuilt lower shift box simply as icing as it goes back together.
False... if you don't have the shifter box aligned you may not be fully in gear causing it to pop out. There's a reason the stock shifter has a centering pin and MGW has a centering plate.
Yes trans can be the issue, but checking the shifter box is always the first step.
Sincerely appreciate your recommendations and knowledge on this. I’m pulling my interior out within the next few months to correct some deficiencies and audio issues there, so I will check the shifter at that time (fingers crossed). If necessary will address the trans later as the car is certainly drivable now. Once again, thank you for the responses and I will post updates.
The lower shift box mounted to the torque tube with the shift rod in place. Nothing has changed from the factory.
You buy a new shifter or remove one for whatever reason... the theory of shifter alignment is so when the transmission is in neutral and internally aligned in 3rd/4th... you align your shifter so you could push forward and have in 3rd and pull for 4th lined up. That “alignment” is a farce.
The bolt holes on the shifter only allow so much room for movement. Guess what? I know someone that bought a C5 that had the shifter mounted BACKWARDS and it was shifting just fine. You think it can’t be done? Next time you have your shifter off, flip it around backwards, bolt it down with zero concern, in fact shift it to the furthest corner the bolts will allow (pick any corner) and snug the bolts down.
Start the car and push in the clutch and shift into 1st gear and all the rest with your shifter mounted backwards, and towards the furthest corner you can manage. Tell me it doesn’t go perfectly into gear.
Do you have any idea how much slop is in the entire external linkage, and internal (shift rods,fingers and forks) to begin with? It’s designed that way.
So... backwards shifter or perfectly “aligned” -that’s not the reason it pops out of gear.
Might as well check your tire pressure too, all basic stuff you hear from the goof troop. Unbolt your shifter and “align” it. Lower shift box rebuild will fix it. Change fluid. Pray.
Josh, I humbly disagree with your statements. There are tons of folks that have had success resolving there engagement problems with realigning the shifter. Your statement about 3/N/4 would be “relatively” true if the shift box was limited to only front/rear movement. But that’s not true. There is also left/right adjustment as well which most certainly impacts shift engagement. If you understand the applicable geometry and physicals, you’re increasing the pivot angle of the shift pattern with the fulcrum being the knuckle in the linkage at the transmission. It may only be by a degree or two, but all of which will translate to more/less travel of the entire assembly into the transmission aka increasing/decreasing the hypotenuse of the invisible shift linkage triangle. If your shift box is set to the front right corner let’s say (towards 5th gear), when you shift into 2nd, your shift rod assembly may not travel far enough for full engagement into 2nd. Sure, the play in the rest of the system, as well as wear of the internals of the transmission may exaggerate the issue, but I assure you alignment of the shifter box impacts shifter engagement. GM doesn’t provide that pin for fun.
I normally just ignore ignorant posts like yours, but I am an engineer for a major motorcycle manufacturer and I spent a couple years specializing in drivetrain design...when you start your post off with “further insight from someone who knows” you immediately discredit your response by insulting everyone else who contributed to the thread...you don’t know everything. Sorry to be the one to break the bad news to you.
You suggest to rebuild the lower shift box. That’s basically (not quite) doing what realigning the shifter box would do. Instead of correcting a potential incorrect linkage angle, you’re tightening the tolerance of the entire unit which will decrease the angle. And that is only true if the rebuilt box is installed properly aligned. The shifting assembly/transmission boils down to a large tolerance stakeup. The shift box alignment is one variable in a quite complex equation that translates into shift engagement.
Your buddy that had a backwards shift box makes no sense. There is no way it would bolt to the torque tube...the design is pokayoked. Unless you were referring to the upper shifter assembly. In that case, the design is centered so the pivot point of the shifter won’t change...
Take my .02 for what it’s worth, thanks for reading
Last edited by wscott62893; Mar 1, 2019 at 07:22 AM.
Josh... I've build multiple C5s from the chassis up... I know these cars. The OEM lower shift box bolt holes that mount it to the torque tube are slotted for a reason. If you were to bolt it up too far forward or back you may not have enough shifter throw to get it all the way in gear. Plus, C5s are getting old and the rubber bushings in the lower box get old and deteriorate. There's very little downside to replacing the lower shifter box on a C5 at this point. There's a guy who refurbishes OEM ones and they're a couple hundred bucks.
Here's my last C5 I built from scratch... but WTF do I know
Last edited by RapidC84B; Mar 1, 2019 at 09:36 AM.
His shifter popping out of gear is potentially caused by a shifter mis-aligned in the lower box?
You obviously discredited yourself!
Have you rebuilt any t-56 gearboxes from the ground up?
Do you know how what you said can’t be true the way the collar/gear setup works not to mention the ball detents within the transmission? Obviously not.
And aside from that, wrap your ignorant mind around what I said about a shifter being mounted BACKWARDS and the customer not knowing as it was shifting properly.
I am not going to blow up the OPs thread with a pissing match. It's okay Josh, you're right. I'm sure you won't ever provide incorrect information/misguidance with all the knowledge you have. I am the inferior human being
Best of luck to the OP in resolving his issue!
Last edited by wscott62893; Mar 1, 2019 at 10:45 AM.
So you suggest him pulling the trans (a ton of work on a C5/6/7) and digging into it vs. trying the easy stuff first? That's just silly. Plus, popping out of gear once in a while happens with these gearboxes. Had a '99 vert that did it once every few months when I didn't get it fully engaged in first at a light. Wasn't anything worth ripping the car apart over.
Again... if you had the shift shaft not perfectly in neutral and the gear shift not centered in neutral when you bolt it to the torque tube you can create a condition where the car won't go fully into gear. It's cheap to check the shifter box first and upgrading the lower box to a fresh unit is good practice on an aged C5.
Years ago there was a guy C4C5 specialist who ran his own Corvette Mechanic forum. He always recommended checking shifter alignment first before doing anything. It's just logical.
Oh and if you read the C7 forums a lot of people find the TR6070 pops out of 5th gear even when new. It's due to the softness of the OEM shifter and the torque capacity of the 6070 and just not getting it in gear. Most put a MGW in there which has a firmer engagement so you really know if you got it all the way in gear. It's not an internal trans failure... just the "nature of the beast" with a manual made to handle high torque.
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Notchy 1st and shifter not completely engaging
