Clutch release problem

[Racngrn]

Hi all. Looking for some advice/knowledge. 1970 Dart 340. Basically stock with a833. Has a Macleod diaphragm 10.95 that was installed circa 2004 during restoration. Going down the road the car shifts smoothly and no odd noises. It occasionally is tough to engage 1st or 2nd and will often grind slightly into reverse. Better if I find 1st gear then go into reverse. I have free play at a bare minimum so I can engage gears at a stop. Probably around 1/4 to 1/2 at the pedal. Any more and it’s very hard to disengage the clutch. Clutch engagement is very smooth and grabs well. Pedal effort is moderate. I’m running Pennzoil synchromesh in the box. Happy with that.
I’ve read every thread I can find and many get pretty technical - beyond my abilities. That said, my general sense is that a couple issues may be at play. Failing pressure plate ( is that possible/likely??) or a failing pilot bearing. Given the age and unknown mileage/load on the clutch the past 20 years I’m inclined to install a new street clutch kit, but wondering if folks can give advice on how to evaluate the possibility of a pilot bearing failing? Really appreciate the help. Super nice Dart that runs great. Want to be sure I get things corrected to avoid bigger damage. Thanks

 

[jeff alder]

you would have to back the trans out to inspect the pilot bushing/bearing. You can visibly inspect the throw out bearing clutch and pressure plate.

 

[Inertia]

What is it you are trying to do?
A slight grind into reverse is not unusual, I find if I pull it into 2nd gear first, it seems to go into 1st and reverse more easily, it was explained to me that pulling into 2nd spins all the gears to help them engage. Might be bs, but it seems to work .
Try it.

Good luck.

 

[AJ/FormS]

You have several problems.
1) is insufficient plate departure.
2) Your disc is probably a little warped
3) Your blocker rings are NOT biting hard enough on the brake-cones, and
4) you may have the wrong pedal ratio, or "stiction" in the system.
5) your leg may be having difficulty over a certain range.

As for solutions;
IMO; I have no respect for synthetic synchromesh oil. But to get it all out, the Trans has to come apart, and be thoroughly washed out.
At that time, you can replace the failing blockers, tighten the strut springs, inspect the forks and external linkages, Address the dragging clutch, check the TO-bearing, install a BB pilot, and dial-indicate the BH, looking for parallelism and concentricity.
Finally, you need to get under the dash and verify that you have a V8 pedal ratio, and that nothing is binding, and if you have a Diaphragm PP, that the over-center spring has been removed.
As to freeplay, you can run as little as you like as long as the TO bearing stays off the fingers. and, make sure your clutch-fork, at rest, is as far towards the rad as is possible, and you can still get the rubber boot installed. If this is not the case, something is wrong. Most likely, the fork pedestal is wrong. and if it is, then the adjuster will be wrong too, or it has been modified, or the Z-bar is also wrong/modified. So, there's that, lol.
If your car was originally a six-cylinder manual trans, then more than likely, it still has the six-cylinder clutch pedal, which is gunna have to be either swapped out for a V8 one, or modified to the same ratio..

Going back to synthetic oil;
My opinion comes from my experience in trying to make it work, and taking the trans down FOUR times in two weeks to try and make it happen. The fourth time was just to wash it all out, one part atta time.
My conclusion was, that it was just too doggone slippery for used brass to grab even deglazed brake cones. I tried everything!
After I washed it out, I put my original cocktail of 50/50 dextron2 and 85/115 extreme pressure oils, back in, and then, the thing shifted like lightning, and no more waiting for the N>First shift, nor did I get more than an occasional noise on the N>Reverse shift.! I learned my lesson.
Others have other stories.

IMO, the A833 gears are pretty doggone heavy, and if you have a light oil in the box, those gears continue spinning for a long time. Add to that a slightly dragging disc, and not enough departure, and you can be waiting several seconds to claim reverse without grinding.
ATF will squeeze out of the Synchros the quickest.
140 wt Extreme Pressure lube will be the slowest.
Synthetic is somewhere in the middle, but offers superior cluster-pin protection to ATF.
I have been very happy with a 50/50 mix of
ATF and 85/115EP . the EP oil is for the clusterpin. I have run it down to 25% just to see if the brass could shift quicker, but on the street, could not tell any difference, so back to 50% I went.

Make sure your BH retainer opening is the correct size for the retainer on your trans, and before you take the trans down, make sure the z-bar is;
parallel to the ground and at very near to at 90* to the centerline of the car, that the fork is near the front of the opening in the BH, and, that the Z-bar is fixed in position on the frame end, by the horseshoe-wire locked in the nylon bushings.

 

[Infiniti Dave]

Sounds like you're being a little quick engaging gears while at rest and not giving the transmission gear train time to stop. Reverse especially common noise when engaging too quickly since it's not synchronized.

 

[Murray]

Reluctant to blame trans until I was certain that the linkage adjustment was correct.

 

[AJ/FormS]

What is it you are trying to do?
A slight grind into reverse is not unusual, I find if I pull it into 2nd gear first, it seems to go into 1st and reverse more easily, it was explained to me that pulling into 2nd spins all the gears to help them engage. Might be bs, but it seems to work .
Try it.

Good luck.

Atta a stop, the output shaft is stationary, together with the two synchronizer assemblies .
Engine idling, foot off the clutch, all the gears are spinning.
Clutch pushed in, the viscosity of the oil is the only thing that slows the spinning parts. until
you attempt a forward shift. At this time, the blocker ring brakes whatever gear you are trying to access, to match it to the speed of the Synchronizer assembly.
If the clutch is dragging on the flywheel/PP, this is nearly impossible and will result in grinding.
As for reverse, there is no synchronizer for it, and the operator has to wait for the cluster to stop spinning. The cluster is driven by the input gear, which is driven by the disc. So that cluster, no matter how thick the oil is, if the disc won't stop, it's gunna grind.
That cluster is on Needle-rollers, and all the other gears are spinning with it; sooooooo with thin oil or synthetic, it/they are in no mood to stop spinning. That disc HAS to not be dragging and/or departure has to be adequate to not let the spinning parts touch the disc.
A trick I use to catch first-gear quietly, is to grab it just before the car stops moving and while the synchronizers are still coming to a stop.
This only works in reverse, if the car is already rolling backwards.

 

[Racngrn]

Thanks guys. Not sure I understood much of the details above, but some. While I know that the trans itself could be a problem, my gut says it is more about clutch and or pilot bushing. I read that these pilot bushings are very durable and long lasting, so that's that, but also that they can contribute to difficulty in shifting into gears at standstill. Maybe I am wrong about that. As for a warped clutch disc, I do not have any vibrations whatsoever during engagement or driving down the road. Seems like a warped disc would create some chatter at engagement. Again, may be wrong about that too. The car is quite original and is an authentic H code 340 Swinger, so Z bar and other components are stock to the car. I did look carefully at the Z bar and the adjusting rod, fork and other components to make sure there is nothing unusual or out of alignment. All looks good from that perspective. An expert would find a problem that I would not see however. As for fluid, I read lots of threads on fluid and see pretty much a split between GL-4 Stalube and the Penzoil Synchromesh gear oil ( which is not synthetic, but measurably thinner than the GL-4 for certian. Sounds like I should try taking a bit of time ahead of reverse shifts and see if that helps. If the trans needs a rebuild sooner than later, that is not horrible, but was hoping to get some use ahead of that day I know there are a number of sources for rebuild and I've gone that route before in my Buick days. I'll plan to get a Macleod Street Clutch kit and a new pilot bushing and start with that to at least eliminate those issues and know exacly what I have in there as a good start to owning this car. Lots of paperwork with the car dating back over 20 years, so that is great but prefer to know precisely what is in there and it's condition. Really appreciate your help with this.
One last question, is a bushing preferred or do most go with a bearing when its time to change it out? I would say quality bushing , but interested in what others have to say. Many thanks.

 

[Kendog 170]

It's been a while but make sure your shifter is adjusted properly by sticking a 1/4" pin thru it and adjust your shift rods. Make sure your bushing aren't worn as well. I thought I raed that if reverse wasn't adjusted right it could cause issues but not sure on that. This you can check without removing.
How To Install A Hurst Shifter Linkage To Your Mopar - Shifter Shakedown

 

[AJ/FormS]

Since my first Mopar 4 speed in 1970, to the last, and nearly 55 years in between of driving, maintaining, and rebuilding them, I have never witnessed a pilot bushing problem. I guess you could be the first............

A warped disc does not vibrate.
I warped disc just drags on the pressure rings and fails to release cleanly. These I have seen plenty of .
And, if you slip them out all grandpa-like, you might feel some "judder". I mean, some people might call that a vibration upon engagement....... I suppose.
But, judder is usually caused by a warped PP or Flywheel, usually both. We call it warped but really it's just worn badly with hot/blu spots the that grab differently than the regular surfaces. You can install a brand new disc on that, and it will still judder.

 

[Racngrn]

Thanks very much. Warped disc sounds plausible given that. I’m working on finding a street clutch kit that should help. I believe the current Macleod is more of a street/strip set up which probably contributes to the heavier pedal feel. Really appreciate this feedback.

 

[Dave999]

occasionally having to go to first then into reverse, is a feature of many types of manual boxes from new. depends what you were doing before you decided to go for reverse. counter shaft momentum still spinning all unengaged gears on the main shaft after you pop it out of the gear it was in, with the clutch down. Reverse is gonna be hard to find putting it in first stops everything moving i.e you used 1st gear synchro to achieve a steady state so that reverse can be selected without bashing another chunk out of the leading edge of one of its teeth.... again they all do that to some extent.

otherwise it sounds like a synchro problem could be related to your chosen lube or ware.
provided the clutch does actually disengage.

the only other problem i can think of if all else is good, is that you have run with a little too much bellhousing run out for the life of the car in its current state. a mis alignment between crank centre and input shaft centre means the main shaft, supported only by the yoke bushing, rear bearing, and the pocket and rollers in the back end of the input shaft is mis aligned and not perpendicular to the flywheel.
If the input is sitting a little squinty you have cantilevered the front end of the main shaft slightly in 1 direction away from the centre of the input shaft bearing, This will eventually have an impact on your synchros engagement teeth and the ware on the gears.
this is the "2 identical cars one shifts great and one doesn't" scenario

we are talking radial run out and how flat the bellhousing face, trans face and motor mounting flange face are 2 checks to do
an off centre problem or a transmission not perpendicular to the flywheel face, problem.

a roller spigot bearing is less forgiving in this situation than a bush in the end of the crank...
basically if you take the trans out use it as an opportunity to check the runout and squareness of the bellhousing.

its the kind of problem that impacts someone running original bell and transmission that were aligned by the factory, on a motor that has been align bored. the crank now sits higher in the motor than it ever did on day 1= misaligned with the trans.

again just a guess possibly bullsheedo....as with any suggestion i make here, its based on limited in-shed hobby-est fiddling with a couple of 4 speeds a t5 and bits of VW van and bug over the last 30 years i have no qualifications other than skinned knuckles

but worth a check if the transmission comes out. start with how much waggle does your transmission input shaft have? how worn is that input bearing, it plays a part in aligning what goes on behind, they should last 100 000 +miles with proper servicing in a street driven car....

Dave

 

[Racngrn]

Thanks Dave. Makes sense and I’ll add that to the diagnosis sheet for the clutch work. Lots to check when it’s apart. Steve