833 Transmission won't disengage at stop after 100 miles.

[Duggie]

I've rambled about this issue lightly elsewhere, and finally had the chance to take it all apart today for a look.

'64 Dart /6. converted from an auto to 4 spd by someone else. I rebuilt the transmission, new clutch, throw out bearing, and surfaced the flywheel. The Z bar doesn't look right compared to one I saw on a '64 Dart at Layson's today.

My Z bar hits the exhaust and angles toward the throw out bearing arm at the bellhousing;

The /6 Dart's Z bar at Layson's is closer to the bellhousing and looks like a straight back movement to the throw out arm (and just looks different). Both Z bar arms look to be the same length. Something is funky here, but the transmission disengaged okay with the old, oil soaked clutch.

The clutch / tranny was functioning well at the beginning of the 2,800 mile road trip. About 500 miles into the trip (about the end of the second day), the transmission started to not completely disengage to the point where I had to turn the motor off to get it into 1st or reverse when at a full stop.

Then the throw out bearing started to scream when cold. Two shops along our trip fiddled with the clutch linkage. It shifted better cold, but after 100 or so miles into each day (1st pee stop), it wouldn't go into 1st when stopped unless I shut the motor off. We made 2,000 miles out of the 2,800 in the Dart, and the middle 800 miles in a rental car while a shop fiddled with the linkage.

Got to take it all apart today. I was told the transmission input shaft could be heating up in the pilot bushing and causing the shaft to bind - continue to spin when the clutch is depressed. I really can't recall what the nose of the input shaft looked like when I reassembled the car. The Factory Service Manual said to put the grease into the pilot bushing opening. I did not lube the nose of the pilot shaft on assembly.

Does this look like heat bluing or just crud?

I was also told the fingers on the pressure plate may not be even or warped, causing release issues when hot. There is a groove cut into one pressure plate finger, a good scuff on finger #2, and barely any mark on the third finger.

What's up with that?

And the throw out bearing threw grease everywhere so my shiny clutch, and resurfaced flywheel now looks like this.

Brewer's sent me a replacement throw out bearing before I took it apart (good people!). I'd love to learn from you all's experience what you think before I talk to Brewer's next week in case I should be looking at or measuring other parts.

And while this is getting sorted out, I'm disassembling the Hurst shifter on Canyon Carver's recommendation, for a good scrubbing and lube. The little woman asked me how hard it would be to turn it back into an automatic. I said for me, HARD!!

Thanks in advance for the help, you guys. I wouldn't be able to keep this little cutie running without you!!

 

[rustycowll69]

I'm confused you have pictures of two different "z-bars"? which one is yours?
One of them looks modified with an extra strap. I'm guessing somebody modified it. If you have a heavier than stock clutch, that isn't necessarily a bad thing, because I've peeled that arm off of the cross-tube a couple of times, but perhaps someone clocked the arms incorrectly so you're not getting enough travel out of the bellcrank (z-bar)

 

[67Dart273]

That is one of those damned "scalloped" pressure plates, which is supposed to allow an oversized disk in a "too small" cover. The 440-6 70 RR I had used one. 10 1/2" pattern cover, scalloped PP and 10.9" (depending on what you read) disk. Mine, I believe, was slightly misaligned bell. In any case I had a lot of problems with the thing releasing "clean." With use, the disk generates "fuzz" on the outer rim of the disk from normal wear. This evidently catches on the scallops and prevents a "clean" release.

Not sure if this is your trouble, but keep it in mind. You might consider tossing the next smaller diameter disk in there.

What size is that disk?

 

[Duggie]

I'm confused you have pictures of two different "z-bars"? which one is yours?
One of them looks modified with an extra strap. I'm guessing somebody modified it. If you have a heavier than stock clutch, that isn't necessarily a bad thing, because I've peeled that arm off of the cross-tube a couple of times, but perhaps someone clocked the arms incorrectly so you're not getting enough travel out of the bellcrank (z-bar)

My Z bar is the top pic, hitting the exhaust pipe. The comparison one is the 2nd pic with the rod closer to the bellhousing.

I looked at my Z bar, and only one end has holes for a retention clip. The FSM shows the clip end of the Z bar towards the firewall.

 

[rustycowll69]

ok, you need to check the disk, first. you need spin it between centers to make sure the hub is not bent and the disk runs true. The disks can be bent by someone installing the trans, and allowing the trans to "hang" on the splines before it is fully seated in the BH counterbore. Then bolt the pressure plate and disk back onto the flywheel and check that the fingers are even. I don't know what the tolerances are, offhand, but I would guess you wouldn't want more than 0.015" or 0.020" difference on the finger height. One of the fingers has been damaged, so you might want to fix that beforehand.
If that's your car, the 64 dart gt vert, please don't give up on the 4spd. The sl/6 is SO much more fun with a 4spd.

 

[Duggie]

That is one of those damned "scalloped" pressure plates, which is supposed to allow an oversized disk in a "too small" cover. The 440-6 70 RR I had used one. 10 1/2" pattern cover, scalloped PP and 10.9" (depending on what you read) disk. Mine, I believe, was slightly misaligned bell. In any case I had a lot of problems with the thing releasing "clean." With use, the disk generates "fuzz" on the outer rim of the disk from normal wear. This evidently catches on the scallops and prevents a "clean" release.

Not sure if this is your trouble, but keep it in mind. You might consider tossing the next smaller diameter disk in there.

What size is that disk?

This one has a 10" outside diameter. Those finger rub marks are strange to me.

 

[toolmanmike]

My first thought was adjustment. I always adjust mine by removing the inspection cover and adjusting the air gap between the throw out beating and the pressure plate fingers. If you have 1/8"-3/16" gap after cycling the pedal a few times, the clutch will operate properly with no issues. If you have marks on the fingers, the bearing has been riding on the fingers followed with a noisy bearing. It has failed and is not designed to constantly ride the fingers. If it oes, it is partially disengaging the clutch (which is why it got worse with more miles and more heat. You might want to start with a fresh clutch, surface the flywheel and adjust it properly from the start.

 

[Duggie]

My first thought was adjustment. I always adjust mine by removing the inspection cover and adjusting the air gap between the throw out beating and the pressure plate fingers. If you have 1/8"-3/16" gap after cycling the pedal a few times, the clutch will operate properly with no issues. If you have marks on the fingers, the bearing has been riding on the fingers followed with a noisy bearing. It has failed and is not designed to constantly ride the fingers. If it oes, it is partially disengaging the clutch (which is why it got worse with more miles and more heat. You might want to start with a fresh clutch, surface the flywheel and adjust it properly from the start.

Awh crap. I was afraid the grooves were from the shops adjusting the clutch too tight. Why do you think the groves are uneven? I started with 5/16" free play at the TO arm, per the FSM. Do you think the input shaft binding was the start?

 

[moparmat2000]

The input shaft looks like it got hot. I had an issue like your mentioned with a needle bearing cup input shaft bearing on my pickup. Truck would not go in first or reverse when the engine was idling because the input shaft was bound up on the input shaft bearing in the crank and when the clutch disc was disengaged the shaft kept turning with the crank.

I'd clean and polish that input shaft with a very fine sandpaper or crocus cloth to make it very smooth and polished up. Grease up that input shaft bushing. Do not use a lot of grease. Since it can spray out and foul up the disc. Bolt it back in and try it again.

As far as the Z bar goes. Probably find the one that fits correctly and install it. For such short miles on a relatively new clutch, that's certainly a lot of wear and heat checking on it. Do you drive it with a heavy foot on the clutch?

 

[Daves69]

New PP time.

From the picture, what I see on the worn PP finger (unless it's an optical conclusion) it appears twisted or off center.
Does the working face look centered in the cover housing?

 

[AJ/FormS]

The flattest side of the disc should be marked "flywheel side". In your pic,above, it sorta looks backwards.
Here are some guidelines;
Your Z-bar should run parallel to the road, and at 90* to the centerline of the car in plan-view. The outboard end should be secured with the big wire horse-shoe clip,going into the nylon bushings to keep the downrod in about the center of the firewall window, transversely.You can shift the Z-bar laterally by shimming the outboard anchor.
The inboard Z-bar pivot bracket must be secured to the BH with TWO bolts. If the pivot ends up in the wrong place, then; either it is wrong, or the engine is not in the right place,or the BH is wrong for the application.
With these two in their correct positions, the inboard lever should be swinging front to back,parallel to the centerline of the vehicle.

The correctly installed TO fork should be about centered vertically in the BH window, and should be very near the front of the window. The part of the TO fork where the adjuster-rod fits should be about parallel to the Z-bar, ie not bent backwards or forwards. It can be slightly biased forward.There should an "anti-rattle" spring pulling the TO fork back to the front of the window, to retract the TO bearing OFF the clutch fingers. The To bearing must not spin full-time, it will wear out prematurely.
From here, the installed adjuster rod should again be parallel to the centerline of the vehicle in plan-view, and about parallel to the road in side-view.
Some tips;
The "freeplay" at the pedal, should be about 1/2 inch, to achieve a minimum .080 clutch departure. The freeplay could be less, so long as adequate departure is achieved, and the TO bearing stays OFF the fingers. Also; you do not have to push the pedal to the floor! You only need to push as far as it takes to either: pull a clean shift, and/or put it into gear at a stop. see note 1
The over-center spring up under the dash, should park the clutch pedal with a nice "thunk" up on it's stopper.
If the clutch seems hard to push or modulate,with the over-center assist spring installed, your pedal ratio may be wrong.
The engine mounts need to keep the engine in place laterally and the trans mount needs to keep it all in place longitudinally.

Brewers has several combinations of parts that you can select from to help you achieve these guidelines.

Note 1
If the engine originally came with an automatic;
the crank hole may not have been finish-sized for a pilot bushing. If so, then it takes a DIFFERENT pilot bushing, from a standard transmission crank, to provide the necessary bushing to input gear clearance.
That bronze bushing is porous and needs very little grease to operate. New, they come impregnated with lube. I put some hi-temp grease into the crank, and just smear the bushing, and none on the input. If you put grease on the input, installing the trans will push it up towards the splines, and as soon as you drive away, it will fling off, and end up in all the wrong places. The idea is that whenever the grease in the cavity warms up it will be forced outwards by centrifugal force and flow into the pores of the bushing. A thin regular-temp grease will get runny, come all the way thru, and as before, be flung into all the wrong places. But if the wrong bushing was installed, the clearance will be too tight, the grease will not find it's way into the pores/clearance, and whatever grease was in there will cook out, and the bushing will tighten up on the input gear,perhaps even giving metal to it, as yours seems to have done.
Some guys have crudely resized the outside diameter of the wrong bushing and managed to force it into the crank, with predictable results.
You need a new, correct for your crank,bushing. Remove the current one and measure the bored crank-hole. Then order the correct bushing for the hole-size. Then throw the current one out; it is no good; it is too tight,is dried out, and has suffered too much metal-transfer.

Note 2
Check to see if your finger heights are all the same. If they are not; then you will have modulation issues, by way of uneven clutch-departure. Also check to see that you have the correct TO bearing diameter, so that it sits at the right place on the fingers, throughout it's travel.
Happy HotRodding

 

[Duggie]

The input shaft looks like it got hot. I had an issue like your mentioned with a needle bearing cup input shaft bearing on my pickup. Truck would not go in first or reverse when the engine was idling.

I'd clean and polish that input shaft with a very fine sandpaper as per or crocus cloth to make it very smooth and polished up. Grease up that input shaft bushing. Do not use a lot of grease. Since it can spray out and foul up the disc. Bolt it back in and try it again.

As far as the Z bar goes. Probably find the one that fits correctly and install it. For such short miles on a relatively new clutch, that's certainly a lot of wear and heat checking on it. Do you drive it with a heavy foot on the clutch?

I did stand on the clutch with the trans in 1st gear at signal lights while driving through small towns and the bunched traffic into / out of the Golden Gate Bridge. The rear end that came with the car has 2:45 gears, rumored to be out of a '72 or newer B Body. The engine turns at about 2K RPM at 65 MPH, and any uphill start takes a little more clutch work than I'm used to.

And I think the Z bar search is on!

 

[Duggie]

View attachment 1715623053
The flattest side of the disc should be marked "flywheel side". In your pic,above, it sorta looks backwards.

I just laid it down for the pic.

Here are some guidelines;
Your Z-bar should run parallel to the road, and at 90* to the centerline of the car in plan-view. The outboard end should be secured with the big wire horse-shoe clip,going into the nylon bushings to keep the downrod in about the center of the firewall window, transversely.You can shift the Z-bar laterally by shimming the outboard anchor.

I was laying awake last night, thinking about if I could shim the Z bar towards the BH, and how far I could shim it before the rod going through the firewall would bind.

The inboard Z-bar pivot bracket must be secured to the BH with TWO bolts. If the pivot ends up in the wrong place, then; either it is wrong, or the engine is not in the right place,or the BH is wrong for the application.
With these two in their correct positions, the inboard lever should be swinging front to back,parallel to the centerline of the vehicle.

I think it would be on CL if I can shim the Z bar over. The two comparison Z bar pics above show the "other" Z bar overlapping the BH ball stud by a lot more than mine.

The correctly installed TO fork should be about centered vertically in the BH window, and should be very near the front of the window. The part of the TO fork where the adjuster-rod fits should be about parallel to the Z-bar, ie not bent backwards or forwards. It can be slightly biased forward.There should an "anti-rattle" spring pulling the TO fork back to the front of the window, to retract the TO bearing OFF the clutch fingers. The To bearing must not spin full-time, it will wear out prematurely.
From here, the installed adjuster rod should again be parallel to the centerline of the vehicle in plan-view, and about parallel to the road in side-view.

I'll look far this on reassembly. Thanks!

Some tips;
The "freeplay" at the pedal, should be about 1/2 inch, to achieve a minimum .080 clutch departure. The freeplay could be less, so long as adequate departure is achieved, and the TO bearing stays OFF the fingers. Also; you do not have to push the pedal to the floor! You only need to push as far as it takes to either: pull a clean shift, and/or put it into gear at a stop. see note 1
The over-center spring up under the dash, should park the clutch pedal with a nice "thunk" up on it's stopper.
If the clutch seems hard to push or modulate,with the over-center assist spring installed, your pedal ratio may be wrong.
The engine mounts need to keep the engine in place laterally and the trans mount needs to keep it all in place longitudinally.

Brewers has several combinations of parts that you can select from to help you achieve these guidelines.

Note 1
If the engine originally came with an automatic;
the crank hole may not have been finish-sized for a pilot bushing. If so, then it takes a DIFFERENT pilot bushing, from a standard transmission crank, to provide the necessary bushing to input gear clearance.
That bronze bushing is porous and needs very little grease to operate. New, they come impregnated with lube. I put some hi-temp grease into the crank, and just smear the bushing, and none on the input. If you put grease on the input, installing the trans will push it up towards the splines, and as soon as you drive away, it will fling off, and end up in all the wrong places. The idea is that whenever the grease in the cavity warms up it will be forced outwards by centrifugal force and flow into the pores of the bushing. A thin regular-temp grease will get runny, come all the way thru, and as before, be flung into all the wrong places. But if the wrong bushing was installed, the clearance will be too tight, the grease will not find it's way into the pores/clearance, and whatever grease was in there will cook out, and the bushing will tighten up on the input gear,perhaps even giving metal to it, as yours seems to have done.
Some guys have crudely resized the outside diameter of the wrong bushing and managed to force it into the crank, with predictable results.
You need a new, correct for your crank,bushing. Remove the current one and measure the bored crank-hole. Then order the correct bushing for the hole-size. Then throw the current one out; it is no good; it is too tight,is dried out, and has suffered too much metal-transfer.

I'm removing the old bushing and measuring the crank hole today in prep for my Monday AM call to Brewer's.

Note 2
Check to see if your finger heights are all the same. If they are not; then you will have modulation issues, by way of uneven clutch-departure. Also check to see that you have the correct TO bearing diameter, so that it sits at the right place on the fingers, throughout it's travel.

I'm assuming the finger height should be measured with the PP torqued down to the flywheel, and the shaft of my dial calipers will be touching the friction plate. Is there an acceptable variance for proper clutch operation?

Happy HotRodding

(I made comments inside the quote.)You've got a gift in being able to articulate this information, AJ. Thank you so much for taking the time to detail so many variables. I'm humbled. On a different note; If you ever have the opportunity to make a video of your back cutting of synchro teeth, you would be educating the wanna be's for years to come.

 

[AJ/FormS]

I'm assuming the finger height should be measured with the PP torqued down to the flywheel, and the shaft of my dial calipers will be touching the friction plate. Is there an acceptable variance for proper clutch operation?

No, just to see how close it is, you can do this on any flat surface . But I don't think you will be able to use a caliper, as the fingers have a curved surface. You can hunt up a deep socket and a crosspiece with a couple of shims and that will get you close.
Alternatively, I guess you could float a flat disc over the fingers and caliper it, adjacent to the fingers. If you you do it as I imagine it,lol, that will get you real close.

 

[rustycowll69]

I did stand on the clutch with the trans in 1st gear at signal lights while driving through small towns and the bunched traffic into / out of the Golden Gate Bridge. The rear end that came with the car has 2:45 gears, rumored to be out of a '72 or newer B Body. The engine turns at about 2K RPM at 65 MPH, and any uphill start takes a little more clutch work than I'm used to.

And I think the Z bar search is on!

What 833 do you have? You probably could use a 3.09 first gear 4spd. they came in 64-66 sl/6 4spds, and I think some if not all overdrive 4spds. I would also suggest a 3.23 or maybe a 3.55 rear gear. That will help a lot in traffic and hills.

 

[rustycowll69]

No, just to see how close it is, you can do this on any flat surface . But I don't think you will be able to use a caliper, as the fingers have a curved surface. You can hunt up a deep socket and a crosspiece with a couple of shims and that will get you close.
Alternatively, I guess you could float a flat disc over the fingers and caliper it, adjacent to the fingers. If you you do it as I imagine it,lol, that will get you real close.

you could probably measure it in-car with a magnetic base and a dial indicator set up, and rotating the crank with the spark plugs out. Or you could pull the flywheel, assemble clutch flywheel, and PP and set it on a flat surface plate, and measure it with a height gauge setup.

 

[rustycowll69]

I guess you could also buy some keystock at HoDePo at approximately the thickness of your clutch disc, 1/4", 5/16", 3/8", whatever it is. Space 3 or 6 of those evenly around the flywheel clutch surface, bolt the assembly together and then you could probably use your dial calipers to measure the finger height directly from the FW friction surface good enough.

 

[Duggie]

No, just to see how close it is, you can do this on any flat surface . But I don't think you will be able to use a caliper, as the fingers have a curved surface. You can hunt up a deep socket and a crosspiece with a couple of shims and that will get you close.
Alternatively, I guess you could float a flat disc over the fingers and caliper it, adjacent to the fingers. If you you do it as I imagine it,lol, that will get you real close.

Probably won't surprise anyone. The finger with the deepest groove is as much taller (0.020") than the other two as the groove is worn deep.

You need a new, correct for your crank,bushing. Remove the current one and measure the bored crank-hole. Then order the correct bushing for the hole-size. Then throw the current one out; it is no good; it is too tight,is dried out, and has suffered too much metal-transfer.

A buddy told me to remove the old bushing by "just" filling the bushing cavity with grease, and then placing a 3/4" brass drift in the filled cavity, and hitting it with a hammer. Bushing didn't budge on the first try, and I'm not very comfortable putting a side load on the main bearings by pounding on the end of the crankshaft with a BFH. Maybe I can get in there with a hacksaw blade, and cold chisel out the cut through parts.

Not sure how to measure the bushing opening in the end of the crankshaft. It doesn't look like my dial caliper tips will reach in there, and I don't think my neighbor's dial indicator has an attachment that goes that small. I may need better equipped neighbors!

 

[Duggie]

What 833 do you have? You probably could use a 3.09 first gear 4spd. they came in 64-66 sl/6 4spds, and I think some if not all overdrive 4spds. I would also suggest a 3.23 or maybe a 3.55 rear gear. That will help a lot in traffic and hills.

When I overhauled the transmission, I remember the casting numbers and gear teeth matching a 1964 - 4 spd, and the side - shifter plate being the latter model, reinforced plate with '64 era shifter forks.

At some point, I'd like to entertain different rear end gears. For now, I appreciate the 1st gear synchro when turning corners in town and will settle with shifting into 3rd when I approach a hill under 60 MPH. With my foot in it, 2nd to 3rd can be at 55 MPH.

 

[rustycowll69]

Probably won't surprise anyone. The finger with the deepest groove is as much taller (0.020") than the other two as the groove is worn deep.


A buddy told me to remove the old bushing by "just" filling the bushing cavity with grease, and then placing a 3/4" brass drift in the filled cavity, and hitting it with a hammer. Bushing didn't budge on the first try, and I'm not very comfortable putting a side load on the main bearings by pounding on the end of the crankshaft with a BFH. Maybe I can get in there with a hacksaw blade, and cold chisel out the cut through parts.

Not sure how to measure the bushing opening in the end of the crankshaft. It doesn't look like my dial caliper tips will reach in there, and I don't think my neighbor's dial indicator has an attachment that goes that small. I may need better equipped neighbors!

a slide hammer with a "finger" attachment would probably work. It's been decades since I pulled one, but I think that's what I've used, long ago.

 

[Daves69]

....Not sure how to measure the bushing opening in the end of the crankshaft....

Nothing 3/4" diameter and a feeler gauge?

 

[Duggie]

Not sure how to measure the bushing opening in the end of the crankshaft.

Found it!
https://www.harborfreight.com/6-piece-telescoping-gauge-set-5649.html

 

[1965barr]

Hi this is the right tool for pulling the bearing out and check to make sure the input shaft is square to the crank you can get offset dowels from Brewers hope this helps my Dad was a mechanic and bodyman and left me 7 big tool cabinets of tools and lucky he was a mopar guy all his life.

 

[yellow rose]

When I overhauled the transmission, I remember the casting numbers and gear teeth matching a 1964 - 4 spd, and the side - shifter plate being the latter model, reinforced plate with '64 era shifter forks.

At some point, I'd like to entertain different rear end gears. For now, I appreciate the 1st gear synchro when turning corners in town and will settle with shifting into 3rd when I approach a hill under 60 MPH. With my foot in it, 2nd to 3rd can be at 55 MPH.

You have a 3.09 first gear 4 speed.

You can’t check finger height without bolting down the pressure plate.

The input got hot. Either the pilot bushing is too tight or the bell housing needs to be indicated in.

Did you install the disc backwards? As mentioned above, the thick part goes towards the transmission. Or the thin part against the flywheel. Whatever way you want to look at it. The disc will go in either way.

You can use the grease method to get that pilot bushing out. Whatever you use to beat on has to be a pretty tight fit. And, you have to load it up with grease. It takes a BUNCH of grease. You may even get the bushing out part way and need to *** some grease.

Some guys use wet bread and smash it in there. That may be easier to clean up than grease. Either one will work.

 

[RustyRatRod]

The pressure plate is very obviously engaging crooked. With heavy wear on only one of the three arms, that's pretty obvious. Either the pressure plate cover is bent, or the pressure plate arms are not equidistant heights off the flywheel with the pressure plate bolted down. You should measure the distance from the flywheel to the arm ends where the throw out bearing makes contact. I believe you will find some discrepancy and that could also be the problem of not disengaging the clutch enough. From the pictures you've posted so far, that's my only explanation.