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1960 Plymouth - A833 4 speed OD with hydraulic throwout bearing Jump to page : 1 Now viewing page 1 [50 messages per page] | View previous thread :: View next thread |
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jboymechanic |
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Expert Posts: 2196 Location: Muskego, WI | I have a 1960 Plymouth with the following drivetrain in it: 1966 Poly 318 1975 to 1980 F body bell housing 1978 to 1987 Dodge Truck A833 4 speed overdrive (aluminum case, cast iron extension housing), completely rebuilt by a professional Wilwood clutch MC # 260-10374 (7/8" bore x 1.125" stroke) American Powertrain hydraulic throwout bearing # CACH-30005HM I have only driven the car a few times as it sat for 30+ years, it just now has solid performing brakes so I'm now working on making it go. My issue is hard shifting, so I had my wife press the clutch pedal while I observed the clutch. The clutch isn't releasing fully; the throwout bearing isn't extending fully with the pedal to the floor (I have checked and re-checked that the clutch hydraulics are bled and air free). I am so close to having this thing being ready to drive, here are my questions: 1. I plan to update to a 1" bore x 1.125" stroke MC, Wilwood # 260-10375. This will up my fluid volume from 0.67 to 0.87 cubic inches, or about 30%. This will give me more throwout bearing stroke with the same amount clutch pedal movement, correct? I can prevent over-stroking by adjusting my clutch pedal down if a 30% increase is too much. 2. I currently have a borg-beck type clutch pressure plate (3 clutch levers), Brute Power # 503409 (see rockauto link below). Are there different types of pressure plates that have different levers that release more with less throwout bearing throw (so different lever ratios)? Do diaphragm type pressure plates offer more movement? I just picked a clutch kit that was the correct size and matched my transmission's original application. https://www.rockauto.com/en/parts/brute+power/perfection+clutch,9033... 3. Are there any alternatives to the American Powertrain hydraulic throwout bearing? Just the bearing and spacer is $450, which is outrageous. The A833 OD transmissions use the same throwout bearings as any other 23 input spline A833 4 speed, so I would think there would be more options. Any help is appreciated. | ||
jboymechanic |
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Expert Posts: 2196 Location: Muskego, WI | If it helps for question 3, the sleeve that the throwout bearing rides on is 1.250" diameter. | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | Increasing the bore/volume to get more travel is a good first step and should work BUT, have you asked the manufacturers the same questions? They should know their products. As an aside, did you look at and discard the idea of using oem parts? | ||
57chizler |
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Expert Posts: 3776 Location: NorCal | How much of the MC's 1 1/8" travel is being used by the pedal ratio? Is the leg pressure needed to depress the pedal tolerable? Increasing the MC diameter will probably solve your release problem but the leg pressure will increase also. If the current setup isn't using most of the MC's available travel, you might be able to retain the current MC by altering the pedal travel. | ||
jboymechanic |
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Expert Posts: 2196 Location: Muskego, WI | Wayfarer, I thought about using stock parts, but it too would have been a pretty ambitious research project as well. I would have to fab together the stock fork for the bell housing to the Z bar and linkage for a 1960 Plymouth. Having a hydraulic TO bearing and MC was seamed to be (at the time, any way) the quickest and cheapest way to convert to stick shift. I forgot to mention that my car was originally a 2 speed auto, so I would have had to source the original parts as well. | ||
jboymechanic |
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Expert Posts: 2196 Location: Muskego, WI | 57chizler, I'm not using 100% of the clutch pedal, I have the linkage placed on the pedal so it is in line with the mount of the clutch MC. The MC was placed in just about the only place I could and I'd hate to angle the push rod as I'd worry about longevity. So I have more mechanical advantage on the pedal as a result, so my pedal pushes pretty easy currently. | ||
LostDeere59 |
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Extreme Veteran Posts: 406 Location: Hilltown, PA | " 2. I currently have a borg-beck type clutch pressure plate (3 clutch levers), Brute Power # 503409 (see rockauto link below). Are there different types of pressure plates that have different levers that release more with less throwout bearing throw (so different lever ratios)? Do diaphragm type pressure plates offer more movement? I just picked a clutch kit that was the correct size and matched my transmission's original application. " If I recall correctly from my junior racer days the borg-beck style with the coils springs and fabricated levers is capable of generating higher clamping forces, especially at higher rpm, but as a result has a higher pedal effort. The Long style - identified by no visible coil springs and multiple "levers" in a fan around the center of the cover (this is actually the spring) has much lower pedal effort at the sacrifice of some clamping pressure. Unless you're running something that can out-torque your pressure plate, switching to the Long style will lighten the pedal effort - possibly enough (or more) to offset your increase in effort from changing the master cylinder size. It might take some looking to find a Long style pressure plate for a Mopar since they tended to favor the Borg-Beck from the factory. Gregg | ||
wayfarer |
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Elite Veteran Posts: 888 Location: Peoples Republic of Oregon | Pardon my confusion at this point. The clutch is shy of full release and you are not using all of the pedal travel...is the mc maxed out at this point in travel? If this is the hangup then get the larger mc. If there is still a little bit of mc available then adjust your pedal stop. Remember that you only need 'daylight' between the disc and the plate. Excess clearance is excess travel. Earlier, I was thinking in terms of the Jeep oem hydraulic t/o and associated parts which could have been bone-yard items. Skipping the hyd t/o bearing you could have also used a hyd slave. An oem fork should be the easy part. | ||
jboymechanic |
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Expert Posts: 2196 Location: Muskego, WI | Update. The 1" bore MC is now in the car. Pedal is still reasonable to push and I now have full release of the clutch. This have been confirmed visually, my wife pushing the pedal while I look at the flywheel, clutch disc and pressure plate under the car. Hope to test drive on Tuesday or Wednesday. I'd still love to know any more information about question 3 in my original post. Thanks. | ||
49pair |
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Member Posts: 26 | To answer question #3, as Wayfarer already said, you could put all stock linkage and pedal in. This would require some hunting for factory parts but they are out there. The other option is to adapt a hydraulic clutch assy. as used on many of the dodge trucks in the 60s. These used a standard throw out bearing and fork and the slave cylinder bolted onto the outside of the bellhousing. | ||
jboymechanic |
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Expert Posts: 2196 Location: Muskego, WI | Ah, didn't know about hydraulic setups from the 1960s Dodge Trucks. I've done some searching and dropping these links here for future reference if my hydraulic TO bearing doesn't hold up well. https://www.youtube.com/watch?v=IjlDyrahbKw http://www.bigblockdart.com/techpages/clutch.shtml http://www.sweptline.org/forums/viewtopic.php?t=36223 | ||
57burb |
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Expert Posts: 3967 Location: DFW, TX | jboymechanic - 2018-06-08 11:43 AM 57chizler, I'm not using 100% of the clutch pedal, I have the linkage placed on the pedal so it is in line with the mount of the clutch MC. The MC was placed in just about the only place I could and I'd hate to angle the push rod as I'd worry about longevity. So I have more mechanical advantage on the pedal as a result, so my pedal pushes pretty easy currently. The clutch pedal always swings in an arc, so that's why push rods are designed to articulate. From what you said in this post, it sounds like your issue may have been that you just didn't have enough "throw" of the push rod to actuate the master. Moving the push rod pivot location may have a) given you the additional push rod sweep to make your old master cylinder work, and b) made the clutch a little harder to push. It sounds like you achieved basically the same thing by increasing the bore diameter to move more fluid per stroke. Glad to hear this car is going to be on the road soon! | ||
jboymechanic |
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Expert Posts: 2196 Location: Muskego, WI | I put about 15 to 20 miles on the car last night, shifts smoothly into reverse and into all forward gears so I believe my clutch and TO bearing are all in working order and adjusted. I'm still having a hard time downshifting from 3rd to 2nd, so I'm guessing I have a synchronizer issue there. | ||
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