318 poly wide block

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megan95

megan95

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I need some advise, I recently bought a 1965 dodge s400 (it's a school bus) with a 318 poly engine. I need to replace the clutch. The only clutch I can find is for a 318 la engine. I need to know if the transmissions were the same or at least similar enough for the clutch to work. From my understanding there are a couple of different transmission that the 318 poly could have. I can't say I know which one I have, I know it's a 4 speed. But there is so much old grease on it I can't find any numbers. I am hoping someone can educate me on this a bit better. I've been searching forums but most people talking about the differences in engines don't talk about the transmissions.
 
Please don't call these a "wide block." If you stripped one of these down to the block, and set it next to an LA, you would have to take a "second look" to see the difference. "Poly?" Just fine

These are properly called an "A" block (vs B block for the big block and RB for "raised block"). The "LA" gets it's name because it's a "light" A block

So far as clutches, Any Borg and Beck, whether Poncho, Chev, Dodge, or "something else" has the same flywheel pattern in a given size/ configuration.

The clutch disc must fit the transmission spline, AKA Ford gearbox in a Bronco mated to Chev SB, use appropriate Ford clutch disk

In something that big, "heavy truck" I doubt it's a 23 spline transmission. If you cannot find a listing you are in the wrong parts store or talking to the wrong parts "person." If you are in "any kind" of city look for a "clutch and brake" rebuilder

You could also put a diaphragm clutch in there, but these are generally not thought of as "heavy truck" pressure plates.
 
Alright I won't call it a wide block that's what someone on another forum had informed me that it was. Are you still saying that the clutch for the 318 LA will work? all the clutch says is that it's for a chrysler 318,340,360, and 383
And from my understanding the motor I have is not one of these engines because those are LA models

Okay so new question this is the main reason I have put off ordering the clutch. Take into account I am in no way a mechanic I am only 21 years old and I'm trying to figure all of this **** out. I do not know all the proper terms. But I have replaced the master cylinder and slave cylinder for the clutch, I also had to build a new pedalrod but now I have barely a 1/4 inch of play with the pedal I understand it is supposed to be very hard to press but it will not go any further and it's at least 6 inches from the floor. And the fork is what I think it's called what ever comes out of the slave cylinder and pushes on the plate (I think is what it pushes on at least) is also only moving that much. I really don't know at this point if I actually need a new clutch or if things just need to be adjusted. Does anyone have any input on this matter?
 
On the clutch, no, sorry. If you could get pictures ..... where's @RustyRatRod ??
He would probably know this!

The older A engine is sometimes called wide block because of the Mirage created by the style cylinder head & the odd look of the intake manifold.

I did a major posting on this years ago in someone's thread. I had the two blocks side by side.

If you weren't a MoPar guy into playing with blocks or at least slick enough to catch the small details you would not know the difference between them. It would take a close look.
 
I think I may have read a bit of that post but I really don't know enough about motors and I'm soley going off of what others have told me. Here's a pic of my motor I can take a better one tomorrow if this is not sufficient.
I also have videos of the clutch pedal movement and the slave cylinder. That I could post links to if that helps at all.
20170620_181714.jpg


20170620_181714.jpg
 
Oh yea! Old style "A" engine! There be a "Poly" pictured there!

Yea man! A picture and/or a video would be ace! I know there is a few fellas here that would know. Myself, I'm not so sure of what it all looks like and works at this moment.
 



Okay here it is for anyone who can help.
Some more info on the bus it starts no problem, the guy I bought it from power shifted from Reno nevada to placerville california roughly 150 miles to bring me the bus.
The problem is I do not want to drive it that way. I need the clutch to be working properly. The guy said he thought the clutch just needed to be bled but I ended up replacing the master cylinder and slave cylinder because the MC he put on there was no where near the correct on and the slave was completely shot. He also for what ever reason replaced the the clutch push rod and it was to short and I had to put one together to make it long enough and to go in straight. I had someone come bleed the system and so that is all fine idk if the push rod is still not the right length or if something else is going on that just needs to be adjusted. I'm hoping it's not that I need a whole new clutch but I can't figure out what it could be.
 
thing that big, "heavy truck" I doubt it's a 23 spline transmission. If you cannot find a listing you are in the wrong parts store or talking to the wrong parts "person." If you are in "any kind" of city look for a "clutch and brake" rebuilder


I did not see this part. But I can try and do that. I dont live in a city but i can get to one fairly quick. I'm just not sure if I actually even need to replace the clutch. It's not like it's slipping or anything honestly I'm hoping it's just adjustments but I wanted to find a replacement just incase.
 
If its a 4 speed and it is original equipment it should be an NP420. These had a 10 spline input shaft. You wont have any luck at the parts store for the clutch disk. I bought one at a place called "HR Clutch" for my powerwagon. If your bus has an 11" clutch like my truck then the standard pressure plate from a later model truck will work, but that thing might have a bigger one.
 
"318 Wide Block " may be incorrect terminology, but thats what I have always heard people call them, that and "318 Big Block".
 
megan95 said:
Are you still saying that the clutch for the 318 LA will work?
Click to expand...

I would bet money the clutch driven disc normally called "the disc" IS NOT the common "car/ light truck" 23 spline. That means the pressure plate might work but the disk will not

megan95 said:
But I have replaced the master cylinder and slave cylinder for the clutch, I also had to build a new pedalrod but now I have barely a 1/4 inch of play with the pedal I understand it is supposed to be very hard to press but it will not go any further and it's at least 6 inches from the floor. And the fork is what I think it's called what ever comes out of the slave cylinder and pushes on the plate (I think is what it pushes on at least) is also only moving that much. I really don't know at this point if I actually need a new clutch or if things just need to be adjusted. Does anyone have any input on this matter?
Click to expand...

You lost me. How far does the slave/ pushrod/ clutch fork move when the pedal is depressed?

Does it have a fairly "solid" feed at the pedal when depressed? It may need to be bled

You are doing fine. I do realize that "wide block" is a common term. That doesn't make it correct and I do wish people would stop insisting on it. You are not "guilty" here LOL
 
67Dart273 said:
I would bet money the clutch driven disc normally called "the disc" IS NOT the common "car/ light truck" 23 spline. That means the pressure plate might work but the disk will not



You lost me. How far does the slave/ pushrod/ clutch fork move when the pedal is depressed?

Does it have a fairly "solid" feed at the pedal when depressed? It may need to be bled

You are doing fine. I do realize that "wide block" is a common term. That doesn't make it correct and I do wish people would stop insisting on it. You are not "guilty" here LOL
Click to expand...
It only move's about 1/4 of an inch I posted videos. The pedal still has at least 6 inches before the floor it won't go any further.
 
What kind of power do those Poly 318's make? Are they like the Ford 351-400M's big CI numbers, but small power output?
 
OK are you saying when you "give up" on depressing the pedal you can only get it down so far, and there's 6" left between the pedal and floor?

Some generalities:

IF the above is true certainly is not right. Start by opening a bleeder and see if the pedal goes on down freely. This will tell you if there is a mechanical bind problem in the master/ pedal/ mount/ pushrod setup

If that allows the pedal to depress fully, then:

1.....Slave/ master might be so mismatched that slave is running out of travel

2....Might be clutch fork/ throwout bearing is bent/ broken/ off the fork pivot/ pivot broke, etc

3...Does not appear to me that slave is moving far enough. You might have a situation IE example "junk" rust in the slave or NOT ENOUGH travel in the slave to start with, the slave might be "part way" extended when you THINK it is all the way retracted.

Only way I know to approach that is to:

Remove slave, measure bore, try to find out what size bore the truck CAME with (if this is original type master)

Take slave apart make sure it's clean and that piston has full travel of slave bore.

Try to get flashlight/ mirror/ camera/ etc and wiggle the fork around and inspect. Try to determine if fork pivot is loose / broken or even present and if TO bearing / fork seem free etc

Saying "know it is hard to depress" is somewhat subjective. That clutch might be "firm" but if you've driven a 1/2 or 3/4 T "stick" pickup it should not necessarily be any tougher to operate
 
Dartswinger70 said:
What kind of power do those Poly 318's make? Are they like the Ford 351-400M's big CI numbers, but small power output?
Click to expand...
Well mine has anew exhaust leak so I'm not getting proper power from it but it sure doesn't like to go fast especially up hills but this is also a 26 ft long bus with cabinets and furniture in it so I'm sure in a smaller vehicle it would have a lot of power especially if everything was in working order.
 
67Dart273 said:
OK are you saying when you "give up" on depressing the pedal you can only get it down so far, and there's 6" left between the pedal and floor?

Some generalities:

IF the above is true certainly is not right. Start by opening a bleeder and see if the pedal goes on down freely. This will tell you if there is a mechanical bind problem in the master/ pedal/ mount/ pushrod setup

If that allows the pedal to depress fully, then:

1.....Slave/ master might be so mismatched that slave is running out of travel

2....Might be clutch fork/ throwout bearing is bent/ broken/ off the fork pivot/ pivot broke, etc

3...Does not appear to me that slave is moving far enough. You might have a situation IE example "junk" rust in the slave or NOT ENOUGH travel in the slave to start with, the slave might be "part way" extended when you THINK it is all the way retracted.

Only way I know to approach that is to:

Remove slave, measure bore, try to find out what size bore the truck CAME with (if this is original type master)

Take slave apart make sure it's clean and that piston has full travel of slave bore.

Try to get flashlight/ mirror/ camera/ etc and wiggle the fork around and inspect. Try to determine if fork pivot is loose / broken or even present and if TO bearing / fork seem free etc

Saying "know it is hard to depress" is somewhat subjective. That clutch might be "firm" but if you've driven a 1/2 or 3/4 T "stick" pickup it should not necessarily be any tougher to operate
Click to expand...


So from what I know the slave that was on it before I matched and bought this new one it may be the wrong one but it sure does look right bolted up there and that may not mean anything.

when we put the slave and master on and we were bleeding it yes the pedal would go all of the way to the floor.

I was just under the bus messing with the fork and it is kinda just wiggling where it goes into the piston for the slave I tightened it and that made it move even less when I loosened it the slave piston moved substainstianally more but it didn't seem as though it was pushing the fork any further. Although it did let the pedal depress quite a bit more and the slave piston moved alot more. I tightened it back up because it seemed like it would fall off if I didn't but now that it's back where it was we have the same pedal depression as before.
I do not know what the bore of the slave/master are or how I would measure them but if given instruction I'm confident I could figure it out. I would need lamence terms though.
 
I was watching your "clutch movement" video and something isnt right (But you know this don't you) It appears to me that something isn't moving mechanically.

Is the clutch release bearing moving on the input shaft? can you disconnect the clutch down to just the fork and see how that feels? Look up through the fork opening and see if the clutch release bearing slides on the input shaft?

Also , in your slave cylinder video, their doesn't seem to be "enough" travel IMO.
Assuming that that is the correct setup, (Slave Cylinder, the pedal goes to the floor when bled, the linkage travels properly when the slave cylinder is disconnected) Id say your clutch is done, time to take it apart. Did that thing have a slave cylinder from 1965? I would think it is a linkage setup, maybe that is a retrofit that never was working correctly.
 
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Dartswinger70 said:
I was watching your "clutch movement" video and something isnt right (But you know this don't you) It appears to me that something isn't moving mechanically.

Is the clutch release bearing moving on the input shaft? can you disconnect the clutch down to just the fork and see how that feels? Look up through the fork opening and see if the clutch release bearing slides on the input shaft?

Also , in your slave cylinder video, their doesn't seem to be "enough" travel IMO.
Assuming that that is the correct setup, (Slave Cylinder, the pedal goes to the floor when bled, the linkage travels properly when the slave cylinder is disconnected) Id say your clutch is done, time to take it apart. Did that thing have a slave cylinder from 1965? I would think it is a linkage setup, maybe that is a retrofit that never was working correctly.
Click to expand...

So by saying the clutch is done do you mean I need a new clutch?
And I am unsure if the slave was original or not the one I took off looked like it had been there for quite some time but the piston I believe is what it's called was stuck in place all the way back and not moving at all.
I was thinking the linkage could be something that was rigged and never worked properly I can get back under there and take a video of what is going on, I'll just have to wait till my fiance gets off work so he can be pushing on the pedal he will be home in a couple of hours. But in the mean time I'll post a picture of the linkage.
 
megan95 said:
So by saying the clutch is done do you mean I need a new clutch?
And I am unsure if the slave was original or not the one I took off looked like it had been there for quite some time but the piston I believe is what it's called was stuck in place all the way back and not moving at all.
I was thinking the linkage could be something that was rigged and never worked properly I can get back under there and take a video of what is going on, I'll just have to wait till my fiance gets off work so he can be pushing on the pedal he will be home in a couple of hours. But in the mean time I'll post a picture of the linkage.
Click to expand...

Yes, in a slave cylinder system the clutch will work untill the disc wears down to nothing, like brake pads, then the pressure plate spring loaded section moves closer to the flywheel, pressing on the worn thinner disc, The slave cylinder pushrod cannot move the pressure plate far enough to disengage the clutch, because the disc is worn too far. it looks to me like your clutch fork isnt moving enough to disengage the clutch, which is why the driver had to "hard shift " it without a clutch to move it.
 
Dartswinger70 said:
Yes, in a slave cylinder system the clutch will work untill the disc wears down to nothing, like brake pads, then the pressure plate spring loaded section moves closer to the flywheel, pressing on the worn thinner disc, The slave cylinder pushrod cannot move the pressure plate far enough to disengage the clutch, because the disc is worn too far. it looks to me like your clutch fork isnt moving enough to disengage the clutch, which is why the driver had to "hard shift " it without a clutch to move it.
Click to expand...

So I should be trying to locate a clutch. My problem is, I don't know what size clutch I need. The transmission is so covered in grease it'll take me hours to clean before I could ever find a serial number. And I wouldn't even begin to know how to clean it properly.
So I'm pretty much left with I have to take it apart and measure the clutch, yeah?
Here's pictures of the linkage if it even matters.

20170629_122638.jpg


20170629_122923.jpg
 
megan95 said:
So I should be trying to locate a clutch. My problem is, I don't know what size clutch I need. The transmission is so covered in grease it'll take me hours to clean before I could ever find a serial number. And I wouldn't even begin to know how to clean it properly.
So I'm pretty much left with I have to take it apart and measure the clutch, yeah?
Here's pictures of the linkage if it even matters.

View attachment 1715061947

View attachment 1715061949
Click to expand...

I did do a quick search and a 65 Dodge truck does call for a slave cylinder, so that setup looks correct, what is interesting is that there is a threaded ajustment on the linkage, you could try to adjust that rod, this adjustment would compensate for the clutch disc wear that I mentioned earlier. I would look for a shop manual with the procedure, but looking at your clutch slave cylinder movement Id say it needs to be longer. You could try that before installing a clutch. It is called 'clutch free play ajustment" in most shop manuals. Check this link out, it is about Clutch free play ajustment : Sweptline.ORG • View topic - Clutch adjustment on a 67 d-100 4 speed w/ granny gear?
 
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