tranny question

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dartfreak75

dartfreak75

Restore it, Dont part it!
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hey guys iv got an 1986 318 with the orginal converter and i got a 78-79 904 off a 360 will this tranny work with the 318 converter or should i use the 360 converter? also im doing a slant six switch will the 318 904 combo work with the orginal drive shaft im using shumaker engine swap mounts they say the stock drive shaft will work but my tranny is a good foot longer than the slant 6 tranny! thanks
 
You can only use a 360 converter behind a 360 engine because the 360 is externally balanced. If you use a 360 converter behind a 318 it'll vibrate like there's no tomorrow unless you knock off the weight that's on the front of the converter to balance it for a 360. Another problem you may run into is if the 86 904 is a lockup and the 79 trans isn't. They won't interchange. Splines are different count and the input shaft is machined different.

If your trans is a foot longer than the /6 trans their not the same trans. All 904's are the same length. Heck even the 727 (the big trans) is no where near a foot longer than a 904. I don't have a clue what you have if it's that long. Post pics and maybe I can tell.
 
ok il post some pics i have the oringal tranny from the 318 but it has some issues before i pulled it it woundnt shift right it would completly skip 2nd gear then not down shift no matter what until you came to a complete stop so i was just gonna juck it and use the other tranny i had whick is the one off the 360 how can i tell the diference between a lock up and non lock up?
 
i have the exact oposite problem from you, to bad were so far away from each other we could just swap trannys and be done with it.
 
dartfreak75 said:
hey guys iv got an 1986 318 with the orginal converter and i got a 78-79 904 off a 360 will this tranny work with the 318 converter or should i use the 360 converter? also im doing a slant six switch will the 318 904 combo work with the orginal drive shaft im using shumaker engine swap mounts they say the stock drive shaft will work but my tranny is a good foot longer than the slant 6 tranny! thanks
Click to expand...

Dartfreak,

since your 318 is an '86 model, I'm willing to bet it's externally balanced, which means you can use the 360 trans and converter. Both are external balance, and both have the requisite weights necessary to mate up to your engine. As noted, however, you cannot interchange converters between transmissions (727 to 904).

On the driveshaft - I can't answer that question, but you can do a few quick measurements to verify.
 
Southernman said:
Dartfreak,

since your 318 is an '86 model, I'm willing to bet it's externally balanced, which means you can use the 360 trans and converter. Both are external balance, and both have the requisite weights necessary to mate up to your engine. As noted, however, you cannot interchange converters between transmissions (727 to 904).

On the driveshaft - I can't answer that question, but you can do a few quick measurements to verify.
Click to expand...

No 318 LA was externally balanced. That's mis-information that's been floating around for some time. I don't know who started it but they were WRONG. Even if a 318 was externally balanced it probably wouldn't require the same amount of balance weight a 360 does to balance it. Some 440's were externally balanced yet you just can't swap 440 and 360 externally balanced converters. There's only 20 grams of difference in the balance but it's enough to cause damage to the engine bearings.
 
dartfreak75 said:
ok il post some pics i have the oringal tranny from the 318 but it has some issues before i pulled it it woundnt shift right it would completly skip 2nd gear then not down shift no matter what until you came to a complete stop so i was just gonna juck it and use the other tranny i had whick is the one off the 360 how can i tell the diference between a lock up and non lock up?
Click to expand...

I'd actually like to see both trans. since you say there is over a foot difference in length. If you can take a pic of the input shaft that'd be good too cause I could tell you if it's a lock up trans. or not.

BTW: the trans. that came behind the 86 318 might be a 998/999 series that has the low first gear set. They put them behind low powered engines like the 80's 318's were. You can't tell them from a regular 904 by looking at them on the outside. The difference is internally. I wish you were close to me cause I'd like to have one.
 
fishy68 said:
No 318 LA was externally balanced. That's mis-information that's been floating around for some time. I don't know who started it but they were WRONG. Even if a 318 was externally balanced it probably wouldn't require the same amount of balance weight a 360 does to balance it. Some 440's were externally balanced yet you just can't swap 440 and 360 externally balanced converters. There's only 20 grams of difference in the balance but it's enough to cause damage to the engine bearings.
Click to expand...

That's intersting feedback and thanks for posting, but I've never encountered an internally balance Mopar engine after 1974 - in big or small block.

I've also never had any problems swapping between any of the small and big block assy's as long as I matched external and internal components. Even when I reference Allpar, there's nothing after '78 that was internally balanced - they all used cast cranks (cheaper to put weights on HB and TC than to internally balance them).

From Allpar:

Chrysler's most compact V-8 ­(318) designed to be rugged and dependable - is equipped with the second-generation for 1978. Features include:
  • Hydraulic valve lifter (tappets)-no periodic adjustments required
  • Induction-hardened exhaust-valve seats
  • Cast ductile crankshaft
  • Aluminized steel exhaust and tail pipe
Again, I don't doubt what you're saying here, but my experience has been the opposite - for street applications with occassional trips to the strip.

Southernman
 
fishy68 said:
No 318 LA was externally balanced. That's mis-information that's been floating around for some time. I don't know who started it but they were WRONG. Even if a 318 was externally balanced it probably wouldn't require the same amount of balance weight a 360 does to balance it. Some 440's were externally balanced yet you just can't swap 440 and 360 externally balanced converters. There's only 20 grams of difference in the balance but it's enough to cause damage to the engine bearings.
Click to expand...

The confusion comes in I think because of the other engines. Steel crank=internal balance cast crank=external balance. But, that's not so for the 318 and slant. Both of them are internally balanced with the cast or forged crank.....but they are underdogs and get no attention so why would anybody notice?
 
ok i went up to the shop and took another look see the tranny and converter off the 318 is a lock up 904 and the tranny that i am using is a 904 non lockup! so eithor im gonna have to buy a converter or fix the tranny off the 318 i was wrong about the lenght the slant 6 and 360 are the same lenght the 360 had a plate on the tail shaft that makes it appear longer but its not!
 
i dont have the money to buy a new converter what can i do to make the 360 converter work?
 
fishy68 said:
You can only use a 360 converter behind a 360 engine because the 360 is externally balanced. If you use a 360 converter behind a 318 it'll vibrate like there's no tomorrow unless you knock off the weight that's on the front of the converter to balance it for a 360. Another problem you may run into is if the 86 904 is a lockup and the 79 trans isn't. They won't interchange. Splines are different count and the input shaft is machined different.

If your trans is a foot longer than the /6 trans their not the same trans. All 904's are the same length. Heck even the 727 (the big trans) is no where near a foot longer than a 904. I don't have a clue what you have if it's that long. Post pics and maybe I can tell.
Click to expand...
you are exaclty right the 79 isnt a lock up and the 86 is
 
It's cheaper to get a replacement converter than it is to rebuild the transmission. A stock rebuilt converter should be under $100.
 
will the slant six converter work it looks the same size as the 360 i see the weights on the 360 your talking about
 
dartfreak75 said:
will the slant six converter work it looks the same size as the 360 i see the weights on the 360 your talking about
Click to expand...

I think it'll work but I haven't tried it. You can make the 360 converter work by just removing the weight on the front side of it. That basically converts it to a neutral balance converter which is what you need for a 318.
 
Southernman said:
That's intersting feedback and thanks for posting, but I've never encountered an internally balance Mopar engine after 1974 - in big or small block.

I've also never had any problems swapping between any of the small and big block assy's as long as I matched external and internal components. Even when I reference Allpar, there's nothing after '78 that was internally balanced - they all used cast cranks (cheaper to put weights on HB and TC than to internally balance them).

From Allpar:

Chrysler's most compact V-8 *(318) designed to be rugged and dependable - is equipped with the second-generation for 1978. Features include:
  • Hydraulic valve lifter (tappets)-no periodic adjustments required
  • Induction-hardened exhaust-valve seats
  • Cast ductile crankshaft
  • Aluminized steel exhaust and tail pipe
Again, I don't doubt what you're saying here, but my experience has been the opposite - for street applications with occassional trips to the strip.

Southernman
Click to expand...

Hi Southernman. Allpar is one source of confusion that started all this mess. I don't know who wrote that site but it has it's share of error's, one being the 318 was externally balanced. A cast vs. a steel crank is not what determines if an engine will be externally or internally balanced although cast cranks are lighter so sometimes (as in the case of a 360) they don't have enough weight on the counterweights to balance the reciprocating assy.

I understand it's not a problem swapping parts as long as they are matched (internal vs. external balance).

Thanks for the feedback.
 
StrokerScamp said:
The confusion comes in I think because of the other engines. Steel crank=internal balance cast crank=external balance. But, that's not so for the 318 and slant. Both of them are internally balanced with the cast or forged crank.....but they are underdogs and get no attention so why would anybody notice?
Click to expand...

Yep
 
fishy68 said:
Hi Southernman. Allpar is one source of confusion that started all this mess. I don't know who wrote that site but it has it's share of error's, one being the 318 was externally balanced. A cast vs. a steel crank is not what determines if an engine will be externally or internally balanced although cast cranks are lighter so sometimes (as in the case of a 360) they don't have enough weight on the counterweights to balance the reciprocating assy.

I understand it's not a problem swapping parts as long as they are matched (internal vs. external balance).

Thanks for the feedback.
Click to expand...

Thank you for updating us on that. During the years I built 318's I always used the early model units with steel crank and internal balancing. They were about the toughest engines I've even messed with and damned near impossible to blow 'em up. In fact, I ran mine so hard the rings always gave up long before the other parts. With good heads, they would scream 7000+ rpms all day long. Talk about cheap fun. Those were the good old days... ~{:>)

Again, nice chattin' with you too.

Southernman
 
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