Advice on 76-78 crankshafts for AMC360

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NorthGaAire
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Advice on 76-78 crankshafts for AMC360

Post by NorthGaAire »

Looking for information on crankshafts for 76-78 AMC360:
I see references to automatic and manual cranks. (Mine 78 is a manual.)

What to I need to look for when buying a new crank?

Do the new units today work for either style tranny?

Thanks.
1978 Cherokee 4dr, 360v8, T18 4spd, Twin stick Dana 20, SOA conversion (7" lift), trac lock rear axle, 3.54 axle ratio, 33"x10.5"-15 Toyo MT's on factory steel wheels, Cliff hanger front bumper, Evil Twin rear bumper with swing out spare.
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tgreese
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Re: Advice on 76-78 crankshafts for AMC360

Post by tgreese »

The only difference that I know of is the presence or absence of a thin bushing needed to support the nose of the TH400 torque convertor. The AMC cars all used the Chrysler transmissions and the crankshaft is sized to fit the larger nose of the Chrysler transmissions. Bushing or not, should not matter for a manual transmission application.

I would be surprised if there are any new AMC 360 crankshafts available, other than aftermarket forged steel stroker crankshafts priced in the thousands of dollars. The original crankshafts for the 304 and 360 are cast iron, typical of most such crankshafts. If you need a replacement crankshaft, it will be reconditioned, not new. A crank kit will come with the reconditioned crankshaft and bearings sized to work with the resized journals. Usually you get a crank in exchange that is one size under the core you supply. Ie, if you turn in a virgin crank, the crank you get back will will have 10-thou undersized journals with matching bearings. Turn in a 10-under core and get back a 20-under replacement, etc. Ask your local automotive machine shop about this.
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Stuka
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Re: Advice on 76-78 crankshafts for AMC360

Post by Stuka »

I have seen reman crank shafts, but no new ones outside of race applications like tgreese mentions.

There is a pilot bushing for use with manual transmissions also.

As far as what crankshafts will work, I think any 71-91 360 crank shaft will work. (1970 will NOT work)
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Pevious Jeeps: 1981 J10, 1975 Cherokee, 2008 JK, 2005 KJ, 1989 XJ

Topic author
NorthGaAire
Posts: 47
Joined: Thu Mar 22, 2018 6:30 am

Re: Advice on 76-78 crankshafts for AMC360

Post by NorthGaAire »

Thanks gentlemen.
1978 Cherokee 4dr, 360v8, T18 4spd, Twin stick Dana 20, SOA conversion (7" lift), trac lock rear axle, 3.54 axle ratio, 33"x10.5"-15 Toyo MT's on factory steel wheels, Cliff hanger front bumper, Evil Twin rear bumper with swing out spare.
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