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92 4x4 Auto to NV5600 conversion question

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My son wore out the auto in his 92 and decided to convert to a 6 speed. He started the project without doing any research (he's young). Today he attempted to mate up the transmission with the engine and found out that the crank shaft is not machined to accept the transmission input shaft.

I didn't see what he had first hand, but it sounds like there was no pilot bushing/bearing and no place to put one.



Is the crank for an auto different from the crank for a manual transmission.



Has anybody else encountered this?



Any recommendations?



Ian
 
crank

The crank is the same in all cases. There are spacers, bushing, etc, which are application specific. What is required is available. Nothing has to be invented. You just have to find it.



James
 
Thanks for the feed back. So if the input shaft is hitting the rear of the crank before the transmission mates to the bell-housing it sounds like he needs either a bell-housing spacer/adapter or a different bell-housing.



Does anyone know which he should be looking for?
 
Yep, you will need a later model engine adapter to space it out if the input shaft is bottoming out. Your local cummins dealer can get you one if you give the engine number and application.
 
cerberusiam,



Is engine adapter the same thing as bell-housing, or is it an additional adapter between the existing bell-housing and the new transmission?
 
ihegdal said:
cerberusiam,



Is engine adapter the same thing as bell-housing?



Yes. I would assume he needs the adapter from an engine originally equipped with a 6 speed. The six speed has a larger input shaft than the 5 speeds. Kinda shootin from the hip here but I think the clutches designed for the 6 speeda are 13" so you need a flywheel to match. Should verify all this with a Cummins dealer though. If you're not in a big hurry you can probably score an adapter on Ebay for under $150.

Danny
 
I'm not very inclined when it comes to this stuff, but isn't the bellhousing an integral part of the nv5600? If its an 1 3/8" input shaft you will need a new clutch and starter I believe too. Marty1 did a good writeup on swapping from a 5sp to 6sp.
 
What I meant by bellhousing/engine adapter was the part that bolts to the back of the engine that the transmission bolts to. What is the official name of that part anyway? It seems to be a perpetual source of confusion...

Danny
 
If the manuals are like the autos the engine adapter is another piece between the tran and engine. I know the autos use a different adapter and assume for cost sake the same adapter will work for autos or manuals in the later models. It doesn't make sense to bolt the bellhousing directly to the engine since the 5600 is used in other applications.



The other problem he will run into is there is no direct conversion for the clutch slave cylinder and throw pieces to fit the gen1 pieces. That will have to all be fabricated. The couple conversions I have seen were problematic as the pieces wore out about once a year and had to be redone. There may be better ways of doing so a search may help you.
 
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