Need help i.d.'ing transmission / spindle count - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Uwe Blab · 05-20-2009, 01:45 PM

I have the casting numbers from my truck's gear box (3925647) and tailhousing (3880042). The truck is a 1970 Chevy LWB fleetside, straight 6, 3-speed on the column. Is there any way to identify the spindle count and diameters for the input and output shafts from these numbers? Also, can I verify the overall transmission length? I put a tap measure to it and it looks like 21-1/2", but if there's a way to verify I'd appreciate it.

Thanks for any help.

Adam

**mr48chev** · 05-20-2009, 02:01 PM

Il believe you are looking for "spline" count.

The input shaft should be ten spline x 1.125 which is standard for that year. Normally they have a 11 inch disk.

I'm not sure what year they went from a what we refer to as a course spline to a fine spline output shaft and yoke.

Uwe Blab · 05-20-2009, 02:29 PM

D'oh! I meant spline. Not sure where I came up with spindle. Maybe one of the mods can change to name of this thread.

Thanks mr48chev for your help.

I'm trying to see if a '55 3-speed o/d transmission would bolt right up to what I already have.

05-20-2009, 01:45 PM	#1
Uwe Blab Registered User Join Date: Feb 2009 Location: Overland Park, Kansas Posts: 134	Need help i.d.'ing transmission / spindle count I have the casting numbers from my truck's gear box (3925647) and tailhousing (3880042). The truck is a 1970 Chevy LWB fleetside, straight 6, 3-speed on the column. Is there any way to identify the spindle count and diameters for the input and output shafts from these numbers? Also, can I verify the overall transmission length? I put a tap measure to it and it looks like 21-1/2", but if there's a way to verify I'd appreciate it. Thanks for any help. Adam

05-20-2009, 02:01 PM	#2
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,721	Re: Need help i.d.'ing transmission / spindle count Il believe you are looking for "spline" count. The input shaft should be ten spline x 1.125 which is standard for that year. Normally they have a 11 inch disk. I'm not sure what year they went from a what we refer to as a course spline to a fine spline output shaft and yoke.

05-20-2009, 02:29 PM	#3
Uwe Blab Registered User Join Date: Feb 2009 Location: Overland Park, Kansas Posts: 134	Re: Need help i.d.'ing transmission / spindle count D'oh! I meant spline. Not sure where I came up with spindle. Maybe one of the mods can change to name of this thread. Thanks mr48chev for your help. I'm trying to see if a '55 3-speed o/d transmission would bolt right up to what I already have.



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