Steering Column Interchange - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Super_Dave · 12-08-2016, 07:29 PM

I am looking to swap a tilt column into my 1974 C20 Project. I am starting to look for a tilt column and came across this interchange info on another forum:

1973-77 Column shift; automatic transmission; tilt

238-237A ----------

BLAZER/JIMMY (full size) 73-77 Column Shift; AT, w/tilt

CHEVROLET 10 PICKUP 73-77 Column Shift; AT, w/tilt

CHEVROLET 20 PICKUP 73-77 Column Shift; AT, w/tilt

CHEVROLET 30 PICKUP 73-77 Column Shift; AT, w/tilt

GMC 1500 PICKUP 73-77 Column Shift; AT, w/tilt

GMC 2500 PICKUP 73-77 Column Shift; AT, w/tilt wheel

GMC 3500 PICKUP 73-77 Column Shift; AT, w/tilt wheel

SUBURBAN 10 73-77 Column Shift; AT, w/tilt wheel

SUBURBAN 1500 73-77 Column Shift; AT, w/tilt wheel

SUBURBAN 20 73-77 Column Shift; AT, w/tilt wheel

SUBURBAN 2500 73-77 Column Shift; AT, w/tilt wheel

Am I safe in assuming that any tilt column from the list above will be a bolt in affair and plug into my new AAW Harness... might have to replace the new ignition module, but no big deal there.

**old Rusty C10** · 12-08-2016, 09:31 PM

I believe you can go up to 82.... if its got the thin turn signal stalk it should bolt right in and wire up the same I believe the newer columns started in 83 with the thick stalk and the wipers in the turn signal switch and that would be different. I would also make sure I got the correct lower shaft for the new column so it works they will all bolt to the steering box

Super_Dave · 12-08-2016, 11:19 PM

This is one of the columns I am looking at... Says it's a 73-87 GMC/Chevy column from a Jimmy/Blazer...

**hatzie** · 12-09-2016, 09:19 AM

73-83 had several different harmonica connectors but the core column is the same.
84-91 have the larger turn stalk with the dimmer and wiper switches on the column.

73-77 harmonica connectors can be removed and re-installed on your new column.
78-83 will interchange without changing anything.

You can install the 84-91 column in the 73-77 trucks by replacing and re-pinning the harmonica plug.
The 78 and later trucks harmonica plug will mate with any 78 and later truck. You can even move the wiper and dimmer controls to the column if you wish.

Super_Dave · 12-09-2016, 02:57 PM

hatzie: Thanks for the info...

Quote:

Originally Posted by hatzie

73-77 harmonica connectors can be removed and re-installed on your new column.

You can install the 84-91 column in the 73-77 trucks by replacing and re-pinning the harmonica plug.
wish.

Is there a thread or FAQ showing the re-pinning process?

Super_Dave · 12-09-2016, 03:04 PM

Quote:

Originally Posted by old Rusty C10

I believe you can go up to 82.... if its got the thin turn signal stalk it should bolt right in and wire up the same I believe the newer columns started in 83 with the thick stalk and the wipers in the turn signal switch and that would be different. I would also make sure I got the correct lower shaft for the new column so it works they will all bolt to the steering box

Rusty... Thanks for the info. In the image above, it shows the thin turn indicator, so I assume it fits your criteria. It comes complete sans the steering wheel, but mine is pristine, so no issue there.

Other than maybe needing a new ignition module for a tilt column and a new Neutral Safety Switch (since it's already out and they are not that expensive), it should be a plug-n-play with my new AAW Harness, correct?

Super_Dave · 12-09-2016, 03:21 PM

Owner got back to me on the one above. It's from a 1978 K20. As long as I have the correct ignition module for a tilt column, I should be golden. Is this a correct understanding?

**old Rusty C10** · 12-09-2016, 05:39 PM

Yes Dave... you can probably swap over the one you have now
I know I had no issues when I did this on my 82 with exception of the lower shaft one had the D connector the other a gear kinda thing but it was plug and play

**1774btcrew** · 12-09-2016, 09:29 PM

The harmonic plug is very easy to repin. Just do one wire at a time a tiny screwdriver will release the pins or you can buy a pin release set from one of the better tool trucks

**hatzie** · 12-10-2016, 12:04 PM

The Harmonica plug is a PAK CON connector just like some wiper motors, the ATC fuse panels, and the original Delco radios. They're almost as simple to remove and insert as the Packard 56 & Packard 59 connectors.
I would recommend matching the column side connector pinout to the cab connector so you can go back to the original column if needed. Get the wiring diagrams for your donor and recipient year. See my signature.

Jegs has the GM Pak Con harmonica plug shells and terminals for the GM Saginaw steering columns. http://www.jegs.com/i/JEGS-Performan...10415/10002/-1

http://www.youtube.com/watch?v=f2iBmOZN3g4

12-08-2016, 07:29 PM	#1
Super_Dave Registered User Join Date: Jul 2014 Location: Sherwood, Oregon Posts: 974	Steering Column Interchange I am looking to swap a tilt column into my 1974 C20 Project. I am starting to look for a tilt column and came across this interchange info on another forum: 1973-77 Column shift; automatic transmission; tilt 238-237A ---------- BLAZER/JIMMY (full size) 73-77 Column Shift; AT, w/tilt CHEVROLET 10 PICKUP 73-77 Column Shift; AT, w/tilt CHEVROLET 20 PICKUP 73-77 Column Shift; AT, w/tilt CHEVROLET 30 PICKUP 73-77 Column Shift; AT, w/tilt GMC 1500 PICKUP 73-77 Column Shift; AT, w/tilt GMC 2500 PICKUP 73-77 Column Shift; AT, w/tilt wheel GMC 3500 PICKUP 73-77 Column Shift; AT, w/tilt wheel SUBURBAN 10 73-77 Column Shift; AT, w/tilt wheel SUBURBAN 1500 73-77 Column Shift; AT, w/tilt wheel SUBURBAN 20 73-77 Column Shift; AT, w/tilt wheel SUBURBAN 2500 73-77 Column Shift; AT, w/tilt wheel Am I safe in assuming that any tilt column from the list above will be a bolt in affair and plug into my new AAW Harness... might have to replace the new ignition module, but no big deal there. __________________ --Project BABA YAGA!... http://67-72chevytrucks.com/vboard/s...d.php?t=655783 --Project BABA YAGA!... http://67-72chevytrucks.com/vboard/s...ghlight=Belair "Life is tough - wear a cup!" "Old Enough to Know Better - Too Young to Resist" "Junk is something you will need three weeks after you throw it away." Last edited by Super_Dave; 12-08-2016 at 09:09 PM.

12-08-2016, 09:31 PM	#2
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,287	Re: Steering Column Interchange I believe you can go up to 82.... if its got the thin turn signal stalk it should bolt right in and wire up the same I believe the newer columns started in 83 with the thick stalk and the wipers in the turn signal switch and that would be different. I would also make sure I got the correct lower shaft for the new column so it works they will all bolt to the steering box __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

12-08-2016, 11:19 PM	#3
Super_Dave Registered User Join Date: Jul 2014 Location: Sherwood, Oregon Posts: 974	Re: Steering Column Interchange This is one of the columns I am looking at... Says it's a 73-87 GMC/Chevy column from a Jimmy/Blazer... Attached Images __________________ --Project BABA YAGA!... http://67-72chevytrucks.com/vboard/s...d.php?t=655783 --Project BABA YAGA!... http://67-72chevytrucks.com/vboard/s...ghlight=Belair "Life is tough - wear a cup!" "Old Enough to Know Better - Too Young to Resist" "Junk is something you will need three weeks after you throw it away."

12-09-2016, 09:19 AM	#4
hatzie Moderator Join Date: Oct 2008 Location: Wentworth, NH Posts: 4,950	Re: Steering Column Interchange 73-83 had several different harmonica connectors but the core column is the same. 84-91 have the larger turn stalk with the dimmer and wiper switches on the column. 73-77 harmonica connectors can be removed and re-installed on your new column. 78-83 will interchange without changing anything. You can install the 84-91 column in the 73-77 trucks by replacing and re-pinning the harmonica plug. The 78 and later trucks harmonica plug will mate with any 78 and later truck. You can even move the wiper and dimmer controls to the column if you wish. __________________ 1959 M35A2 LDT465-1D SOLD 1967 Dodge W200 B383, NP420/NP201 SOLD 1969 Dodge Polara 500 B383, A833 SOLD 1972 Ford F250 FE390, NP435/NP205 SOLD 1976 Chevy K20, 6.5L, NV4500/NP208 SOLD 1986 M1008 CUCV SOLD 2000 GMC C2500, TD6.5L, NV4500 2005 Chevy Silverado LS 2500HD 6.0L 4L80E/NP263 2009 Impala SS LS4 V8 RTFM... GM Parts Books, GM Schematics, GM service manuals, and GM training materials... 1973-1991 GM Light Truck Service, Unit/Overhaul, Wiring Manuals, Parts Books and Some 1968-1999 GM Service Training textbooks in PDF 1988-1998 GMT400 CK service manual project 1988-1993 GMT400 CK parts books. 1967-1972 GM Light, Medium, & Heavy Truck Service Manuals in PDF Please include at least the year and model in your threads. It'll be easier to answer your questions. And please let us know if and how your repairs were successful.

12-09-2016, 03:21 PM	#7
Super_Dave Registered User Join Date: Jul 2014 Location: Sherwood, Oregon Posts: 974	Re: Steering Column Interchange Owner got back to me on the one above. It's from a 1978 K20. As long as I have the correct ignition module for a tilt column, I should be golden. Is this a correct understanding? __________________ --Project BABA YAGA!... http://67-72chevytrucks.com/vboard/s...d.php?t=655783 --Project BABA YAGA!... http://67-72chevytrucks.com/vboard/s...ghlight=Belair "Life is tough - wear a cup!" "Old Enough to Know Better - Too Young to Resist" "Junk is something you will need three weeks after you throw it away."

12-09-2016, 05:39 PM	#8
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,287	Re: Steering Column Interchange Yes Dave... you can probably swap over the one you have now I know I had no issues when I did this on my 82 with exception of the lower shaft one had the D connector the other a gear kinda thing but it was plug and play __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

12-09-2016, 09:29 PM	#9
1774btcrew Senior Member Join Date: Jun 2009 Location: Phoenix AZ Posts: 4,557	Re: Steering Column Interchange The harmonic plug is very easy to repin. Just do one wire at a time a tiny screwdriver will release the pins or you can buy a pin release set from one of the better tool trucks __________________ AZPartsLocators on Instagram 1972 Cheyenne Super Short Bed big block "Blackie" 1977 Crew Cab GMC Short bed with 4BT Intercooled Cummins Diesel and a 4L80e "The Junkyard Dog" 1985 Crew Cab Chevy dually with 5.9 Cummins "The Big Dog" This is what my dad liked to be called by the grandkids before he passed so it seems fitting for his old truck.



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