Author Topic: auto to 3 speed swap..  (Read 18721 times)

Offline hotrod24

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auto to 3 speed swap..
« on: October 28, 2011, 11:50:13 am »
Ok i have a 1980 c10 with a low hump and i am going to swap back to a manual 3 speed because thats what the truck was before i think lol, It looks like it has a brake pedal from a clutch set up so thats what made me think it used to be 3 speed and someone just took the clutch out but it does not have the bracket on the frame for the bell crank and i cannot find the clutch rod hole going to the bell crank, What would be the best way of finding out if it used to be a 3 speed?

Thanks







1980 1/2 ton shortbed project...
1978 pontiac grand prix...

Offline 1980c10

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Re: auto to 3 speed swap..
« Reply #1 on: October 28, 2011, 02:16:13 pm »
I think your answer is in your question. Most likely with no signs of linkage pieces, It probably was an A/T. Its unlikely that someone would have caught every piece. Look for signs of rivets for the frame bracket(cutting or grinding marks). do you have an auto dash? look for a properly installed neutral saftey switch as if this was changed the wires may have connecters just before the plug.  my 1980 c10 had the sm465 and had a removable cover on the floor hump.

forgive the modications but you get the idea.

Anyway, that does look like a clutch-brake pedal as I believe it would have been larger if an auto.
The purple and yellow wires hanging below your steering column would have originially gone to the neutral saftey switch for a clutch. Look to see if the are connected to one another.

The pedal assembly on the right would have been correct in your truck

I don't know what the auto pedal assembly looks like but the manual version has both the clutch and brake pedal hanging from the same bracket so look for where the clutch pedal would have hung from that

Offline zieg85

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Re: auto to 3 speed swap..
« Reply #2 on: October 28, 2011, 03:32:26 pm »
Look for a hole in the firewall which the clutch rod would have gone through.  If it is not there your truck was most likely never a standard shift truck.  I have seen that small brake pedal on automatic trucks on some of the base model trucks.  My $.02
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline Captkaos

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Re: auto to 3 speed swap..
« Reply #3 on: October 28, 2011, 03:48:23 pm »
Based on the pictures of your floorpan that cab never had a manual in it.  The hole that Zieg is talking about is missing.

Offline hotrod24

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Re: auto to 3 speed swap..
« Reply #4 on: October 28, 2011, 09:56:39 pm »
Thanks guys, I am wanting to switch it to a 3 speed on the column so there would not be any reason to have a floor shift hole, But like chris said it has a low hump but i have heard of guys saying that they had a manual with the low hump. The brake housing set up looks nothing like the clutch set up. If it was never a manaul it will be one lol, I will keep looking for signs tho...

Also i will get some pics of the bracket linkage, The bracket is bolted not rivted so thats one other thing that made me think it was a manual...
1980 1/2 ton shortbed project...
1978 pontiac grand prix...

Offline 1980c10

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Re: auto to 3 speed swap..
« Reply #5 on: October 28, 2011, 10:29:02 pm »
Given the condition of your floors and your goals it may not be a bad idea to find an entire cab or parts truck for that matter with a m/t. Are you looking to go with a column shifter only?

Offline hotrod24

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Re: auto to 3 speed swap..
« Reply #6 on: October 28, 2011, 10:38:10 pm »
lol Yea i plan to get a welder and repair my floors or swap cabs. Its taking me a bit to get the cash up, But yea i am going with the column shifter for now...
1980 1/2 ton shortbed project...
1978 pontiac grand prix...

Offline zieg85

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Re: auto to 3 speed swap..
« Reply #7 on: October 28, 2011, 10:49:23 pm »
FYI, the 3 speed column shift was one of GM's weak links IMO during the 73-87 era.  They seemed to wear out or completely brake, parts are next to impossible to find, or I just have had zero luck in finding any good ones in my area.  I gave up looking trying to convert my 86 C10 back to original, couldn't find a good column or the linkage needed.  Best of luck in your search...
Carl 
1985 C20 Scottsdale 7.4L 4 speed 3.21
1986 C10 under construction
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Offline HAULIN IT

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Re: auto to 3 speed swap..
« Reply #8 on: October 28, 2011, 10:58:52 pm »
Also i will get some pics of the bracket linkage, The bracket is bolted not rivted so thats one other thing that made me think it was a manual...
Which "bracket" are you referring to?
 As mentioned, the 2nd picture you posted would have a hole (or patched area) near the dimmer switch where the clutch rod goes down through the floor to the pivot on the frame.
I also have seen quite a few "low option" trucks with an auto trans. & the small brake pedal. The Yellow color also makes me think of "Fleet, D.O.T. , ect. which goes along with the low option truck. Is it a non-power brake set-up by chance?
If the option label is in the glovebox by some odd chance, it will tell you what trans., ect. the truck came with...assuming the cab, VIN. ect. match the decal.
Unfortunately, looking at that cab...you have much needed work than changing the trans, column, ect.
Lorne

Offline Captkaos

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Re: auto to 3 speed swap..
« Reply #9 on: October 29, 2011, 01:45:29 am »
Also i will get some pics of the bracket linkage, The bracket is bolted not rivted so thats one other thing that made me think it was a manual...

Auto brackets were held on with bolts.

Offline hotrod24

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Re: auto to 3 speed swap..
« Reply #10 on: October 29, 2011, 01:05:01 pm »
Yea some of the 3 speed coulmns are messed up but i guess you just got to find the right one.  My dad had a 67 c10 with a three on the tree and it work great.  I have alot of junk yards around me plus my i have a close relative with one that has about everything so i think i am good there and thanks for the good luck zieg85 ;) The bracket that i am talking about Lorne is the one that the linkage goes to from the tranny to the lower side of the frame right beside the tranny, I will look beside the dimmer switch and see, That area has rust holes so that might be where the hole was lol and yea it does have manual brakes and i thought the same thing about it being a state truck.  The only sticker that it has on the glove box is the camper information I know i am in need of working on other things at the this time but i am kind of just planning what will come i am getting a front clip and changing integrated head to non and looking to see if i can find a solid cab then changing the tranny i am just trying to figure out where i am at and chris yea the bracket is bolted like you said this bracket is the same one that my shop manual shows for the 3 speed confusing i know lol...

Thanks
Dusty

1980 1/2 ton shortbed project...
1978 pontiac grand prix...

Offline Captkaos

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Re: auto to 3 speed swap..
« Reply #11 on: October 29, 2011, 05:15:07 pm »
The manual tab  on the ones I have worked on were always riveted on.

Offline hotrod24

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Re: auto to 3 speed swap..
« Reply #12 on: October 29, 2011, 06:45:55 pm »
Yep my 78 had the bracket that the bell crank goes to and it was riveted and it shows it rivted in my shop manual to, Now the bracket that we was talking about earlier is bolted. Thats what my auto linkage goes to...
« Last Edit: October 29, 2011, 07:03:02 pm by hotrod24 »
1980 1/2 ton shortbed project...
1978 pontiac grand prix...

Offline hotrod24

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Re: auto to 3 speed swap..
« Reply #13 on: November 01, 2011, 06:01:30 pm »
OK i found some holes, I think they are for the bell crank bracket but they might be to far apart? Also here is the bracket that i was talking about that the 3 speed tranny used that my auto lever is going to... 





Could i use this bracket with my 3 speed manual?


1980 1/2 ton shortbed project...
1978 pontiac grand prix...

Offline 1979C20

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Re: auto to 3 speed swap..
« Reply #14 on: November 01, 2011, 07:55:29 pm »
Unless they replaced the cab, there would be holes for the clutch rod and the shifter. check your rpo codes to see what tranny it had.
1979 SCLB C20 Q-jet 350 SM465 14b F.F. 4.10 G80
1989 GMC Suburban V2500 TBI350 TH400 4in lift 35's 14b SF