Transmission Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

rcbildr · 10-28-2011, 01:11 AM

Unfortunately I don't have the time to do a good search on this. Anyways, my girlfriend bought a 1954 3800 series flatbed farm truck a couple years ago...from what we have been told it's spent all of it's life on our road. It has the 235 six and a manual trans. I know I can get the engine running, but I want to make the truck drivable for her until we can really "modernize" the running gear. Her plans are to do a 350/350 combo but have the engine look like it was a 1955 small block.

For now I was wondering what are my options for putting an automatic trans behind the 235? Any help will be greatly appreciated. Thanks!

Wrenchbender Ret · 10-28-2011, 09:43 AM

It is difficult. The only bolt in would be a Hydramatic from a similar truck. They are heavy, aukward, & scarse. There is an adapter available to put a modern AT in a 235 but it is expensive & you will have to do extensive mods to the chassis.
It seems to me you both could learn to drive the manual. It is probably a 4 speed with a floor shift. The clutches are soft on those. It will be more fun to drive then with an AT.

mr48chev · 10-28-2011, 10:33 AM

I'd have to agree 100% With Wrenchbender Ret in that swapping to an automatic that would go behind the 235 would be a bit difficult and quite expensive. The Hydromatics that were in those trucks new are pretty hard to find and rebuilding one would probably cost more than a decent 350/350 combination installed. The adapters for a late trans behind those run pretty expensive by the time you are done. From Tom Langdon http://stoveboltengineco.com/index.p...roduct=1396439 The adapter runs 350.00 plus you still need a trans, crossmember and cooler along with linkage.

It isn't that hard to drive a stick in one of these trucks.

OrrieG · 10-28-2011, 12:10 PM

I will agree Mr48 and Wrenchbender because I don't have time to find the thread where this was discussed in detail about 4 months ago. 235>>auto is a lot of work and expense. For the same time and less money you can drop the SBC in with an auto. To get a 350 to look like an early motor you need to use early heads. On carbed 350's should be ok. You will also need to run a short waterpump and find early accessory bracket sets.

rcbildr · 10-28-2011, 06:59 PM

Thanks for the info. I've actually came across two of the hydramatic transmissions...one was at the swap meet a few weeks ago and was extremely expensive and the other was in a truck at a car show I went to last week.

We both know how to drive sticks, it's just my girlfriend has bad arthritis in her left knee and ankle which makes driving a manual painful.

It looks like for now I'll try to get it running and then go from there. Thanks for the help.

mr48chev · 10-28-2011, 07:35 PM

As you aren't planning on keeping the six I'd just put the cost of swapping an automatic aside and add it to the V8 swap kitty. The worse problem with buying an old/original type transmission is that most likely you will have to have it rebuilt which is very expensive or pay a premium for one that has just been rebuilt and that is money that most likely you won't be able to recover when you go to sell the 235 and transmission.

mike16 · 10-29-2011, 10:10 PM

regardless, no hydro behind a six will handle a load in a 2 ton truck. unless you want to hunt down a military truck from the same era and retrofit it.(you dont,). and if you think a civilian hydro is hard to rebuild... then there is the anual tranny adjustments...oh and those specialised tools...

best bet is to install a clark 5 speed with a 5th gear overdrive and do a few asprin befor you drive.

dicer · 10-31-2011, 07:34 PM

With the proper size torque converter and something similar to B&M's old style turbo clutch adapters it maybe possible to use the stock bellhousing and adapt a turbo 350 to a 235.

Not what I was thinking of but this will adapt a 235 to the V8 style bolt pattern.
http://www.transmissionadapters.com/...V8%20Style.htm

iehotrod · 11-10-2011, 09:46 PM

well I have powerglide trans I just removed from my 235 it was all in a 57 bel air dont know if this is something that would work. It is a cast iron trans.

dicer · 11-11-2011, 03:26 AM

Oh I forgot. And not sure how it would fit in the AD series trucks, but a powermatic was the heavy truck automatic transmission of the day. It should be a plug and play deal at least in 56 up.

10-28-2011, 01:11 AM	#1
rcbildr Registered User Join Date: Sep 2000 Location: Gold Bar, WA Posts: 1,216	Transmission Question Unfortunately I don't have the time to do a good search on this. Anyways, my girlfriend bought a 1954 3800 series flatbed farm truck a couple years ago...from what we have been told it's spent all of it's life on our road. It has the 235 six and a manual trans. I know I can get the engine running, but I want to make the truck drivable for her until we can really "modernize" the running gear. Her plans are to do a 350/350 combo but have the engine look like it was a 1955 small block. For now I was wondering what are my options for putting an automatic trans behind the 235? Any help will be greatly appreciated. Thanks! __________________ My Projects: 1960 GMC 1/2ton with 305 V6 (daily driver) 1963 Chevy 1/2ton 2wd...converting to 4x4 1967 Suburban 1/2ton 2wd My Girlfriends Projects 1985 Chevy Suburban 3/4ton 4x4 with 6.2L diesel, 4" lift, converted to TH-400, Warn Premium manual hubs, & Wildcat 315/75/R16 tires. (daily driver) 1978 Camaro Type LT with a Marine 350 & vortec heads, Rochester Carb, & roller cam 1978 Camaro Z28

10-28-2011, 09:43 AM	#2
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,203	Re: Transmission Question It is difficult. The only bolt in would be a Hydramatic from a similar truck. They are heavy, aukward, & scarse. There is an adapter available to put a modern AT in a 235 but it is expensive & you will have to do extensive mods to the chassis. It seems to me you both could learn to drive the manual. It is probably a 4 speed with a floor shift. The clutches are soft on those. It will be more fun to drive then with an AT.

10-28-2011, 10:33 AM	#3
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,410	Re: Transmission Question I'd have to agree 100% With Wrenchbender Ret in that swapping to an automatic that would go behind the 235 would be a bit difficult and quite expensive. The Hydromatics that were in those trucks new are pretty hard to find and rebuilding one would probably cost more than a decent 350/350 combination installed. The adapters for a late trans behind those run pretty expensive by the time you are done. From Tom Langdon http://stoveboltengineco.com/index.p...roduct=1396439 The adapter runs 350.00 plus you still need a trans, crossmember and cooler along with linkage. It isn't that hard to drive a stick in one of these trucks.

10-28-2011, 12:10 PM	#4
OrrieG Registered User Join Date: Jun 2006 Location: Idaho Posts: 8,800	Re: Transmission Question I will agree Mr48 and Wrenchbender because I don't have time to find the thread where this was discussed in detail about 4 months ago. 235>>auto is a lot of work and expense. For the same time and less money you can drop the SBC in with an auto. To get a 350 to look like an early motor you need to use early heads. On carbed 350's should be ok. You will also need to run a short waterpump and find early accessory bracket sets. __________________ 1959 Chevy Short Fleetside w/ 74 4WD drive train (current project) OrrieG Build Thread 1964 Chevelle Malibu w/ 355-350TH (daily driver) Helpful AD and TF Manual Site Old Car Manual Project

10-28-2011, 06:59 PM	#5
rcbildr Registered User Join Date: Sep 2000 Location: Gold Bar, WA Posts: 1,216	Re: Transmission Question Thanks for the info. I've actually came across two of the hydramatic transmissions...one was at the swap meet a few weeks ago and was extremely expensive and the other was in a truck at a car show I went to last week. We both know how to drive sticks, it's just my girlfriend has bad arthritis in her left knee and ankle which makes driving a manual painful. It looks like for now I'll try to get it running and then go from there. Thanks for the help. __________________ My Projects: 1960 GMC 1/2ton with 305 V6 (daily driver) 1963 Chevy 1/2ton 2wd...converting to 4x4 1967 Suburban 1/2ton 2wd My Girlfriends Projects 1985 Chevy Suburban 3/4ton 4x4 with 6.2L diesel, 4" lift, converted to TH-400, Warn Premium manual hubs, & Wildcat 315/75/R16 tires. (daily driver) 1978 Camaro Type LT with a Marine 350 & vortec heads, Rochester Carb, & roller cam 1978 Camaro Z28

10-28-2011, 07:35 PM	#6
mr48chev Registered User Join Date: Jul 2007 Location: Toppenish, WA Posts: 15,410	Re: Transmission Question As you aren't planning on keeping the six I'd just put the cost of swapping an automatic aside and add it to the V8 swap kitty. The worse problem with buying an old/original type transmission is that most likely you will have to have it rebuilt which is very expensive or pay a premium for one that has just been rebuilt and that is money that most likely you won't be able to recover when you go to sell the 235 and transmission.

10-29-2011, 10:10 PM	#7
mike16 Registered User Join Date: Dec 2009 Location: bisbee, arizona Posts: 1,529	Re: Transmission Question regardless, no hydro behind a six will handle a load in a 2 ton truck. unless you want to hunt down a military truck from the same era and retrofit it.(you dont,). and if you think a civilian hydro is hard to rebuild... then there is the anual tranny adjustments...oh and those specialised tools... best bet is to install a clark 5 speed with a 5th gear overdrive and do a few asprin befor you drive.

10-31-2011, 07:34 PM	#8
dicer Registered User Join Date: Dec 2010 Location: seattle, wa Posts: 529	Re: Transmission Question With the proper size torque converter and something similar to B&M's old style turbo clutch adapters it maybe possible to use the stock bellhousing and adapt a turbo 350 to a 235. Not what I was thinking of but this will adapt a 235 to the V8 style bolt pattern. http://www.transmissionadapters.com/...V8%20Style.htm Last edited by dicer; 10-31-2011 at 07:56 PM.

11-10-2011, 09:46 PM	#9
iehotrod Registered User Join Date: Dec 2008 Location: Oak Hills, California Posts: 393	Re: Transmission Question well I have powerglide trans I just removed from my 235 it was all in a 57 bel air dont know if this is something that would work. It is a cast iron trans. __________________ 1952 Chevy Pick Up 1962 Chevy C10 Short Bed 1963 Chevy C10 Long Bed 1986 Chevy Silverado Short Bed 2004 Chevy Suburban-wifies ride

11-11-2011, 03:26 AM	#10
dicer Registered User Join Date: Dec 2010 Location: seattle, wa Posts: 529	Re: Transmission Question Oh I forgot. And not sure how it would fit in the AD series trucks, but a powermatic was the heavy truck automatic transmission of the day. It should be a plug and play deal at least in 56 up.



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