Trans question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**ScottH** · 03-22-2005, 03:28 PM

Looking at a 1980 K20 dually with 350/350 combo. Haven't seen it yet other than pics. Owner says good except needs brakes (no big deal). The only item that bothers me is he says trans shifts fine going thru gears, however you must manually down shift it when going down hills, etc. due to shift kit installed?? Also he thinks the trans came from a 69 Chevelle originally??

Can a 2wd car 350 be converted/used in a 4wd truck? Any suggestions as to what to look for or check out? Also any transfer/4wd items recommended to check out?

I have no knowledge of 4wd trucks so any info or suggestions are greatly appreciated.

Thanks.

crosby · 03-22-2005, 08:39 PM

Hi Scott. Are you sure it's a K20? That should be a 3/4 ton truck, which did not have dual rear wheels (to my knowledge). Even worse, a 350/350 combo doesn't sound right either. I suppose you could use a 2wd 350 (tranny) but you'd need to change the output cone, and possibly other parts. Manually shifting down going down hills? That sounds pretty normal to me. Usually, a truck or car will want the higher gear under less load, going downhill. Post some pics for everyone, okay? Good luck, I am sure someone with more information will post a reply shortly.

**ScottH** · 03-22-2005, 11:17 PM

Crosby, thanks for your input. Here is a link to the truck -

http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT

VIN number appears to be correct.

Any options would be appreciated.

Thanks.

bloertcher · 03-24-2005, 09:12 PM

It's probably been fooled with a bit,not always bad as long as the perpetrater knows what hes doing.The down shift thing sounds like a misadjusted kickdown cable(or even unhooked),as far as using a rwd 350 case,thats actually very common.All you have to do is swap in the 4wd tailshaft and remove the tail cone completely,thats what mounts to the transfer case adapter.However,be advised that a rwd case is much weaker in the bellhouse area than a 4wd case.This is due to the dustcover.For a rwd,it is tin or even plastic.On a 4wd case,it's cast aluminum.Usually not a problem,but it it's abused,it can cause the tranny case to break.It's certainly not a deal breaker if the trucks a buy,just inspect that area of the trans carefully.

bigarmzz · 03-24-2005, 11:12 PM

i clicked on the link

looks like ya got a decent truck

i'd say the kickdown cable is unhooked or needs adjusted

03-22-2005, 03:28 PM	#1
ScottH Senior Member Join Date: Sep 2002 Location: Hampstead, NC Posts: 8,187	Trans question Looking at a 1980 K20 dually with 350/350 combo. Haven't seen it yet other than pics. Owner says good except needs brakes (no big deal). The only item that bothers me is he says trans shifts fine going thru gears, however you must manually down shift it when going down hills, etc. due to shift kit installed?? Also he thinks the trans came from a 69 Chevelle originally?? Can a 2wd car 350 be converted/used in a 4wd truck? Any suggestions as to what to look for or check out? Also any transfer/4wd items recommended to check out? I have no knowledge of 4wd trucks so any info or suggestions are greatly appreciated. Thanks.

03-22-2005, 08:39 PM	#2
crosby Registered User Join Date: Aug 2004 Location: New Hampshire Posts: 437	Hi Scott. Are you sure it's a K20? That should be a 3/4 ton truck, which did not have dual rear wheels (to my knowledge). Even worse, a 350/350 combo doesn't sound right either. I suppose you could use a 2wd 350 (tranny) but you'd need to change the output cone, and possibly other parts. Manually shifting down going down hills? That sounds pretty normal to me. Usually, a truck or car will want the higher gear under less load, going downhill. Post some pics for everyone, okay? Good luck, I am sure someone with more information will post a reply shortly. __________________ Crosby 1978 Chevrolet K10 stepside NH

03-24-2005, 11:12 PM	#5
bigarmzz Registered User Join Date: Sep 2004 Location: Elkins, West Virginia Posts: 2,542	i clicked on the link looks like ya got a decent truck i'd say the kickdown cable is unhooked or needs adjusted __________________ 1987 350 TBI lowered 5/7

03-22-2005, 11:17 PM	#3
ScottH Senior Member Join Date: Sep 2002 Location: Hampstead, NC Posts: 8,187	Crosby, thanks for your input. Here is a link to the truck - http://cgi.ebay.com/ebaymotors/ws/eB...RK%3AMEWA%3AIT VIN number appears to be correct. Any options would be appreciated. Thanks.

03-24-2005, 09:12 PM	#4
bloertcher Registered User Join Date: Jul 2003 Location: Springfield,Mo. Posts: 305	It's probably been fooled with a bit,not always bad as long as the perpetrater knows what hes doing.The down shift thing sounds like a misadjusted kickdown cable(or even unhooked),as far as using a rwd 350 case,thats actually very common.All you have to do is swap in the 4wd tailshaft and remove the tail cone completely,thats what mounts to the transfer case adapter.However,be advised that a rwd case is much weaker in the bellhouse area than a 4wd case.This is due to the dustcover.For a rwd,it is tin or even plastic.On a 4wd case,it's cast aluminum.Usually not a problem,but it it's abused,it can cause the tranny case to break.It's certainly not a deal breaker if the trucks a buy,just inspect that area of the trans carefully.



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