TH-350 locking up in reverse?? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**JQ-72** · 01-06-2018, 06:42 PM

I just bought a 1978 1/2 ton 2wd from original owner with 97k miles, but it's been sitting since 2008. After plugs, fresh gas and 2 quarts of trans fluid, she's back to life! However, when I put it in reverse it bogs real bad and tries to go dead. I gave it about half pedal and it just sits there and bogs like the e-brake is on. What gives?? Thanks got any info.
Joshua

garyd1961 · 01-06-2018, 08:56 PM

Does it go forward when you put it in drive? If not the brakes are probably seized/locked up.

**JQ-72** · 01-06-2018, 09:32 PM

Yes, I drove it about 150 yards to the end of my driveway then tried to turn around. That's when reverse locked up. I put it back in drive and drove it back to my house. I tested reverse again when I got to the garage and same problem.

andyh1956 · 01-07-2018, 01:51 AM

I bet your trans is in two gears at once. Most likely something stuck in the valve body or a band stuck from siting.

**PGSigns** · 01-07-2018, 10:17 AM

Jack it up and try and turn the rear wheels with the trans in neutral and the truck not running. They should turn easily with a little drag. If they are tight pull the drums. After sitting that long there is a good chance the brakes need going through.
Jimmy

**JQ-72** · 01-07-2018, 06:04 PM

Gotta be the trans. I tried it again today and now it stuck in drive no matter gear I put it in

**PGSigns** · 01-07-2018, 08:44 PM

Have you jacked it up and checked the brakes? A truck that has sat that long with any amount of water in the brake fluid with have wheel cylinder problems. The more you push on the brakes the tighter things will get. I have seen this on many vehicles in my more than 40 years of working on cars. Having issues in reverse first and now all locked up is brakes.
Jimmy

**Ironangel** · 01-08-2018, 04:38 AM

Quote:

Originally Posted by PGSigns

Have you jacked it up and checked the brakes? A truck that has sat that long with any amount of water in the brake fluid with have wheel cylinder problems. The more you push on the brakes the tighter things will get. I have seen this on many vehicles in my more than 40 years of working on cars. Having issues in reverse first and now all locked up is brakes.
Jimmy

Agreed...

**Ironangel** · 01-08-2018, 04:54 AM

Quote:

Originally Posted by JQ-72

Gotta be the trans. I tried it again today and now it stuck in drive no matter gear I put it in

If the rear wheels rotate freely yet the tranny is stuck in drive then the valve body has sticking valves. A half gallon low on fluid would indicate something wrong and if ran low like that before it was parked 10 years ago would just about cook a transmission. Drop the pan and see whats laying in the bottom of that pan. If it's full of mud start shopping for a good used transmission, they can be had for cheap from local junk yards and transmission shops...

cadillac_al · 01-08-2018, 10:30 AM

I'm with Andy and something is stuck in your valve body. I would drop the pan and see what it looks like in there. I'll bet cleaning the valve body would most likely fix it but I would blow $22 and put a Transgo shift kit in it at the same time. If you look at Transgo's web site their trans video will show you how easy the valve body comes apart. I'm sure something is stuck in there.

01-06-2018, 06:42 PM	#1
JQ-72 Senior Member Join Date: Feb 2001 Location: Killen, Alabama USA Posts: 3,528	TH-350 locking up in reverse?? I just bought a 1978 1/2 ton 2wd from original owner with 97k miles, but it's been sitting since 2008. After plugs, fresh gas and 2 quarts of trans fluid, she's back to life! However, when I put it in reverse it bogs real bad and tries to go dead. I gave it about half pedal and it just sits there and bogs like the e-brake is on. What gives?? Thanks got any info. Joshua __________________ 72 Cheyenne Super swb. Factory 402/400,tach,posi,AM/FM, A/C. Adding cruise, 8-track 72 Cheyenne Super swb. 350/350 A/C, bucket seats 72 Cheyenne swb. Factory 402/400, tilt, posi, A/C 72 Cheyenne Super K-10. 350/4 spd., posi. 72 Suburban 350/350 tilt, tach, AM/FM, A/C, luggage rack 72 GMC Sierra lwb. 350/350, A/C. medium green/olive interior

01-06-2018, 08:56 PM	#2
garyd1961 Registered User Join Date: May 2016 Location: Henderson NC Posts: 975	Re: TH-350 locking up in reverse?? Does it go forward when you put it in drive? If not the brakes are probably seized/locked up.

01-06-2018, 09:32 PM	#3
JQ-72 Senior Member Join Date: Feb 2001 Location: Killen, Alabama USA Posts: 3,528	Re: TH-350 locking up in reverse?? Yes, I drove it about 150 yards to the end of my driveway then tried to turn around. That's when reverse locked up. I put it back in drive and drove it back to my house. I tested reverse again when I got to the garage and same problem. __________________ 72 Cheyenne Super swb. Factory 402/400,tach,posi,AM/FM, A/C. Adding cruise, 8-track 72 Cheyenne Super swb. 350/350 A/C, bucket seats 72 Cheyenne swb. Factory 402/400, tilt, posi, A/C 72 Cheyenne Super K-10. 350/4 spd., posi. 72 Suburban 350/350 tilt, tach, AM/FM, A/C, luggage rack 72 GMC Sierra lwb. 350/350, A/C. medium green/olive interior

01-07-2018, 01:51 AM	#4
andyh1956 Registered User Join Date: Mar 2010 Location: thomastown mississippi Posts: 1,261	Re: TH-350 locking up in reverse?? I bet your trans is in two gears at once. Most likely something stuck in the valve body or a band stuck from siting.

01-07-2018, 10:17 AM	#5
PGSigns Senior Member Join Date: Jan 2011 Location: Hayes Va Posts: 4,569	Re: TH-350 locking up in reverse?? Jack it up and try and turn the rear wheels with the trans in neutral and the truck not running. They should turn easily with a little drag. If they are tight pull the drums. After sitting that long there is a good chance the brakes need going through. Jimmy __________________ 60 to 66 Chevy and GMC window decals http://67-72chevytrucks.com/vboard/s...d.php?t=661131 Good friends, good food and a hotrod what else do you need? 1966 BBW long fleet Daily driver 1965 BBW short fleet Sold and going to a good home 1965 Suburban 2003 3500 Duramax 2005 Ultra Classic

01-07-2018, 06:04 PM	#6
JQ-72 Senior Member Join Date: Feb 2001 Location: Killen, Alabama USA Posts: 3,528	Re: TH-350 locking up in reverse?? Gotta be the trans. I tried it again today and now it stuck in drive no matter gear I put it in __________________ 72 Cheyenne Super swb. Factory 402/400,tach,posi,AM/FM, A/C. Adding cruise, 8-track 72 Cheyenne Super swb. 350/350 A/C, bucket seats 72 Cheyenne swb. Factory 402/400, tilt, posi, A/C 72 Cheyenne Super K-10. 350/4 spd., posi. 72 Suburban 350/350 tilt, tach, AM/FM, A/C, luggage rack 72 GMC Sierra lwb. 350/350, A/C. medium green/olive interior

01-07-2018, 08:44 PM	#7
PGSigns Senior Member Join Date: Jan 2011 Location: Hayes Va Posts: 4,569	Re: TH-350 locking up in reverse?? Have you jacked it up and checked the brakes? A truck that has sat that long with any amount of water in the brake fluid with have wheel cylinder problems. The more you push on the brakes the tighter things will get. I have seen this on many vehicles in my more than 40 years of working on cars. Having issues in reverse first and now all locked up is brakes. Jimmy Attached Images __________________ 60 to 66 Chevy and GMC window decals http://67-72chevytrucks.com/vboard/s...d.php?t=661131 Good friends, good food and a hotrod what else do you need? 1966 BBW long fleet Daily driver 1965 BBW short fleet Sold and going to a good home 1965 Suburban 2003 3500 Duramax 2005 Ultra Classic

01-08-2018, 10:30 AM	#10
cadillac_al Registered User Join Date: Oct 2013 Location: Maine Posts: 2,332	Re: TH-350 locking up in reverse?? I'm with Andy and something is stuck in your valve body. I would drop the pan and see what it looks like in there. I'll bet cleaning the valve body would most likely fix it but I would blow $22 and put a Transgo shift kit in it at the same time. If you look at Transgo's web site their trans video will show you how easy the valve body comes apart. I'm sure something is stuck in there. __________________ 76 Chevy K20 76 GMC K15 77 Chevy C10 77 Chevy K10

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