turbo 350 shifts hard into reverse - The 1947 - Present Chevrolet & GMC Truck Message Board Network

peglegs · 03-16-2012, 12:56 AM

1987 4x4 305 turbo 350 1st, 2nd & 3rd shifts quick/crisp but very hard into reverse it was suggested that some po installed a shift kit which is the reason it slams into reverse??? doesnt sound right. I thought it shifted smooth & quick through the 3 forward gears what do u think, thanks

jfortvalley · 03-16-2012, 10:41 PM

probably has a shift kit but sounds more like whoever built it may have left the wave plate out of direct but you really dont want a stock 350 in a 4 wheel drive how hard is like chirp the tires when put in to rev hard on asphalt ?

peglegs · 03-17-2012, 12:48 AM

ty for responding j, no its not that hard of a clunk if i took my foot off the brake & put it in reverse it wouldnt do much i realize its hard to diagnose like this. tis is a recent purchase and will check out the universals when this rain storm pass' next week but i really dont think its that. isnt this 350 stock to this truck? the vin indicated that

Gumby · 03-17-2012, 12:54 AM

Sounds odd, I got a built TH350 in the wagon, and chose the firm shift kit when asked, also Im using RP racing ATF that shifts even firmer and have no such trouble.

up shifts are easily controled with my right foot, from un-noticeable to break your neck.

Does it do this every time? Are you parked in a slant when it happens or level ground does it too?

cableguy0 · 03-17-2012, 11:24 AM

Ok, First thing to check is your u joints. The clunk your hearing could be free play in a u-joint. When your going forward the u joint will stay quiet and not clunk because its locked in one direction. When you put the trans in reverse the driveshaft turns the other way Which cause the u joint to clunk or slam from the change in direction. Your going to need another person to verify. With your foot on the brake Put the trans into drive with the engine running. Now with your foot still on the brake put it in reverse. Have someone watch the u joints. What your looking for is movement between the yoke and the shaft itself.

Wrenchbender Ret · 03-17-2012, 06:24 PM

350,s will do this if idleing too fast. Try slowing down the idle speed as much as you can & still get a decent idle when in drive.

03-16-2012, 12:56 AM	#1
peglegs Registered User Join Date: Jul 2009 Location: grants pass, oregon Posts: 390	turbo 350 shifts hard into reverse 1987 4x4 305 turbo 350 1st, 2nd & 3rd shifts quick/crisp but very hard into reverse it was suggested that some po installed a shift kit which is the reason it slams into reverse??? doesnt sound right. I thought it shifted smooth & quick through the 3 forward gears what do u think, thanks __________________ 1990 chevy 4x4 with a 1940 IHC body

03-16-2012, 10:41 PM	#2
jfortvalley Registered User Join Date: Mar 2012 Location: fortvalley ga Posts: 345	Re: turbo 350 shifts hard into reverse probably has a shift kit but sounds more like whoever built it may have left the wave plate out of direct but you really dont want a stock 350 in a 4 wheel drive how hard is like chirp the tires when put in to rev hard on asphalt ?

03-17-2012, 12:48 AM	#3
peglegs Registered User Join Date: Jul 2009 Location: grants pass, oregon Posts: 390	Re: turbo 350 shifts hard into reverse ty for responding j, no its not that hard of a clunk if i took my foot off the brake & put it in reverse it wouldnt do much i realize its hard to diagnose like this. tis is a recent purchase and will check out the universals when this rain storm pass' next week but i really dont think its that. isnt this 350 stock to this truck? the vin indicated that __________________ 1990 chevy 4x4 with a 1940 IHC body

03-17-2012, 12:54 AM	#4
Gumby Registered User Join Date: Dec 2008 Location: NW-Ohio Posts: 2,525	Re: turbo 350 shifts hard into reverse Sounds odd, I got a built TH350 in the wagon, and chose the firm shift kit when asked, also Im using RP racing ATF that shifts even firmer and have no such trouble. up shifts are easily controled with my right foot, from un-noticeable to break your neck. Does it do this every time? Are you parked in a slant when it happens or level ground does it too? __________________ Chevy GMC Trucks Find Of The Day https://www.facebook.com/ChevyGmcTrucksFindOfTheDay or http://ChevyGMCTrucks.com

03-17-2012, 11:24 AM	#5
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,948	Re: turbo 350 shifts hard into reverse Ok, First thing to check is your u joints. The clunk your hearing could be free play in a u-joint. When your going forward the u joint will stay quiet and not clunk because its locked in one direction. When you put the trans in reverse the driveshaft turns the other way Which cause the u joint to clunk or slam from the change in direction. Your going to need another person to verify. With your foot on the brake Put the trans into drive with the engine running. Now with your foot still on the brake put it in reverse. Have someone watch the u joints. What your looking for is movement between the yoke and the shaft itself. __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

03-17-2012, 06:24 PM	#6
Wrenchbender Ret Registered User Join Date: Oct 2005 Location: Overland Park, Ks. Posts: 5,229	Re: turbo 350 shifts hard into reverse 350,s will do this if idleing too fast. Try slowing down the idle speed as much as you can & still get a decent idle when in drive.



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