73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: frotosride on June 19, 2013, 10:30:20 pm
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Ok so I have lived with this long enough. Drive train is stock 350 TBI th700-r4 NP208. When placed in drive it is noticeable but mostly when I go into reverse. No matter which gear I am coming from either park, drive or neutral the tranny seems to just slam into reverse jerking the truck and a very auditable clunking sound as if I were pressing the gass and slamming it into reverse. Could this just be a valve sticking or worn parts inside the tranny. Thanks for the input!
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it sound like slop in the rear. have someone shift from rev to drive with their foot on the brakes and you look at the drive shaft it shouldn't move that much. if it does then your rear needs to be rebuilt or replaced. easier to replace and no special tools needed. just make sure you match the ratios
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It's the tranny not the rear end, rear ends all have an amount of slop between the axles and the lash in the gears, tranny has too much apply pressure to reverse gear see that quite often, could be dirt a valve sticking?, the TH400 in my 86 dually did it when I got it come to find out that when they put a shift kit in they in they messed up the VB to case gasket somehow, put a new one in and everything was good..
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Check the transfer case mounts. The rubber could be collapsed and going metal to metal when the torque twists everything to that side.
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Well, the drive shaft barely moves as it shouldn't move much anyway when placed in reverse and brakes on but I can definitely hear it slamming into reverse in the tranny. All my mounts are good despite how old they are. Last thing I want to do now is pull the transmission especially since I don't have my swap engine yet. I have a new filter with gasket and new fluid so maybe some investigation is in order hen I get in there. I know that there hasn't been any upgrades to this tranny or the truck for that matter(except for what I've done in the last few years) because it's been in the family since purchased from the dealer and I'm only the third owner.
If I can figure out how to post a video of it I will.
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Ok first of all....what is your truck idling at when you shift it into gear? also check to make sure the transmission to engine bolts are tight....also make sure the torque convertor bolts are tight.
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74 the only reason i said that was because my 86 back in 05 or so would slam into gear. and would clunk. had someone look at the shaft as i shifted and it would move a little less than 1/8th of a turn before stopping. then a couple month later hit some water spun the tires then once she hit dry pavement it made the rear end exploded so hard the dif cover had a bug dent into it. but a little check like he did eliminated it as a probable problem.
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Out of curiosity how did you check the mounts? did you look at them or have someone switched the gears back and forth as you looked at it?.....or take a jack and place it under the transfer case and jack it up up seeing if you had any play at all on the mount?
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Out of curiosity how did you check the mounts? did you look at them or have someone switched the gears back and forth as you looked at it?.....or take a jack and place it under the transfer case and jack it up up seeing if you had any play at all on the mount?
I used my jack at different angels because my wife just had heart surgery and I don't trust my 7,5,3 or 1 year old to shift through the gears with me under it...although I did have to convince myself not to let my oldest do it because my E-brake works really good not! Maybe I can get a neighbor to do it just to make sure I didn't miss anything.
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74 the only reason i said that was because my 86 back in 05 or so would slam into gear. and would clunk. had someone look at the shaft as i shifted and it would move a little less than 1/8th of a turn before stopping. then a couple month later hit some water spun the tires then once she hit dry pavement it made the rear end exploded so hard the dif cover had a bug dent into it. but a little check like he did eliminated it as a probable problem.
LOL, I done that once rpm to the moon and when it grabbed kaboom, except I left the all the internals on the road,lol...
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74 i was like wth was that, it stalled the engine so i coasted into walmarts parking lot started the engine and couldnt move then i saw my drive shaft was just a spinning lol. but froto i know if i had life insurance i wouldnt get my wife to step on the brakes lol. but you could improvise with a camera
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but froto i know if i had life insurance i wouldnt get my wife to step on the brakes lol. but you could improvise with a camera
Good point....I have a $400k policy so maybe I will trust my son. Actually my neighbor's boy friend is usung my jack stand to replace the blocks on his rear with custom leafs s looks like he's indebted to help me bleed my brakes!!! ;D So looks like he will be hitting a few hears for ma as well!