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73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Buddy on November 02, 2010, 06:49:02 pm
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I have a 305 and a 700r tranny. Dont know much history about them other than the previous owner told me they where rebuilds. I am just getting the truck back together and i have noticed when I switch gears in goes in gear real hard. it shifts fine with the shifter but seems to bang and jump into gear. Nothing crazy just seems to clunk hard. kinda hard to explain I guess. I also noticed that i have waty to much tranny fliud in there and I am going to get that out this week. I am not driving this truck as of yet stroll in the re build phase. this is just what i have noticed taking it in and out of the shop. any ideas?
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I had a similar snapping sound when going from park to drive and it turned out to be bad u-joints, and one was even the wrong size. I would check your u joints for excessive play.
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Mine also "clunks" into gear. Doesn't seem to be specifically related to engine or transmission, but as the whole vehicle "jerks" backward into Reverse or "jerks" forward into Overdrive. When I say, "jerks", I mean that (normal) feeling when a person puts any kind of vehicle into forward or reverse gear....simply has an extra noise. I believe this is what the OP is referring to. For my pick-up, I am curious as to the conditions of the transmission rubber mount and the u-joints, as mentioned.
Park to Reverse
Park to Overdrive
Reverse to Overdrive
Overdrive to Reverse
= embarrassing, audible clunk.
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things that can cause it bad mounts, bad u joints and slop in rear. get some one to help you out keep the e brake and brake on and get them to make it pop and clunk and see where it comes from what moves first and all. I think a bad u joint is a higher ping due to the material it’s made out of and the echo of the drive shaft while the rear is a clunk due to again the material and the mounts well its kind of a clunk also lol
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all my mounts are new and my u joints are also new, I am leaning towards to high of an idle
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I almost mentioned a high idle, but thought you might had ruled that out already.
Pick-up I have doesn't have a tachometer, but a few weeks ago I bought a Craftsman Professional digital timing light that has all kinds of features including a tachometer. Works really well, I love it.
Good idea, Irish_Alley, to have someone put it in and out of gear while someone watches underneath.
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Does it move forward when you do put it in gear? You don't have a tach. Also did it do it before you changed u joints
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I dont know if it did this before as i never drove it, just bought and tore it down. As far as moving forward i would say yes maybe a little. all i know for sure is that is far from smooth
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I would definitely see what your rpms are