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BIG MUDDN 04-30-2011 03:26 PM

84 3/4 ton chevy, i get a horrible shake the faster i go
okay, so i have a rlly bad shake in my truck, its an 84 3/4 ton with a newly rebuilt vortec 350. i was wondering if one of the reasons for my shaking could be that, i noticed there are 2 bolts missing out of my tranny, where my bell housing connects to the rest of my tranny. and also having about a 3 second delay when i stomp the pedal to the floor. y is that? plz help me.

poncho62 04-30-2011 03:47 PM

Transmission being loose could cause this....Bad "U" joints could too....

Not sure what you mean with this 3 second delay, but sounds like you need a tune up.

richard stewart 3rd 04-30-2011 03:48 PM

Hi :welcome:
Welcome to Glad to have you with us

By a really bad shake do you mean vibration? or shaking as if a couple cylinders are missing?
As for the missing tranny bolts. I'd say there having no effect on vibrations or shaking, but I'd get two in there asap. Since you didn't know the bolts were missing, I assume someone else did the rebuild & insulation. makes you wonder what else wasn't don correctly.

BIG MUDDN 04-30-2011 03:53 PM

okay, its vibrating like horribly, but all cylinders are firing. all thats fine, i do need to replace one wire though, i just noticed it melted to my header. but has been shaking before that, umm. yeah, that delay is pissn me off. and pretty much everything on the motor is new. new gaskets, carb., distributor. i just replaced all the plugs, but, like i said. i gotta get a new wire.

BIG MUDDN 04-30-2011 03:55 PM

oh and i bought new u joints and were gunna replace them but was told mine were fine. so i took them back to auto zone.

mud bros 04-30-2011 05:06 PM


Originally Posted by BIG MUDDN
oh and i bought new u joints and were gunna replace them but was told mine were fine. so i took them back to auto zone.

get a second opinion

did they check all 6 of them? front axle joints are common to use up when your big muddn.

also make sure its in neutral with a wheel chocked verry common to check them in park or gear, and it holds them together.

look for a rust colored dust around the joint we call this death dust.

how about a bit more info too


123pugsy 04-30-2011 05:50 PM

Is it shaking under acceleration, at coast , at coast in neutral?

Delay sounds like a fuel delivery problem.

Spark plugs are firing but is fuel getting to the cylinders?

Firing order correct?

Did one of your fan blades break off?

BIG MUDDN 04-30-2011 06:16 PM

no they didnt check all 6, only the back ones. ummm, oh and idk about the t- case but just sent it in to get rebuilt. umm i looked all over the tranny and nothing. i cant figure out what exact type it is, but its a granny 4 speed. umm oh and the axels and everything besides a 2 0r 3 inch lift is stock. do u think my tires would cause such a severe vibration? and how do i fix the delay? could that be my fuel pump, i have an electric one i could put on there.

BIG MUDDN 04-30-2011 06:27 PM

no the fan blade didnt break off, and yes the firing order is correct, 1 8 4 3 6 5 7 2. and i changed all the plugs and need to change one wire for sure, but going to change all anyways, couldnt hurt. and it shakes when i get about 50 or 55 mph. the faster i go the more shake, it vibrates so bad it gets loud and cant hear anything.

lowROLLERchevy 04-30-2011 07:16 PM

66 Attachment(s)

Originally Posted by 123pugsy
Is it shaking under acceleration, at coast , at coast in neutral?

This is always a very important question that will narrow down where the vibration can be.

For example my 89 grand am would shake me so hard my vision would blur and I bit my own tongue a few times, but only between 72 & 76 mph, and had a lesser but very similar vibration around 35-40mph. Happened no matter what gear it was in, weather i was on the gas, cruising steady speed or coasting down.

The car had an out of round wheel in the rear which at certain speeds matched the "frequency" required to make the entire car vibrate as a unit, instead of just making a lot of road noise.

oldschool hero 04-30-2011 07:53 PM

You may want to check your tires to see if you have broken belts. I use to do the four wheeling thing back in the 80s and busted the belts on a set of Michelens with only 18,000 mi. on them. It took a front end man to figure it out which took him about 10 sec. when he stood in front of it while I drove toward him and he said it was duck walking,thats when I learned a lesson on vibration.

BIG MUDDN 05-01-2011 03:58 PM

okay, thank yall. as soon as i get my t-case back ill get someone infront of me when i drive towards them. my rear tire looks like someone got stuck on a rock and peeled out on it. but all the shake seems to be coming from the front.

SSedan64 05-01-2011 04:12 PM

Check the front steering & suspension parts, Tie Rods, Ball Joints, Pitman & Idler Arms etc..

BIG MUDDN 05-01-2011 04:16 PM

okay, i will. anything else it could be?

willowbilly3 05-01-2011 05:38 PM

Start with the simple stuff, mud in the wheels? Lots of those trucks need a shimmy shock or stabilizer, get one if you don't have it. Spin the tires and look for a lump or separation. Oh, and fix the stuff you already see wrong. You can't say an engine is running right if you have a plug wire melted to the header.
I recently had my van foul a plug and it sounded pretty normal but when the converter locked up it shook like a dog passing razor blades.
Who would tell you your u-joints are ok and not even look at all of them. How did they determine they were ok?
The hesitation could be a lot of things, what were you messing with just before it started doing that?

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