Shaky Ride

Tiny
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I have a 1990 Chevy 1500. It is a single cab, long wheel base model housing a 350 V8-5.9L. I had allowed someone to borrow the vehicle and during that time my driver side brakes evidently locked up. I ending up replacing everything on that hub including the brake lines. I finally retrieved the truck with a flat tire and immediately had a set of 4 new tires put on and a bent idler arm replaced. Approximately 2 weeks later I noticed that when slowly speeding up the truck would randomly start to shudder. I replaed the plugs, wires, rotor button, distributor cap, U-Joints, and fuel filter. It is now about 6 months later and the truck is almost not driveable. It seems to hesitate randomly during driving ( no engine rev ) and shakes when beginning to speed up and when I take my foot off of the pedal. The truck seems to be running fine, but shakes tremendously only when I am beginning to speed up or immediately when I am letting off of the gas. Some times after I stop and the truck is running it will sit smooth and then "jump" with a thud and start shaking. It seems as if something is engaging or disengaging and shutter or hesitates wen doing so. I started the truck this morning and the Parking Brake light was on. Of course the parking brake was not engaged and I did not have any feeling of lurching while driving. Could this be related, but most importantly what is causing this shaking?
Tuesday, August 7th, 2007 AT 12:59 PM

16 Replies

Tiny
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Not sure without having it. Would you say it is a mis-fire from the engine? Almost sounds like the rear end is having problems. May need to run it up on a lift.
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Tuesday, August 7th, 2007 AT 1:13 PM
Tiny
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I have had others tell me it is possibly a rear end problem. I appreciate your input.
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Tuesday, August 7th, 2007 AT 10:01 PM
Tiny
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Once it is up on a lift and in gear, the noise is a lot easier to narrow down. You can pull the rear cover on the differential and get a good look at the fluid condition. That may be a tell tale sign. The fluid level is good I hope.
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Wednesday, August 8th, 2007 AT 5:03 AM
Tiny
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Yes sir. I have checked the fluid level and it is sufficient. The noise however is not something that you hear constantly. Also,
I want to clarify that the shaking can be relieved by either pressing the gas harder or by releasing the gas pedal. I have also been told that it seems s if it is my transmission, but the truck never rev's even during the hestation. It seems as if something is not catching and then it will catch either if I press the gas harder or if I release the pedal. When I have the hesitation or shaking, if I hold the pedal steady it will work out of it with a jolt. Like something catches. Is this indicative of a rear end problem?

PS: I really appreciate your help and this web site. I have never visited it and found it in a google search. HUGE HELP!
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Wednesday, August 8th, 2007 AT 6:28 PM
Tiny
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Yes the Internet is truley a god-send. How cool is it that you can talk one on one about any problem imaginable and get some solid feedback?...Too Cool!!


https://www.2carpros.com/forum/automotive_pictures/30961_fonzi_5.jpg



Have you check the u-joints? Do you know how?

Do you have one piece drive shaft?
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Sunday, August 12th, 2007 AT 8:27 PM
Tiny
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The noise however is not something that you hear constantly (intermittant)

The shaking can be relieved by either pressing the gas harder or by releasing the gas pedal. ( Happens at cruising speed)

The truck never rev's even during the hestation.
(-So it isn;t slippng)

It will catch either if I press the gas harder or if I release the pedal.

When I have the hesitation or shaking, if I hold the pedal steady it will work out of it with a jolt. Like something catches. Is this indicative of a rear end problem
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Sunday, August 12th, 2007 AT 8:44 PM
Tiny
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Yes, I have actually changed the U-Joints and I do have a 1 piece drive shaft. This w/e my truck died at a red light. It would crank and turn, but not start. I put a new coil and Control Module (Distributor) in and it began working. When the truck died; however a trouble code for a TPS Sensor came up. The truck is actually riding smootherl, but the shakiness has continued.

The shaking happens occasionally while idoling and at a steady ride, but consistantly when speeding up slowly at speeds above 45. It does happen at speeds below 45, but only occasionally. Now, accompanying the shaking is a hesitating or lurching when taking off. I seem to also have a huge loss of power at the top of my gears.. (I.E on interstate when speeding up it will not "kick into high gear". Seems to stay in the same gear giving me no power) but, again, NO REV? (Doesnt feel like the transmission is slipping, but does feel as though it is not changing gears correctly)

I am thinking Torque Converter? Would this fit the bill?
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Sunday, August 12th, 2007 AT 9:52 PM
Tiny
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It may lead to the converter or the TCC or more. With the tps code, you have to go after this first and is likley related.
This is the circuit:


https://www.2carpros.com/forum/automotive_pictures/30961_tps_1.jpg



The TPS is NOT adjustable on this one. The voltage should be 1.25-5.0.

Install jumper wires to enable a connection of a DVOM in paralel between TPS harness connectors. Connect DVOM positive lead to Dark Blue wire Terminal. Connect negative lead to Black wire termnal.

Turn the ignition on, engine off. Signal voltage should gradually change form less than one volt at closed throttle to about 5.0 volts and wide open throttle position.
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Monday, August 13th, 2007 AT 10:13 AM
Tiny
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Okay I will do that. The trouble code went out after I had the coil and Control Module replaced.I am waiting on the drive cycle to complete (not sure of the cycle on this truck) before checking again. If so I believe this to be a seperate problem as theTHE ENGINE RUNS PERFECT, EVEN WHEN THE SHAKING IS HAPPENING. I have little problems in the first 2 or 3 gears. It is the interstate and above 50 that gives me fits.
I have taken the information that you have given me to a friend (mechanic) who (after driving) believes it to be the torque converter, but still feels it could be the rear end. I am having it changed on Sat. I am hoping that this is the problem. Today while on the interstate I was doing around 70 and I sped up to go around a car. The truck changed momentum slowly, but did not seem to change gears. I slowed and got back behind the vehicle now doing around 50. During this I never felt the gears change. I then tried to speed up and the shaking happened. Then it jerked into gear and kept going. This is the first and only time I have ever felt anything that points to slipping issue. I am hoping that this is torque converter, but I know little about advanced maitenance. I have no clue about the transmission or how it works and am having a hard time figuring this out.

Any more advise?
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Monday, August 13th, 2007 AT 7:16 PM
Tiny
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I didn't realize the code went out. Post how you make out on Sunday.
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Monday, August 13th, 2007 AT 8:50 PM
Tiny
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I had the towue converter changed out this w/e. My mechanic said that he shook it and it sounded like a half empty cereal box. He could here a bunch of parts just rattling around in there. I was happy to hear that being that I was hoping it would be the problem. Even the new torque converter isnt lockingout. It feels as if I am in the same gear at any speed above 45. If I get up to 65-80 the truck is running at HIGH RPM, but then I will let off to 45-50MPH and I will have no power and will take forever to speed up. The torque converter isnt locking up in the "coupling" stage (gotta love wikipedia). Could this still be a problem with the TPS or the throttle wire? Or am I just plain hosed?
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Tuesday, August 21st, 2007 AT 3:01 PM
Tiny
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In my opinion your transmission is burning up due to damage within the trans it self. The more you drive on a clutch (within the trans) that is either damaged or wearing out from ware and tare the faster you shorten the life-span of the trans itself.

Try this to make sure your motor is not the problem. Put the car back on lifts or secured on jack stands, start the car and leave it running sounds risky I no but before you do this make sure your parking brake is engaged and you no for sure it works, usually you no its good if it gets tight after 3 to 4 clicks. Now listen to the motor as it spends, if the motor is the problem you should here issues around the cam something like taps or sounds like rocks. Just because the motor sounds fine dose not mean it is. I drove a car on bad bearings for a year before it went out. Just an example. If the motor sounds clear then your transmission needs to be taken to an honest transmission mechanic whom can test the solenoids in the transmission to make sure the problem is not electrical. This of course would require that the trans be removed from the car. I want to say that it sounds to me that the trans either needs to be swapped or rebuilt but I no cheaper is better.

A lot of typing I no bare with me. Last but not least would be your differential gears, they could be damaged have you checked them visually to make sure their fine and not chipped or broken, even though I believe this is a long shot.

I will check back soon to see what the status is.
Hope this helps

Richard
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Tuesday, August 21st, 2007 AT 3:39 PM
Tiny
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Have you run the truck while up in the air like I mentioned early on?
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Tuesday, August 21st, 2007 AT 5:42 PM
Tiny
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Yes sir, I ran the truck in the air and did not hear any clanking. My mechanic today reset the throttle (wire?). I am going try that tomorrow and see if it helps. It seemed to run a little better, but I haven't gotten it up to speed yet. Ill post it in morning.
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Tuesday, August 21st, 2007 AT 8:42 PM
Tiny
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I am getting alot better response from the truck after resetting the throttle wire. The truck is still a little jumpy, but it seems more of an engine miss than anything else. With 200,000 miles, I guess it's always something. Im going to continue to dial it in, but I am relieved to see the transmission and torque converter doing their jobs! Thanks!
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Thursday, August 23rd, 2007 AT 6:36 PM
Tiny
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You lnow what you might want to try is running some seafoam carbon remover through the system.
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Friday, August 24th, 2007 AT 5:24 AM

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