Truck shakes violently

Chanzilla

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Feb 15, 2013
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San Antonio
This is a long story, because its been a snow ball effect. I apologize in advance, and thank you for any help whatsoever.
1st off. I had a barely noticeable leak from my fuel filter housing. I put it off for around 3 weeks until it got pretty bad. I swapped housings the same week. Doing so fixed my leak.
After that, I was getting a p2152 code (Fuel Injector Group C Supply Voltage Circ/Open). The exhaust sounded odd, like a small surge or like it was missing. On my 3 hour drive home from school, I ended up losing my #2 injector, which is grouped with the #5 injector, so inherently, both were not working on my way home. It had low power (obviously) and would shake and random times throughout the drive and shifted oddly. I figure all of that was normal. I pulled resistance from the #2 and 5 injectors, and #2 was toast. I replaced it and it began working again. It did not fix my #5 injector though.
It turns out, that fuel leaked into the #5 fuel injector connection and was causing the problems. I cleaned and dried out the connector and all was well on the injector side of things.
I assumed that would fix things, but when I went to test drive, it would shake violently after around 16 miles an hour. I went back home and put it in drive and put some pedal down to check the motor mount, and the drivers side was shot, It was completely separated from the metal. I just replaced that 4 days ago and It still shakes. I Have not had time to change the other motor mount but I will when I have time. (It is finals week here in college so I have other things going on).
I haven't been driving it until today, I drove backroads to discount tire (15 mph)to see if the tire came apart inside itself. I was told to go check that by a mechanic friend back home. Turns out the tires are fine.
Finally, I was able to cruise down a hill on the way home. I put it in neutral and got to around 27 mph and it was riding smooth like our chevy's do. So I've pretty much ruled out suspension, driveshaft, and tires.
I am so lost right now. Any help would be great. Thanks, Chandler!
 

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May the farce be with you
Jun 9, 2012
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So, Chandler, the engine now idles smooth, revs fine in neutral and in general seems to run fine, but does it still have no power under load? We're there codes, and did you clear them?

well, you shouldn't discard suspension and chassis just yet, have you checked the wheel bearings and CV shafts? Those are general wear and tear maintenance and replacement parts that typically get overlooked

I'm sorry to say, shaking violently isn't the best sign:(
what does the exhaust look and smell like?
Do you know what the balance rates are?
I have terrible "luck" so if it were me it might be time to check for some more serious issues
just my thoughts...

good luck man
 
Last edited:

Chanzilla

Member
Feb 15, 2013
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San Antonio
I feel like it might be the transfer case..

The truck idles smooth, revs fine, and yes generally seems to run fine. Its kind of hard to tell if there is any loss of power still being that I am confined to >17 mph.
The wheel bearings are good, I replaced them around 4 thousand miles ago and the cv shafts seem to be fine. I know they are ripped and will replace them during my christmas break.
The exhaust looks and smells fine. I cannot read balance rates with my auto cal, Which I thought was a capability... But I guess not.
Yes I have a feeling something is in pretty bad shape. When I under the pickup swapping motor mounts I noticed there was a decent amount of reddish fluid around the trans cross member, Im not sure if that is transmission or transfer case fluid. Are they different?
Thank you both for the information. Chandler
 

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May the farce be with you
Jun 9, 2012
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I feel like it might be the transfer case..

The truck idles smooth, revs fine, and yes generally seems to run fine. Its kind of hard to tell if there is any loss of power still being that I am confined to >17 mph.
The wheel bearings are good, I replaced them around 4 thousand miles ago and the cv shafts seem to be fine. I know they are ripped and will replace them during my christmas break.
The exhaust looks and smells fine. I cannot read balance rates with my auto cal, Which I thought was a capability... But I guess not.
Yes I have a feeling something is in pretty bad shape. When I under the pickup swapping motor mounts I noticed there was a decent amount of reddish fluid around the trans cross member, Im not sure if that is transmission or transfer case fluid. Are they different?
Thank you both for the information. Chandler

typically, yes they are different fluids.
the transfer case gets GM Auto-Trac2, is blue
less than 17mph...wow
seems odd this wasn't an issue before the injector issues?
 

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May the farce be with you
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ATF in the transfer case. The blue stuff is for the auto 4WD applications

:confused:
really, standard automatic transmission fluid is what GM fills our transfer cases with rolling off the factory line?

My GM service dept gave me 2qts auto-trac when I came in to buy fluid, but come to think about it, I really have no idea what's in there now :(
I didn't service it last and ya never know, unless ya know.
 

clrussell

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Sep 23, 2013
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:confused:

really, standard automatic transmission fluid is what GM fills our transfer cases with rolling off the factory line?



My GM service dept gave me 2qts auto-trac when I came in to buy fluid, but come to think about it, I really have no idea what's in there now :(

I didn't service it last and ya never know, unless ya know.


Yep dex 3.. Unless it has the auto button.. Or 5-30 oil works too


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TeaBagger2006

Im a Garrett Nut Swinger
May 11, 2008
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Check your u joints on your driveshaft. Remove the shaft and check them. I had a similar problem and it turned out to be a seized u joint. I couldn't tell with the shaft on the truck but when I removed it it was obvious there was a problem with one of them. They are 1410 Spicer units
 

Chanzilla

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Feb 15, 2013
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San Antonio
Okay, I will also check that. If the transfer case is going out, are there any other clues? like feeling the transmission take longer to switch into drive or reverse etc, or not be quite as smooth while doing so?
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
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Not really, it will bang every once in awhile when you put it reverse. The dr.smooth t case has an issue with breaking snap rings and the pieces taking out the pump. Mine ended up breaking the forks before it gave up on me...
 

hipp11B

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Apr 1, 2015
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Very strange, when mine shook violently it turned out I cracked a piston when my injector hung open, but that doesn't really sound like your problem since you say it is idling fine now....may still be worth doin a compression test or getting a bores cope and checking each cylinder. Good luck man hope it pans out as something in expensive


Lbz, built trans, efi by Eisenhart diesel, Danville 68, full egr delete, mbrp down pipe, 5" mbrp to 7" stack, ppe guages, custom traction bars, airdog2 165, ppe fuel rail mods, s&b, age blade runner, Arp head studs..died March 2015
 

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May the farce be with you
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Yep dex 3.. Unless it has the auto button.. Or 5-30 oil works too


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sure, I've read it's acceptable to use, but I wasn't aware that GM rolled them off the line with anything other than autotrac2
 

motoking_1990

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May 9, 2011
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sure, I've read it's acceptable to use, but I wasn't aware that GM rolled them off the line with anything other than autotrac2
Rebuilt the in laws 03 Sierra trans this past summer and it wasn't auto 4x4. The blue autotrac2 came out and that's what I replaced it with. The stuff is NOT CHEAP. Think we paid like 15 bucks a quart or something.

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clrussell

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Sep 23, 2013
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sure, I've read it's acceptable to use, but I wasn't aware that GM rolled them off the line with anything other than autotrac2


Ohhhhh now that might be true.. I have no idea lol


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Chanzilla

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Feb 15, 2013
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UPDATE:
I took the truck out tonight to see how it would act at lower speeds in 4hi and what not. It shook earlier than it would in 2hi. I put her back in 2hi and was driving back to my apartment, (the trip was around a 1/4 mile loop). I got to about 18 miles an hour and it popped and i heard scraping. I pulled over and saw the first part of my drive shaft in the road and the main part laying on the ground. I laughed it off for a minute and took off the driveshaft from the axle.
I put it back in 4hi and started driving, and the truck ran beautifully... So, Im thinking the transfer case is fine? and that it was strictly a driveshaft issue? Im towing the truck home later this week, and will replace the driveshaft.
Thoughts anybody?
Thanks, Chandler.
 

NC-smokinlmm

<<<Future tuna killer
May 29, 2011
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Check your u joints on your driveshaft. Remove the shaft and check them. I had a similar problem and it turned out to be a seized u joint. I couldn't tell with the shaft on the truck but when I removed it it was obvious there was a problem with one of them. They are 1410 Spicer units

Sounds like this happened to you...