Vibration that's not speed related...

C.Berry

C.Berry

Bad News
Joined
Aug 10, 2008
Location
Blacksburg, Va
I understand my junks oldish and all that but this is annoying as hell!
First off it's 99 suburban 5.7/4l80e/241 it has 171k! I've had a vibration when pulling out since I've owned it but also felt a vibration under load or on hills. So I figured the obvious and replaced, u joints, cv shafts front diff half shaft bearing and seal, had it timed "properly" no one knows how to use the damn snapon 10k computers around here apparently... so the only other time I've felt this vibration is when I ended up with needle bearings in the pan on my 94burb 1500... is this Dejavu all over again?? When I cold start the engine the vibration is bad at idle in park after warming a lil bit and driving it's only noticeable when I get to the 3200rpm range if it shifts to next gear it'll calm down bc rpm drop but still noticeable if near 3k. Any possibility of crankshaft or cam out of balance? is there any type of vibration test a dealership should be able to do? I've heard of such but never seen or witnessed such machine lol!! Any help would be great it's my dd/work truck...
 
I've read for 2weeks with no helpful info besides ppl swapping engine and trans to fix prob... I can't go that route, I've rebuilt a Tcase can it be much harder than a trans??? Haha jk I know they are
 
They aren't too bed but take lots of patience and special tools. And you have to be willing to pull it back out if you miss a little detail. It sucks sometimes. Especially if you aren't sure what the problem area is before you get it on the bench. Good trans tech can tell you what's wrong with a trans before pulling it. I'd suspect something with the rear planetary set / rear sprag of it's at low speed if it is indeed in the trans. Don't hold me to it, I'm not quite that good at trans, yet.

Yes they do have vibration analyzers with several sensors that you mount. I had the idea to build one about ten years ago and create a laptop program to analyze different vibes but I would have needed funding and bad parts to develope it.
 
It can't be the transfer case if it does it in park...think about it. You know what DOES spin the entire time the motor is running though? The torque converter and the flex plate. I wouldn't be surprised if the flexplate was messed up or the converter lost a balancing weight.
 
Croatan_Kid said:
It can't be the transfer case if it does it in park...think about it. You know what DOES spin the entire time the motor is running though? The torque converter and the flex plate. I wouldn't be surprised if the flexplate was messed up or the converter lost a balancing weight.
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Yeah I wasn't thinking tcase at all but now that ya mention it when I opened tcase fill bolt to add tcase fluid when pulling rear shaft it was overfilled so maybe I have a seal bad but trans fluid never dropped...?
 
My flexplate bolts had come loose from converter on the 94 and then ended up with bearings in pan after tightening them back up gonna pop inspection plate tom at some point would be sweet if it was just a cracked flexplate... I'm not so lucky usually lol
 
Well I have a real high pitch squel that only goes away in neautral... damn trucks drivin me nuts lol
 
eighth digit of VIN an R ?

vibe is on start when cold most noticeable ?

what about tuneup stuff ? the "spider" cap is known for cross firing internally, aftermarket even worse. A worn distributor housing will also cause odd running quirks. Dizzy housing is plastic, the shaft wears on the housing as the cam pushes UP and to the rear. to find the wear you'll need to pull the cap pull up and twist the rotor a bit then rock the whole shaft forward and back. good time to check for carbon tracking on rotor as well.
I replace a lot of 4.3 distributors in forklift engines for similar findings, about the only time i use and aftermarket part intentionally, OEM is still plastic, aftermarket is aluminum.

5.7 "R" engine also has the "spider injection" the poppets on the injector tubes tend to carbon up and dribble, been a long time since i've messed with those so i'm lacking in detail

intake gaskets can suck air and not set a Check Engine, leans out one cylinder, which could potentially burn a valve, remember seeing a few "tuliped" valves due to high cylinder temps from lean out.

one instance where the "R" engine intake casting had actually cracked in a runner causing misfire issues. THAT was a tough find.
 
@Blkvoodoo it is a VinR! The vibration is def more noticeable here recently on cold startups and very noticeable over 3200rpm, the spider injectors have been upgraded to the mpfi had the distributor out recently and looked brand new it is a aftermarket billet shaft with oem cap! Had it on computer and it timed correct but vib never went away!
 
Also no notice of okay to cam gear when dizzy almost all the way in gears seemed tight!
 
C.Berry said:
@Blkvoodoo it is a VinR! The vibration is def more noticeable here recently on cold startups and very noticeable over 3200rpm, the spider injectors have been upgraded to the mpfi had the distributor out recently and looked brand new it is a aftermarket billet shaft with oem cap! Had it on computer and it timed correct but vib never went away!
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5 and 7 wires not crossed at the cap ? easy to over look and will make you mad as hell when you find it has been the issue the whole time, seen it a lot done it a few times myself ( you learn after a few times too )
 
I just walked out and Checked their in right place. I wish it was something that simple
 
C.Berry said:
I understand my junks oldish and all that but this is annoying as hell!
First off it's 99 suburban 5.7/4l80e/241 it has 171k! I've had a vibration when pulling out since I've owned it but also felt a vibration under load or on hills. So I figured the obvious and replaced, u joints, cv shafts front diff half shaft bearing and seal, had it timed "properly" no one knows how to use the damn snapon 10k computers around here apparently... so the only other time I've felt this vibration is when I ended up with needle bearings in the pan on my 94burb 1500... is this Dejavu all over again?? When I cold start the engine the vibration is bad at idle in park after warming a lil bit and driving it's only noticeable when I get to the 3200rpm range if it shifts to next gear it'll calm down bc rpm drop but still noticeable if near 3k. Any possibility of crankshaft or cam out of balance? is there any type of vibration test a dealership should be able to do? I've heard of such but never seen or witnessed such machine lol!! Any help would be great it's my dd/work truck...
Click to expand...

fify lol #boredintheartic
 
CasterTroy said:
Have you checked the upholstery?

:cool:
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I do have a bolt loose in driver seat... hmmmmm damn water pump went out on me go figure, swapped it out in the freezing cold got down my driveway and realized I didn't tighten a hose up.... all my coolant gone fml lol gonna attempt to pull trans inspection cover to see if anything is loose or out of ordinary this afternoon when it finally reaches that high of 32...
 
ckruzer said:
fify lol #boredintheartic
Click to expand...
What am I missing? Lol what did ya fix for me?? My punctuation and grammar are terrible if that was it and my ma is a teacher haha
 
Let me also add it has a random sluggish start every few days like it wants to start but barely can then it's normal... would it be wise to drop trans pan and replace oil magnet, and filter and flush converter out? Speakership said GM says to not replace auto trans fluid but I agreed it has a viscosity like engine oil after 150k I'd imagine that shits broke down a good bit, he said that's "just what they say"!!!
 
So after some research and driving this thing last few days I've come to conclusion that my torque converter is taking a dump on me!! Here's my reasoning, no low end torque at all, terrible shudder up hills, vibration on cold start that slightly goes away after warm, random hard shift in gears especially when under heavy acceleration!!! What y'all think? 171k on this burb I'm guessing it's time for tconverter anyway!?
 
now the question what converter??? I use this burb for dd/work truck it hauls 6k on occasions short distances! Any benefit from better brand converter or just stock?
 
You can ALWAYS get a better torque converter than stock in any vehicle. Lots of companies make a good, heavy duty, towing converter for the 4L80E. However, it's like everything else....you'll get what you pay for. A good converter isn't cheap. I'm also not a fan of putting a new converter in a transmission that isn't fresh, but it should be fine.

Summit Racing has Hughes, TCI, B&M, and maybe one or two other brands. Just don't go getting one that stalls any lower. Most people think you need as low of a stall as you can possibly get for towing, but it's not exactly true.
 
I was considering tci bc I know they work hard and last from abuse from guys running em at thunder valley in TN, gonna dig around on those! I'm assuming this would be a good time for new trans sensors, filter,even valve body since theirs 8 sensors in these 400s?? I mean I wasn't looking to rebuild the trans bc it works fine I just don't want this vibration/issue to cause more damage but I also don't wanna pull it again soon haha
 
I'd either do a full rebuild at the same time or just toss in the new converter and then drop the pan and filter to attempt to get as much clean fluid in it as possible. No sense in replacing ALMOST everything, but not doing a rebuild.
 
Maybe a stupid question but have you checked the trans fluid level?

My truck had a shudder under load and come to find out the seal between trans and tcase has a ver slow leak and the trans was low on fluid, tcase over full. I didn't have time to get it fixed so i just monitored it. Shudder is gone and about once a year I relevel the fluids. Been that way for 3 yrs now and the leak hasnt seemed to speed up :lol:
 
Ya know I've checked the trans fluid it seems full but I did have a overfilled tcase when I did ujoints! My tcase calls for diff fluid then trans fluid I believe tho so maybe this is causing it? Will a 241 run on trans fluid or is replacing seals only option? I have no leak in between trans and tcase
 
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