LUVTruck.com

I have checked the threads and only found one similar thread regarding this topic. I drove the truck this weekend from San Jose to Sacramento without any problems. On the drive back, about half way to San Jose the truck started to shake violently and I can hear something grinding right underneath me. This was a very scary sound and it felt like something was about to fall apart. The truck fires and shifting is okay but I can hear the grinding nose underneath me. On 4th gear the truck shakes really violently. Any suggestions?

Sau

Driveshaft and/or U-joints?

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FIAA: Color Guard

Climb under there and try to wiggle the driveshaft around. If it is a ujoint you should be able to see it moving. If it is the rear end it will wiggle the shaft going into the rear axle. That is the two most likely problems, besides obvious things like loose wheels or a tire coming apart on ya. Let us know what you find.

My experience is that ujoints sound worse than the rear end. A loose pinion on the rear axle just growls a lot, but ujoints will vibrate worse and make a loud clang noise when you back up and take off forward again.

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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)

MEPR: Man, my 4x4 makes all other LUVs look good

A yellow Luv I had did that once, the pinion nut came loose and I quickly skidded to a stop. Hopefully its just your Ujoints.

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Click on C.M. logo to go to my webpage


RIP R.J.B.

I am going to give it a check as soon as possible. The shaking was so violent that I parked the truck at a Valero gas station and called a towing company. Towed it back to San Jose for $225. If it is the drive shaft or u-joints, is that an easy fix? I am doing some reading and normally the whole shaft has to be replaced? Where would I get one? Its a 1973 Luv.

Sau

ive got one from a '79 id just give yab but idk about shipping... let us know what you find out, and work out from there... it may be a loose exhaust too...

Ujoints are replacable unless they got so bad they were wearing on the yokes and if it is the rear axle you can probably tighten up the pinion nut and it will go for quite a while. To see the pinion nut take off the 4 bolts that hold the driveline to the rear axle and it will be right in the middle of the input shaft. It is fairly big, I think I used a 1 1/4" socket or something close to that. I believe the book says the pre-load torque should be 80 or 85 ft/lbs, and then it should be adjusted from there but I just put mine to 85ish and let it go. I think those numbers are right, might check the haynes manual if you have one though.

On my old 76 the pinion nut used to back off all the time so it just became a 6 month thing to check it. Never had that problem with my 77 or either of my 79 4x4s though.

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95 Isuzu Trooper Daily Driver
86 Isuzu Trooper reliable backup
77 LUV 2wd stock beltway blaster (resting)
79 4x4 LUV project: 2.6L, 5spd, 31s (eventually)

MEPR: Man, my 4x4 makes all other LUVs look good

please tell me you're joking

my bet would be on the drive line...right before all 4 of the rear drive shaft bolts let go my '80 had some real bad shakes coming of the line from a stop. check the driveshaft bolts and as 800 said also the rear pinion nut

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'80 Luv 4x4, 3" BL, 1.5" SL, 32/36, 2.25" exhaust...and fuzzy dice.
'95 Toyota 4Runner Limited 5-Speed.

One of my missions in Sacramento was to head to this shop that specializes in all Haynes manuals of all known vehicles. He also has original service manuals not from Haynes. His prices are excellent. $8.00 for most manuals in good condition. He gave me a deal on my Chevrolet Luv Haynes manual, only $5.00

I will do all what you guys have instructed and get back to you on what the culprit is.

Sau

I agree with the u-joints. I could maybe see something like a broken tranny mount or engine mount, but that would be more of a front to back movement during acceleration or deceleration, probably not a constant vibration.

I would have to say definetely NOT loose exhaust. That could cause a rattleing sound, or if it was completely severed, it could swing from the hangers and maybe tap on the bottom of the floor boards, but it would not cause a vibration.

Is this vibration at a certain speed or rpm? Or is it all the time? Does the vibration get faster or louder at higher speeds?

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No LUV anymore, but still in the GM truck family. Running a lifted 2002 Silverado Z-71!

UgotLUV- I think he meant, were you joking about it being loose exhaust. I think most of us agree that loose exhaust probably wouldn't cause a vibration. Noise yes, but not an actual vibration that could be felt.

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No LUV anymore, but still in the GM truck family. Running a lifted 2002 Silverado Z-71!

I was hoping you were joking about the loose exhaust...if you read my post carefully (and also what I quoted) you would see that I was referring to what you said in the bold letters. I'm not bashing you for offering him a drive shaft, (although with his truck being a 73 I don't know if it would fit or not). Please don't take my post in an offensive matter, as that is not how I intended it to be.

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'80 Luv 4x4, 3" BL, 1.5" SL, 32/36, 2.25" exhaust...and fuzzy dice.
'95 Toyota 4Runner Limited 5-Speed.

oooh none taken! now i dont think we shood hijak his thread... idk if it will work either but someone mentioned it could be that, so i offered him it cuz i really dont need it or any other stock luv engine parts i have

Rrrreeeaaallllly? Now I wonder who the heck that was???

Well lets see. When I have it in first gear there isn't much vibration but I can hear something clanging right underneath me, and I can feel it in the shifter. like *bam...half second pause....bam....bam....*, there isn't much vibration here....in third gear its starts to vibrate....but in 4th gear you are about to shit in your pants cause the vibration is so bad, it feels like its coming from the back of the cab right underneath the truck. Its a very scary sound. You know for a fact that something is wrong. Still haven't wiggled the shaft yet (you know what I mean), or checked the u-joints. Will do it later today...


Sau

It has to be the drive shaft / u joints. It constant when moving, and gets worse with speed. You got the (bad) shaft my friend.

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OK, I'm over it. Where's the beer?

Is this a long bed?

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-Old ride-82 Luv diesel 5spd with some upgrades
-Past rides-82 Sierra, 78 Coupe De'Ville, 91 2dr Blazer, 86 RX7, 86 Porsche 944T (rear-ended and totaled)
-Curr. rides- 1970 Ford LTD 4dr, 390 4Bbl, 2nd owner! With a few Extras 00' Civic beater...

I thought of that too Finalman, (carrier bearing) but looked and he has a 73 and 73 didnt have a long bed option I believe.

_________________
Click on C.M. logo to go to my webpage


RIP R.J.B.

Well guys its not the driveshaft or u-joint. It seems solid to me. My friend suggested I take it down the street to a shop that he frequents and get a good diagnostic. What the heck, $85.00 just to have a experienced mechanic take a looky-loo. I dropped it off this morning at around 8:30am.

He gave me a call about 11:45 to tell me the bad news.

Mechanic : How much do you love your chevy luv? (i swear that is what he said)

Me : Oh shit this does not sound good.

Mechanic : Well I took it for a drive down the street and knew right away the problem, your drive line is shot, your clutch has issues...blah..blah..mechanical terms up the wazoo...I can get you a rebuilt transmission for $900, a clutch for $300, but you will need other parts...you are currently looking at $1700 but it may get higher...

Me : Oh crap, let me get back to you on that... *HANG UP PHONE*

ah guys....damn...get if repaired or do a swap? I am thinking a swap is my best bet...

Sau