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Discussion Starter · #1 ·
It's hard to pinpoint when this started because I haven't been driving long distances since my lift, but it was not there beforehand for sure. The steering wheel, seat, and dash have a slight vibration that is fine for short trips but after an hour or two drives me nuts. Passengers agree. I hate driving it on road trips now. To me, it feels like a wobbling vibration. I don't really hear any hum.

Before symptoms: stock ride height, stock tire size General Grabber AT/X

Symptoms started after: torsion bar lift, rear coilover shocks, Kenda Klever AT2 29.5" tires, AND I once lost a wheel on the highway because it wasn't seated properly and the lugs sheared off.

I've got a list of things to cross off of my suspect list, hoping for some advice on it:

Torsion bar lift - I originally had them cranked to 2 turns out from max. Went down 4 more turns just to check, front lowered by about 1". no change in ride comfort. Need alignment now though

Rear Coilovers- Could these be stiff enough to cause such vibrations? I have regular shocks in the front, not a lot of weight in the back.

Idler arms/steering - replaced both due to significant play. No more steering play and movement, still a rough ride/vibration. I still have some L/R play in my wheel, but it's very minimal now. Not sure if minimal play is okay.

Rear driveshaft pinion angle - many have suggested to suggest this. I have to inspect this still. I'm a noob so I need to look up how to do it

Rims/Balance - mechanic says all 4 are bent when he checked balance. Going to take it to another shop just to be sure, because I have had no impacts or anything I can remember so it's hard to believe

Tires - Could it be just that these tires are more aggressive and that's what I'm feeling? The Grabber AT/x didn't do it though, but the Kendas look more aggressive. I wish I kept the other tires so I could just try them back on.

Engine mounts - engine does seem to move backwards on acceleration. Sometimes there's a clunking sound on accelerated turns from a stop, which I was told was probably a CV axle though. It does vibrate the steering wheel/dash/seat slightly at idle. I already replaced the trans mount this week, no change.

Sticking caliper - Van pulls right when hard braking. Could a sticking caliper cause vibration like that?

Damage from rear tire flying off at highway speeds - replaced rear brake drums in case that was damaged out of balance, replaced rim and wheel studs that were destroyed. Anything else to check for?

I'm going to check the easy stuff first, especially the rim/balance, and have a mechanic look at it if I can't figure it out. The few good mechanics in town are booked out so I have some time before my appointment.

Any other ideas/suggestions?

Thanks
 

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2000 Lifted 4x4 Astro 92 V8-350 Shorty
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mechanic says all 4 are bent when he checked balance
Why are you wasting so much time writing about all this?
In one line... you ALREADY have an answer.
Of course bigger tires just amplify the problem.

If your pinion angles are bad... FIX IT
If your caliper is sticking... FIX IT
Torsion lift.. you already knew the consequences

STOP SPECULATING and fix the known issues
That's my suggestion (since you asked)

You lost a wheel while driving?
That's pretty messed up.
Bet that wheel is a little messed up too

Sorry... good luck
 

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2004 Safari RWD, 2002 Astro AWD
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339 Posts
I will also add that if your engine moves too much and you changed your tranny mount then next logical thing to do is replace the engine mounts.
I also assume that the roads were you live must real good. Were I live there are alot of pot holes, expansion joints uneven old paving and tons of road construction to mess up the suspension and rims/tires.
Wheel pulling during can also be can be caused by old rubber brake hoses from caliper to brake line or air in line. Replace and bleed the air out.
 

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Discussion Starter · #4 ·
Why are you wasting so much time writing about all this?
In one line... you ALREADY have an answer.
Of course bigger tires just amplify the problem.

If your pinion angles are bad... FIX IT
If your caliper is sticking... FIX IT
Torsion lift.. you already knew the consequences

STOP SPECULATING and fix the known issues
That's my suggestion (since you asked)

You lost a wheel while driving?
That's pretty messed up.
Bet that wheel is a little messed up too

Sorry... good luck
The reason I couldn't fathom the rims is because they were fine when I had them mounted and I barely drove it since, but it has become clear that the shop probably did a bum job and didn't notice they were already bent. You mentioned the bigger tires amplifying the problem, which is something I didn't know, and that might be why I didn't notice before. New shop confirmed all 4 bent, and I swapped them out with some new ones I got. Haven't been able to test just yet.

There still are a few unknowns to me. Specifically the tire tread question, coilovers, and just how much a torsion lift to where I have it could be contributing to this.

I will also add that if your engine moves too much and you changed your tranny mount then next logical thing to do is replace the engine mounts.
I also assume that the roads were you live must real good. Were I live there are alot of pot holes, expansion joints uneven old paving and tons of road construction to mess up the suspension and rims/tires.
Wheel pulling during can also be can be caused by old rubber brake hoses from caliper to brake line or air in line. Replace and bleed the air out.
Yeah I'm working on that. That sucker was not fun to get off and is a pain to line up right. Got the new one in but can't line up the hole when lowering the jack. When I lower the jack the bracket towards the FRONT of the vehicle lands on top of the rubber part, instead of going over it where I can put the bolt through. I'm taking a break for now.
 

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2004 Safari RWD, 2002 Astro AWD
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Loosen the transmission mount so it has some wiggle room.
I had both engine bolts out when I lowered the engine.
I placed the jack in the center of oil pan with a board on top spreading the force across the bottom of pan.
This way it drops evenly back were it was raised from.
 

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Discussion Starter · #6 ·
Loosen the transmission mount so it has some wiggle room.
I had both engine bolts out when I lowered the engine.
I placed the jack in the center of oil pan with a board on top spreading the force across the bottom of pan.
This way it drops evenly back were it was raised from.
Thanks. I actually just replaced the transmission mount, I should have thought of keeping it loose first. I'll give that a try.

Is the transmission mount supposed to have any kind of rubber like the engine mounts? The aftermarket part I bought is just a block of metal with some kind of rod in the middle that allows a bit of flex on the bottom part of the mount. But my old mount had some residual rubber. Not sure if this matters.
 

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1998 LS AWD Forest Green metallic
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I cannot get to mine at the moment to confirm or photograph, but I am very sure mine has a rubber block molded into it.
I would think the rear transmission mount would have to have a rubber component to it, or all manner of noise and vibrations would be transmitted through the frame, just the same as a bad motor mount.

Rod J
Issaquah, WA
 

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2004 Safari RWD, 2002 Astro AWD
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I just changed RWD Trans Mount.
I need to change my AWD Tans Mount, see the cracks in the rubber.
There is no metal link between the the Trans and the cross frame.
The rubber separates the two.
See both pictures below:

Automotive tire Motor vehicle Automotive exterior Bumper Automotive exhaust

Automotive tire Automotive design Grey Automotive exterior Wood
 

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Discussion Starter · #9 ·
Loosen the transmission mount so it has some wiggle room.
I had both engine bolts out when I lowered the engine.
I placed the jack in the center of oil pan with a board on top spreading the force across the bottom of pan.
This way it drops evenly back were it was raised from.
I did that and it worked to get it over the top of the rubber. But now the damn holes won't line up. I read about people using prybars and stuff, but it just seems impossible to get the right angle. Do you need to loosen the other side or something? Because I guess I can give it a try, but as much of a nightmare as this was...I didn't even want to attempt the other side.
 

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Discussion Starter · #10 ·
In case anyone was wondering, the issue is mostly fixed. Going back to less aggressive tires fixed most of the issue, along with realizing my front shocks, which were only a few months old, had already crapped out and leaked. The ride is finally bearable.
 

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2004 Safari RWD, 2002 Astro AWD
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I replaced my transmission mount. The picture above is the old one.
I had trouble removing mount. I raised till I started lifting the van.
Hand to remove transfer case guard plate.
The electrical connected motor was still interfering.
Looked at videos on line and non had that motor thing shown where I have mine.
Nobody even had the guard plate.
The factory shop manual didn't even mention there was a plate.
See picture below .
The factory mount has a lot heavier metal and seams to be larger and not just swollen old rubber.
Does any body else have the guard plate on bottom of transfer case.?

Wood Rectangle Brick Font Building material


Tire Wheel Automotive tire Hood Vehicle


Wheel Tire Automotive lighting Hood Automotive tire


Automotive lighting Automotive tire Hood Motor vehicle Vehicle
 
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