front end vibration, i'm at a loss

THIS FORUM IS FOR ANY QUESTIONS ON THE 7.25" IFS FRONT DIFF, CV HALF SHAFTS AND FRONT DRIVE SHAFT.
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plumbcrazy
I am merely driving my van
I am merely driving my van
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Joined: Fri Mar 04, 2011 4:27 pm

front end vibration, i'm at a loss

Post by plumbcrazy »

new to this forum, seems to be alot of knowledge here. i have a 1998 astro awd, i have a pronounced vibration in my front end especially starting @ 62-65mph stays until 70-73mph, much worse if i let off the gas and coast at these speeds.(much quieter under a load) i have changed the front hub bearings; they had some wear. i changed the front halfshafts they also had some wear. in the last year all four universal joints have been changed. i try to stay ahead as this is my third astro. this is however my first all wheel drive. i have every over the counter manual you can buy& they have very little info on the awd or none at all. i do have a bravada manual which gives me a picture but thats about all. i have checked and filled front differential as well as transfer case, neither smelled burnt or were low. i am second owner of this van but it was immaculate when i got it 2 years ago. problem has never gotten any worse but it sure aint getting any better. i have had to travel for work the last five years due the economy, i am off right now but work is coming with the thaw; i get nervous about some catastrophe i.e- getting stuck 5-700 miles from home& the local mr. badwrench giving me a f---ing! any info you guys can give me would greatly be appreciated. might also add that i tried to remove front propeller shaft to further isolate problems, van didn't want to move and when it did i had to rev it pretty good, must have the model i read about that won't operate without front shaft installed. ONCE AGAIN THANKS IN ADVANCE FOR ANY AND ALL INFORMATION ON MY PROBLEMS!!! plumbcrazy in ohio.
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Smiliesafari
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Re: front end vibration, i'm at a loss

Post by Smiliesafari »

You didn't mention tire balance. One common problem with these vans is worn idler arms.
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Topic author
plumbcrazy
I am merely driving my van
I am merely driving my van
Posts: 3
Joined: Fri Mar 04, 2011 4:27 pm

Re: front end vibration, i'm at a loss

Post by plumbcrazy »

thanks man forgot to mention tires are all tip top and well balanced , also no bent rims. 1 of the idler arms was replaced about 5,000 miles ago & the other still looks, feels good. van runs great i love it, this problem is driving me :rolleyes: i definitely can handle the mechanical repairs but i just am having a hard time getting solid info. been to the reference section at the library, all the parts stores etc. etc. i've been shafted (get it) at repair joint's , i don't mind paying it just seems like most of these outfits have as little info as i do and are guessing what to fix.-- hell i can do that. once again thanks for the input have a great day!!

JaxSPL
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Re: front end vibration, i'm at a loss

Post by JaxSPL »

I have experienced this, exactly as you've explained it. It ended up being the driver side sway bar bushing. I bought a repair kit from Autozone that had the bushings, washers, bolt, and nut. Took me about 1/2 hour to rip out the old one and install the new one. Haven't had a problem since. the kit cost something like $4.00 if I remember right.
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doyoulikeithere
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Re: front end vibration, i'm at a loss

Post by doyoulikeithere »

Mine was a worn out centre link.
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LiftedAWDAstro
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Re: front end vibration, i'm at a loss

Post by LiftedAWDAstro »

plumbcrazy wrote:might also add that i tried to remove front propeller shaft to further isolate problems, van didn't want to move and when it did i had to rev it pretty good, must have the model i read about that won't operate without front shaft installed. ONCE AGAIN THANKS IN ADVANCE FOR ANY AND ALL INFORMATION ON MY PROBLEMS!!! plumbcrazy in ohio.
Here is where the issue is. The front shaft being removed on the BW4472 AWD t-case will not hinder forward movement at all. I could chirp the tires on my 98 when I removed mine for testing purposes. The only issue that removing the front shaft causes is the ability of the van to roll downhill slowly when parked and no e-brake.

Here's what you need to do. Remove the front shaft and have a helper look at the rear drive shaft while trying to lightly go forward. Be VERY careful here and have the helper lay away from the van. Post back the results and we can go from there. I am going to suspect you have a worn out t-case.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy

Topic author
plumbcrazy
I am merely driving my van
I am merely driving my van
Posts: 3
Joined: Fri Mar 04, 2011 4:27 pm

Re: front end vibration, i'm at a loss

Post by plumbcrazy »

sorry meant to get back sooner but have been very busy. i actually took the front shaft off in the middle of another repair thinking i could then drive it to the parts store, however when i put it in reverse it didn't engage, then i let it coast back into the street figuring i would see what it did in forward. well it sat there and laughed at me at first and after revving the engine slightly it seemed to jerk into gear and i went forward, i drove it around 1 city block and stopped at a traffic light when it turned green it did the same thing almost like i was in neutral i revved a little and it ''jerked or somewhat slammed into gear'' not sure of the right way to put it. when i got back to my house i put the shaft back on and it drove like normal or as normal as it ever did. does that sound like transfer case? i sure as hell thought my vibration was in the front end & i have heard an awful lot of stories about bad front differentials so thats where i have spent most of my investigative time. i'm at the library now and have been trying on and off to diagnose this for about 3 months, weathers starting to break in cleveland & i want to get on this problem fairly soon. i stated in an earlier post i thought i had a t/f case that wouldn't operate without the front shaft installed and from one of the replies i received i guess thts not the case with the borg warner i have on my 98 awd. i get the concept as this is not my first adventure with 4X4's etc. but i have limited knowledge of this set up, am i looking at some kind of clutch, viscous clutch or should i start looking for another transfer case? THANKS AGAIN FOR YOUR INPUT, KNOWLEDGE OR JUST POINTING ME IN THE RIGHT DIRECTION ! =D>

LiftedAWDAstro
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Re: front end vibration, i'm at a loss

Post by LiftedAWDAstro »

I would start looking for a t-case from the sounds of it. I would say the viscous clutch is going out.
Current rides:
2013 Toyota Tundra DC 4x4
2008 Dodge Nitro 4x4
2005 Nissan Sentra 1.8S Special Edition

Mileage spreadsheet

Vans owned:
1986 Safari 2.5L 4 speed manual - scrapped
1995 Astro 2WD conversion 4.11 posi, shift kit, DHC rock rails - sold to Skippy
1998 Astro 4x4 D44, D60, NP231, full hydraulic system with 9k# Milemarker winch and snow plow - sold to Lockdoc
2003 Astro AWD all stock - traded for a 3/4 ton truck
2005 AWD, 4.10's - sold to skippy
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thegreenmachine
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Re: front end vibration, i'm at a loss

Post by thegreenmachine »

u joints. or pinion nut dont know if it has been suggested yet......
2003 Chevrolet Astro 4wd np233c transfercase 245/75/16 ETS Trailermaster tires
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Previous:
1995 Safari AWD (death by torsion bar. a.k.a. "the final straw")
1999 Safari AWD ( death by tree x2 )
1997 safari rwd cargo ( sold @ 450,000+ km )
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