New intermittent highway speed vibration

[Mudbath]

This started yesterday at 120 kph and slowly got worse, it is in the drive train and interesting enough blows the 30 amp aux B fuse in the under the hood fuse box. When the fuse is blow the brakes act very strange and effect the ABS. I replaced the fuse and all was fine, until I got to highway speeds again and the vibration occurred, when stopping the brakes were whacked again (blew the fuse again). The ABS light does not light indicating a problem and the paper clip OBD1 method shows no code. I am not sure this method will show ABS codes though. Does any one know for sure? If not, does GMTDScan Tech show ABS codes?? I am going to have a look at the front hub/speed sensor assembly. It is almost like something is worn there and maybe something is hitting the speed sensor and causing the fuse to blow. I will be in in a hour or so to check emails so if you have any great ideas I'm all ears. Thanks Bob

 

[NVW]

ScanTech doesn't show ABS codes. I check out your front end carefully, something is wrong in it. Leo

 

[Mudbath]

Thanks for the reply Leo, Just came in from round one and the front hubs seem very tight and the ABS cable going to them are visible good. Took the chance with wheels off to lube the ball joints and tie rod ends and found the pitman arm with a lot of play in it. Must be all the snow and 4 wheel Hi over the last 2 month that has finished it off. The idle arm isn't bad YET but both are infamous for wear. So it would explain the vibration but not the blowing of the Aux fuse which is tied into the brakes/ABS. Still could be the front speed sensors but they are pretty much sealed in the hub assembly. How would a guy find out the ABS codes? Bob

 

[Turbine Doc]

That was EXACT scenario I was having vibes & ABS code minus blowing fuses; when bearling assembly let go and axle snapped, if you have originals on it and seeing that yours is a 95 I'd highly recommend new cartridges, my snap on scanner reads ABS I don't know if part store scanner reads ABS codes

 

[bk95td]

On the 8-lug 2500s the speed sensors are removable. 1500s are part of the hub.The pitman arm on the steering box shouldn't cause bad vibration. Just slop in the steering. To check wheel bearing hubs you need to push the brake caliper in to release pad pressure on the rotor. The fuse blowing seems weird.

 

[Mudbath]

TD my ABS light doesn't come on, would there be codes stored any ways? I just checked the hubs 1) with wheel on jacked up and grabbed top and bottom of wheel and there was zero movement. 2) Pull caliper and rotor spun it no roughness, metal filings and ABS cable in good shape. bk95td mine is a LD 2500 6 stud and is seal in hub. I have had bad pitman arms and bad idle arms give a highway shimmy, but should not blow a fuse for the Brake/ABS. The fuse is really messing with my mind wtf? :mad2:

P.S. Canadian Tire has a code reader for ABS for $39.00 on my way to get it.

 

[Mudbath]

Well I just finished round two. :boxing_smiley: The code reader I bought that reads ECM and ABS showed no codes at all. I went to replace the fuse which was blown yesterday when the brakes went funny and it was good. But that is good as it did not make any sense to me (been a licensed mechanic for almost 30 years)

So the shutter at hi speeds I am going to attribute to the bad pitman arm for now and replace it. The fuse hopefully is a non issue. The brakes issue maybe due to the frozen pavement which has been thawing the last couple of day, and my very hard 3 year old tires.

After reading TD's hub/speed sensor problem I am glad I really got in and checked mine any ways. I will get the pitman arm replaced and test it again and let you all know. Thanks Bob