Guide me in front suspension service, 99 Sub 4wd

[redfishsc]

This Suburban is the first 4-wheel drive I've ever owned. I got it basically for free, just put new head gaskets and all sorts of other replacement goodies under the hood. Engine runs like a top now.

230k miles

There are two things I know for sure are not right, based on sound.

You can hear a clacking noise coming from under the driver seat, mostly when you're decelerating. I'm just going to replace all the U-joints in this thing because I think that's what it is. U joints are cake, I've done them before, so I think I'm going to be alright with that.

The other sound however, I'm not as confident about in diagnosing. when you're turning the steering wheel right or left at low speeds, you often hear a loud thunk come from the driver side front. maybe a shot control arm bushing?

Assume I'm going to jack the vehicle up. I'm going to replace the front shocks since they definitely need it, front U joints.

Also assume that I really don't know a whole lot about front ends. tell me what I need to be looking for, and what sort of consumables I need to be replacing just because I'm in there..

I'm grateful for everybody's help, I would have never got the head gaskets done on this if it wasn't for you guys.

 

[1999gmc]

Could be a tie rod end, ball joint, or idler or pitman arm. I've had them make a pop or thump type noise when turning.

 

[redfishsc]

I'll be ripping into it today just to see. I know the sway bar links are shot, no rubber on them, so I have new Moogs to put there. We'll see what else is hoopajooped when I get it up on the jackstands

 

[magimerlin]

The popping when turning left or right could also be one of the cv shafst. Just like in a fwd vehicle, they will start popping in corners when going bad.

Sent from my SAMSUNG-SM-G891A using Tapatalk

 

[SierraDully]

Stabilizer bar end links commonly break off at the studs and make a sound like you are describing as well.

Front ends are weak on obs 4x4's. If it's new to you, probably best to check over everything. Before you take the front wheels off, check for movement in both directions will help diagnose steering and bearing play as well.
Good luck with it. 230 is nothing. Probably get another 230k out of it

 

[redfishsc]

Got the sway bar end links swapped out. Dang they are a pain to get out, the angle of the nut at the bottom made it nearly impossible for me to get a socket on it, and it was equally hard to pull up and out since the upper control arm basically has it blocked.

Either way, got the new Moog end links installed. Noise gone. Truck rides a lot more confident too. The driver's side was missing the entire upper bushing.

Also got the front U-joints replaced. The one up at the front diff was really hoopajooped. Rear u-joints are still very tight. Some whackadoodle beat the ever-lovin hell out of the front yoke. Hammer strike marks all over it and it's pinched in by a flea's hair .... I had a bear of a time getting the C-clips on to the new U-joints. I'm predicting the front ones won't last as they should.

 

[redfishsc]

By the way, I did yank on the tires in each direction. Fortunately they are nice and solid, no flop.

 

[Coveman]

i rebuilt my 99's front end around 130 while doing the nbs brake swap, the idler arm on our trucks get sloppy loose and should be swapped out, that'll take some squish out of the steering as well.

keep the zerks lubed up too, i try to LOF twice a year, and that helps keep the front end nice and quiet.