Front end binds in low speed, sharp turns

[NoDak Ninja]

I have a problem and I have no idea where to start:

I've had this Bravada for about 3 months now. About two weeks after we got it, on the way back home from vacation, the front end started binding when turning sharp at low speed. Like when pulling into a parking spot or up to the gas pump. This being my first 4WD I thought maybe the 4WD was kicking in for some reason. The next morning I got in it to drive it and try to figure it out, but it had "fixed itself".

The problem didn't reoccur until just a week ago. Now it does it all the time. I've been trying to find posts with similar issues, but have been unable to find anyone who had the same issue. (maybe I am just horrible at searching!) Now the wife just called me and said it is making a kind of metal on metal "howl" while turning also.

Like I said, my first thought was that the 4WD was kicking in. But after paying closer attention, they front tires don't seem to be pulling. It's more like the brakes are engaging, or the front tires are at the wrong angles to travel smoothly through the turn. There is enough resistance that you have to get on the gas to get through the turn. And if you are on gravel, or there is some sand on the concrete, the back tires will slip a little from the force needed to push the vehicle through the turn.

I am pretty comfortable working on engines, but have never done any work on anything in the drive train after the engine (other than brakes). Add to that my total unfamiliarity with 4WD, and I just have no idea where to start looking. If anyone can give me some ideas on what to look at first, I would appreciate it!

It's a 2002 Olds Bravada with 107,000 miles. I did check the air pressure in the tires, and the tires all have plenty of tread and all are worn evenly.

 

[DDonnie]

definately something with the all wheel drive. Looking for a thread that popped up a few months ago, gimme a few.

 

[NoDak Ninja]

definately something with the all wheel drive. Looking for a thread that popped up a few months ago, gimme a few.

Thank you!

 

[DDonnie]

http://gmtnation.com/f24/saab-9-7x-stuck-all-wheel-drive-7497/


This is the thread i was thinking of. Give it a once over. It might be as simple as doing a diff fluid drain and fill.

 

[Moots12]

I've been having the same problem.. Although I am lifted I had a problem with one of my lower ball joints and replaced that and still had the clunk/binding noise. It also only happens when the tires are on the ground and pressure is being put on the tires.. My TRE are fine and my cvs are fine, and I popped both TRE out and jammed the rack both left and right and did not get a clunk. But then again I wonder if it's something with the taper of the TRE in my spindle seeing that I have silverado TRE.. But for that I would check all those items that I have talked about.. If I can figure out the problem with mine maybe it'll help you.

 

[DDonnie]

I've been having the same problem.. Although I am lifted I had a problem with one of my lower ball joints and replaced that and still had the clunk/binding noise. It also only happens when the tires are on the ground and pressure is being put on the tires.. My TRE are fine and my cvs are fine, and I popped both TRE out and jammed the rack both left and right and did not get a clunk. But then again I wonder if it's something with the taper of the TRE in my spindle seeing that I have silverado TRE.. But for that I would check all those items that I have talked about.. If I can figure out the problem with mine maybe it'll help you.

You having this in 2wd? Try putting the truck on a lift and see if all 4 wheels are turning in 2wd. If you are only experiencing it in 4wd, that's normal. These trucks arent meant to be driven with 4wd on dry/solid ground.

 

[NoDak Ninja]

http://gmtnation.com/f24/saab-9-7x-stuck-all-wheel-drive-7497/


This is the thread i was thinking of. Give it a once over. It might be as simple as doing a diff fluid drain and fill.

Thanks DDonnie. That is a very informative post.

Since I don't know the history of my Bravada -and it has over 100,000 miles- changing all the drivetrain fluids would probably be a good idea regardless. (I'm glad my new Haynes came in the mail yesterday!) I will start with the differential and see if that clears it up.

 

[Moots12]

You having this in 2wd? Try putting the truck on a lift and see if all 4 wheels are turning in 2wd. If you are only experiencing it in 4wd, that's normal. These trucks arent meant to be driven with 4wd on dry/solid ground.

I'm not in 4wd and my truck could be sitting still..

 

[The_Roadie]

Bravadas have no selection switch. No 2WD only mode. The problem is the encoder motor or more like a never serviced transfer case with low or no fluid. 50k mileage between fluid changes or grabby/dead clutches is the result.

 

[DDonnie]

Bravadas have no selection switch. No 2WD only mode. The problem is the encoder motor or more like a never serviced transfer case with low or no fluid. 50k mileage between fluid changes or grabby/dead clutches is the result.

I was replying to the other guy when I mentioned the switch

 

[The_Roadie]

In general, the transfer case is a LOT less forgiving than the differential(s) and the service interval is half.

The reason for the binding is if the transfer case is locked from grabby clutches, the turning radius of the front diff is longer than the rear, so the wheels are attempting to spin at different RPMs and the transfer case won't let them.

 

[Moots12]

In general, the transfer case is a LOT less forgiving than the differential(s) and the service interval is half.

The reason for the binding is if the transfer case is locked from grabby clutches, the turning radius of the front diff is longer than the rear, so the wheels are attempting to spin at different RPMs and the transfer case won't let them.

Now what if the clunking is in 2WD and I get the clunk sitting still, I have tested all the parts I can think of, but I am wondering the procedure of testing the rack and pinion.

 

[NoDak Ninja]

Now what if the clunking is in 2WD and I get the clunk sitting still, I have tested all the parts I can think of, but I am wondering the procedure of testing the rack and pinion.

I don't want to be a jerk, but perhaps you could start your own thread to ask that question?

Roadie: Thanks for the help and the info. I will check the fluid level of the transfer case tomorrow. It sure will be nice if it's something simple. Although, if it's low then my new problem is "why". But, I'll cross that bridge when I get to it.

 

[NoDak Ninja]

So I didn't get a chance to crawl under the Bravada until today. The picture in my Haynes showed the fill and drain plugs as being bolt heads. Low and behold, when I crawled under there I found that they are allen-type plugs. I don't have any big enough, plus I'm assuming they are metric anyway.

Does anyone know what size they are so I can buy one tomorrow? Thanks!

 

[C-ya]

The transfer case plugs take a 10mm allen.

(I just crawled under and checked - didn't trust my memory!)

 

[NoDak Ninja]

The transfer case plugs take a 10mm allen.

(I just crawled under and checked - didn't trust my memory!)

Thank you very much! That's awesome that you actually crawled under there to check!

 

[seanpooh]

And both plugs are to be tightened to 20 ft lbs.

 

[NoDak Ninja]

And both plugs are to be tightened to 20 ft lbs.

Thanks Sean. A torque wrench is on the shopping list as well. Yeah, I know...I should already have one.

 

[NoDak Ninja]

Well, I changed the transfer case fluid. As soon as i pulled the plug I got discouraged; it looked quite clean and clear-blue. But I soldiered on and hoped to see results. The next couple days there was no change as I was researching my next move. Then this am the wife texted me to say it freed up. So I'll keep my fingers crossed for a while and hope that all it needed was some fresh transfer case fluid.

The differential cases oil are next. Any other preventative-type maintenance I should be performing on the drive train while crawling around under there?

Oh, and I guess I posted this in the wrong sub-forum. Was clueless early on, but it appears to be drive train related and not brakes.

 

[C-ya]

Glad to hear the progress report! One thing to keep in mind is that if it was that bad, you may want to change it again in 500-1000 miles just to flush that stuff out.

I did my diffs recently. Both were ready to be changed. The rear had lots of small particles on the magnet. Tranny is next for me. Gotta get it done before winter.

Not sure what else to suggest, but while you're under there, check u-joints, sway bar end links (front and rear) and just generally eyeball stuff to see if anything looks odd or out of place. Sometimes we think we know how something is under there until we look. I know I learned some stuff when I crawled around under there when my muffler blew a seam.