how to stop binding AWD

I bet this is a widely known problem with these things... But my parents 2000 AWD Safari totally binds up when turning. You can't even pull into a parking spot without the clunk...clunk...clunk. Are there ANY known remedies for this? I've heard replacing the fluid in the front differential helps. Is this true?

yes, I replaced all front, rear, and tranfor case with synthetic. it worked.

What grade synthetic did you use? Are the fill/ drain plugs easy to work with?

the front and the tranfer case have drains, but the rear has to be pumped out. i did it using ramps. no problems. I dont remember the grade but it was factory grade.

GM also sells a limited slip additive that may help,,,,dealerships should stock it!!!

How can I tell if I have limited slip?
Would the front differential ever require limited slip?
The transfer case takes transmission fluid, correct?

I have a 2002 astro van with the same issue just starting out. According to the dealership that does most of the work on the van? They state in my case it would be needed to drain the fluid from the transfer case and refill it with the syn. fluid. The fluid runs about $25-$35 a quart and is some "magic" mixture. According to them the only cure is to drain & refill with new fluid..drive the van around for a while and see if it cures the locking up clutch pack...if not then repeat the process again to see if enough of the crud gets drained out with the fluid to free the clutch pack up. If it does'ent work on the 2nd time? I've been told the transfer case would have to be torn down and rebuilt or replaced.

Not quite great news, but I was warned about the fluid type used..some shops will dump in the fluid, being syn. But there's something unique about this system that needs fluid that runs about 30 bucks a quart??

I'm planning on taking mine in soon to have this done, this van has already cost the company I work for about $2500.00 in repairs over the last 3 months.

S-

Thanks for the info, but could anyone verify what this magical synthetic transfer case fluid is? I have a 4x4 gmc jimmy, and it binds a little bit when turning, but not nearly as bad as the van.

What were the $2500 in repairs? - just curious

Let's see...about $2500 and counting:
Basic maintence first:

4 tires M/Bal. w stems
4 wheel brake job w. front rotors
both idler arms replaced
rear pinion seal replaced
--
extras:
haveing the rear diff blow out all 4 bearings due to the shop over tighting the pinion nut...about $585.00 in repairs
The fuel tank pressure sensor failing..about $275 most in labor for dropping the tank.
Blown front left wheel bearing..$975 for the hub/bearing assy..$85.00 to install the part...

Now I have a problem with the door locks just as people have posted here as well LOL...and the Neutral saftey switch needs replacement (cold weather it mis-reports the trannie shift posistion..all built in one unit)

I'm not sure exactly what the fluid is..about $30 a quart seems very pricy? The shop stated there should be a "tag" attached to the transfer case stateing the fluid type needed.. If I can find the name of that fluid for the transfer case I'll post it for ya.

All Best-
S

The magic transfer fluid you all are looking for is the blue Auto Track II fluid sold by Chevrolet dealers approx $4.99 per quart. I got mine at Westfall GMC in Kansas City Mo BTW Truck centers are about 10% cheaper than car dealers.

Makes me wonder how the dealership up here wound up givin' me a quote for about 30.00 a quart then. I think he was probably pulling the number out of his fanny in that case. I'll research it a bit more with the other dealerships in the area. The one that normally does the work only charges 55.00 hr for labor (cheapest in the area) but if they are padding down the parts? We'll have a little conversation.. (considering the company I work for has dropped about $1200 in repairs so far at that shop)

Thanks for the information!!
All best-
S-

the transfer-case has an internal slip clutch which AIN'T slippen so good,,,if the additive does not improve the situation,,the t-c may need
to be looked at

you should also check your cv shaft or u joints at the wheel since you said that you hear clunk clunk. ujoint if it is freezing up will do it or cv if the boot is bad and the joint is now dry and dirty it will also they are inbetween the pumkin and the wheels. God bless. and good luck.

If you can feel the vehicle lifting and falling in turns, it is almost for sure the U/CV joints. I had that problem in my truck, it eventually got so bad it would lift the truck a couple inches in sharp turns

Transfer case was serviced...flushed it out once...drove it around for a few...flushed it out a 2nd time to get anything missed the first time out. It's been doing great so far. The intermid. "Bucking" at 55-65mph under light accel has'ent returned yet. Also the "bucking" under accel from 25-45's pretty much gone. Given the fact I'm in upstate/central NY? We'll see how it holds up under all the snow we normally get.

S-

Transfer case was serviced...flushed it out once...drove it around for a few...flushed it out a 2nd time to get anything missed the first time out. It's been doing great so far. The intermid. "Bucking" at 55-65mph under light accel has'ent returned yet. Also the "bucking" under accel from 25-45's pretty much gone. Given the fact I'm in upstate/central NY? We'll see how it holds up under all the snow we normally get.

S-

What fluid did you use? Was it that blue autotrack fluid from the dealer?

On the transfer case there will be a "tag" attached to it. In my case it was the auto-trac blue fluid. cleared things up rather well.

For the other posts with "binding" on turns? If you are hearing a "clicking" or "binding" on hard turns left or right? Very possible CV outer joint on one side or the other is bad. The click click click is very well known to mechanics.

S-

I'm hoping it is the fluid, because that is something I can easily fix next week. It doesn't click, but it lurches and binds as if the wheels are supposed to slip but they don't at all when turning sharply. I hear cv joints look "wet" when they're shot.

btw, I'm from Rochester NY, lets hope this January isn't as bad as last year... Actually when it's icy out the AWD doesn't bind quite so bad because the wheels actually do slip like they should (because of poor traction) on the ice.

The only real thing about CV joints from "appearence" is if the boot that protects the joint is "torn" or "leaking" out it's grease...Normally the outer CV joints are the first to fail...and you'll hear a binding "click" type sounds, more pronounced during very tight corners.

With the Transfer case, from what the dealership told myself. When the "clutches" in the case start to 'bind' up they tend to grab and release rapidly.. In my case it was going in just about all stright directions..moderate accel.. At about 20mph-25mph it would start almost...let's say it felt like someone was grabbing all 4 brakes for a split second then releaseing all 4 brakes. Kinda like it was doing a very fast "lurch" and "retreat". At first I figured it was the trannie slipping, but the dealership told me it's a classic sign of the transfer case yelling for help. It was also doing it from time to time under light/moderate accel at 55-65mph as well...When it did it then? It felt extreamly "harsh". Thankfully I pull off the highway and let it 'cool' a bit. After a short rest it was back to normal? (at least for those speeds)

It's something a dealership with a decent tech (thankfully LaQua's 481 chevy dealership in Fulton has one) can quickly figure out.

On a side note? I had a front wheel bearing give out a couple of weeks ago. It started as a slight viberation which increased in severity quickly..and started to feel like a mini-jackhammer hitting the floor pan. Hope you do not have this issue, as the freaken part alone is listed at $975.00 for the part alone. (bearing is built into the awd front "hub" assy)

All Best

Steve

(and yes...I'm hopefull for a mild winter. Fulton got nailed with 2 storms within a few weeks of each other last year...both carried 3' worth of the white stuff each time. Gotta love Lake Effect)

I'm sorry about all the questions, but this is my last one...

How much fluid should I buy if I do the procedure you did (flush first time, keep the second), I mean for filling the transfercase twice?

That I'm not sure of..considering the shop billed it out as "units". Might as well pick up a Haynes manual or something specific to that year. Normally they have fuild capacities listed for everything. I'm not sure how 'easy' it is to get to the drain and refill plug? The shop did it on the lift. The tech said normally drain..refill...drive it around a bit...drain it again..and a final refill normally does the trick. If it does'ent? It can be a costly repair if the transfer case "seizes" up.

S-

I used Mobil 1 synthetic automatic trans. fld. in mine. No problems before or after. 250,000 miles.

rockout, What year is your van? I bought fluid, just am waiting for a warmer day to put it in.

It is a 1994. Most transfer cases these days take automatic trans. fld. Thats why I used It. I also used synthetic gear lube in the front and rear differentials. I also use Mobil 1 in the engine.

My 2002 Safari AWD started acting up - jerking upon acceration and when turning - so I picked up two quarts of GM Auto Track II transfer case fluid and changed the fluid in the transfer case. The owners manual says to change the automatic transmission and transfer case fluids at 50,000 miles. After changing the fluid the AWD smoothed out and the van doesn't jerk or bind when turning.

Yeah, I forgot to mention that I ended up changing the fluid in my parents van back in january, and now it's august and the thing still turns like new. The autotrack fluid is the answer!!!