front drive axle, play where tripodshafts enter

[muskydreams]

My front wheels locked up when I pulled to the side of the road. I was towing my 18' boat on snow and and ice covered roads. I pulled over to check something on the trailer after about 30 mi, on AWD. It was sliding and I pressed hard on the brakes and was turning the wheels sharp left to avoid going off the side of the road. The front wheels locked up and I could not go forward. I switched to 2WD and was able to go forward and continued home ok. I drove it the next day and there was some clunking and rattling in 2WD. The next day I crawled under and found that the right tripod housing shaft has a lot of side to side play where it enters the intermediate shaft housing and the left tripod housing shaft has similar play where it enters the front differential carrier case. I am assuming that the bearings that support them and the outer seals are shot.

Am I correct in thinking that the intermediate shaft housing will have to be rebuilt or replaced.

Also, in regard to the the differential, is it likely that it will need more than just a bearing and a seal? Would it be best to just replace it?

Is it possible that there could be damage to the shafts of the tripod housings. If so, would it be best or less expensive to have the parts replaced or will the shaft Assemblies have to be replaced.

I don't intend to do the work myself. I just want to make sure I don't get ripped off. It would be nice to know, going in, how much the job should cost me and if there is any way I can save anything on the cost.

I am not a mechanic. I am a Biomedical equipment technician Looking for work. I just did the research and spent a lot of time looking at the service manual. I do some work on my trailblazer but this is something I don't want to tackle in my driveway.


Thank you very much for any help.

 

[Sparky]

Which vehicle specifically is it?

Usually bad axle seals/bearings won't cause stuff to seize up, unless that caused enough leakage on the differential side to run it dry and cook the gear set.

Your disconnect on the passenger side will need rebuilt if it has slop in it, yes. It might just need a bearing and seal, but while you would have it apart i would recommend planning on replacing all the bearings in there, plus thrust washers as they are cheap and get worn also. The exact parts list will vary depending on whether you have a Trailblazer/Envoy (4WD) or Bravada/Rainier (AWD).

Was the clunking and rattling coming from the front end, could you tell?

Pull the front differential fill plug and peer in there with a flashlight to see how it looks inside.

 

[muskydreams]

After the lockup problem happened, I drove it about another 20 miles but there was too much road noise to hear any noise coming from the truck. I smelled a gear oil smell outside the truck after it was locked up and I was trying to get it to move forward.

I haven't driven it much since it happened because I am afraid of causing more damage or lock up again. Just drove a few miles a couple of times and not over 40 MPH. Also I haven't tried to put it in AWD again since it happened. I was afraid it would lock up permanently. It sounds like the rattling and clunking is coming from the front. I can hear it at 20 MPH or less. When I brake I feel and hear a grumbling as I am coming to a stop.

Should I try putting it in AWD to see what happens?

Would jacking it up and turning the wheels manually give me an clues?

I figured the disconnect would have to be rebuilt or replaced. What about the differential? Since there is also a lot of play in the bearing on the driver's side, could the bearing going bad have caused other damage in the differential?

I don't want to get involve with tearing anything apart myself. I am planning on taking it to a transmission shop to have it checked out. I just want to make sure I know enough about it to make sure they are fair and honest with me and they know what they are doing. I have had too many bad experiences in the past. If you have any suggestions on how I can make sure they are doing me justice, I would appreciate it.

Your trailblazer looks like it is in better shape than mine. Mine has several areas where rust is bubbling out.

I went to the Ohio Institute of Technology in Columbus. Now I believe it called Devry University. Graduated in 1975. Lived by Ohio State and used to go to the bars on High St. all the time. The winters are a lot milder there. I remember that if there was an inch and a half of snow on the ground, everything would come to a standstill.

Thanks for any help you can give me.

 

[Sparky]

If you smelled gear oil that's not good. But that's why I recommended just pulling the front diff fill plug out and taking a quick peek inside. It will give you an idea of what you're up against.

As far as rust, well, mine is bubbling out all across the liftgate and the seam at the driver rear wheel well is pretty much gone. Passenger side isn't too far behind either and it is starting to bubble further back. My truck was a NY vehicle first, then Cleveland, so over the 10 years it has seen lots of salt.

 

[The_Roadie]

A bad differential bearing could allow contamination to get in, or the rollers in a dying bearing itself could have gotten inside and started internal gear damage, and that will probably result in needing a new diff. They typically run $500-700 from recyclers. Difficult to install, though. The passenger side disconnect is available from one aftermarket company on Amazon and elsewhere for about $500. Buying each of the individual pieces from GM dealers will total closer to $800. Junkyards sometimes have the diffs and disconnects as a set, but they know how often the disconnects go bad, so they get a premium price for them. Not a huge amount of savings mostly. Check Ebay to get a look at typical prices, or call junkyards. Your mechanic should also have excellent sources of used parts if they are used to customers who need to save their $$.

I would not even think of engaging A4WD or 4HI at this point.

 

[muskydreams]

Do you know if there is anything I can do easily to try to determine if there is damage to the diff.? I didn't see any evidence of oil leaking from it.

If I jack the front wheels off the ground, is there any determination that can be made by manually turning the wheels in 2WD or AWD?

Do you have any suggestions on how to find a shop is capable, honest and has my best interests in mind. Should I go to a transmission shop? It seems that they often try to sell service and parts that you don't really need. Or am I better off going to a private garage. How do I determine if they are the right ones to do the job?

Would it be good to mark the parts somehow and/or have them show me what they have determined needs to be done to repair it.

Is it advisable to have them rebuild the parts, replace with new or rebuilt, original equipment or aftermarket?

 

[Sparky]

I rebuilt my disconnect for just under $200 and that included having to buy another one at a junkyard for a new housing as I broke mine (Got it for $100 which I understand is a steal for these things). I got new bearings seals and washers from GM parts direct or the likes.

I still think popping the fill plug on the differential is going to tell you the most as you'll be able to see right inside there.

 

[navigator]

......I still think popping the fill plug on the differential is going to tell you the most as you'll be able to see right inside there.

I agree, I would start by opening the fill plug and look around in the diff and drain the fluid and look for any metal shavings. If you have a good bit of metal, you know you have issues. If the fluid was clean I might concentrate more on the disconnect.

Here is a nice write up from offroadtb that might help you in troubleshooting.

Offroadtb.com Diagnosing the 4WD System

 

[The_Roadie]

Rotating the tires while off the ground will only tell you something if it "catches" or grinds while you're doing it. Silence may not be a guarantee of anything.

To find a local shop you need boots on the ground. The 10,000 foot view from an Internet forum is not going to help. Chain shops like most transmission shops cost more because of the franchise fees, and the culture (honest or crooked) is 100% driven by the local management and service writers. Talk to friends or co-workers with similar vehicles and I highly recommend checking Yelp. I'm extremely pleased with a local independent mechanic who spent over ten years in a GM dealership, and who ONLY works on GM vehicles now. I only give him problems that are too messy or annoying for me to deal with, but we have a good partnership.

Interview shops like you would a house cleaning service. Do you trust them after a short talk? Does the place seem clean and well-organized, or are the tools in disarray and the lighting poor?

 

[v7guy]

The tripots have play in the bearing even when all the parts are new so some play isn't necessarily a sign of destruction.
You also state that there is no fluid leaking and no sign that fluid has leaked so it leads me to believe the seals are intact and the housing at the disconnect and the diff are ok, unless it's out of gear oil.
This video shows normal play in the assembly... apologies, the first half is awful shaky while I got positioned and the is cv grease from a split cv boot

http://static.photobucket.com/playe...v7guy/trailblazer/2011-10-23_12-10-08_647.mp4



Unless you're willing to get down there and do some more digging it's going to be essentially impossible to help you determine what might be wrong.



As far as picking a shop, word of mouth, yelp, google etc are all very helpful tools. Best of luck.

 

[muskydreams]

Thank you.
This sheds a little light on my situation. That is about the amount of play I have on both sides. I also saw the other video showing the play with the old and new bearings. I'm thinking that the front wheel lockup I experienced is not related to the play since the play seems to be normal.

I did take it to a local franchise muffler shop because the manager is the brother in law of a friend of mine. They told me it would have to be checked out further but they also told me that the left hub bearing was bad. I am now wondering if the noise I am hearing in 2WD at slow speeds (less than 20 mph) and the grumbling I am feeling and hearing when I am coming to a stop are from the hub bearing.

I don't know if they tried putting it in AWD.

I was thinking that maybe I should Jack the left front wheel off the ground and turn the wheel manually to see if I hear any noise. Do you think the hub bearing could have caused the lock up because I turned the the wheels hard left while I was sliding to a stop in the snow with AWD on? I was thinking of just trying to put in in AWD again to see what happens. I was thinking that if the hub bearing is going bad, that it might have locked up under those conditions with torque on it and then when I put it back into 2WD, it released the torque pressure on the bearing and allowed it to become free again. So I think checking the hub bearing might shed some light on the situation. It would be nice if all I need is a new hub assembly. By the way, I only have a little over 100K miles on it and both the hubs were replaced around 50K. It seems like they should last longer than that.

 

[Sparky]

If the hub bearing locked it wouldn't matter if it was in 2WD or 4WD. Usually they don't lock up though, just start making noise (like you're hearing it sounds like) and then eventually can come apart if left for too long.

Just curious (and don't take this the wrong way) but why haven't you pulled the fill plug yet on front differential and looked inside? You keep checking out everything else but the differential...

 

[v7guy]

Are you sure the front wheels had locked up?

I'd be very skeptical that a wheel bearing would cause the front end to lock up. Roadie had a wheel bearing so bad that the wheel was wobbling after getting back from an offroad trip and the vehicle was still moving forward.

I'm having trouble imagining a scenario where the front wheels would lock up without causing a tremendous amount of carnage.

 

[muskydreams]

In 2WD, I raised the driver side front tore off the ground and turned the wheel. It was very tight and there was nasty squeaking which was without a doubt, coming from the diff. Also the prop shaft was not turning as I believe it should have been. Turning the wheel forward and back a short distance was looser and then continuing in either direction would be much tighter (as if I was feeling play in a gear set). Also I could not turn the prop shaft by hand. It was locked up solid. If I grab the prop shaft past the coupler, right where it enters the transfer case, I could feel a slight amount of rotating play. But at the other side of the coupler it is solid.

Judging from the squeaking, which sounds like dry metal on metal, and the fact that the prop shaft is locked solid, my diagnosis is that the diff is toast. And I guess the axle will have to be removed to really tell if the hub is OK. Am I correct?

 

[v7guy]

From your description the diff is toast. If there's any fluid in the diff you could drain it and you'll likely see metal parts.
Unfortunately assuming this is the problem, this isn't going to be even remotely easy or cheap to fix.

Removing the CV probably won't show any obvious damage. But rotating the wheel and hearing any kind of squealing, grinding crunching from the diff is pretty telling.

 

[muskydreams]

Thanks to everyone for the help.

I found an independent shop to repair it. They seemed pretty good. The diff had no oil in it and here was a crack in the case. The seal and bearing for the drivers side axle were shot and the axle shaft was damaged. they showed me all the parts. They gave me options of new or three used diffs of various mileage ranges. I picked one with 70 some thousand miles on it. They had a hard time removing the shaft that goes through the oil pan and it wasn't usable. They must have replaced it with a used one but did not charge me for it. The whole job, including a new axle, axle seals and everything else cost me about $1500. It includes a 90 day part and labor warranty on the diff. I would definitely return to them for work and recommended them to others.

 

[The_Roadie]

Thanks for the report - sorry it cost you so much. How many miles on the truck in the first place, and what was the maintenance history on the differentials? I'm sorry if I already asked you this, but the diffs are 100K typically, and the transfer case is a surprisingly short 50K fluid change interval. Just making sure you don't have an undetected leak in either of your OTHER important driveline elements.

 

[muskydreams]

It has a little over 100k miles. I got it with a little under 50k on it as a GM certified vehicle. I have never changed or checked the fluid in the diffs or the transfer case. I don't know if if was done before I got it.

 

[The_Roadie]

Then you should be all over the rear diff and transfer case for servicing now. Or did your mechanic do them when they did the front diff swap? Would have been a perfect time to mention the need.

 

[muskydreams]

A few weeks ago, when there was a break in the weather, I was doing an oil change and noticed oil leaking from the shaft seal on the oil pan side. The weather has been so crappy with snow that I didn't notice there was oil leaking onto the driveway. I brought it to the mechanic and they looked at it and I scheduled to bring it to them the following Tuesday. Meanwhile, there was a good size puddle of oil every day and then it slowed down to only a couple drips. So the level had probably dropped below the level of the seals. They had it two days and said they replaced the seal. Supposedly they replaced the seals when they installed the replacement diff. When I picked it up, I asked for a receipt and he said "oh we don't need one".

Today there was a break in the weather I crawled under and tool a look at it and found that they just gobbed black silicone around where the diff meets up with the oil pan. There is also only a small amount of oil dripping out from the other side of the oil pan. I'm thinking that they did nothing else but put the silicone on and left the oil level low so I might not notice any leaking. They were probably thinking that as long as I don't see any oil leaking, it would last past the 90 day warranty before it fails. I don't know how long it can be driven that way before the bearings and seals are damaged and then further damage inside.

I called my Credit Union(were my credit card is from) today and registered a complaint with them. I don't know if there is much they can do but they have a dept. that deals with disputes. The money has already been paid to the garage. I"m going to have to contact then and see if I can get them to fix it right this time but I don't know if I can trust them now. If they work on it again I'm going to have to make sure they do it right this time.