GM IFS 8.25 axle stub play - is it time to rebuild?

[marioski]

I would think that any "play" in the shaft as you described is not a good thing. Jarrod on here who did the right up is pretty busy but should chime in. He is the man on these IFS.

Oh, and welcome to TMC.

his left up was better though

Nice GT you got there in your sig! I have an 01 myself!

Way too much side to side movement in that flange. It should move but only a very small bit. Looks like you may have found your noise. Doubtful that the whole unit needs rebuilding. Probably just needs the side bearings replaced.

That's what I'm thinking to but I'm not sure you can just replace the axle stub support bearing with the unit still on the vehicle. Might have to be pulled off the vehicle and by them it's one of those "might as well just do an over haul on it".

I have two trips coming up, one to Michigan and back this weekend about 600 miles total and then one to Ohio in about a week. I have no time to do this right now so I'm hoping it'll be good for a another two weeks and not get any worse.

 

[Hickspanic]

I would think that any "play" in the shaft as you described is not a good thing. Jarrod on here who did the right up is pretty busy but should chime in. He is the man on these IFS.

Oh, and welcome to TMC.

his left up was better though

Nice GT you got there in your sig! I have an 01 myself!

That GT is pure sex, I love the look of it.

 

[marioski]

Thanks!


Well I have decided that I'm going to drive it over the driveline shop where they will do the rebuild if I go that route and have the mechanic take a look at it before I decide on pulling the trigger on doing it.

I am a little stumped now as in 4wd hi mode, there is absolutely no play what so ever. I do know that in 2wd mode there there is play and I know that common sense says there shouldn't be any.

Are they are any tricks in pulling these out of the car? Looks simple enough. Unbolt driveshaft, unbolt cv's, unplug electrical, vac, remove four bolts lower unit out.

 

[Bigredmariner]

You've definitely got something wrong going on inside there. A little play in and out is ok but that wobble is a bad deal.
Pulling that diff out isn't too bad, jack it up. Put some good jack stands under the vehicle. Remove the skid plate, Unbolt the axle shafts at the flanges, remove the driveshaft, unplug wiring and or hoses. Then there's only like 4 bolts to drop it out, my write up is for an 06, the frame is a little different on your 08 but shouldn't be that much different. It can be wrestled out of there without a jack if you've had your Wheaties! If not then by all means grab a jack and a buddy to give you a hand, it has to be kind of twisted and rolled down as it comes out. It won't just drop straight down. If you've got questions feel free to ask or pm me.


Posted from my iPad via Tapatalk HD.

 

[marioski]

You've definitely got something wrong going on inside there. A little play in and out is ok but that wobble is a bad deal.
Pulling that diff out isn't too bad, jack it up. Put some good jack stands under the vehicle. Remove the skid plate, Unbolt the axle shafts at the flanges, remove the driveshaft, unplug wiring and or hoses. Then there's only like 4 bolts to drop it out, my write up is for an 06, the frame is a little different on your 08 but shouldn't be that much different. It can be wrestled out of there without a jack if you've had your Wheaties! If not then by all means grab a jack and a buddy to give you a hand, it has to be kind of twisted and rolled down as it comes out. It won't just drop straight down. If you've got questions feel free to ask or pm me.


Posted from my iPad via Tapatalk HD.

Thank you everyone for your responses. I just put on about 400 miles and have about 10 days before I need the truck and head out to Ohio. I decided on yanking it out and having it rebuild before any more damage happens inside. I did see you're write up on the 06 and figured it is similar. I' ll have to remember to turn the wheels to the right and it doesn't seem like it'll take to long. My plan is to have it yanked tomorrow, drop the diff off Monday morning at the drivetrain shop. They said it should be about a 2-3 day turn around time and hopefully have it back up by Thursday and Friday.

 

[marioski]

Slight change of plan. After jacking her up today, I noticed my drivers side hub has developed play since the last time I had it inspected, about 5-6 miles ago. It's about the same time I started hearing the bearing hum. Not going to pull the diff just yet. Going to replace the bearings, see if any of the bearing noise goes away. At least then I can eliminate it down to the diff as the truck will have new hubs, already has new cv shafts, and the suspension is new. So the only last part would be the diff.

Here's short video I shot of the play in the hub.
Wheel bearing - YouTube

 

[marioski]

Well diff is out. Just decided to do all of it at once. She's going to get two new MOOG wheel hubs (already picked them up), and I'm going to replace the cv shaft on the drivers side (where my issue was on the diff and hub) just as a precaution especially since I still have a warranty on it. Figured it was way to damn coincidental that every rotating part on that side of the truck is having an issue. So did the wobbly axle stub wear out the hub, or vice versa. Either way, all getting fixed now.

Bigredmariner, you're right, there is definitely something going on inside my IFS. I didn't drain the fluid, put stood it up right and pulled the plug. Let's just say there was a LOT of fillings attached to it. I then pulled the big ass fill plug, ,ring gear looked good and nothing abnormal there. Fluid was at the proper level too. I stuck a magnet in there and kind of tried to get as far in as possible several times, and lets just say I pulled out some nice fillings out of her. Fillings that are very questionable, as they are too big to be considered "normal were and tear" as they are not fine. They are very shiny so I have a feeling a bearing was on the path of self destruction. I think I caught it just in time before things turned worse.

Hard to see in a picture but there is way to much attached to the magnet and some of it is very shiny metallic and gritty. Thinking a bearing race.

Oh btw, you were right. It was a pice of cake to remove. Couldn't believe how easy it was. The part that put up a fight was my driveshaft u-joint. It just didn't want to come off the yoke.

I'll keep you guys posted.

 

[Bigredmariner]

Good deal, nice to see you're making progress.

 

[marioski]

Well good thing I pulled it and dropped it off at the shop. Just got a call not to long ago, they tore it down and I was told an adjustor is broken and the bearing on that side (short axle stub side) was pitted and failing. So a new oem adjuster is on it's way with a complete overhaul and she'll be ready for pickup tomorrow or Wednesday.

 

[Hickspanic]

Well good thing I pulled it and dropped it off at the shop. Just got a call not to long ago, they tore it down and I was told an adjustor is broken and the bearing on that side (short axle stub side) was pitted and failing. So a new oem adjuster is on it's way with a complete overhaul and she'll be ready for pickup tomorrow or Wednesday.

better to catch it now than on the road trip.