help with front axles [Archive] - Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum

: help with front axles


scoats
08-22-2008, 05:44 PM
i was wondering if i can take out the front axles. Im in the process of putting a new motor in and my front differential doesnt work so i wanted to know if i can take it out. i was told the wheel bearing is held on by the axle but i did a little research and the wheelbearins for the 4x4 is the same part number as the 2 wheel drive

the roadie
08-22-2008, 06:05 PM
The wheel bearing hub is indeed held by a 35mm nut on the end of the axle, but its real mounting is three bolts from the rear of the steering knuckle. To remove the CV shaft, you have to remove this nut, the brake caliper, the tie rod end, and then the upper ball joint. Then you can tilt the steering knuckle down, rap on the end of the CV shaft and get its splines out of the bearing. The bearing comes out from the outside. Then bang on the inboard side of the CV shaft's tripot to release its c-clip.

http://www.roadie.org/susp.jpg

If you're putting in a new motor, then you can remove the differential altogether. Lucky thing the oil pan has a tube running through it so the removal of the diff and its shaft won't cause the oil to run out. And the CV shafts aren't needed for the bearings to work.

One warning for others thinking about similar projects, if you remove the driver's side CV shaft and leave the diff in, the differential oil will drool out through the hole. This would not enhance the differential's lifetime if you replaced the shaft later. :D

markarock
08-22-2008, 08:47 PM
TRIPOT: A telescopic tripot universal joint comprises an outer drive member having three longitudinal drive channels which include two opposing concave side surfaces, an inner drive member having three radial trunnions having a radially outward facing semi-spherical surface for tiltably mounting a drive ball assembly which has a bearing train disposed radially between an inner ball tiltably engaged to the trunnion and an outer ball having a tread face which directly opposes the concave side surfaces of the drive channels. The ball assembly being free to wobble about a Z-axis wherein the assembly pivots about an X-axis disposed laterally to the outer drive member and pivots about a Y-axis disposed longitudinally to the outer drive member. The channel carries a guide rail which extends longitudinally lengthwise to the channel and projects radially inward in order to contact the outer ball when the ball assembly pivots about the X-axis, i.e., tilts relative to the axis of the outer drive member.

So, where exactly do we bang? I'm confused. And do we have to bang? Can we pry? Or can we pull? Help! :)

Mark

drolds72
08-23-2008, 06:59 PM
You can hit the heavy metal assembly with a drift outward, or if you can get a small prybar inbetween that metal piece and the diff, it will just pop out.

In the above picture, its the 2 or 3 inch wide rusted metal band that is inbetween the inboard cv boot and the front diff.

Don't pull if you want to reuse the front axle! It will pull the tripot apart inside the boot.

markarock
08-24-2008, 07:17 AM
That's the info I needed. Thanks.

Doesn't look like there is much room to swing. Maybe prying would be easier. Guess I'll find out when I get under there.

My problem is on the driver's side. Leaking inner boot. Any words of advice or caution?

Thanks.

Mark

the roadie
08-24-2008, 11:03 AM
I used a 18" long 3/4" socket extension, but a good 1/2" length of galvanized pipe would have done as well. And a 3 pound hand sledge. And at 65K miles in the otherwise benign CA air, I was still dismayed by how many whacks it took to get the splines moving. You can start a few days ahead of time using PB blaster on the outer hub splines, but the inner ones are protected by a seal, so the lubricant won't penetrate. I reassembled mine with a bit of grease on the splines to make it easier next time.

They make two piece replacement boots - if slinging grease is your only symptom and the CV joints aren't making noise or vibrating, why take out the entire shaft?

markarock
08-24-2008, 12:53 PM
Thanks for the info.

I have a noise in the left front that I have diagnosed as a bad hub bearing (noise related to vehicle speed only, louder when the wheel is turned slightly right). I also want to replace my front struts "while I am at it" and have things mostly disassembled.

I just figured it would be convenient to take care of this grease slinging problem while I had everything apart. But if it is difficult or problematic to remove the old axle/CV joint, and I can achieve what I need with a two piece boot, that seems to be a better/simpler/cheaper solution. I'll look into it.

Thanks!

Mark

drolds72
08-24-2008, 01:37 PM
Check the driver side axle seal for leakage. That was the reason I had to remove mine. the seal is about $20.

markarock
08-24-2008, 02:58 PM
Ok. The wife has it in Pittsburgh this weekend so I can't check now.

When I rotated the tires I wiped everything off with paper towels and brake cleaner so I could drive it and then get a better idea what was leaking, and perhaps even see where. I'll pull the wheel and look again one evening this week.

I did notice that the side of the front differential case around the seal was only lightly filmed, that the boot was totally shiny/black but not really wet like an oil, and that the stuff I wiped up smelled like grease, not like differential fluid--but I'm not sure if this differential fluid is different, and I don't have the manual handy to check. If it is different, it may not smell like the ordinary 75-90W stuff I am accustomed to.

Thanks for the tip.

Mark

pjturley
09-18-2008, 07:15 PM
Was changing the brakes today and noticed the front left inner CV boot had some grease "sprayed" on the underbody around it. Got a pretty good look at it and can't see that the boot has a tear in it anywhere. Is there just a seal that may need replacing? If so, what's it called and how difficult is it to do? I was considering replacing the entire half shaft on that side, but if it's just a seal issue I'd certainly rather do that. I haven't noticed anything wrong with the ride yet, but my wife has said a couple of times she noticed vibration at highway speed. Thanks for any help

markarock
09-18-2008, 08:30 PM
I finally got a chance to look at mine once the wife got back from Pittsburgh.

In the beginning I had the inner boot totally covered with...something. Didn't smell like differential oil, so I figured it was probably grease from the inner CV joint. I cleaned everything up with brake cleaner, the boot, the tripot, the housing, and the frame, and sent the wife on her way.

Now I see that the boot is totally dry, but the front diff case and the tripot are wet. It doesn't smell like the differential fluid I am accustomed to, but it is definitely oil, not grease. So, my diagnosis is that my seal is leaking. I already bought a replacement CV joint assembly/axle (about $51 plus shipping from Rock Auto) so I will replace it when I do the seal on Saturday. But I could have just replaced the seal if I had but waited to make an accurate diagnosis. (Sigh!)

I don't know what the seal is called--axle seal or differential seal or ?--I'll find out when I go to Napa on Saturday. It is a part that commonly needs replaced, or so it appears from posts I have seen here.

Lots of things can cause vibration at highway speeds. CV joints typically don't do that, at least not until really bad, as far as I know, but I don't have a lot of experience with bad ones.

Mark

markarock
09-20-2008, 08:45 PM
Grrrrrrrrr!

Got the axle out easily. There was room to swing, and it only took a few hits to get it to release. But that was when the problem started.

Earlier this Saturday morning I had stopped at the Pontiac GMC dealer for a quart of the special transfer case fluid--figured I might as well change it while the truck was up in the air. Then I went to Napa and bought a seal for the front differential. I hadn't taken the axle out yet, so I didn't know what the seal looked like. The one he sold me looked a little small, but he assured me it was the right one.

By the time I got to the point where I got the axle out, it was early afternoon. I was taking my time. I wasn't in any hurry.

Then I looked. The seal was much larger than the one I was sold. I copied the numbers and letters off of it:

46002075
SABO 7517

So, back into town to Napa. Bad news. The numbers I gave them don't cross reference to anything in their computer. The one they sold me is the only seal they list. Went to Federated. Nope there also. Dealer item.

Back to the dealer and of course the parts window was closed. So I'm stuck, up on jackstands till Monday.

GRRRRRRRRRRRRR!

I could have bought the seal at the stealership, but I was trying to save a few pennies. Sure wish I had known that it was a dealer only item.

GRRRRRRRRRRRRR!

Mark

markarock
09-20-2008, 11:30 PM
Now that I look at the photo I took, my old eyes may have deceived me. I need to go back and check the seal number again.

Anyway, I have located the manufacturer. It is in Brazil! Yet they sell to GM.

Here is a link to a page describing the function and properties of some of their oil seals. http://www.sabo.com.br/si/site/0503?idioma=ingles

Anyway, I'm now thinking that the part number may be 46002026. Haven't yet found any info on that number, unfortunately. I'd really like to get this back together tomorrow, and to do that I need to locate an aftermarket seal.

Also, in the photo, is the bolt with what looks to be a big washer under it to the left of the seal the fill plug for the front differential?

Mark

markarock
09-21-2008, 08:29 AM
Anybody have an aftermarket source for the front differential axle seal?

Anybody?

Mark

drolds72
09-21-2008, 10:51 AM
Sorry guy, I bought my seal from the dealer for about $20. Yes that big "washer" to the left is actually the very large plug for the front diff.

When you go to reinstall the seal, you are not going to be able to hit it straight on if you do not have a long handled seal driver. Use what you got in your garage and be patient. Needs to go in square. Good Luck!

markarock
09-21-2008, 11:56 AM
Well, now that I have an extra day, maybe I'll make a long seal driver. Shouldn't be too hard.

I was also thinking about making a seal removal tool. How did you get yours out? How hard was it?

Anybody out there have an aftermarket part number for this seal?

Thanks.

Mark

markarock
09-21-2008, 04:49 PM
Just trying to keep this on the new post page.

Anybody know why some days there are three pages of new posts, and some days it hits 20 or 30 and starts all over?

Mark

drolds72
09-21-2008, 06:40 PM
I actually already owned a seal puller. You can probably pry it out with a long stout screwdriver though.

markarock
09-21-2008, 07:40 PM
I reached in with my finger. There is something right behind the seal that moves easily in and out, in till it hits the axle bearing and out till it hits the seal. Anyone know what it is. Is it something I need to replace along with the seal? It seems like it fits over the axle with very little clearance, best as I can tell. I looked at a drawing, but it was not detailed enough to tell me what the part is.

Mark

drolds72
09-21-2008, 10:01 PM
All I replaced was the seal. I don't remember anything moving around behind it.

markarock
09-22-2008, 09:43 AM
Stopped at the dealership this morning (wasn't a stealership today much to my surprise!). Picked up a new seal. List price was $13.19, with tax the total was $14.22.

For historical and research purposes, the info on the front driver's side differential axle seal is:

Group 6.056

Part Number 12471618

Description Seal Frt Drv

From the description, it appears that this seal is for the driver's side only. I didn't ask about the other side.

Finally, I did ask what was inboard of the seal, between the seal and the bearing. The parts guy told me it was an "adjuster" and that it was not sold separately, that it came with the bearing. List price for the bearing and the adjuster? $116. I said I would pass for now, at least until I got the old seal out and could tell if my "adjuster" was bad or not.

Interestingly the new seal has a bunch of angled teeth on the inside. I'll post pictures tonight. Not sure what their purpose is yet, or how they function. Maybe I'll figure it out tonight.

And oh yes, the seal is indeed "Made in Brazil'. The manufacturer's (Sabo) number on the new one is now 40050495 although it has the same 4 digit number 7517.

Mark

markarock
09-23-2008, 10:14 AM
Got the old seal out and the new seal in last night. Filled the differential with fresh fluid. Installed a new axle/CV joint. Installed a new hub bearing. Installed a new shock. Done.

Forgot one thing--to take a photo when the seal was out. D'oh!

Anyway, I figured out what the adjuster is, and what the "splines" are for on the back of the seal.

The adjuster is on the outside of the bearing, and it has recesses that match to the "splines" on the seal. The splines fit in the recesses and keep the adjuster from moving/loosening.

Pried the old seal out with a lever type seal puller and some steel for bracing/making a fulcrum/pivot point.

Tapped the new seal in place with a flat piece of steel against the seal and a short drift which I pressed against the center of the steel and hit with a hammer. It went in fairly easily. I lubricated the outside, which is ridged rubber, with gear oil first. I first marked it so the splines would align with the recesses in the adjuster, and marked the exterior of the case, so that when I drove it in, the splines would engage the recesses in the adjuster. Judging from the old one, the splines bend over and nestle in the recesses when the seal is hammered home.

There wasn't anything loose in there. Must have been a figment of my imagination. I was feeling the bearing I guess. Dunno.

Check the photos.

I cleaned the differential housing with brake clean and will check in a few days to verify that the leak is now gone.

The differential was down about 3/4 of a quart of fluid. It had been leaking for a while. I can see how somebody could burn up a differential if they ran totally out of fluid. I bought the gear oil from the dealership, and it was uber expensive, about $26. But I know I have the "right stuff". It was not easy to fill--plastic tubing attached to the quart bottle and snaked to the opening. A little messy, but I got it in.

The big nut/washer looking thing is the fill opening, and it seals with a large o-ring. I didn't replace the o-ring.

I replaced the hub bearing at the same time, and now the truck is totally quiet again. It is amazing how noisy the old bearing was. The new bearing is an AC Delco unit, but the ABS wire had the wrong connector on the frame end, so I just used the old wire in the new hub. It works fine.

Mark

the roadie
09-23-2008, 10:20 AM
Great writeup and pics. Appreciated! :thumbsup:

drolds72
09-23-2008, 04:42 PM
Nice work! I use the short end of an allen key to check the front diff level every oil change. Put it in the hole with the short end pointed down. It is usually down a few ounces. I use a pump type filler, similar to the one I use to fill lower units on my outboard with. I switched my diff fluid over to the Amsoil severe duty, and it always flushes pretty clean.

stopher2
10-13-2008, 10:34 AM
i have a core from my TB Ext driver side that i replaced.
i am figuring the issue was a burned out tripot but i am not interested in restoring it.

anyone know if there is value in the core axle ? where can i sell it or should it go to metal recycle ?

markarock
10-13-2008, 11:12 AM
New ones are so cheap (about $51 plus shipping for an A1Cardone unit from Rockauto.com) that they probably don't have any value beyond scrap value.

About all I can think of is to Sawzall the tripots off the ends and save the bar in the middle for use as a very hefty drift. It will probably come in handy for something at least once in the next 50 years, as have so many of the "pieces" I saved over the years. Hmmmm. Maybe that's part of the reason my barn is so full. :)

You can be certain, however, that if you toss it out, you will have a use for it in the next sixty days, guaranteed! And if you don't toss it out, it could take all of those 50 years for you to encounter the need for it. :crazy:

Mark

stopher2
03-01-2009, 09:32 AM
even keeping the parts to be reused as utility tools, it is impossible to inventory everything and keep it organized when i need it ...IF i should need it :ugh:

flexeril
11-08-2010, 07:43 PM
Got the old seal out and the new seal in last night. Filled the differential with fresh fluid. Installed a new axle/CV joint. Installed a new hub bearing. Installed a new shock. Done.

Forgot one thing--to take a photo when the seal was out. D'oh!

Anyway, I figured out what the adjuster is, and what the "splines" are for on the back of the seal.

The adjuster is on the outside of the bearing, and it has recesses that match to the "splines" on the seal. The splines fit in the recesses and keep the adjuster from moving/loosening.

Pried the old seal out with a lever type seal puller and some steel for bracing/making a fulcrum/pivot point.

Tapped the new seal in place with a flat piece of steel against the seal and a short drift which I pressed against the center of the steel and hit with a hammer. It went in fairly easily. I lubricated the outside, which is ridged rubber, with gear oil first. I first marked it so the splines would align with the recesses in the adjuster, and marked the exterior of the case, so that when I drove it in, the splines would engage the recesses in the adjuster. Judging from the old one, the splines bend over and nestle in the recesses when the seal is hammered home.

There wasn't anything loose in there. Must have been a figment of my imagination. I was feeling the bearing I guess. Dunno.

Check the photos.

I cleaned the differential housing with brake clean and will check in a few days to verify that the leak is now gone.

The differential was down about 3/4 of a quart of fluid. It had been leaking for a while. I can see how somebody could burn up a differential if they ran totally out of fluid. I bought the gear oil from the dealership, and it was uber expensive, about $26. But I know I have the "right stuff". It was not easy to fill--plastic tubing attached to the quart bottle and snaked to the opening. A little messy, but I got it in.

The big nut/washer looking thing is the fill opening, and it seals with a large o-ring. I didn't replace the o-ring.

I replaced the hub bearing at the same time, and now the truck is totally quiet again. It is amazing how noisy the old bearing was. The new bearing is an AC Delco unit, but the ABS wire had the wrong connector on the frame end, so I just used the old wire in the new hub. It works fine.

Mark


Mark,

thanks a lot for posting all this info about this so blessed part. I have been tearing my head and venting in this forum for a few days while searching for the part number. This is a great forum but there are a lot of threads that make it somewhat impossible to find the info you seek.

I ordered what the dealer thought it was what I wanted but I could tell it was the wrong part right away when I picked it up today. They ordered part # 12471614 with a description: seal 5.469... anyone knows what that 5.469 is????

To make things more complicated, this part ordered is special order only and there are no refunds. I will now have to attempt to have the dealer refund this money or I will have the bank pull it back since I paid with cc.

I am curious to now what that part that they ordered is and where it goes. I pulled the part on compnine but it does not give me a listing and all I get is a diagram.

Any ideas anyone?