9" third member freshen up questions

[SSLance]

So on the way home from my last two autocross events, I've felt a drivetrain shudder under load at highway speeds that was new. After the first time, I put the car on the lift and looked things over, nothing looked out of place but I could not hold my hand on the back side of the differential housing. It wasn't so hot that I couldn't touch it, but it was hot enough that it was uncomfortable to hold my hand on it for very long.


Then it sat for a couple weeks and when I pulled it out of the garage to get ready for the next event, I noticed the passenger side axle seal had started to leak once again and had soaked my tire with gear oil. It had been leak free for over 500 miles and 30+ autocross runs so far this year. I went ahead and ran it like that and felt the same shudder on the way home. Under normal everyday driving it still feels great, but after racing it the shudder shows up.

I pulled the passenger side axle out yesterday and the axle bearing is starting to give up. If you hold it just right you can feel a little play in it and it's just a little bit rough feeling when spinning the bearing around. I'm 95% sure this is the shudder I'm feeling and I'm not really surprised this bearing is starting to give up. That's an easy find and fix.


I drained the rear end gear oil over a cheese cloth. Here's what I found.


https://static1.pt-content.com/images/pt/2014/05/IMG_20140510_144825_593-1.jpg


https://static1.pt-content.com/images/pt/2014/05/IMG_20140510_144832_002-1.jpg


Those grey clumps are a very fine mixture of metal shavings and gear oil, they smear out and are pretty fine...but it's still metal and if you hold the light just right on the cheese cloth you can see other glints of metal on there as well.


At first I thought the third member was probably alright, the metal is just normal wear. Then as I thought about it more, plus the fact that I already have an axle out, I went ahead and pulled the other axle out and pulled the third member.


The ring and pinion look great. Very minimal wear on the gear teeth and the backlash still feels perfect. There might be just a bit of roughness feel through the bearings when rotating the gears. It's negligible at most. Again, at first I'm thinking it's fine...flush everything back out real good, seal it all back up and run it. Now I'm second guessing myself. It's already out...is it money well spent to freshen it up with new bearings and a pinion seal. The pinion seal is starting to leak a bit...I'd like to replace it either way.


Here's some pics of the gears.


https://static1.pt-content.com/images/pt/2014/05/IMG_20140511_093527_780-1.jpg


https://static1.pt-content.com/images/pt/2014/05/IMG_20140511_093549_661-1.jpg


https://static1.pt-content.com/images/pt/2014/05/IMG_20140511_093611_382-1.jpg


https://static1.pt-content.com/images/pt/2014/05/IMG_20140511_093618_046-1.jpg


So...what are the thoughts here? Remember that I'm going to have 7 autocross events in 36 days July -August and throw in a USCA event at Gateway right in the middle of that.


I'm certain that I could put it all back together and it would run for a while, I definitely caught things early. I'm going to reseal both axle ends and put new sealed axle bearings on the axles for sure. I want to replace the pinion seal...as I hate leaks. It's not dripping yet, but seeping enough to soak the bottom of the housing.


Should I put a bearing kit in the third member? And if so, should I attempt this myself or take it to a shop to get it done. Typically what do the parts cost and how much labor should be involved in this. The diff is a trac lock I believe and it has been working fine. I always run regular 75W-90 and a bottle of friction additive for the diff. The fluid has been drained 3 times in 5 years and about 5,000 miles now...but it has been abused pretty hard the last two years with a lot of autocross runs and a few track days on it.


What do you all think?

[indyjps]

I would run it as is. Axle Bearing seem to be the issue and you are addresing that. Gear wear pattern looks good. How old are the bearings in the center section? Was it set up new 5000 miles ago?

[SSLance]

The center section was new, all set up by Quick Performance when I bought it about 5 years ago.

The third member should be ready tomorrow. I took it to a local shop that specializes in driveline stuff and he agreed with our assessment, it would probably be alright for a while still, but eventually it'll start to eat itself and since it's already all apart, $250 for new bearings and seals is just good insurance. The metal in the gear oil that came out of it and the pinion seal leaking were the deciding factors. I'll bet he finds some wear in the pinion bearing when he pulls it apart.

I felt some brand new Moser Axle bearings while there and for sure mine are toast... I've ordered the new axle bearings and seals, they'll be here mid-week then I'll get the old ones pressed off and new ones back on. Then it'll be all fresh sealed and ready to last the summer.

Looks like I might just plan on replacing the axle bearings once a year if I keep abusing them like I am. I know that one of the axle tubes is off just a bit because of the rear camber issues we found on the alignment rack. It's not off a ton but that plus the extreme forces put on the bearings the past 3 years both overwork the bearings. On top of that the design of the sealed bearing axle ends leaves just the grease inside the bearing to lube it, no rear end gear oil gets to them. Probably not the ultimate setup for what I'm doing with the car but replacing axle bearings once a year is a LOT cheaper than replacing custom rear end housings.

The driver side has NEVER leaked...it is always the passenger side. And the driver side bearing feels just as rough as the passenger side.

[indyjps]

Glad you got it figured out, with that many events stacked up sounds like a good idea. If youre tearing into it consider a yoke with a pulley for a rear end pump and cooler, you can set the pump, cooler, ducting up later. Heres one fron yukon, shop around nascar stuff for the same parts and a pump. http://www.ringpinion.com/b2c/ProductDetails.aspx?ProdID=11900&Product=YY_F900634&Brand=Yukon_Gear_and_Axle

[LS1-IROC]

Do you have the tapered axle bearings or straight?

[SSLance]

Straight sealed bearings, Big Ford style 3.150 x 1.531

[SSLance]

Shop called and said that the pinion seal surface was trashed so a new yoke has been ordered.

[SSLance]

The differential I run is a Trac-Loc, trying to figure out what I can use now for a slippery gear oil that will still let the clutch type diff work properly. I need to call Royal purple, their website says their lube is good for limited slip diffs...but I want to be sure.

The new axle bearings are here, the O-Ring on the outside of them should help seal things up. Also, the inner last seal I used had an ID of 1.562, the new inner seals are 1.531 which is the same OD as the axle. Between those two things, hopefully that gets the ends sealed up good now.

The new yoke was ordered and installed. The third member is ready for me to pick up. All of the bearings were a bit loose in the third member, you could spin it over pretty easy. He used the same shims when he put it back together and he says it feels much tighter now. Hopefully that will fix any issues with it as well.

Tomorrow I'll get the new bearings pressed on the axles and the third member picked up, then re-installation can commence. I also just ordered some new EBC Yellowstuff pads for the rear and I am going to fab up some new hard lines on the rear as the old ones are pretty beat up from things (mainly the exhaust when dropped down) hitting them too much over the years.

Everything back there should be new and fresh once it's all back together.

[71RS/SS396]

The differential I run is a Trac-Loc, trying to figure out what I can use now for a slippery gear oil that will still let the clutch type diff work properly. I need to call Royal purple, their website says their lube is good for limited slip diffs...but I want to be sure.

The new axle bearings are here, the O-Ring on the outside of them should help seal things up. Also, the inner last seal I used had an ID of 1.562, the new inner seals are 1.531 which is the same OD as the axle. Between those two things, hopefully that gets the ends sealed up good now.

The new yoke was ordered and installed. The third member is ready for me to pick up. All of the bearings were a bit loose in the third member, you could spin it over pretty easy. He used the same shims when he put it back together and he says it feels much tighter now. Hopefully that will fix any issues with it as well.

Tomorrow I'll get the new bearings pressed on the axles and the third member picked up, then re-installation can commence. I also just ordered some new EBC Yellowstuff pads for the rear and I am going to fab up some new hard lines on the rear as the old ones are pretty beat up from things (mainly the exhaust when dropped down) hitting them too much over the years.

Everything back there should be new and fresh once it's all back together.

Those sealed bearings will not live over the long term when used for auto-x or track use. I've had better luck with the A20 bearing that Ford used on the full size cars, it has a better seal set-up and it's a large tapered roller bearing. The fly in the ointment is they won't work with your current axles most likely and also require a different bearing retainer on the housing end.

[SSLance]

Okay, with the third member all freshened up and the new axle bearings and keepers pressed onto the axles, I'm ready to start putting it all back together. I have what may be somewhat of a dumb question, but remember, there are no dumb questions right...

Should this axle seal be put in the housing end the other direction?

https://static1.pt-content.com/images/pt/2014/05/IMG_20140510_153800_203-1.jpg

https://static1.pt-content.com/images/pt/2014/05/IMG_20140510_153744_577-1.jpg

The reason I ask is you can see the ring where the keeper wore against the seal a little bit the last time I put it in. I thought I drove it all the way home when installing it the first time, but it was a bear getting it started and really took some force to drive it in.

If the seal was installed facing the other direction that would give just a little bit more room for the keeper. It doesn't seem right to me though considering which way the lip on the rubber part of the seal faces. Curious what everyone else thinks?

[SSLance]

I think I found my answer...


PRODUCT DESCRIPTION
Moser Engineering Inner Housing Seal. Designed to be used with 1.531" & 1.562" Ball Bearings.

The Inner Housing Seal installs flat side facing you and is driven into the housing end until it seats.

Sold in Pairs

Guess I did it right, I'll just have to really drive on it to make sure it seats home this time.



Here's some pics from the machine shop yesterday.

Trying to press the old bearing and keeper off of the axle...

https://static1.pt-content.com/images/pt/2014/05/IMG_20140515_124930_576-1.jpg

It wouldn't budge.

The keeper is a .005" tolerance fit on the axle.

So we cut it off on the lathe

https://static1.pt-content.com/images/pt/2014/05/IMG_20140515_125928_305-1.jpg

https://static1.pt-content.com/images/pt/2014/05/IMG_20140515_130651_548-1.jpg

After it was off the old bearings pressed right off and the new bearings went on pretty easy.

https://static1.pt-content.com/images/pt/2014/05/IMG_20140515_134049_479-1.jpg

We then tried to heat the keepers up to expand them before reinstalling but once dropped on the first one didn't go far enough, then got stuck.

So we had to set the axle up in the great big hydraulic press to finish driving the keeper home onto the axle.

I'm not sure how people do this at home without these tools. The guy that set my third member up said that he just cuts the keeper and bearing off the axle with a cut off wheel and presses the new ones on...it was at that point that I put the axles back in my truck and said "I'll take care of that myself"

Also, here are some pictures of the yoke that Quick Performance sent out with the rear end kit I bought from them.


https://static1.pt-content.com/images/pt/2014/05/IMG_20140516_074553_371-1.jpg

https://static1.pt-content.com/images/pt/2014/05/IMG_20140516_074606_671-1.jpg


I'm not sure how it ever held gear oil in in the first place. That yoke looks to have been used on at least 3 different installs.

[83hurstguy]

Hard to tell from pics, but you want a seal to face so that internal pressure forces the lip seal against the axle. If you face the seal the incorrect way, internal pressure (just the hydrostatic force of the oil column) would cause the seal to fold away from the axle and seep out.

The top half of this picture shows what I am describing. If this isn't a standard lip seal, it may not apply...

http://tribology.asmedigitalcollection.asme.org/data/Journals/JOTRE9/28753/017704jtq1.jpeg


Edit: looks like you got it while I was posting, haha.

[SSLance]

Thanks Luke, I've learned quite a bit about seals today and that helps even more.

Here's the close up pics of these particular seals.

https://static1.pt-content.com/images/pt/2014/05/IMG_20140516_074320_349-1.jpg

https://static1.pt-content.com/images/pt/2014/05/IMG_20140516_074458_808-1.jpg

https://static1.pt-content.com/images/pt/2014/05/IMG_20140516_074420_919-1.jpg

[SSLance]

Got everything bolted back together last night. I bought a new seal driver kit and was able to drive the seals in much further than I did the last time, this should give plenty of room between the seal and keeper ring. It all went together smooth and feels much tighter now than before. I'm certain we gave it every chance we could to seal up tight and not leak anymore. I'm giving the RTV lots of time to set up before filling the diff with Royal Purple Max Gear 75W-90. RP says their synthetic gear oil is designed specifically to be used with limited slip clutch type diffs and already has the friction modifier in it. Hopefully this is one more step to reduce heat, friction and maybe even some of the noise the 9" is well known for making.

Road test maybe later on today...