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.





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.









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?

[jarhead]

I was Googling today and found this similar post of yours on the other board. It appears you have this all sorted out now.

I noticed the "vendor name" you purchased your third member from and was curious if you have been happy with it, and the vendor over the years. Are they a vendor here?

I have been working with them on a quote the last couple of days and they are literally the best price I can find. I would be getting a Yukon true trac, motive gears, timken bearings, and a 9" reconditioned case.

Thanks, Joe

[SSLance]

I guess I am mostly happy with it. Realize that you are purchasing an old most likely a ford truck center housing that has had new axle tubes and ends welded to it along with the mounts for your specific application. it is not a brand new fabbed housing. For the price it is a good deal as a Currie, Strange or other high end 9" housing is at least 30-40% more. Also realize that you'll get loose parts and will be assembling them into one unit yourself.

The center section is fine, I bought their trac loc setup and it's been fine. I have had some issues with the passenger side axle seal (or the lack thereof) leaking but hopefully I've found a way to fix that now.

If you decide to go with them and have any questions once you are ready to assemble and install, just ask away. Be sure to find the correct axle seals and get them installed correctly.

[jarhead]

thanks, I just was getting a center section. I already have the housing in my Torino.

I appreciate the information.

[SSLance]

Their center section was set up great.