Tight Rear, Loose Rear

IMG_0018I like a tight rear end. I picked up my diff and axle housing from Pacfic Automotive on Friday. Ken was still working on the axle bearings, and was going at it with an air chisel when I went to his shop. I’m glad I left this job to him. I’m sure I would have been cursing at that point, & my rickety mystery China hydraulic press would prob be in dangerous shape and no longer a parallelogram. When I got it back home, I repainted it with my favorite kryptonite paint, POR-15. Thats the stuff I used on my control arms where I forgot to press a metal sleeve out of and we had to torch the end to heat it to extract it. The paint was intact and pretty unscathed even after that. It’s name is Paint Over Rust meaning you can paint it over surface rust. The surface does need to be clean of oil, I can never seem to get it totally clean of that, I have some spots where the paint didn’t stick. But if the paint sticks, look out! If you get any on your skin, that’s it. If you don’t immediately wipe it off, it’s there until the layer of skin peels off. Painting implements are pretty much toast afterward. Its not cheap stuff, buy only what you can use, once you open the can any left over is pretty much toast. They advise you to use some kind of scoop to take paint out of can, you get it on the lid lip and when you close the can, its toast. It’ll seal up the can tight and you’ll end up destroying the can reopening it. If you keep it clean, you can extend storage a bit by sealing it tight and in another container with dessicant, this paint is moisture cured. Oh well, I made a mess of things so this entire $30 pint goes for painting the rear axle.

IMG_0020Saturday morning I check it out. Paint’s pretty much dried solid, I try to clean off the bare spots and repaint, helps a bit. I pull the axle end seals with my favorite slide hammer. Not sure why I like it so much. I then rummage in my box-o-DRMO bits and find a bit of correct diameter to drive the new seal in, but then find out its not deep enough! Doh! Luckily, not too much later Ken calls me to tell me the axle shafts bearings are on and done. I He-man the rear end into the back of the Suzuki and drive on down to Pacific Automotive. There’s an Aston Martin and old Lambo, so you know there are others aside from the old Toyotas, 4×4’s, Starlets, Jeeps, 68 Camaros that trust him. Ken taps the new seals in and tells me that he uses a bit of rtv silicone on the outside metal of these seals, says they sometimes leak there if there’s imperfections/scratches on the surfaces. Nice tip. It’s still early afternoon so time isn’t too bad, but I hightail it out of there for home.

I drag it out of the Suzuki once again onto one of the handy dandy SGI roller bases. Those things have been great! They’re not on casters so steering them isn’t soo easy, but otherwise they roll great and are strong. Works good for rolling the axle back under the car and lining it up with the suspension links. Getting the lower links in and lined up do give a challenge and take a bit of struggling. That new paint gets scuffed up a bit. The other links go together easy, the axles slide in without much effort. Turning the hub to move access hole to tighten down the axle retainer takes some effort, this rebuilt rear is nice and tight!

Aside from the initial struggle of getting the first links in, things seem to be going together pretty well, but I guess all the little things eat time. It’s well after dark when I finish wrapping it up and have everything tightened up and the diff filled with oil. Looks like I won’t be making the Jodo Shu Bon dance tonight. Gomen mom! At this point I could have called it a night and get ready for the race tomorrow, but I had earlier in the week drained the tranny so I could try and address a slow leak issue. I think what is happening is after I rebuilt the tranny and was reassembling the case, I didn’t fully rtv sealant the case joints. I had ran sealant all along the outer edge, but neglected to circle the bolt holes. Boo, I’m pretty sure that where it’s leaking from. To properly seal this would require dropping the entire tranny again, which I didn’t want to do. So instead I’m going to try removing bolts one at a time and applying generous amounts of rtv sealant to the bolt and reinstalling. You’re actually suppose to do this anyway, which again I had neglected. The only problem with doing this after the fact is that there’s already oil in there. I clean them as best as can, hopefully this will help. I’m getting pretty tired, so I only do the bolts on the lower edge of the case. Hopefully this will help. It’s now 10PM and the okonomiyaki I made for lunch has long since ran out. It’s not the greatest, but there aren’t much options this late, I hit Zippys and actually have something of a leisurely meal. I take my time figuring I’d give the rtv some time to set. Really it should be 24 hours, but I don’t have that luxury.

When I get back, I clean up and then the last thing I do is fill the tranny with oil. The car is finally back down on the ground.  Almost another midnite wrenching session, it’s just past midnight when everything is wrapped up and I back out for the test drive. I don’t notice anything really different as I back out the driveway, except that I had forgotten how that clutch grabs! And then when I slowly back down the curb, when the front tires hit the dip there’s the tiniest bit of slip in the rear wheel and then it catches and I can pull right out. No embarassing sitting half out the road spinning the tire and not going anywhere and having to try to push the car back to get some traction. Transfers power from the wheel that slips, to the wheel… actually to both wheels. Getting it out onto the neighborhood streets, I don’t notice any unusual sounds which a lot of people report with clutch LSDs. I did get the “Super-Q” version. What I do notice is the steering feels a little heavier, car likes to go straight. Stop at the gas station and take a peek under to check for leaks, looks good! I then drive back up to the park up my street. They’ve posted closed hours now there and there’s a big gate on the entrance, but I have yet to see them close it. The park looks empty so I go into the lower parking lot and decide to do some of the break in procedure, even though this version is supposed to not need it. You drive figure eights accelerating only on the straights, neutral in the full lock curves. You’re supposed to do this for half an hour! I think I may have been at it for 10-15 minutes. Haven’t heard any unusual sounds for the entire time driving, so I figure its good. Head home and turn in, gotta wake up in four hours to go race!

The race was an eye opener! With the LSD the car felt like an entirely different vehicle! First time out on course it really caught me off guard and I had the car flailing all over the place, mashing the gas too early out of the corners made the rear immediately kick out. Wow, having a tight diff in the rear has made for a loose rear! Anyway, once I started figuring things out, it was heck of fun! And my rear suspension behaviour seems to have been cured too, so I’d have to say anyone running a high rate and dropped suspension, make sure you have a LSD, otherwise it’ll be pretty close to useless. Fun fun fun!

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