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Thread: Outer wheel bearings, and greasing the front end
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Brad
Rotorhead
Posts: 1672
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posted March 04, 2015 11:33 AM |
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Outer wheel bearings, and greasing the front end
Recent project is to diagnose a wandering steering issue that got unbearable. Rocked the front tires top and bottom and they rocked more that should. Removed wheel, rocked the hub with a slight 'klink'. Pulled the front hubs and outer wheel bearings are almost dry, and smell burnt. Grease on the outer hub area smells and looks burnt. Clean them and super fine metal particles come out. Tips of the rollers on the small end were quite worn. Races looked good. Gobs of play on the outer bearings. New outer bearings ordered. Inner bearings are fine, greased and no play!
I wasn't running hub caps for a few years, and it may have been several, several thousand miles ago since I've checked or greased the front bearings. I think water and soap from car wash got into the dust caps and removed the grease. So word to the wise, run a hubcap. Additionally I'm putting a bead of silicone on the lip of the dust cap before tapping it on.
Lastly, the last time I installed the hubs I tightened the hub nuts to factory specs, using the little pull scale method to set # of pounds of pressure required to rotate the hub. This time, I'm torquing the nut to 8 ft/lbs as it doesn't wobble, bearings don't rumble, and its not too tight at 8 ft/lbs. Plus I can use a torque wrench to get a consistent tightness.
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Also re-greased the entire front end. Poly sway bar bushings were dry even though I grease them unregularly. I couldn't move the sway bar by hand, had to hit it with a deadblow hammer to move it. That definitely increased the front wheel rate (spring rate measured at the wheel) since it wasn't free moving. One Lower control arm ball joint was dry as was the outer tie rod on the same side. Idler arm needed a lot of grease too. Very interesting.
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Last year I drove REPU 3 times across the Golden State on vacation. Ride was FIRM and unpleasant. Potholes were unbearable. Why do I need such a firm suspension for a cruiser ? I don't autocross anymore.
Trying some Gabriel Ultra front shocks, the Bilsteins are great for handling but man they're firm. If I try to quickly and firmly push the Bilstein shock down, I can't move it more than 1/4 ". Same test on the Ultra and it absorbs the force and moves the rod about 2 ". Ultras have 'velocity sensing technology' which sounds like what I need.
Also trying some softer front springs....512# front is stock, I use 500#, trying 375#. I remember 1st gen rx7 stock front springs are 100#, eibach pro kit fronts are 171#. On a 1st gen racecar we use 375#. REPU only weighs 350 to 550 lbs more than a 1st gen so I think the stock REPU spring rates are overkill for cruiser or even sporty driving. Must be for hauling heavy loads. I'll let everyone know how my test turns out.
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-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge
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TimPA136
Redlining
Posts: 325
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posted March 07, 2015 07:06 PM |
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I know that the poly strut bushings make all the difference
for handling and response. When you are happy, that is gonna be a great handling truck! Keep in touch.
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Brad
Rotorhead
Posts: 1672
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posted March 10, 2015 09:15 AM |
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Hi Tim, yeah the Bilsteins have poly shock bushings, very firm. Great for response. Gabriels have rubber shock bushings...softer ...compliant. they were dry when new so i even softened the rubber ones with GOOP hand cleaner.
Poly sway bar bushings I think I'll keep, just grease them and run the frame bushings a little loose so they won't bind.
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Brad
Rotorhead
Posts: 1672
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posted March 12, 2015 12:14 PM |
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After dorking around with the front brake hardware, trying to install new front pads without the metal clips / springs popping out and starting all over. then sliding the silly wedge shims in. I'm starting to consider using B2200 front brakes / hubs / knuckles / etc as they have the newer style calipers that slide on with a pin and a bolt. Like 1st gen brakes.
Am I the only one who gets brake pad wear that is uneven? Like the pads wearing at an angle.
/ /
instead of
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Brad
Rotorhead
Posts: 1672
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posted March 17, 2015 11:03 AM |
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Took it for test drives in the neighborhood. Softer springs and Gabriel shocks greatly increased the comfort level. I instinctively cringed when going over manhole covers but suspension absorbed it like a champ unlike before. Just 25-35mph stuff so far. I'm also running the sway bar body mounts looser, so they can swing freely. If too tight they just bind and act like a torsion bar, increasing front suspension stiffness.
Softer springs lowered the truck about 1.125 inch more than before, didn't think it would go down that low. Ordered some 2" taller threaded sleeves for the coilovers, should be here Friday.
Front calipers are sticking, don't want to move much in either direction, even after a rebuild. Had some rust in the calipers, need to remove more of that. Drivers side more than passenger side. Flushed the drivers side brake flex hose and hardline out with brake cleaner, no debris in it. Found out you're supposed to put silicone grease on the caliper square seal, caliper piston, and the caliper cylinder bore. To make it move smoothly and prevent rust. On order, will be here tomorrow. Dow Corning Molykote 111.
I can tell the new outer wheel bearings have made the steering a bit more consistent, less wandering. I also pulled some caster out of the front alignment by rotating the adjusters on the upper a-arm. Much less effort to turn the steering wheel now. At least that worked out !
If everything goes according to plan I should be on the freeway this Sunday.
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-brad-
74 REPU Lawn Green
81 Rx-7 racecar. 12a J-
Bridge
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kansei
Redlining
Wankelized
Posts: 423
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posted March 23, 2015 12:07 PM |
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Brad,
I'm curious if you ever did any front spring research before you went to coilovers... ? It would be nice to find softer springs that swap out for the stock fronts. I learned something from your post as well.. I thought stock SA/FB front springs were more along the lines of 175# and the rears were ~100# (except the SE, of course). Even to carry a 1400# payload, why in the world would the stock REPU front springs need to be more than five times stiffer than SA/FB fronts? IIRC, the 1st gens had payload ratings of around 800# (too lazy to go out back and check one of the tags).
Neal.
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Neal A.E. Swigert
Greenville, Michigan
1974 REPU Resto Project
1976 808 Wagon
1977 Cosmo
1978 Savanna RX-7 GT
1980 Leather Sport RX-7
1980 Petty Targa RX-7 #11
1985 GSL-SE RX-7
1988 RX-7 10th Ann
1993 RX-7 VR Touring
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Brad
Rotorhead
Posts: 1672
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posted March 23, 2015 04:17 PM |
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quote:
Brad,
I'm curious if you ever did any front spring research before you went to coilovers... ? It would be nice to find softer springs that swap out for the stock fronts. I learned something from your post as well.. I thought stock SA/FB front springs were more along the lines of 175# and the rears were ~100# (except the SE, of course). Even to carry a 1400# payload, why in the world would the stock REPU front springs need to be more than five times stiffer than SA/FB fronts? IIRC, the 1st gens had payload ratings of around 800# (too lazy to go out back and check one of the tags).
Neal.
Hi Neal, I haven't researched a spring to just swap out with. I wanted adjust-ability so went with the threaded coilover approach. You could just take a REPU spring to a shop that manufacturers them and ask them to wind a pair with a softer spring rate, and the ride height you want (stock, low, etc..). But you have to be careful it won't coil bind. Thats where the coils are compressed to the point they rub on each other.
I got my 1st gen spring rates off this page: https://www.mazdatrix.com/h4579-85.htm
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