So ive gone through three hubs in about 7 months....what is going on? my hub just failed again today i AAA'd it home took it off and the metal has turned blue from the heat that was going on down there. The grease has all burned off and a thick black sludge is everywhere. What could be causing the hubs to be going bad? I fail to believe that i have bought three faulty hubs. The axel has a bit of play in it, it travels 3/4 of an inch into the transmission once the hub is off. It also doesnt seem to be bent. so im at a loss and at the end of my own ideas PLEASE HELP!!!!!!!!
Shawn
------------------ 1987 5spd GT-----Sheerah
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08:11 PM
PFF
System Bot
May 26th, 2008
shawnk Member
Posts: 968 From: San Francisco, California, USA Registered: Mar 2008
The only thing I can think of that would do this three times in such a short period of time is an installation problem. How much torque are you putting on the axle retaining nut? I suppose it's possible that too much torque could be overloading the bearings, causing excess friction and heat which then cooks the grease out of the bearings.
Cheers
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08:55 PM
May 28th, 2008
Fierobsessed Member
Posts: 4782 From: Las Vegas, NV Registered: Dec 2001
Brake condition, and alignment are important for bearing life. If your brake sliders are siezed, the brake piston will put heavy sideloads on the bearing, wearing it prematurely. Alignment will do the same. Usually the bearings don't die too quickly from either of these problems.
I agree with TiredGXP, it looks most like the axle nut was either too tight, or possibly too loose.
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06:48 AM
TiredGXP Member
Posts: 712 From: A cold, miserable place Registered: Jan 2008
Just as follow-up, I was looking through the Haynes manual: NEW hub nuts should be torqued to 200 ft-lb, OLD hub nuts should be torqued to only 70 ft-lb. Since these are lock nuts, the only reason I can see for the lower torque on reused nuts is that the locking portion of new nuts apply much more "clamping" force that needs to be overcome than reused nuts.
Cheers
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07:35 AM
shawnk Member
Posts: 968 From: San Francisco, California, USA Registered: Mar 2008
well thanks guys ill try everybodys suggestions. im getting a new caliper and the hub is on the way so maybe it will be fixed. i just hope thats the problem. i have another fiero on the way to me right now so if the new parts dont fix it then im swapping out the rear drivetrain as a last ditch effort.
Used nut is supposed to be 170fp according to some notes. The 20 pound reduction accounts for the wear in the nut after it's used once.
This is also a dry specification.... DO NOT lube the threads. Lube on the threads means you will be over tight even tho the wrench says the right number. If you need to prevent corrosion, coat the exposed section of axle after your done with the assembly work.
Either way, you should not be reusing the nut. It's considered a one time use item. They are available at many parts stores for that reason. (Check the MotorMite/Dorman racks.)
To kill three of them that fast... Most likely your crushing the unit by running the nut up too tight. While they are a press fit inside... The hubs are mainly held together by the axle. Too tight and you can deform the parts enough to eat the bearing.
That said, I have to wonder at the quality of some on the aftermarket. Try another brand if you haven't already.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
so i replaced the brake caliper and the hub. I also did not over tighten the axel nut. But........as i set her wheels back down i noticed the toe of the tire is off. are the fiero rear wheels set at an angle? Both of my rear wheels are having uneven tire wear and by uneven i mean the outside is bald and the inside is still treaded. so just another problem that i need to sort out. any ideas?
Take it in for an alignment, tire problems like you describe are a dead giveaway that your alignment's off. That may or may not fix the hub problem, but like in any complex failure scenario you need to knock out the stuff you do know about before you'll be able to solve the stuff you don't.
JazzMan
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05:42 PM
shawnk Member
Posts: 968 From: San Francisco, California, USA Registered: Mar 2008
well im getting new back tires at 2pm and an alignment. im also having my toe( or tow) adjusted i think it seems to be off. soooooo hopefully this will solve the problem thanks all for the help
------------------ 1987 5spd GT-----Sheerah
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03:55 PM
shawnk Member
Posts: 968 From: San Francisco, California, USA Registered: Mar 2008
so i went got new tires and found out that my tie rods and front bearings are bad....f*** if its not one thing its another.
I was just about to type this and I read your post. I recently relaced my tie rods and because I counted the revolutions when I installed them, I did not get an alignment. That was the wrong thing to do. I had racing slicks on the rear tires within 2 weeks. Bad alignment in the rear might cause undue strees on the hubs also. You'll just have to fix it and see what happens.
