View Full Version : How hot do your hubs get?
CrnCnn
01/05/2010, 10:36 AM
So I got new rotors and pads from R1 and finally put them on a few months ago. While I was in there I repacked my bearings. It seems like my hubs are really hot when I get done driving now.
The problem is that I never really payed attention before.
alterastro
01/05/2010, 10:47 AM
Hot hubs usually indicate bearing problems. If you repacked a while ago they may just need adjusting. Check them first.
Nick
nfpgasmask
01/05/2010, 01:01 PM
Do you still have your CVs out? I've never taken apart the front end of my VX before, so I don't know if it is the same as the 91 Trooper, but is there a hub nut in there? Did you possibly over tighten it? Other than lack of grease I can't imagine anything else causing too much friction.
Bart
CrnCnn
01/05/2010, 01:29 PM
Hot hubs usually indicate bearing problems. If you repacked a while ago they may just need adjusting. Check them first.
Nick
Do you still have your CVs out? I've never taken apart the front end of my VX before, so I don't know if it is the same as the 91 Trooper, but is there a hub nut in there? Did you possibly over tighten it? Other than lack of grease I can't imagine anything else causing too much friction.
Bart
No, everything is back in and normal, the only change other than rotors is the diff brackets. There is not a nut for the CV's, just for the hubs to remove the rotor. If I loosen the nut then the rotor seemed to have play.
Triathlete
01/05/2010, 01:48 PM
I believe the load for the bearing adjustment is 5-5.5 lbs.
CrnCnn
01/05/2010, 03:14 PM
well my hands arent really calibrated for 5lbs. Should I have gotten a tool? The hub nut just pretty much unscrewed when I tapped it with a flathead then spun right out so I didnt put it on too tight as far as I could tell. just tight enough to where there was no play in the rotor.
Do you still have your CVs out? I've never taken apart the front end of my VX before, so I don't know if it is the same as the 91 Trooper, but is there a hub nut in there? Did you possibly over tighten it? Other than lack of grease I can't imagine anything else causing too much friction.
Bart
Too much grease can also cause a build up of heat in the hubs.
You need to pack the bearings well and have residual grease in the hub, but not have it packed tight with grease.
PK
CrnCnn
01/05/2010, 03:27 PM
Too much grease can also cause a build up of heat in the hubs.
You need to pack the bearings well and have residual grease in the hub, but not have it packed tight with grease.
PK
really?? hmmm cause I got 'em pretty full. I mean I was always taught to pack them til they are basically full
I measured the temperature on my hubs after having them repacked. I drove about 15 minutes ( my commute to work ) then took the temperature with a infrared thermal thingy. I did this for 3 days in a row , temperature read between 140 fahrenheit and 150 fahrenheit . It was summer time so ambient temps. were in the 90's. I haven't a clue if those temps are normal.
CrnCnn
01/05/2010, 04:01 PM
It could be normal. They aren't glowing or anything. I just was sniffing out my new brakes and felt the hub cause I was there.
Triathlete
01/05/2010, 05:33 PM
There is a write up on the site. They used a fish scale.
SlowPro48
01/05/2010, 06:22 PM
"Really hot"?
Brakes are dragging!
You're not doing a lot of heavy braking right before you check the temp are you? Brakes will easily put a lot of heat into the hub/wheel even if they're dragging just a little. Bearings - not so much - unless things are BAD wrong. You'd have to crank down on the bearing preload quite a bit - or have totally shot bearings - to get "really" hot - as in can't keep your hand on the wheel very long. Might want to jack a wheel off the tarmac and see how much brake drag you've got...
BTW the 4.4 - 5.5 lbs is for a new bearing and seal. For used bearing/new seal the preload is 2.6 - 4.0 lbs. And you don't even need a a fish scale - just find an object with the desired mass and hang it on a lug bolt at 3 o'clock. I use a gallon milk jug half full of water - hang it on the lug bolt with some wire and turn the preload down until the 4.15 lbs of water won't turn the hub then back off a hair and call it good. This way you don't have to have three hands - gravity takes care of the tension leaving you one hand free to spin and one to tighten...
ibmx2
01/05/2010, 07:35 PM
" And you don't even need a a fish scale - just find an object with the desired mass and hang it on a lug bolt at 3 o'clock. I use a gallon milk jug half full of water - hang it on the lug bolt with some wire and turn the preload down until the 4.15 lbs of water won't turn the hub then back off a hair and call it good. This way you don't have to have three hands - gravity takes care of the tension leaving you one hand free to spin and one to tighten...
dam now i am pi$$ i spent all that money on my snap on inch & foot pound torque wrenches
quite genius & great for the road side fix !!!
CrnCnn
01/06/2010, 07:00 AM
I will check my brakes then. What are the odds I could have two sticky calipers? Other than that I don't know why they would be dragging.
SlowPro48
01/06/2010, 08:29 AM
Well... you say this problem cropped up after you installed new rotors and pads, right? When you replaced the rotors and pads did you remove the rubber bellows from the caliper bores and inspect/clean the exposed part of the pistons before pushing them back into the calipers to make room for the new pads? If not, then odds are pretty good you could have sticky calipers!
The pads take years to wear so a band of crud can develop around the exposed part of the piston. The boot provides good protection from stream fording, pressure washing, salt spray, etc. but it's not 100% leak proof. If in the process of installing fat new pads, you just shove that crudded up part of the piston back into the bore, you run the risk of dragging brakes. (and possibly ruined seal too although it is set back into the bore far enough to avoid that in most cases) Best to take the time to remove the boots and inspect the pistons. If dirty, clean the piston with a brass brush or some brass wool or fine steel wool and rubber friendly solvent (brake fluid works well) hose it off with perc then blow it off with air - especially if you used steel wool. Now you can push the part of the piston that has been exposed for several years back into the bore without fear of it sticking.
Or hey - maybe the new rotors and pads are just a tad thicker than OEM and the tolerances stacked up and you're getting brake drag from that...
nfpgasmask
01/06/2010, 09:07 AM
Yeah, I used a cheap fish scale, cost maybe $5.
There used to be a decent tutorial on PlanetIsuzoo for the wheel bearing repack but it seems to have disappeared??? :wtfy:
The hubs on my Trooper get pretty warm to the touch. But nothing that I can't keep my hand on.
Bart
CrnCnn
01/06/2010, 09:12 AM
I didn't remove the rubber piece. My pads were still fairly new so the piston wasnt all that far out (I know that doesnt mean its not dirty) the rotors were garbage so I replaced it all at the same time. The pads and rotors were pretty think so maybe they are just dragging. I did notice they were a lot more on the warm side in the first few days and they dont seem as hot now, but is has also been pretty cold here so I didnt know if that had anything to do with it.
I am gonna be driving about 1000 miles soon and dont want any grenading happening.
There used to be a decent tutorial on PlanetIsuzoo for the wheel bearing repack but it seems to have disappeared??? :wtfy:
Bart
Isn't it the same one by David Chang, that's in our "how to" section?
http://www.vehicross.info/misc/pdf_files/Dave_Chang's_bearing_repack.pdf
CrnCnn
01/06/2010, 09:18 AM
But nothing that I can't keep my hand on.
Bart
That's about where these are, pretty warm but not burn you. Maybe its all for nothing
nfpgasmask
01/06/2010, 09:50 AM
Isn't it the same one by David Chang, that's in our "how to" section?
http://www.vehicross.info/misc/pdf_files/Dave_Chang's_bearing_repack.pdf
Yeah, that's it! It was in the how-to section on the Planet and I just looked for it and couldn't find it??
:thumbup:
Bart
SlowPro48
01/06/2010, 07:10 PM
That's about where these are, pretty warm but not burn you. Maybe its all for nothing
Yup - really hot is a guaranteed problem - pretty warm is probably nothing unless it's accompanied by the roar of worn out bearings. Drive on!
Rule of thumb -
If you spit on it, and it sizzles, it is tooooo hot.
PK
tom4bren
01/07/2010, 03:15 AM
Rule of thumb -
If you spit on it, and it sizzles, it is tooooo hot.
PK
ROFL - a true red neck mechanic. I likey.
CrnCnn
01/07/2010, 07:21 AM
Thanks everyone for easing my mind.
deermagnet
01/07/2010, 03:21 PM
Today while I was out I checked some temps with an infrared thermometer right after I stopped.
Air temps were in the 20's. I have a stock set up with the '99 caps, so I can't get that close to the hubs.
Rotors-
http://www.drivehq.com/file/df.aspx/publish/mgpa/vx/vx7/574.jpg
Caliper-
http://www.drivehq.com/file/df.aspx/publish/mgpa/vx/vx7/571.jpg
Lug nut-
http://www.drivehq.com/file/df.aspx/publish/mgpa/vx/vx7/573.jpg
I got the infrared from ThermoWorks for only $20. They now have a similar unit for a nice price-
http://www.thermoworks.com/products/ir/ir_mini.html (http://www.thermoworks.com/products/ir/ir_mini.html)
I highly recommend getting one of these neat little gadgets. :yesy:
Mark Griffin
tom4bren
01/08/2010, 05:38 AM
I got the infrared from Thermo Works for only $20. They now have a similar unit for a nice price-
http://www.thermoworks.com/products/ir/ir_mini.html (http://www.thermoworks.com/products/ir/ir_mini.html)
I highly recommend getting one of these neat little gadgets. :yesy:
Mark Griffin
But PK's method is even cheaper:)
But PK's method is even cheaper:)
Damn technology - making me redundant again.:mad::(:bwgy:
PK
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