Visit our Popular Forums

Michael W · 06-15-2006, 09:43 AM

I checked the curbside wheels today and had movement. I removed the wheels and brake drums. Both sets of bearings were discarded as the front bearing cage was bent and the rear wheel bearing had score lines in the race and bearing. I call Dexter Axle Corp. when the castle nut would not line up with the carter pin hole. The service engineer said to torque the nut to 50 foot lbs then loosen the nut and tighten finger tight. Well. the nut and hole still did not lign up. He said to back off the nut until the hole and the nut would accept the carter pin. When I did this I still ended up with a wheel that has too much play. Help would be appreciated.

Frank S · 06-15-2006, 10:55 AM

Hi Michael W--Taper roller bearings on wheel with stationary axles are supposed to run loose. For the shade tree mechanic, here is the way to do it. Tighten the nut to reduce all the play (from what Dexter says this is 50 ft lbs). I tighten nut lightly with a wrench, then rotate to insure grease is spread out. Grab wheel top and bottom and rock. Should be no play. Loosen nut to the first position where spindle hole and nut groove line up. Rock wheel as before. If there is play (looseness), insert cotter pin. If still no play, loosen one more postition, and rock. The correct position is the first position you can rock, after no rock. This may seem excessive to your feel for the amount of looseness, but it is not. Wheel bearings like to run loose, and burn up if they are tight (preloaded). If you set up the bearings correctly, and keep them sealed and lubed, they should last the life of the trailer. 39-years in the bearing business.--Frank S

D Bishop · 06-15-2006, 04:33 PM

If you absolutely have to you can place a shim washer behind the Castle nut to get the nut and cotter lined up. The reason for some slack in the bearing is when it heats up on the road the bearing will get tighter.

D Bishop

Nye Thatcher · 06-15-2006, 04:36 PM

Hi Michael. What I have done in this situation is clean and pack the bearings and mount the drums back on the spindles. Then tighten the nut, turn the drum a few times, back off the nut, then tighten to 4lb torque. If your cotter key does not line up, try the nut off the other side hub. If the key doesn't line up, take a sheet of emery paper on a perfectly flat surface and customize the nut (the nut is not made of a hard material). Hope it will help. Good Luck

Inland RV Center, In · 06-15-2006, 04:49 PM

Quote:

Originally Posted by Frank S

Hi Michael W--Taper roller bearings on wheel with stationary axles are supposed to run loose. For the shade tree mechanic, here is the way to do it. Tighten the nut to reduce all the play (from what Dexter says this is 50 ft lbs). I tighten nut lightly with a wrench, then rotate to insure grease is spread out. Grab wheel top and bottom and rock. Should be no play. Loosen nut to the first position where spindle hole and nut groove line up. Rock wheel as before. If there is play (looseness), insert cotter pin. If still no play, loosen one more postition, and rock. The correct position is the first position you can rock, after no rock. This may seem excessive to your feel for the amount of looseness, but it is not. Wheel bearings like to run loose, and burn up if they are tight (preloaded). If you set up the bearings correctly, and keep them sealed and lubed, they should last the life of the trailer. 39-years in the bearing business.--Frank S

Absolutely correct.

A preload for the bearings, on an Airstream trailer should "NEVER" be done. The friction between the nut and the spindle, can itself, be very misleading.

Additionally that load will increase as the bearing warms up. Again, wrong thing to do.

Frank described the proper procedure to a "T".

Andy

**Action** · 06-15-2006, 05:49 PM

Michael,

I would question the 50 foot pound data. 50 foot pounds is a lot of torque, may be enough to crush the bearing into the race. Fifty INCH pounds may be more like it.

>>>>>>>>>>>>>>>>>>Action

markdoane · 06-15-2006, 05:55 PM

50 ft-lbs is correct. On truck steering axles the presetting torque ranges from 200 ft-lbs to 400 ft-lbs, depending on size. This is done while the wheel is being rotated.

If you can crush a bearing into the race with 50 ft-lbs, you're using really cheap bearings.

The whole idea is to make sure the races are very firmly seated in the hubs.

**Action** · 06-15-2006, 05:58 PM

I have never used more than about 17 to 25 foot pounds on an initial tightening (for car truck or trailers) when spinning the wheel. Going double that amount seems to me as too much. However if you say so, I will defer to it. Not that I am going to do it, cause based on past results, I am doing good so far.

>>>>>>>>>>>>>>>>>Action

jimmickle · 06-15-2006, 06:01 PM

50 lb ft is correct! It needs to be enough to seat the bearings. If you have an pound inch torque wrench, you can tighten to 50 lb in rather than finger tight, but the result will be the same. How did you determine that there was too much play? Feel or a dial indicator? End play should be .005 to .007 inch. If you have to err, err on the side of loose. Tight will burn up the bearings.

Inland RV Center, In · 06-15-2006, 06:09 PM

Quote:

Originally Posted by Action

Michael,

I would question the 50 foot pound data. 50 foot pounds is a lot of torque, may be enough to crush the bearing into the race. Fifty INCH pounds may be more like it.

>>>>>>>>>>>>>>>>>>Action

Action.

A 50 foot pound bearing preload, would sure cause a lot of fire works within the bearings, "QUICKLY".

In the mid 60's Airstream did say 3 to 5 foot pound preload. However it was demonstrated that the friction between the nut and spindle could cause that much.

Airstream then changed their teachings to say exactly what Frank said, namely, back off the castle nut until you can feel a small movement by rocking the tire.

Further proof, tighten one bearing and use Franks directions on another. Tow the trailer a few miles, stop, and check the hub temperatures.

You will find that the cooler of the two, will be the hub that had the small play locked in.

Don't try to go very far with the preloaded hub. It won't go there, very long.

Andy

markdoane · 06-15-2006, 06:21 PM

I think we have a confusion of terms here. Nobody is suggesting you use 50 ft-lb preload on the bearings, and leave them at that.

The procedure is to torque the spindle nut while rotating the wheel, to insure that the outer races are seated in the bores.

THEN YOU BACK THE NUT COMPLETELY OFF!

And then you tighten it finger tight, then do the final setting as described by FrankS.

Beginner · 06-15-2006, 06:40 PM

Michael, You don't mention a washer with a tab that goes between the castelated nut and the bearing.
Was it there? IT MUST BE.
50 lbs/ft sweems right to me. The Dexter figures agree with this.
Remember, the 50 lbs/ft preload is to mash out excess grease between the inner race, the bearing rollers and the outer race. If you don't do this the bearing will be too loose.
Then you tighten the castelated nut finger tight only.
The nut should run on the spindle freely.
If it dosen't, this is a problem. It will prevent you from properly loading the bearings(finger tight). Repair this while you have the brake drum off.
Hope this helps.
Beginner

dwightdi · 06-15-2006, 08:00 PM

On my two Airstreams they used cotter pins. I do not know of any Airstreams that use the lock tab type nut locks.

**Action** · 06-15-2006, 09:34 PM

I go to my past auto experience.

With repacked bearings, spin the brake assy (disc or drum) and tighten nut to 17 to 25 ft pounds to seat bearings in race. Back off nut till loose fit and retighten with fingers. If cotter pin does not slide in back off nut till pin slides in. (less than a 1/16 rotation) I do it by feel as far as tightness of the nut.

It's worked for me in the past or I've just been lucky. In either case it's worked for dozens of times on many different applications.

>>>>>>>>>>>>>>>>>>>>>>>>Action

**Action** · 06-15-2006, 09:37 PM

Quote:

Originally Posted by markdoane

I think we have a confusion of terms here. Nobody is suggesting you use 50 ft-lb preload on the bearings, and leave them at that.

Thats not what I meant either. However the initial 50 foot pound tighten seems a bit high to me. And I guess it's OK based on what everyone else has posted. I just don't go there.

>>>>>>>>>>>>>Action

Nye Thatcher · 06-16-2006, 09:35 AM

ACTION I am sorry to confuse any one. The 4 LB spec. I mentioned was recommened by GM and Timpkin bearings and was used by personel to get experience. 4LB is about finger tight. Again I apoligize. I did not know there was a difference between an Airstream trailer hub and a front hub on a truck carrying aproximatly the same weight. We live and learn. THANKS

**Action** · 06-16-2006, 11:11 AM

NYE,

Don't appoligize to me. I was under the same set of ideas. I actually don't use a torque wrench any more. (still have the wrench) I repack. Install everything. Put a wrench on the nut, spin the rotor/drum until I feel it being tight enough. Back off and tighten to take out most of the slack. Slide in the cotter pin and button up the rest of the job. My frame of reference is front wheel bearings on cars from the 60's and 70's. The initial torque for that kind of vehicle is about 15 foot pounds. Back off and finger tighten. My Lincoln listed below has sealed bearings and they have never been repacked in 140,000 miles.

>>>>>>>>>>>>>>>>>>>>Action

Beginner · 06-17-2006, 06:06 AM

Of course there is a cotter pin that goes through the slots in the casteleated nut and through the hole in the spindle.
What I am talking about is the washer that goes between the castelated nut and the outside bearing inner race. It has a tab that engages the square slot in the spindle. Sort of added protection to prevent the inner race from spinning the nut off.

Zeppelinium · 06-17-2006, 06:16 PM

Quote:

Originally Posted by dwightdi

On my two Airstreams they used cotter pins. I do not know of any Airstreams that use the lock tab type nut locks.

my "quick lube" spindles use the lock tabs rather than cotter pins.

dmac · 06-26-2006, 09:21 AM

I adjusted my bearings by tightening the nut with a wrench to about 20 ft-lbs, spin the tire, back off the nut, tighten by hand, then loosen nut to the next available cotter pin slot. The hubs are near ambient temperature based on carefully placing my hand on the drum center after driving. I'll have to buy an IR thermometer to know for sure. I did not check for looseness by rocking the tire... will need to do that next time.

Yesterday I adjusted my brakes... very easy to do, only took about 30 minutes including driving the trailer up on ramps 4 times. Remove rubber plug, turn star wheel up until noticable drag when rotating wheel, rotate star wheel down ~6 clicks, rotate wheel to ensure no drag and replace rubber plug.