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Topic: Wheel bearing adjustment driving test (Read 601 times) previous topic - next topic

Wheel bearing adjustment driving test

Had the front rotors turned this week and the front wheel seals replaced for a second time.

Cummins dealer refused to preload the bearings for liability reasons.  I went along to see if the difference between preloading and .001 and .003 dial indicated play in the edge of the rotor is noticeable in driving.

Shop service writer was very skeptical that the tiny clearance would be noticed.

They wondered if my slight preload had caused heating in the hub and maybe hurting the seals.

Ok let me try it there way.

Previously with slightly preloaded bearings any rim of the steering wheel resulted in subtle directional changes.  No dead spot.

On a short drive I now need to move the wheel a small amount to make the coach start to change direction. 

If you were not looking for it and had never had driven it with the bearings preloaded you would not think it was not perfect with the legally verifiable play in the hub.

Shop mentioned a new hub design with a crush collar and sealed bearings I think have been mentioned here.

This is a subtle thing and I still have only a tiny dead spot but it's there. 

And was not there after the first seal replacement 20k miles ago.

Like I'm saying it's the difference between a tiny amount and none that makes it noticeable. 

If the preload caused  issues I feel stupid.  If after a longer test drives and more temp checks of the hub during drives the slight play bothers me I will have my old buddy preload them again.

Just thought I'd post the difference.  Hardly noticeable but it's there for those who might have wondered if I was crazier than usual.

We will see in wind and opposite lane truck traffic if any real differences are noticeable.

My two cents. 
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Wheel bearing adjustment driving test

Reply #2 –
Thanks.  I have seen this chart. 
"Riding and rejoicing"
Bob
1997 U320 40' Mid entry, build 5132,  wtbi ce27, 4th owner
2007 Solara convertible
2 prodeco tech outlaw ss electric bikes

1095 watts solar
08 Ls 460 and a sc430
2000 Ford F-250 superduty 4x4

Re: Wheel bearing adjustment driving test

Reply #3 –
If they don't do the "preload " then what do they do?,do you use the newer style one piece nut or the older 2 piece?
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Wheel bearing adjustment driving test

Reply #4 –
Quote from: Caflashbob –
And was not there after the first seal replacement 20k miles ago.
2 weeks ago, I would have had little interest in this thread.  Today, after spending a week looking at the front end components on our coach, I have a better understanding of the subject matter.  Understanding...not knowledge...so I certainly won't be offering any opinions.

During the course of troubleshooting my wheel//brake problem, bearing play did come up.  It seems that after installing the new seal in our RF hub, the tech initially adjusted the bearing clearance "too tight" - i.e. there was zero play on the dial indicator.  I think this is what you are calling a "preloaded" setting?  To correct my installation, they backed off the adjustment to get the play where they wanted it.  I wasn't able to see the dial indicator, so I don't know where it actually ended up.

I asked Kieth (MOT service manager) about the significance of the bearing play.  He mentioned the fact that too tight bearings could overheat.  He also said the slight in and out movement of the hub on the spindle is important in helping the brake pads to retract after they are applied.  Since we were trying to diagnose a overheated brake, this sounded logical to me.

Truthfully, I could not feel any difference in the steering between having the bearing play "too tight" and "correct", but there was a lot going on at the time and it could have been easily overlooked.  Of course, we were only messing with one side - I assume the other side has the recommended bearing clearence.  Also, the roads around NAC are not exactly glass smooth, so any subtle differences would be hard to detect.  At any rate, on the drive home, our steering felt great and nothing got HOT, so I'm happy with wherever the bearings ended up.

You have mentioned the possible connection between your former "preloaded" bearing setting and your axel seals going bad in 20K miles.  Does your "old buddy" think there is any connection, or was it just a coincidence?
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Wheel bearing adjustment driving test

Reply #5 –
Another question,in researching mine I determined there are 2 different type of inner seals availible,was that mentiomed in your case?
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: Wheel bearing adjustment driving test

Reply #6 –
The bearings can take preload and not fail. In many applications the same bearings are likely preloaded.
1998 U270 34'

Re: Wheel bearing adjustment driving test

Reply #7 –
I've thought of doing this experiment too. Use my IR gun to determine the baseline temp on the hub then adjust the preload very slightly tighter. Drive for a while checking temps. If temps do go up back off the preload. Seems to me you would want the bearings to be as tight a possible but not so tight as to cause heat build up. A shop would never have time to do this and would set themselves up to lawsuit if they did get them too tight. They have to follow a MOP to stay legal.

I've spent a lot of time and money getting my steering pretty good but I'm looking to make it great.

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X

Re: Wheel bearing adjustment driving test

Reply #8 –
Quote from: kenhat –
I've thought of doing this experiment too.
Have you thought about how much work is involved in "adjusting the preload very slightly tighter"?
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Wheel bearing adjustment driving test

Reply #9 –
Hummm... I see what you mean.

see ya
ken
The selected media item is not currently available.ken & dori hathaway & Big Agnes
🍺1992 U300 GrandVilla WTBI #4150 FOT FBP 2011
✨6V-92TA DDEC Parlor Coach 350HP Series 92
🏁2011 Nissan XTerra Pro-4X
 

Re: Wheel bearing adjustment driving test

Reply #10 –
@john they can still use the older two nut setup just don't back off the first nut when they torque it and then install the outer locknut. The way it works is that long collar that is in the picture goes between the bearings and actually crushes the same as the preload collar on a Ford nine inch rear end. The collar is only good for so many uses there is a measurement to verify if it needs replacement. I believe it works out to three uses.

Two types of seals, older style seals had a wear sleeve that pushed on with the seal to take the machining action of the rubber seal and when it wore down the seal would leak. Newer style seals have no discernible wear sleeve the inner radius stays stationary with the spindle and the outer turns with the hub the center part of the seal allows rotation. Both work well but upon installation of the newer style seals the wheel can feel noticeably stiffer when you spin the wheel until it gets a few miles on it.
Toby a 94 u280
Cummins 8.3
6 speed Allison
Exhaust brake


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