Dyna-Trac free spin Question

[llotton]

Earlier in May I installed a Free Spin kit on my 2003 with the Dyna Lock hubs. I had to leave my truck with the installer who has been in the business for 35 years and was gone when he installed the hubs. Later I asked him if he packed the hub cavity between the bearings with greese and he said he did not and has never done that. The bearings were packed with a good high quality synthetic greese. The hubs got a little hot after about 3 hrs on the road the and I continued driving home. Later I called Rob at Dyna trac and asked him if filling the hubs was important enough to warrant going back and doing that and he said he thought it was. I planned to reset the preload anyway. I should add that the hubs stay cool as can be on thirty to sixty mile runs at this time.

What is your opinion concerning filling the hubs between the bearings? I will be working on the truck in about a week.

Thanks in advance for your input.

 

[tkerrigan]

You probably know this, but only fill to 1/3 to 1/2 full, if full, grease will churn and heat up.

 

[d6c]

Just discussed in 2nd gen. forum "wheel bearings 95' 3500"... Did my own install, same concerns, dynatrac included a timken info. sheet w/my kit. My right front brake drags enough to put heat into the hub. As to your question, Yes I did load up the void between the bearings with grease. Read that 2nd gen thread, lots of ideas on this stuff. Hope you still have the instructions for the dyna lock assembly...

 

[SierraRam]

I have never filled the hups but pack the wheel bearings and leave quite a gob of excess. I have 40000 miles on my kit and repack every 20000, never had a issue and bearings show no signs of wear.

 

[hcole]

For what its worth, I packed the cavity between the bearings on my dynatracs as I always have on other manual hub trucks I have owned.

 

[llotton]

Yes d6c I did keep the instructions, I was there for that part and in fact have had the DynaLocs apart once already. Thanks.

 

[Tinman]

I just installed mine and filled the space between. Hard to know much will be in there once the hub spins it out. I think it'd be hard put too since the spindle would push out anything above the bearings. That said, I noticed that the hubs do warm up after usual driving.

 

[steved]

There is always airspace left over... even when you think you got that cavity filled.

The main thing is to put enough in that as you drive, the grease is forced into the bearings with centrifugal force... not that the grease packed in the bearings is slung away from the bearing.

 

[SierraRam]

Whenever you use your brakes heat will transfer to the hubs.

 

[EDankievitch]

My Hub kit had said to fill the hubs to help keep the grease in the brearing. The hubs did warm up when new but after the first few hundred miles have run cool. I've got over 116,000 miles on them now never any problems. I had read an article about wheel bearings a long time ago, in a heavy trucking mag. They had said that the number one cause for bearing faiure was improper bearing perload. Too loose and the bearings would chatter and ruin the race. to much and not enough grease or lube they'd over heat. Having followed their recomaditons I've never had a problem. /I]

 

[DGamelin]

I have all ways put allot in them, like steve said you can't fill them all the way. We sell and service trailers, The new hubs being used now have a grease zerk on the end of the spindle. It is drilled like a crank shaft the grease comes out between the seal and bearing, as you pump it up it filles from the inside out and filles the hub completely. The dexter come full with no problems. I tell most customers that I don't have to mess with them for about 4 years. Grease on just the bearings alone isn't enough for me. Low end axles are like that and need service munch sooner.



I am about to buy hubs for my truck.



_________________________

93 250 2wd xc 354 auto 274k

04. 5 3500 4wd qc dully 373 6speed 100k

 

[d6c]

I for one sure hope the zerk system referred to in post #11 actually injects the grease between the bearings, not inside the inner bearing. These systems, by any description, are the absolute best way to promote over-greasing and blowing the seal and greasing your brakes there ever was. Grease on brake shoes make for grabby brakes which flat- spot tires. Poorest excuse for a maintenace system ever devised.

 

[BigRedRam]

The hubs sound great, but I’m interested in what if any savings they provide. If I replace my standard hubs with the free spin hubs, will I save enough fuel to justify the cost?



Other than fuel savings, what are the benefits beyond drive line wear and maintenance back to the transfer case?



Has anyone done a life cycle cost analysis covering maintenance on the free spin kit verses U joint replacement and fuel consumption at say 100,000 miles?



Frankly, I like not having to exit the truck in order to engage 4 wheel drive. Believe if I had the free spin kit, I would leave them engaged 2 or 3 months of the year.

 

[rscurtis]

In addition to the 1-2 MPG highway driving fuel economy benefit, you are virtually eliminating wear on the front U-joints, driveshaft and transfer case. You also have serviceable as opposed to replaceable front wheel bearings.

 

[hcole]

I have had my dynatracs for app. a year and it appears to me that I gained about a 1/2 to 1 mpg better. Also, in the cold weather it appears that the hubs keep me from losing app. 1 1/2 to 2 mpg in winter. In other words, I get about 20. 5 to 21 mpg year round instead of 20 in summer and 18. 5 to 19 in winter.

 

[gbraden]

I've had my Dynatracs about a year. Love the fact that I can back my trailer in 4-Lo which means it just creeps along and I don't wind up slipping the clutch. My mileage checks show that I get an extra 2+ mpg overall.

Glenn

 

[Tinman]

What's a good service interval for repacking the bearings and/or reset the preload?



No reason you can't run the hubs locked if you think there's any chance you might need 4wd on a drive. It'll just make it operate like the stocker.

 

[steved]

The service interval is 50k... and I highly recommend following it. I found a seal had physically failed and took out a stub and spindle bearing... I had lapsed 120k.



Also, make sure you use a water proof or highly water resistant grease as the lockouts don't always sit tight against the hub.