Cadillac Tech Tips - How to fix it Discussion, Trailer towing warning in Item Specific Cadillac Discussion; I posted this in the "Lounge" section but it is easily overlooked there and is certainly important for anyone with ...
- 06-27-05 02:19 PM #1
Trailer towing warning
I posted this in the "Lounge" section but it is easily overlooked there and is certainly important for anyone with a Cadillac that tows trailers....with the Cadillac or any other type of vehicle. If you have a trailer be sure and read this....
I was servicing my snowmobile trailer for next season and uncovered a problem that could be present on most any trailer out there that uses the torsion bar style axle and/or an axle with the EZ Lube style of bearings...i.e...those that have a zerk in the end of the spindle that allows the grease to be forced to the rear bearing. Those axles have a dust cap on the hub with a little rubber grommet sealing the center of the cap that can be removed to see the zerk underneath.
Those style of axles do not use a cotter key to retain the axle nut. They have a tang washer that locks the axle nut from the ID of the nut. The spindle has a flat machined in it that the D shaped hole in the tang washer engages so that it cannot turn. The tang washer has a tang bent off the flat on the ID that forms the "D" that lies inside the nut and engages the castling on the nut from the ID.
Like most people with these style of hubs (that never need disassembling and repacking) I simply pump fresh grease thru the hubs once per year and feel the hub for smoothness and tightness. Imagine my surprise when I finished up and gave the right side tire one last spin (in reverse) when it wobbled and fell off.!!! A moment ago it felt perfectly fine when the tire was off and I spun the hub and felt the bearings.
Upon dissassembly I discovered that the tang on the tang washer had fatigued and broken off and the only thing keeping the axle nut on was the fact that the normal rotation of the wheel was in the "tight" direction.
Imagine my further surprise when I pulled the left hub apart and discovered that the tang washer was broken on that side too!!! Fortunately it had jammed in the threads when it broke off and kept the nut from turning.
Bottom line is that if you have a trailer with the EZ Lube hubs do NOT take for granted that the axle nut retainer is OK. Pop the dust cap off, remove the axle nut, replace the tang washer and reassemble. The only way to tell the condition of the tang washer is to remove it and it is just as easy to replace at that point.
Like many problems like this I am probably not the only/first one to experience this. The axle supplier has changed the axle nut retainer to a totally different design. The latest and greatest is a lock that encapsulates the axle nut AFTER it has been installed and adjusted. The retainer snaps over the nut and engages the flat on the spindle to retain the nut by holding the OD of the nut. You can retrofit your axle nut to this style retainer if you buy the new retainer and a new nut and thicker D shaped thrust washer.
CHECK YOURS TODAY. I was pretty lucky to catch this in the warm garage instead of on I75 in a blizzard after the tire and wheel and hub dissappeared into a snowbank in a ravine....LOL.
- 06-27-05 05:38 PM #2
Re: Trailer towing warning
Good advice. I travel the Garden State Parkway and see boat trailers broken down by the dozen every boating season. It is a miracle that more people don't get killed when stuff flies apart. A lot of people seem to take for granted that just because someone markets a gizmo, it will work. The gizmo here is the hub adaptor that allows one to grease bearings without removing and inspecting. Some of these are known as "Bearing Buddies." Bad idea. The thing will take a whole lot of grease to ever lubricate the inner wheel bearings and even if it gets enough grease to displace all the air in the hub how about the inner grease seal? All that pressure has to go somewhere and if it builds up too fast then the axle grease seal will pop out. The seals lip is not designed to allow pressurized grease past. The only way this would work would be with a different grease seal design. Still a bad idea as the old grease would get everywhere and is a fire hazard.
No substitute for the periodic schedule.
Next big problem with wheel bearings is service being done with chassis lube which is not EP rated.
- 06-27-05 05:42 PM #3
Re: Trailer towing warningOriginally Posted by The Ape Man
- 06-29-05 01:02 AM #4
Re: Trailer towing warningOriginally Posted by The Ape Man
Just to be clear I am not describing some gizmo like "Bearing Buddies". I agree with you that they are virtually useless, BTW.
The current hubs on many trailers, such as I am describing, have the spindle drilled all the way to the rear bearing. The zerk in inside the dust cover screwed into the spindle itself...not on a spring loaded diaphragm in the dust cover like a bearing buddy. The spindle is drilled all the way to the rear bearing locating land where there is a cross drilled passage to the outside of the rear bearing. This way, the grease thru the zerk fitting is pumped directly to the rear bearing and the forward thru the hub to the access hole in the dust cover. This setup positively lubes the rear bearing and allows complete purging of the old grease from the hub. Not a gizmo. A well designed trailer hub/lube system. It makes it entirely feasible to never pull the hubs apart. Just take the access grommet out of the dust cover, grease the hub with fresh grease thru the zerk, check for roughness/end play in the hub bearings by turning it and put the grommet back in place.
My point for posting this is that if you understand these types of hubs you will typically do just what I described and never tear them down. This could lead to a problem due to the weakness in the tang washer nut retention device as described. Knowing this it is still not necessary to tear them down....just remove the dust cap, remove the axle nut and tang washer and replace the tang washer with a new one periodically....and/or retrofit with the new retention device that replaces the tang washer on the OD of the nut.
Nothing to do with maintaining hubs with Bearing Buddies or similiar gizmos. I agree that if someone is using Bearing Buddies or similiar products and thinks that those devices negate the need for regular maintenance they are sadly mistaken....but a setup with Bearing Buddies would not have the problem I described as those older hubs use a cotter key to retain the axle nut.
There is another problem with greasing hubs with Bearing Buddies in that the grease going into the hub from the outside end will actually force the grease seal out of the hub. I have seen this several times. It can also cause the grease to come out the seal end and ruin the brakes on the axle if so equipped.
There are new trailer hub seals on the market now that have dual lips and a garter spring around the inner lip. These seals are more $$$ but FAR superior to the old single lip seals on the hubs.
BTW...if anyone has trouble installing the dust caps onto hugs without damaging them (they require some force and a hammer dents them up severely...) they should feel free to copy my simple "trailer hub dust cap knocker..." LOL It is just a short piece of 2 inch PVC pipe with a cap on one end. It fits perfectly over the cap allowing you to hammer on the land of the cap and the plastic doesn't damage anything...and it is free.