—April 2025—
Blue Ox Aventa II tow bar (circa 1996) came with the RV when I bought the ’02 Winnebago Journey DL in 2016. It was barely used but the fact that there was a trailer brake controller under the dash inside the RV and a blue wire going from that to the 7-Blade towing connector on the rear of the RV indicated the 1st and only other owners of this RV had chosen to use a trailer instead of flat towing but had purchased the tow bar and brake previously, but rarely used it. Many that have a classic car or a non-flat towable car use a trailer or a tow dolly. That was beneficial to me because I fully intended to flat tow and having the Blue Ox tow bar AND the Blue Ox Patriot flat tow automatic brake box they also left saved me over $1,500 at the time. There was also a folder of info in the RV for those products, including the Blue Ox Aventa II Operator, Parts, and Installation Manual which has an exploded view of and listing of all the parts. I referred to that drawing many times during this work. There are also a couple Youtube videos of changing the rubber boots that I watched. The manual can be downloaded here: Blue Ox Aventa II…
Picture from back in 2016 when the tow bar was very clean. If it had ever been used, it was sure hard to tell.
The tow bar, BX7335, is a class IV (10,000 lb) with 2″ receiver. Here’s a link to the setup and some pics of the bar and assorted info about towing: History and setting up to tow…
And here’s what it looked like all set up for my first towed car, a Saturn SL-1.
You can see the small boxes with levers on the top of the bars. Those have mechanical parts inside that latch the bars in the extended position for towing, and allow unlatching by pressing on the lever. This allows the bars to retract into the tubes for storing. When disconnecting the car, push on those levers when there’s little to no pressure on them, which isn’t always easy if the car is still attached, unless on a flat surface and the brake set.
Over the years the bar had it’s scrapes (usually from driving down a slopped driveway onto a street, the car would dive down and occasionally some part of the tow bar would scrape the road) and the rubber boots that weather protected the towing bars developed holes. I usually just sprayed lubricant onto the bars occasionally through those holes but that’s not a long term solution so this April ordered the two Blue Ox kits recommended for maintenance. A kit of the rubber boots with zip ties, BX88384 – $22, and a kit of plastic washers for the numerous pivots, BX88382 – $12, which included both the nylon washers and replacement plastic insert lock nuts used at various places on the assembly. The nylon washers were in pretty good shape on my bar but I thought it would be best to replace them before they got to old and fell apart on their own.
One of the problems that had developed over the years was the drivers side bar wouldn’t reliably latch into towing position. The bar would continue to be free sliding even when tugging that side of the bar to the latching position. The mechanical latching setup didn’t seem to be working correctly. This slowly happened over the years so it didn’t seem that something had broken, just worn out.
While driving in that situation, sometimes the car would wobble side to side on the highway. The car tracks so true that the wobble could be contained with straight driving and good roads. Eventually, it would finally latch on it’s own so it was a minor, but annoying issue. Readers that have a tow bar know that there are methods to get the bars to latch before travel involving turning the car’s wheels all the way towards the side that isn’t latched and backing the car a smidge and that would sometimes work for me, but not always and I’d run into the problem of having to leave the RV park at a certain time to make my schedule and so sometimes I’d just have to drive away with it unlatched, hoping that it would latch while on the road. And often it did. During this maintenance work I expected to find what the latching problem was and fix it.
So now on to the maintenance: to 1) find the issue with the latch, 2) replace the rubber boots, 3) replace the old plastic washers.
1) Find the issue with the latch:
Here are the latching compartments for the arms. You can see where I’ve removed the plastic end cap of the non-functional latch to get a look inside. There are two rubber Cap Plugs, 1 & 1/4″, one on each end of the two latching boxes.
The area that looks like a weld is actually black caulking so easy to peal out of the way.
And inside there was a screw. Looked like an adjustment screw. I turned that CCW around 1&3/4 turns and my passenger side arm was again latching properly. Sprayed the inside of those two assemblies with Silicone lubricant to prevent rust. Reinstalled the cap plugs. So my latching problem was just an issue with adjustment. At least I hope so but if it jiggles out of adjustment again, I’ll have to find a more permanent solution, like Loctite for the adjustment screw .
2) Replacing the rubber boots:
Remove the Triple Lug Pivots, than stand the arms straight up fully extended, one at a time. Cut the top and bottom zip ties on the old boots, than using scissors, cut off the boots. Using a cleaner, clean the shafts. I used Silicon deep penetrating lubricant spray. You may want to put putty around the bottom of the shafts to keep the cleaner from entering the cylinder. I just laid the assembly down at a slight angle while cleaning to prevent that from happening. Wipe clean. Now, using Silicone Grease or even Silicone Paste (do not use Lithium grease as it isn’t as gentle with rubbers and nylon as Silicone is), slather the shafts so there’s a nice layer of grease. Push/pull the rods to the retracted and extended positions several times to spread the grease, than clean up any excess grease. Extend the rods fully to lock position for the next step.
Spray the inside of the new rubber boot and the leg pivot with silicone lubricant. Compare the hole sizes on both ends of the rubber boots and use the larger hole to slip over the leg pivots. Work the boot over the leg pivot to about the middle of the pivot and than with two pair of pliers or medium sized vise grips or channel locks, one on each side of the boot, with the jaws covered with a shop rag, pull the boot down.
In this shot you can see where you’d grip the boot on either side with pliers in order to pull it over the pivot.
Using two hands for this with two grippers is the easiest way. As you pull down the bellows stretch and than pop over the leg pivots. The bar should be extended to make the boot stretch out as you pull so it goes over the leg pivot easily. Grip the boot gently with the pliers so as to not damage the boot. Once on, then zip tie the boots at either end. Using the new plastic insert lock nuts and the new nylon washers from the kit, reassemble the Triple Lug Pivots onto the ends of the leg pivots.
These pictures show the arms after the work was completed and the triple lug pivots had been reinstalled.
3) Replace the old plastic washers:
There are several pivot points on the Blue Ox, and each one of them has a bolt with locking nut, and nylon washers. For each one of those pivots, I used a 12″ breaker bar with socket, and a 12″ adjustable wrench on the bolt head to remove the locking nuts…which was difficult in a couple places because the exposed threaded part of some of the bolts had been bunged up over the years so it took quite a bit of force to get them off. After removing the bolts, cleaned them and any surfaces, did my best to undo the thread damage, slathered the pivot areas with Silicone Paste (it’s what I had on hand and is equivalent to Silicon Grease), installed the new washers and sometimes had to refer to the excellent Blue Ox exploded view in the Aventa II Operator, Parts, and Installation Manual for positioning, put the old bolt back in and used the new locking nuts from the kit. The kit comes with all the nylon washers and new locking nuts that are needed. The Blue Ox documentation does not give a ‘ft-lbs’ rating for any of the nuts and the mechanic is supposed to tighten them down so that the pivots aren’t floppy. Takes some finesse to find that point and takes some force on the breaker bar too as the mechanic is squeezing some thick metal pieces together to create a friction fit. Eventually found the sweet spot so the pivoting places moved with resistance and didn’t flop around. Took some work on a picnic table but having a bench vice would have helped immensely.
The only washer in the kit I didn’t replace was the really big one with a 3″ OD on the Hitch Connection shown above. There is a giant bolt holding it and I didn’t have a socket large enough to fit it. And I’d have needed an extension too, but I don’t have any 1/2″ socket extension required. So all I did was spray that pivot with Silicone Lubricant. The washer that’s there now still looks good. I’ll keep my eye on it and if it starts showing wear, I’ll stop at a shop and have them replace the washer.
One thing I noticed as I worked was that the drivers side arm did NOT have this plastic washer and metal cap installed on the other arm. It’s there to prevent the rod from bottoming out when the rod is retracted. The roll pin is broken and the cap fell out somewhere. There isn’t any kit available from Blue Ox…they recommend contacting one of their authorized dealers. The nearest dealer to me is around 55 miles away so since it doesn’t affect the towing operation, I’ll just not replace those missing parts for now. Here’s a shot of the other arm where those parts are still in place.
This job took two full days of occasional spurts of work, wearing a contractors back brace, two Ace elastic bandages, one on my left wrist and one from my right wrist up to my shoulder. They prevented or reduced tendinitis that became prevalent the first couple hours of work. The back brace prevented the inevitable back strain. In the evenings I’d use some anti-arthritis cream to prevent my joints from freezing up. Old age is a bitch.
And here the Blue Ox is reinstalled and ready to go. Locked in the receiver tube with a keyed lock pin. Can’t be too careful about this $800 item.
