Ford F350 DRW and Trailair pin box problem, help

stanleyz · 08-03-2018, 09:53 PM

MS 2005 36TK3 2014 Ford F350 long bed DRW with factory puck system and Reese 21000 lb hitch. I just bought and installed a Trailair pin box. Hooked up at home and added air to top of arrows on label. Towed around 600 miles with one overnight without unhitching. Arrived at destination in to a fairly level but wlightly uphill site. Front jacks would not raise pin box high enough to permit me to pull jaw release handle. I removed air from trailair and was able to disengauge.

The jacks seemed a little wimpy but I think they were getting fully extended. Other hydraulics are working fine, pump motor was not overly hot and I checked fluid and topped it off before hitching up at home. It looked like the Trailair air bag was pushing the bottom jaw down so far and the DRW springs were pushing truck up so high that they would not come apart.

Any similar experiences or thoughts? Thanks for the help.

Cummins12V98 · 08-04-2018, 06:57 AM

You need something like this.

stanleyz · 08-04-2018, 08:39 AM

I have 4 inch blocks. Tried it with and without.

porthole · 08-04-2018, 10:38 AM

Quote:

Originally Posted by stanleyz

MS 2005 36TK3 2014 Ford F350 long bed DRW with factory puck system and Reese 21000 lb hitch. I just bought and installed a Trailair pin box. Hooked up at home and added air to top of arrows on label. Towed around 600 miles with one overnight without unhitching. Arrived at destination in to a fairly level but wlightly uphill site. Front jacks would not raise pin box high enough to permit me to pull jaw release handle. I removed air from trailair and was able to disengauge.

The jacks seemed a little wimpy but I think they were getting fully extended. Other hydraulics are working fine, pump motor was not overly hot and I checked fluid and topped it off before hitching up at home. It looked like the Trailair air bag was pushing the bottom jaw down so far and the DRW springs were pushing truck up so high that they would not come apart.

Any similar experiences or thoughts? Thanks for the help.

One of the caveats of using an air bag pin box, air bag hitch or auto level truck air bags.

I always dump the air in my hitch when hooking up or unhooking. And if the grade of the site is off, I may dump the air in the truck suspension as well.

stanleyz · 08-04-2018, 11:13 AM

Hey thanks. Do u do that because u would have the samevproblem i had if u didn’t. I don’t carry a compressor on the road. What the smallest i can use on that pin box air bag.

porthole · 08-04-2018, 11:44 AM

I dump the hitch air because if I didn't as I come off the hitch the saddle want to push up almost 6".

Just a much smoother transition for me coming off the saddle with no air. And it means I don't have to raise the trailer to an exaggerated height to reconnect.

porkchop · 08-04-2018, 04:55 PM

Big difference between function of a air ride hitch and an air ride pin box. When I used the air ride pin box it took between 80-95 lbs of pressure to come up to correct height. Keep that in mind if you buy an air compressor. No need to dump air in pin box and it will not help your situation anyway.
If the jacks are not extending far enough to unhitch, you simply have to have a larger block under them so that they will extent far enough. If your problem is the pin and hitch sticking together and trying to lift the truck, just try moving the truck slightly forward or backward to put it in a nonbinding attitude.

Really, dumping the trail air and having to re-inflate it every time is unnecessary and will be a pain real quick. I really enjoyed the trail air, but 21k is the biggest one they make and out santa fe requires a 28k. Lots more gooder than the morryde pin.
Good luck

Bill

WRWGN · 08-04-2018, 06:25 PM

Quote:

Originally Posted by porkchop

If your problem is the pin and hitch sticking together and trying to lift the truck, just try moving the truck slightly forward or backward to put it in a nonbinding attitude.

Last 2 5'ers had air pin boxes, never had an issue hitching or un-hitching. Never had to let air out. I normally put the truck into neutral and take my foot off the brake. That allows the truck to settle into a non-binding situation for easy unhooking.

stanleyz · 08-04-2018, 08:05 PM

I'm no engineer but I don't think that is how it works. All the blocks do is reduce the drop of the legs. The ram on the inside goes to the bottom and the pin box goes up to the same height with or without blocks. The blocks do make the leg drop shorter which reduces the movement of the trailer when set up.

I'm trying to decide if I'm losing some pressure on the ram seal and because of that not getting full extension or if I need to move the pin box up. I still have one hole left but that will put the overhang very close to the truck bed side rails. I bought a small compressor today so I can inflate the trailair after I hitch up. I'm not crazy about that but I can live with it until I get back home.

Duane above has a similar 5er and the same truck and if I read his post right he is having the same problem. If that's the case then my rams are OK and I either have to deflate to hitch and unhitch or move the pin box up a hole and see if that helps. Anyway, thank you for the response.

Cummins12V98 · 08-05-2018, 01:20 PM

Try taller blocks! 4" is really not much.

NEVER have touched the air in my TrailAir pin box to disconnect. I DO set my rear air ride suspension to "tire jack mode" to keep it from trying to re level when taking weight off. I get a small gap between the pin box and hitch plate and simply pull away.

porkchop · 08-05-2018, 01:53 PM

I think one of us is misunderstanding the other.
The legs will extend the length of the ram. If you put a 4" block under it, it will raise 4" higher than it would have without. An 8" block will raise it 8" higher, 12" will raise it 12".
That's not engineering. It's math.

Bill

stanleyz · 08-05-2018, 03:28 PM

I hate this phone. I responded twice and lost both. If you put 8 inch blocks under my jacks on a level lot i would not be able to return the trailer to level once the truck was gone. The blocks dont change the travel available for the ram. If i put 6 inch blocks under the pads on a level site i can only drop the pins a couple holes and i will run out of verticle lift at the same time i would with 4 inch blacks and a 4 hole drop. At leastvthat is how i see it. Now for the real problem which was the jacks not lifting high enough to over come the downward movement of thr inflated trail air and the simulatenous upward of the unloaded truck springs. I tried raising the jacks this morning and they did nothing. I then used a couple bottle jacks to take the weight off the landing gear. They retracted normal and when i extended them they seemed to be working fine and raised the trailer nicely. So I have no idea whats going on. I have to leave in the morning so when my bride gets back from laundry ill hook up one way or the other. I am open for suggestions that do not involve bigger blocks. Thanks for the responses.

Cummins12V98 · 08-06-2018, 10:29 AM

A picture may help here.

stanleyz · 08-06-2018, 10:09 PM

I didn't get a pic but it doesn't matter. I think I see why we come up with different answers about blocks. We are using different equipment. I note on your post above that your landing gear are solid. Because they are solid I agree that you can use a taller block to make the pin go higher.

My jacks are older style. They have an inner tube that can drop from 1 inch to about a max of ten to twelve inches and then be pinned to stay there. After I have set the drop where I want it and pinned the tube I extend the jacks. By adjusting that inner tube downward I am doing the same thing you are doing by putting blocks under solid jacks. Reducing the distance from the bottom of the retracted jacks to a hard surface.

When I park on a level site my trailer is almost level and it is about 10 to 12 inches from the jack pads to the ground. So I usually put down 4 inch blocks and 4 inches of drop on the inner tube. That has always left me with plenty of lift to clear the hitch. The 4 inch block plus the 4 inch drop is the same as an 8 inch block with solid jacks. Now, if I put down 8 inch blocks I can not adjust my inner tube down at all. I need to leave a couple inches of room to make a fine tune adjustment to level. OK. You with me? In the first case I have a 4 inch block plus 4 inch adjustment, or 8 inches plus the hydraulic lift. In the second case I have 8 inches of block and 0 inches of adjustment or 8 inches plus the hydraulic lift. If I chose to I could put down a 6 inch block and 2 inches of adjustment and I would have 8 inches plus the hydraulic lift. All of those would lift the pin box the same distance. On my equipment the taller blocks make no difference.

If you have no way to adjust your jacks then yes you would go higher with 8 inch blocks than with 4. I would not unless I choose to not use the inner tube adjustment but there is no logical reason to do that

stanleyz · 08-06-2018, 10:24 PM

UPDATE Yesterday the jacks would not lift the trailer. I had to lift the frame with a couple bottle jacks to take the weight off the landing gear. Once I did that I was able to retract the landing gear and then cycle it up and down a couple times. Then I put the blocks under and extended the jacks. They lifted the pin right up and I was able to hitch. Today I moved up to MI and when I unhitched I first ran the jacks up and down a couple times and then the jacks worked as designed.

I am thinking that one or more seals in the hydraulic tubes are starting to fail and that by cycling up and down the seals are either getting wetter or being pushed back in to position and that is allowing them to work intermittently. The other possibility is a valve failing. If that's the case I will need professional help. I should have had those landing gear rebuilt this summer but I put it off. If anyone has done the landing gear as a DIY project, how did you remove the drivers side tube. I'm thinking I will have to cut a hole in the sheet metal in the battery room. Help.

porkchop · 08-07-2018, 08:55 AM

Well now, that's starting to make sense! I did not realize you had pin able jacks.

Bill

Cummins12V98 · 08-07-2018, 11:16 AM

Quote:

Originally Posted by porkchop

Well now, that's starting to make sense! I did not realize you had pin able jacks.

Bill

Same here!

elliott-maine · 08-13-2018, 07:53 PM

Bag to the air bag on the Trailair. The top of the arrows is a good starting point. My Redwood rides best when the shock is at the bottom of the arrow head. Trial and error will get you the best adjustment. For me, 75 psi puts it in the right place.