Over An Hour To Drop The Trailer:

[Rob]

Man was I glad it was warm tonight, and pissed at the same time. I spent over an hour getting the jaws to release the pin on my trailer. It is a "Holland" 5th wheel and didn't want to let go. I bent the handle you pull to unlock it cause it was stuck so hard. The adjustment stud that protrudes from the front of the platter would only move about 3/4" and stick fast. Finally after getting a 36" piece of hydraulic cylinder rod to use as a pry, and a two pound sledge to beat on the handle while prying, I got it to release. Suppose I need to take everything apart and lube it up good. This truck hasn't had a trailer attached for some time and there is no grease at all on the platter.

Rob

[Gambi80]

If, after setting the trailer brakes, did you nudge the tractor backwards to make sure the kingpin on the trailer is up against the front of the 5th wheel? Takes the load off the jaws so they pop easier.

[Lmackattack]

Yea. push back on the trailer before you get out to try to pull the handel. if its still tight set the trailer brakes and push on the trailer then let the truck come to a rest with "slack" in the fith wheel. if the wheel is tight find someone to pull the pin while rocking back and forth. then put lost of grease in it for the next time

[Rob]

Yes, pushing back with the tractor against the trailer brakes was tried first. This sucker was just stuck from lack of use. Didn't want to work with it this evening as it was dark. I will tomorrow cause I don't want to do this again!!

Rob

[Lmackattack]

Some old PB blaster will help get that lube into the places that thicker grease wont. Spray it on the under side to get the jaws,springs,bushings and other locking parts lubed. My wheel was dry when I got the truck and it needed some grease to move freely. Also look at the king pin plate to make sure the trailer is not the cause. seen a few old trailers that were well rusted around the plate. the king pin was pushed upward a little and it was trying to pull up on the 5th wheel/jaws.

[Rob]

Some old PB blaster will help get that lube into the places that thicker grease wont. Spray it on the under side to get the jaws,springs,bushings and other locking parts lubed. My wheel was dry when I got the truck and it needed some grease to move freely. Also look at the king pin plate to make sure the trailer is not the cause. seen a few old trailers that were well rusted around the plate. the king pin was pushed upward a little and it was trying to pull up on the 5th wheel/jaws.

I thought about that but not the case here. There was room both on top, and bottom of the area the jaws bite to lock the pin. I actually lifted the trailer via the landing gear till is was not placing top pressure on the jaws. This yielded no joy however. Both truck and trailer were level also.

When I got the prybar against the handle and started easing pressure against it I could feel a severe bind where things should readily move. A little more force and she popped over center and latched open. I just takes a while to figger this stuff out when you've not been around it.

Rob

[Lmackattack]

yep and every truck may be a little diffrent. Lucky for me all the dump trailers I pulled leaked a little hyd fluid and made that 5th wheel nice and slick. One thing on my Fontain "no slack" is the release handel has a "Stop" rod along its bottom part of the shaft. If pulled straight out it will hit the bottom backside of the hole that the rod comes thru and stop its outward movement. So you have to put some upward motion into the pull to release the pin.Its kinda a fail safe design. even if the jaws did not lock the trailer fully the release shaft will stop when the rod hits the stop plate and hold the jaw mostly closed so the trailer cant come off. I only found that out after trying to pull the "stop" rod thru 3/4" steel for about 10 mins LOL!!

[Rob]

yep and every truck may be a little diffrent. Lucky for me all the dump trailers I pulled leaked a little hyd fluid and made that 5th wheel nice and slick. One thing on my Fontain "no slack" is the release handel has a "Stop" rod along its bottom part of the shaft. If pulled straight out it will hit the bottom backside of the hole that the rod comes thru and stop its outward movement. So you have to put some upward motion into the pull to release the pin.Its kinda a fail safe design. even if the jaws did not lock the trailer fully the release shaft will stop when the rod hits the stop plate and hold the jaw mostly closed so the trailer cant come off. I only found that out after trying to pull the "stop" rod thru 3/4" steel for about 10 mins LOL!!

This thing has a lot of grease that is as hard as concrete. I was looking last evening when the truck was back in the shop and I think I'm going to pull the rocker pins and remove the 5th wheel leaving the mounts. This way I can steam clean the underside and see what if anything is worn out. When I pulled the trailer there did not appear to be any slack in the jaws and no banging. It also latched nice, just didn't want to let go!!

I have a brand new plastic disk for the 5th wheel pin. My damned shop cats, (mouser 1, and mouser 2) like to sleep up there so don't want to use grease but that could change. I don't really like cats but these guys serve a good purpose with fields on three sides of the shop.

Rob

[oldmacktrucks]

Sounds like somebody at some time was pulling a trailer with a worn king pin and tightened the fifth wheel to take up the slack, and now you backed under a different trailer with a good king pin...and the fifth wheel is now to tight to unlock I've had this happen a few times

[Rob]

Sounds like somebody at some time was pulling a trailer with a worn king pin and tightened the fifth wheel to take up the slack, and now you backed under a different trailer with a good king pin...and the fifth wheel is now to tight to unlock I've had this happen a few times

Is that what the threaded stud protruding from the front of the platter with the locknut is for? This is to adjust clamping pressure on the king pin? I've never adjusted anything like this.

Rob

[oldmacktrucks]

Is that what the threaded stud protruding from the front of the platter with the locknut is for? This is to adjust clamping pressure on the king pin? I've never adjusted anything like this.

Rob

The bolt sticking out of the front is more than likely your slack adjustment (I know mine has the bolt and thats what its for) Back it off a 1/4 turn at a time counter clockwise...dont go too crazy because you dont want it too loose. The lack of grease would make it harder to release but not to the point where your prying it open. Back it off a 1/4, grease the jaws if your going to use a fifth wheel wear pad you DO NOT want grease on the plate or the trailer...its either the pad or grease NOT both. Back into your trailer and go from there...if its still hard to release back it off another 1/4 turn. When you go to release the jaws dont crank the landing gear down to the point where the trailer is lifting off the fifth wheel plate, that will also make it hard to release...and make sure you lock your trailer brakes then put a little reverse pressure against the trailer...then lock your tractor brake, the slightest forward pressure against the jaws will also make it very hard to release. Hope this helps...-Sean

[Rob]

Appreciate it. I've never had a semi trailer before and my camper 5th wheel had never stuck in any tractor. This one was a surprise. The king pin on the trailer is noticably worn as is the plate. I'm going to replace that next week. The plate I'll have made and I can weld the pin assembly in myself. $65.00 for a replacement pin is not too bad it seems. The jaws are not binding on the pin at all but the jaws do come together and touch each other when closed around the king pin. Should there be some "slack" between the two?

Rob

[oldmacktrucks]

Appreciate it. I've never had a semi trailer before and my camper 5th wheel had never stuck in any tractor. This one was a surprise. The king pin on the trailer is noticably worn as is the plate. I'm going to replace that next week. The plate I'll have made and I can weld the pin assembly in myself. $65.00 for a replacement pin is not too bad it seems. The jaws are not binding on the pin at all but the jaws do come together and touch each other when closed around the king pin. Should there be some "slack" between the two?

Rob

Thats a good question, I would have to look at my tractor and see...and its snowin HARD so thats out for today. I would just play with it, back it off 1/4 and thats it and see what happens, If your going to replace the pin I wouldnt adjust it anymore than a 1/4 turn for now...wait until you have your new king pin then go from there.

[Lmackattack]

it all depends on the type of 5th wheel you have. Do you know what model 5th wheel it is? My Fontain no slack does not have jaws. it simply has a bar that slides in behind and a wedgethat follows it to keep presser on the back of the pin. Others use Jaws that grab from each side. Most of the trucks I drove you could never see the king pin when hitched. If you did see the king pin it was thru a 1/4" gap in the jaws. I have also seen plates that had a "C" cut out of 1" steel that would swing around and grab the pin from the backside. Give us a pic of the wheel and we may shed a little more on what it is.

Regarding the bolt that sticks out from the front...If its the style plate I think it is.... That should be your adjustment bolt. When unhooked that bolt is sticking out about 5" in front of the plate. then when you hook to a trailer you should see it pulled in and resting up against the plate. If you back into a trailer and can see that the bolt is not against the plate thats a sign that it did not fully latch. But again lets see the 5th wheel and we could note what it is and how it latches

Trent

[Rob]

it all depends on the type of 5th wheel you have. Do you know what model 5th wheel it is? My Fontain no slack does not have jaws. it simply has a bar that slides in behind and a wedgethat follows it to keep presser on the back of the pin. Others use Jaws that grab from each side. Most of the trucks I drove you could never see the king pin when hitched. If you did see the king pin it was thru a 1/4" gap in the jaws. I have also seen plates that had a "C" cut out of 1" steel that would swing around and grab the pin from the backside. Give us a pic of the wheel and we may shed a little more on what it is.

Regarding the bolt that sticks out from the front...If its the style plate I think it is.... That should be your adjustment bolt. When unhooked that bolt is sticking out about 5" in front of the plate. then when you hook to a trailer you should see it pulled in and resting up against the plate. If you back into a trailer and can see that the bolt is not against the plate thats a sign that it did not fully latch. But again lets see the 5th wheel and we could note what it is and how it latches

Trent

Thanks and I'll try to do that tonight.

Rob

[MidniteMechanic]

Generally to my knowledge a greaseless wear pad can't be used with a standard kingpin. The shank of the kingpin is not long enough and if you do get it coupled it will bind.

Regarding removing the fifth wheel mounting pins, it will probably require 'heat and beat'. Only heat the ears as there are rubber upshock bushings in the saddle mounts. If the pins are really loose the head is shot.

I use caution speaking of kingpin replacement and fifth wheel work because of liability issues. A lot of companies won't touch it.

Check out this link to Holland fifth wheels to understand what your looking at.My link

Yours is probably a model 3500. The biggest problem of not releasing is the cam plate and rollers are dry or worn or tightened too much. It is a time consuming head to rebuild properly because the lock yoke requires grinding and or welding to properly fit the head.

Yes the bolt sticking out the front is to adjust for wear. There are alternate ways to adjust beside using Hollands method and tools. I can explain in an email later if your interested.

[Rob]

Generally to my knowledge a greaseless wear pad can't be used with a standard kingpin. The shank of the kingpin is not long enough and if you do get it coupled it will bind.

Regarding removing the fifth wheel mounting pins, it will probably require 'heat and beat'. Only heat the ears as there are rubber upshock bushings in the saddle mounts. If the pins are really loose the head is shot.

I use caution speaking of kingpin replacement and fifth wheel work because of liability issues. A lot of companies won't touch it.

Check out this link to Holland fifth wheels to understand what your looking at.My link

Yours is probably a model 3500. The biggest problem of not releasing is the cam plate and rollers are dry or worn or tightened too much. It is a time consuming head to rebuild properly because the lock yoke requires grinding and or welding to properly fit the head.

Yes the bolt sticking out the front is to adjust for wear. There are alternate ways to adjust beside using Hollands method and tools. I can explain in an email later if your interested.

Thank you and yes I would be interested in any alternative method(s). I know the factory "proceedure" is not always the best in practicality and sometimes experience is best. I did get a look at this thing from the bottom tonight. I was able to get the jaws to close using a porta power and piece of pipe and it was hard to get the jaws to release. I loosened the nut on the threaded stud sticking out of the front and it is much easier to release now.

Regarding the hardened grease: While under the truck I could see all the workings of the mechinisims and how they operate. I think rather than try to remove the 5th wheel from the truck I'll just wait for Jaime to really piss me off good and I'll have him degrease it with the pressure washer while laying under the truck on the floor!! LOL!!

Rob

[Rob]

Got the perverbial "wild hair" this afternoon and decided to work with the 5th wheel to try to loosen up the release from the trailer. I warmed the complete 5th wheel with the "electric sun" softening the old grease and dirt, then took a pump sprayer with diesel fuel and sprayed everything I could get to. I then went after it with the steam cleaner and peeled all the old muck off of everything. A two inch paint brush and a bucket of chassis grease coating anything and everything underneath that moves proved quite useful. I hitched to the trailer and much to my surprise a one handed with moderate pressure was all that was needed to snap the jaws open. I then pulled forward, latched and uncoupled two more times to ensure all was going to continue to work smoothly. Then more grease was applied to the moving parts again.

I appreciate the help. Sure seems to work well now.

Rob