R688st frame cut

[Voltronics]

Hey y’all,

 

just bought a 1985 r688st and wondering why someone would cut the rear of the frame. And wondering what can I do to get the slope back so I can get mud flaps and a pintle hitch.

 

thanks 

[Joey Mack]

Was it a dump truck at one time?

[Geoff Weeks]

My guess is the owner had a short-neck drop-deck that was made for a single screw and the frame hit when towed by a tandem drive tractor.

[mechohaulic]

technically that is an easier repair. depends on your future use and access to parts and supplies, good with a welder ??  since it's not in a very critical location such as midframe/ behind cab etc; number of ways. purchase channel steel same size as rails or a scrap yard near by have HD truck parts / ; find a rear section frame set up and splice it into yours. will have two rails/ one or two crossmembers -easy breezy place for lights/flaps  too late to ask why it was done , just forge onward and make it classy.not good with a welder ; what better job to learn on. remember to use old mud flaps to cover the air bags ; welder sparks can ruin an air bag !!(so I.ve been told )

[Geoff Weeks]

The use to pull with a pintle hitch makes it a little more critical, it has to be strong enough for the loaded trailer.

[Mark T]

8 hours ago, mechohaulic said:

technically that is an easier repair. depends on your future use and access to parts and supplies, good with a welder ??  since it's not in a very critical location such as midframe/ behind cab etc; number of ways. purchase channel steel same size as rails or a scrap yard near by have HD truck parts / ; find a rear section frame set up and splice it into yours. will have two rails/ one or two crossmembers -easy breezy place for lights/flaps  too late to ask why it was done , just forge onward and make it classy.not good with a welder ; what better job to learn on. remember to use old mud flaps to cover the air bags ; welder sparks can ruin an air bag !!(so I.ve been told )

IDK Mech, get'n a pintle hook on that one is gonna be a challenge.   🤔now about those sparks and air bags.....

[mechohaulic]

5 hours ago, Geoff Weeks said:

The use to pull with a pintle hitch makes it a little more critical, it has to be strong enough for the loaded trailer.

I totally agree with you;  rear chassis welding is very important , my statement referred to it not being as sophisticated as a mid chassis weld.  welding a piece of channel for a taillight is important . once again BMT is being given bare minimum of details on a question involving many particulars. not knowing experience/shop set up/ availability of parts. etc. reason for reply to a straight square cut=off might be an option. plate the section properly COULD be same as frame it self.

[Voltronics]

16 hours ago, Joey Mack said:

Was it a dump truck at one time?

That’s I can not tell you, I don’t know the full history on it.

[Voltronics]

10 hours ago, mechohaulic said:

technically that is an easier repair. depends on your future use and access to parts and supplies, good with a welder ??  since it's not in a very critical location such as midframe/ behind cab etc; number of ways. purchase channel steel same size as rails or a scrap yard near by have HD truck parts / ; find a rear section frame set up and splice it into yours. will have two rails/ one or two crossmembers -easy breezy place for lights/flaps  too late to ask why it was done , just forge onward and make it classy.not good with a welder ; what better job to learn on. remember to use old mud flaps to cover the air bags ; welder sparks can ruin an air bag !!(so I.ve been told )

Sorry very new to semi trucks as thid is my first one and using to haul grain and we have pintle hitch trailers for moving tractors and would like to put a pintle on the semi to haul them around. I have very little experience with this and may take it to a welder and see what he can do. Thanks for the reply was just asking why someone would cut this and possibly cost of repair for a welder to basically make the “ramp” you see on every semi snd put a heavy plate on back with a pintle hitch holes or hook up

[mechohaulic]

2 hours ago, Mark T said:

IDK Mech, get'n a pintle hook on that one is gonna be a challenge.   🤔now about those sparks and air bags.....

all depends on the situation and experience OR $$$$ behind the project. not knowing complete details or history of the truck . ponder the seller did a half/ ass job cutting the rear off to keep a pintle hook  frame set up ??? with ALL PROPER safety equipment used .good cut-off saw to straighten the taper on frame rails , mate a matching rear section ;; weld in and plate . will be done strong enough to hold a pintle. using a truck cut off section with crossmembers will be square/ straight/ strong >with help of a miracle , locate a rear double frame section and stagger the rails allowing the inner rail to over lap existing truck frame inside. bolts /weld better than new. too many possibilities not knowing the project.

[mechohaulic]

4 minutes ago, Voltronics said:

Sorry very new to semi trucks as thid is my first one and using to haul grain and we have pintle hitch trailers for moving tractors and would like to put a pintle on the semi to haul them around. I have very little experience with this and may take it to a welder and see what he can do. Thanks for the reply was just asking why someone would cut this and possibly cost of repair for a welder to basically make the “ramp” you see on every semi snd put a heavy plate on back with a pintle hitch holes or hook up

NO reason for "sorry" ; without asking knowledge is never learned. in time the statement "have very little experience "will be old news!!! speaking for the BMT crew ; up dates are always appreciated. to be 40 or so yrs younger and bit closer this would be a fun/ challenging easy project to tackle.

[cruiseliner64]

Adding a piece on the end of the frame is not difficult.We have removed a home made hitch from our Cruiseliner and are adding a piece to hold mudflaps/lights.....

Paul

[mechohaulic]

project looking real good. nice job.  the R688 might be a tad more of a challenge since the frame was hacked so bad /short of material close to air bags and suspension :BUT following Your pictures the R688 can be done. 

[mechohaulic]

also the R has to be built much stronger to carry a pintle hitch/ trailer. 

[cruiseliner64]

7 hours ago, mechohaulic said:

also the R has to be built much stronger to carry a pintle hitch/ trailer. 

Yeah I understand that Mech but it still shouldnt be too difficult.It wont interfere with axle tracking or suspension fittings so should be easy fix...

Paul

[Mark T]

11 hours ago, cruiseliner64 said:

Adding a piece on the end of the frame is not difficult.We have removed a home made hitch from our Cruiseliner and are adding a piece to hold mudflaps/lights.....

Paul

🧐  Here I was thinking you were in Ireland. You're going at it like one of those guys in Pakistan. Nice work you're doing there.  Holy cow, what a hitch that thruck had.

[cruiseliner64]

1 hour ago, Mark T said:

🧐  Here I was thinking you were in Ireland. You're going at it like one of those guys in Pakistan. Nice work you're doing there.  Holy cow, what a hitch that thruck had.

Yeah it was a hell of a hitch Mark T.We wanted to return it to a standard road tractor unit as you know we are making a replica of Pig Pen's truck from Convoy.The first owners son told us the hitch was fitted to haul a single spine bolster trailer with a bolster on the fifth wheel to haul 100 foot long 120 ton beams for a motorway ( freeway) bridge project.Ironically from Ireland to the UK.He told us he was the rear steerman on the rear bogie.We found the frame was badly cut to fit it and rust had taken hold around the welds so removal was inevitable....

Paul

[mechohaulic]

2 hours ago, cruiseliner64 said:

Yeah I understand that Mech but it still shouldnt be too difficult.It wont interfere with axle tracking or suspension fittings so should be easy fix...

Paul

want a good laugh OR a scary thought ;; look at the pictures posted on B model auction ; see how the pintle was "attached" to the B model. cut rear cross member middle out ; welded in a pintle hook. !! now that's frightening

[Mark T]

Your truck is a rather large spec compared to the Pig Pen truck. I would have liked to see it doing the job you said it was made for. Impressive piece of equipment doing a demanding job and likely made it look easy. 

[Mark T]

38 minutes ago, mechohaulic said:

want a good laugh OR a scary thought ;; look at the pictures posted on B model auction ; see how the pintle was "attached" to the B model. cut rear cross member middle out ; welded in a pintle hook. !! now that's frightening

Only if you're behind it.

[cruiseliner64]

1 hour ago, Mark T said:

Your truck is a rather large spec compared to the Pig Pen truck. I would have liked to see it doing the job you said it was made for. Impressive piece of equipment doing a demanding job and likely made it look easy. 

Yeah it must have made it look easy.Its a large spec for a Pig Pen truck but we didnt have a lot to choose from.As far as we know theres only 6 Cruiseliners in Europe......just gotta work with what you have....

Paul

Edited 5 minutes ago by cruiseliner64

[cruiseliner64]

1 hour ago, Mark T said:

Your truck is a rather large spec compared to the Pig Pen truck. I would have liked to see it doing the job you said it was made for. Impressive piece of equipment doing a demanding job and likely made it look easy. 

Heres a (bad) picture of it working the beams job.It was in a UK newspaper at the time and was sent to us by the owners son..

Paul