Manual Steering

[Hermjeji]

Have a 2004 T800 C15 MBN. Over here its been known that there have been a series of T800's produced with some issues with the steering boxes. Its a 20k front end, and has dual steering boxes. When the trucks on the road no problem, steering has always been a bit heavy but I like it. I don't drive it anymore, and the folks who do say their arms hurt. When its not moving, it sometimes just goes straight to feeling like it's manual.

Pretty general post, i'll go take a look at the boxes for more details, but high level what the issues could be? I've had it checked over the years, and no one seems to think anything is wrong. After joining this forum, i've been more hands on, so perhaps i'll find a solution. Anyone else have this experience? It'll jam out of the stiffness with a little bit of forward or reverse movement.

[tree98]

I have a 2007 T800 with a 23k front end and dual boxes, turns just fine moving or not. Does yours make any whining sounds? Has anyone ever had one or both of the steering boxes apart? If you don’t know exactly what your doing you could screw one up pretty fast. Have you tried jacking up the steer axle and turning it without any weight on it? Maybe the king pins are freezing up from lack of grease??

[smorgan87]

Id start with #1 verifying the PS fluid filter is ok and #2 the PS pump is actually pumping and producing enough psi. If all thats good u may need to have them steering boxes rebuilt.

[DVT873]

Probably RH Sheppard gears. The phone help used to be tretty good. Have not had to call them for a few years. Good info on their website https://www.rhsheppard.com/customer-serv...bulletins/ If the bot takes down the link google RHsheppard power steering. Should come right up. Had a truck long time ago that one of the gear gear hoses had gotten hit and was restricting flow. In a few cases the truck builder doesn't put a big enough pump on.

Bought one of their flow and pressure test units decades ago. Pricey. http://www.rhsheppard.com/wp-content/upl...2-2019.pdf Rarely ever need it but sometimes it is the only way to find out what is going on. Hopefully you won't need to go that far. Good luck.

If it isn't Sheppard look up TRWRoss. They did not do much with dual gears.

[Rawze]

(02-24-2021 )smorgan87 Wrote:  Id start with #1 verifying the PS fluid filter is ok and #2 the PS pump is actually pumping and producing enough psi. If all thats good u may need to have them steering boxes rebuilt.

yes, I have seen where power steering pumps get weak and provide reduced pressure ... or may be the wrong type for a dual-steering box setup.

Maybe something to consider.

[arch_stanton]

I modify all my power steering pumps by drilling out the brass plug or flow control plug on the pressure side of the pump, it is not pressure but volume that makes the truck harder or easier to steer. You can have a few different problems but an increase in flow will make it steer easier if the rest of the power steering system is working correctly. back in the day trucks with power steering from the mid 1980 and prior you could steer with one finger now the powers that be decided we needed more resistance for our safety. It is also posable that the wrong pump was installed at some point.
If you want to try drilling out the plug do it in small steps no more than 1/16 of an inch at a time, use the back of a drill bit to determine the size of the orifice then drill out 1/16 bigger, you will probably find the orifice to be less than 3/16 remember the bigger you go the smaller the step in size as the volume will increase exponentially, I don't even remove the pump I just flush the pump by adding fluid to the reservoir and use a small brush to clean the hole and debur and do my first flush with carburetor cleaner it quickly flushes the shavings from the front drill side then power steering fluid from the reservoir.

[tree98]

I always wondered why the old stuff steered so much easier.

[Tanker93]

Have you checked the steering uni's and slip shaft? Is there a bearing mounted in the floor that the shaft passes through? id start there. Then jack it up and check it by hand with the engine off. Then knock one balljoint out to isolate either side.

[smorgan87]

Arch done went n taught me somethin. Good to know!