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TRW TAS85 Steering box and pitman arm
#1

We made it home safely and had a wonderful time in FL for the last 3 months except when I got sick, it was a working vacation and I made good progress in getting our coach up to standards or better. The biggest gain was the replacement of the tag axle bushings, my steering going down the road is almost perfect now and before I would get anxiety thinking of driving it. The other major problem is my steering box is not what came with our coach it has been replaced with a unit that is not adjustable and the pitman arm is half the size of a normal pitman arm causing me to loose a lot of turning radius. I am shopping for a TRW TAS85 box and pitman arm but do not have the part number for the pitman arm or even a length of a normal one. The boxes are sold separate from the pitman arm any help would be much appreciated. If anyone has either for sale please let me know.  Soon as I replace the steering box, pitman arm, and the 2 u joints on the column I am certain it will be perfect.

1999 45'  #504 "Magnolia"
Gravette, Arkansas
1996 40 XL Prevost Marathon 
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#2

Jack,
I had steering box/steering arm issues while at the factory. They weren't much help on my older coach, but I did manage to find the casting number for the box and quite a bit of information.

TAS 855289 this is only a casting number. There should be a 6 digit part number stamped someplace on box itself. I was told near the shaft, but couldn't find it. There could be some interchangeability.

My arm (the one that attached to the box and goes down to the rack was bowed. There was/is no replacement and it appears to be a custom part. Thankfully, I was able to use the Newell maintenance shops' hydraulic press and gently/slowly straighten it out. No creases were evident. And the 24hr trip back showed no anomalies.

My steering box has a small weep, and will likely need rebuild at some point. There are several companies I've located that will do the rebuild. and/or straight exchange at somewhat reasonable prices.

https://www.trwaftermarket.com/globalass..._02_07.pdf

https://assets.wellertruck.com/reference...stment.pdf

https://assets.wellertruck.com/reference...stment.pdf

The poppet valves on the steering box are critical to safe operation. See above docs.

Hope this is helpful.

Be seeing you,

Rick Miller
#423
1996, 45'+, Non-slide, Series 60, ABS, 1.5 Bath, Reverse Floorplan


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#3

Thanks Rick, I'm still not sure what box goes into my coach, I'll call Newell on Monday and ask if they have one or the part number for both box and pitman arm, I've not had a lot of luck finding parts at Newell other than slide seal and replacement rear fiberglass finder. The information you provided will help me set up the new box, thanks again.

1999 45'  #504 "Magnolia"
Gravette, Arkansas
1996 40 XL Prevost Marathon 
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#4

Jack,
I'll wager we have the same steering box. Perhaps since you have Dana IFS the attachment will vary.... Do you have any photos?

Be seeing you,

Rick Miller
#423
1996, 45'+, Non-slide, Series 60, ABS, 1.5 Bath, Reverse Floorplan


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#5

I will get some pictures soon right now we have a storm coming through, I know Richard crawled underneath and said "thats not stock you pitman arm is half normal". I would bet your right the original box is TRW TAS85.

1999 45'  #504 "Magnolia"
Gravette, Arkansas
1996 40 XL Prevost Marathon 
Reply
#6

I have searched my files, my receipts, and my notebooks. I cannot find the specific model number of the TRW box. Mine was EXTREMELY difficult to read. It is printed on the bottom on the box as you would see it from the ground. It is on a raised boss, that is ground flat. Your info may be different from mine, but once I found the number, I learned no exchange replacements were available, which led me to rebuild mine with a kit from Wellman. https://newellgurus.com/showthread.php?t...ND+rebuild

Getting the box in and out is hard, rebuilding is pretty straight forward with help of the manual which is already linked above.

I spoke with an engineer at TRW who informed me the box was built for Newell, but declined to answer what was special about it. He really did not want to deal with a DIY guy.

Jack,
Since you are happy with the way the coach drives, maybe you want to look at a few things before you decide what to do. First, if you turn the wheels all the way in one direction, do the steering spindles hit the mechanical stops? If they do, then you are experiencing the abysmal turning radius of a 45 ft Newell. There is a reason they went to a steerable tag. If it is not hitting the steering stops, then I would investigate resetting the poppets on the steering gear box. It may not have been set up correctly to begin with.

If all of that looks ok, you may want to just evaluate a longer pitman arm before you replace the steering gear box. Mine is 10 1/2 OAL, 8 1/2 C to C on box mounting hole to drag ling mounting hole, 1 3/4 thk, and 2 1/2 wide.

I am conscious that there is a close relationship between the internal steering gear ratio and the length of the pitman arm in terms of the steering wheel turn to the steer tire turn.

Richard and Rhonda Entrekin
99 Newell, 512
Maverick Hybrid Toad
Inverness, FL (when we're home Cool )
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#7

Richard thats a world of information I didn't have, thank you. I'm going to call Newell on Monday and see if they have an old box or any information for me on getting one.

When at Josam they left the tag axle switch in the up position and I asked Barry what the beeping noise was, he came out and the coach was on the exit side of Josam so he put it in gear and was going to drive it back around the front to the entrance side, he turned the wheel till it hit the mechanical limits and said THERE IS SOMETHING NOT RIGHT, IT SHOULD MAKE THIS TURN he had to make a two point turn. I said did you check the pitman arm its half size of normal, they had not looked at it. It drives like it should but I have to put to much movement in the wheel to correct or make a turn then it hits the steering box limit. I will jack up the front and turn the wheel and check the amount of travel of the steering spindles and how close they are to the stop. Perhaps its just to short a pitman arm but the box is not the same and there is no adjustment on the worm gear.

1999 45'  #504 "Magnolia"
Gravette, Arkansas
1996 40 XL Prevost Marathon 
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#8

The pitman arm on our coach is 2 in shorter than Richard's coach, my box is not a TRX box so while waiting on the pitman arm removal tool I removed the steering column u joints and replace them. I have also built another support for the lower column just can't find where I placed it before we left for Florida in January.


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1999 45'  #504 "Magnolia"
Gravette, Arkansas
1996 40 XL Prevost Marathon 
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#9

The box I have is a shepherd M110, it has a threaded shaft with a lock nut to hold the pitman arm on. I ordered the tool removal tool for the M110 Box and evidently they are different configurations to hold the pitman arm on and I have the wrong tool for the box I have. The tool I need is $229 which is considerably higher than the one I purchased.


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1999 45'  #504 "Magnolia"
Gravette, Arkansas
1996 40 XL Prevost Marathon 
Reply
#10

Jack I think Foretravel use the Shepherd M100 steer box. Some of the guys on www.foreforums.com have made a tool to remove the arm and they lend it out. Not sure if it will work on yours but here is a link: https://www.foreforums.com/index.php?top...#msg435472

Forest & Cindy Olivier
1987 log cabin
2011 Roadtrek C210P
PO 1999 Foretravel 36'
1998 Newell 45' #486 

1993 Newell 39' #337 
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