Steering Box Play- Sheppard M100 SHIM or Swap for a TRW ?

[Vanwill]

Originally Posted by AF Nomad

I got a response back from John VanLaan at Weller. Unfortunately, my options are limited. John stated that "we have never been able to swap over the M80 PBQ1. We have not found any TRW that matches up even close to it."

So it looks like my options are rebuild the sloppy Sheppard, or.....
weld the holes solid on my steering box mount to create a clean slate, and see if Weller can find a box that will fit on my mount, drill holes and mount a TRW.

The clean slate option sounds like a lot of work. While I would like a tighter steering box, I don't know if the juice is worth the squeeze since I don't to a lot of travel with my MH.

Any thought on Weller vs Redhead Steering for the rebuild?



Alex

Alex,
I’m hoping Craig will chime in here. But the two of us worked together on the TRW / Watts link improvements. The problem with rebuilding the Sheppard box is that there is simply NO way to adjust the box to less lost motion with the original rack and pinion in the steering box. “Rebuilding” them is mostly a matter of renewing seals and small parts. Even a good rebuild is not likely to reduce the lost motion to any appreciable degree. If you do a swap for an already rebuilt unit, you might get one even worse than what you have.

When they are “blueprinted” it is a matter of hand-picking a rack with teeth not cut as deep and a pinion with a larger pitch diameter. All the parts available for hand-picking and selective assembly are likely within the manufacturer’s tolerance. A box with much lost motion is usually just a box with an unfortunate combination of parts that are within manufacturer’s tolerance. To their credit, the Sheppard is a very, very rugged box with much more tooth contact area than the TRW. Unfortunately, the normal lost motion is just too much for a motor home application. Sheppard gears are found on a lot of off-road heavy equipment where lost motion is not an issue. The TRW is quite rugged enough for a motor home application.

When Craig and I first met at an FMCA rally, we discussed changing out his Sheppard box. At that time, we were not aware that there would be TRW-to-Sheppard boxes with interchangeable mounting dimensions. We both accepted that we would have to, as a minimum, drill new mounting holes. We also knew there was a possibility we might have to torch off the mounting plate, make another, and weld it in place. If there had not turned out to be an interchangeable TRW box, that is what we would have done. I’m sure we could have made some TRW box work.

If you have the skills and the tools necessary, I’m sure you could do the same as we had planned to do. Hopefully, Craig will answer. I am not sure, but I think he told me he had found some TRW boxes with two-out-of-three holes matching up. If that were the case, it would be much easier. In light of all the swaps we have seen, I suspect it would NOT be necessary to torch off the mounting plate and start over.

[CrazyKnight]

Originally Posted by AF Nomad

I got a response back from John VanLaan at Weller. Unfortunately, my options are limited. John stated that "we have never been able to swap over the M80 PBQ1. We have not found any TRW that matches up even close to it."

So it looks like my options are rebuild the sloppy Sheppard, or.....
weld the holes solid on my steering box mount to create a clean slate, and see if Weller can find a box that will fit on my mount, drill holes and mount a TRW.

The clean slate option sounds like a lot of work. While I would like a tighter steering box, I don't know if the juice is worth the squeeze since I don't to a lot of travel with my MH.

Any thought on Weller vs Redhead Steering for the rebuild



Alex

Alex,


Van said most of what I intended to tell you. He and I have discussed MANY times over the last few years about a "blank slate" mounting plate to "new" steering gear in a coach. It is not reinventing the wheel. The Sheppard M80 was used, at it limits at times, in many Monaco/HR coaches and a direct spec TRW should not be hard to find. The change to the Sheppard M100, by Monaco HR was a first attempt to put the heavier duty, greater weight capacity, in the coaches hoping for an improvement. MANY warranty replacements on the Sheppard M80 and M100, even the M110 by Monaco/HR in an attempt to "fix" the issue. Like Van said, the Sheppard play is in the design between the rack and pinion gears and it is fixed. The Sheppard steering gear is a heavy duty unit it just has some design characteristics that do not go well with our coaches.

To answer your question:

If I had made the choice not to go through the process of what Van and I discussed. I try and tell people if it was my coach I personally would do "X".

X--- I would contact John at Weller and ask him to blueprint your Sheppard M80.

John is VERY aware of what the issue is in our application. By hand picking a rack and pinion gear that are as tight as they can be in a Sheppard gear to begin with and then doing Weller's normal top notch rebuild you would have a reasonably tight Sheppard. I have seen snug Sheppard steering gears, personally measured over 400 various steering gears by now :-) and they are out there.

Van and I have personally toured Weller's rebuild facility and talked with John at length. We have held the guts of both gears in our hands and discussed the strengths and weaknesses of both steering gears during our very detailed tour.
Weller has more resources available to them most competitors.

Like I said if it was my coach and if I was not going to attempt a TRW replacement, which I do understand, I would do X.

Hope this helps.

Craig



PS. What the gears look like in a Sheppard.

[Farkey]

I have not read the 115 pages of this thread, but I have gone through an awful experience with play in the steering and after $1000’s the play in the steering wheel has gone from about 8-9 inches to about 3-4inches.
Not perfect but reasonably acceptable and got me to South Carolina, albeit 4 months later than we wanted, but we’re here.

I still believe the play comes from the steering box, although 3 “RV mechanics” say no.
Hopefully Ican find someone in SC who will agree with me and tighten it up a bit.

[nodine]

Originally Posted by Farkey

I have not read the 115 pages of this thread, but I have gone through an awful experience with play in the steering and after $1000’s the play in the steering wheel has gone from about 8-9 inches to about 3-4inches.
Not perfect but reasonably acceptable and got me to South Carolina, albeit 4 months later than we wanted, but we’re here.

I still believe the play comes from the steering box, although 3 “RV mechanics” say no.
Hopefully Ican find someone in SC who will agree with me and tighten it up a bit.

This would be my suggestion as a place to troubleshoot your problem.

https://josamusa.com/

Bob

[YC1]

Settle in and read the 115 pages. You too will become a wandering expert on steering boxes. The answers are there.

[Vanwill]

Originally Posted by Farkey

I have not read the 115 pages of this thread, but I have gone through an awful experience with play in the steering and after $1000’s the play in the steering wheel has gone from about 8-9 inches to about 3-4inches.
Not perfect but reasonably acceptable and got me to South Carolina, albeit 4 months later than we wanted, but we’re here.

I still believe the play comes from the steering box, although 3 “RV mechanics” say no.
Hopefully Ican find someone in SC who will agree with me and tighten it up a bit.

The short answer--If you have a Sheppard steering gear, replace it. If you have a TRW gear and it is not damaged, you can adjust it to zero play. If a TRW gear cannot be adjusted to zero play, it is damaged internally--something that is very rare. If the play is not in your steering gear, 9 out of 10 times, it's a worn tie rod end.

[ronspradley]

Originally Posted by Vanwill

The short answer--If you have a Sheppard steering gear, replace it. If you have a TRW gear and it is not damaged, you can adjust it to zero play. If a TRW gear cannot be adjusted to zero play, it is damaged internally--something that is very rare. If the play is not in your steering gear, 9 out of 10 times, it's a worn tie rod end.

I have a TRW gear on my 1995 Windsor that has play in it. I have not adjusted because the gear is not centered, it has about 1.75 turn center to full lock left and near 2 turns center to full lock right. Mike Hughes told me that was a design defect and would not affect the adjustment. So, what is the procedure to adjust? I know how to loosen the large nut and turn the set screw inside. How do I determine when enough is enough? Thanks


ronspradley
.

[eddie g]

I had Redhead rebuild the M80 on a 2001 Diplomat about 5 years ago. It had several inches of play and drove like crap. It had sway bars installed when I bought it but I think they were useless. Redhead was able to get the play almost out (it still had a small amount of play) which changed a frightening drive to a sometimes scary drive. I would call them and discuss this with them before I went further. This was before the watts and TRW threads. Maybe I got lucky but I think it was worth the effort. I sold the coach and bought a 2008 Dip SKQ. The first thing I did was swap the m100 for a TRW and install both watts and cross bars. Your still driving a huge box that’s affected by wind, road surface and truck ruts so it will never be perfect.

[Farkey]

Originally Posted by nodine

This would be my suggestion as a place to troubleshoot your problem.

https://josamusa.com/

Bob

Orlando great, I am in Canada a bit of a drive. But thanks for the info.

[nodine]

Originally Posted by Farkey

Orlando great, I am in Canada a bit of a drive. But thanks for the info.

Sorry, you said find someone in SC and I thought you meant South Carolina which is not that far from Orlando.

Bob

[nodine]

Originally Posted by ronspradley

I have a TRW gear on my 1995 Windsor that has play in it. I have not adjusted because the gear is not centered, it has about 1.75 turn center to full lock left and near 2 turns center to full lock right. Mike Hughes told me that was a design defect and would not affect the adjustment. So, what is the procedure to adjust? I know how to loosen the large nut and turn the set screw inside. How do I determine when enough is enough? Thanks


ronspradley
.

It may be difficult to see but there is a mark on the body of the TRW and another mark on the output shaft. These marks should be aligned when the wheels are pointing straight ahead. That is the only position the TRW should be in when you make the adjustment. Go to post #1414 in this thread for an explanation. That will be the high spot on the gears and that is where the slack should be adjusted out. When the steering is turned left or right from that position there will be play but you don't feel it because you are applying force to the gears. If your wheels are not pointing straight ahead when these two marks are aligned then you need to adjust the drag link so that they are. After correcting for the wheels pointing straight ahead and the marks aligned, if the steering wheel is off center then you correct that by adjusting the spline in the shaft from the steering wheel down to the input shaft of the TRW. That adjustment is usually made inside the coach by removing the cover between the floor and the steering wheel.

Bob

[ronspradley]

Thank you Bob. I will try and work from there. It will be a few days before I can get under coach and I will report back on what I find.


ronspradley
.

[CrazyKnight]

Originally Posted by ronspradley

Thank you Bob. I will try and work from there. It will be a few days before I can get under coach and I will report back on what I find.


ronspradley
.

Good morning,

Regardless of the number of turns lock to lock each direction in the coach, yes there are a few that are different each direction due to the design. It SHOULD be with the coach wheels pointed straight ahead. The TRW gear itself MUST be in the CENTER position BEFORE you begin the adjustment procedure Bob was so kind to reference.


The TRW has a center indicator on the housing (see the bump) and output shaft (see the line). It does not matter where the pitman arm is indexed on the output shaft. The pitman arm might be indexed a few teeth left or right or CENTER . The TRW gear MUST look like this before adjustment begins or it will bind.
Most coaches need a mirror to be able to see the center alignment.
(Do not let my photo angle fools you, it is centered right out of the Weller box)

Cheers,

Craig

[ronspradley]

Thanks again. Yes, I knew the steering box needed to be centere before adjusting the box, that is why I was waiting. I will make sure it is centered and then adjust. Will be a few days, and I will report back. Going to adjust the TRW first and test drive. The cross braces arrived today and I will install those after adjusting the steering box.


ronspradley
.