DrewGeorge

Yes, mine has 8 airbags and interestingly, Scott thought they were still in good shape and didn't require replacement even though they all appeared original from 1991.

Hi everyone,

I wanted to post another update to this thread as I recently went to Source Engineering to have their custom Bilstein shocks installed, which made a huge difference in reducing body roll, allowing higher speeds on windy roads and overall, providing a much better sense of control.  Also while I was there, Scott Zimmerman took a look under my rig and very helpfully told me that I have a Saginaw 710 steering gear (not a TRW).  Based on that information I was able to do some research online and further determined it is more particularly a "Saginaw 710 Dual Piston Metric" steering gear.

To address the significant leak at the sector shaft, I purchased a seal kit from Power Steering Seals, Inc. in Broken Arrow, OK  ( https://powersteeringseals.com/product/saginaw-710-dual-piston-metric/) and while removing the old parts, I discovered that someone had failed to install one of the two seals on that shaft. I put the 2 new seals in 10 days ago and so far, no more leaks!

To summarize, I'm extremely pleased with the steering and handling now, and in case it helps others, I think that the things that made the biggest difference for me were as follows.

1. Reduced Tire Pressure: reducing the tire pressures in all tires, based on weighing all 4 corners and using the manufacturers recommended pressures for those weights.

2. Added Steering Fluid: I had lost a lot of fluid from the sector shaft leak without realizing it, and now I'm wondering if that may have caused air to enter into the steering gear and/or had some other negative effect on my steering.

3, Installed New Shocks: Scott confirmed my working premise that my rig still had the original Monroe shocks on it...and I didn't have to drive very far from their shop to be extremely pleased with my investment in the new shocks! 

And to confirm, I haven't attempted to adjust the steering gear.

My thanks to all for the helpful suggestions and encouragement.

Drew

Wow, that must of been very satisfying!  Yesterday I cleaned the roof on my 91 Dynasty (also with Dawn) and I’m curious about maybe using Mop-n-Glow too, does your roof feel slick now? Any other thoughts or suggestions regarding that product?

Thanks for the replies, and as an update, the steering is much better now that I've filled the hydraulic tank and reduced the air pressure in the front tires to 90 psi.  I don't know if I'll have to adjust the TRW, it seems very good now.

5 hours ago, Robert92867 said:

Thanks for posting the pics.  You have a nice vintage coach that will get you into a lot of State and National Parks that a longer coach will not.  Appears to be in good condition for its age. The 12 valve Cummins is reknown for its longevity, although underpowered by todays standards.

Thanks Robert, and I agree it's underpowered. Since purchasing I've learned that the weak link in the drivetrain is the Allison AT545 4-speed transmission, which does not have a lock-up torque converter - so the engine makes power but the trans basically slips, creating a lot of heat rather than top speed or power up the hills.  I understand that I can fairly easily and cheaply increase the HP and torque of the 12 valve but the transmission won't handle much more than the stock numbers. And apparently there are no options to improve the trans, other than replacing it with something stronger.

Hi,

In case it is helpful to anyone else, my new-to-me 1991 Dynasty 31' came with Falken RI150 ecoRun 255/70R/22.5 tires and I couldn't find any info online regarding the proper inflation pressures so I emailed Falken this morning and they sent me the attached 23-page "2023 Commercial Truck Data Book". 

On page 17 it indicates the following: 

2023 Falken TBR Data book - received 8.10.23 via email.pdf

Hey David, I just read your thread and I'm curious if you figured out what was wrong because I'm having basically the same problem/symptoms in my new-to-me 1991 Dynasty - I'd love to hear an update if possible.

Thanks David, and yes, now that you mention it there was some fluid on the steering box when I bought the motorhome 3 weeks ago, I wiped it off then and totally forgot about it - so thanks for the reminder to examine it further!

21 minutes ago, Frank Bergamo said:

The proper way to determine tire pressure is to weigh the coach. Four individual corners if possible. If not, then individual axle weights. Then look at tire pressure charts for your specific tire brand and adjust accordingly. An under inflated tire can be really dangerous. No guessing, your life and others is of the utmost importance. Hope this helps.

Thanks Frank, and I really like this approach as I was hesitant to reduce the tire pressure that much (so I didn't do it yet), I'll get the coach weighed and adjust as you suggested. 

17 minutes ago, Tom Cherry said:

As mich as I love my Source Bilsteins, unless you spend a bundle for the heaveir front shocks and the standard SOURCE shocks (all SOURCE) and add front and rear Source Sway bars, you are NOT going to see a major, if any  difference in wandering.  A steering stabikizer will improve that slightly, as you are the SEE SAW doing it.  The Watts link will do the most, but only the TRW…

Take that to the BANK!

Thanks Tom and I'm not expecting the shocks to fix my (now greatly reduced) wandering woes, instead my working premise is that my Monroe shocks are 31-year old OEM's therefore it's past time to replace them.

An update as I’ve made some progress: yesterday I discovered that the steering reservoir was very low on fluid, so I added a gallon (yikes!) and changed the filter.
As suggested in the comments in another thread, I then started the engine and let it idle for 10 minutes prior to moving the steering wheel and then went lock-to-lock 5 times to remove air from the system. The steering immediately improved, with a significantly firmer feel and a much smaller area of play now. 
Also I discovered that Monaco recommended lower tire pressures for this model than the tire manufacturer does (85 vs 110) so I’ll try that next. 
To confirm, I haven’t tried adjusting the TRW steering box yet. 
And I’ve spoken with Jim at Source Engineering regarding their shocks, they don’t have any in stock right now but he said he’ll let me know when they come in. 
Thanks to all for the advice, I sincerely appreciate it!

Thanks again, Tom, and I spoke to Mike Hughes this morning and he said the adjustment nut will be on the side up against the frame. So I just checked, and indeed, he was correct!  AND, someone burned a small hole in the frame for easy access to the adjustment nut. Hooray!

21 hours ago, Tom Cherry said:

I say TWR by the shaft.  Shepherd definitely is different.  However, as you stated, this one is an earlier one.  The “double” can with one end cast and the other a press in “seal” is not consistent with what is normally seen.  Have you “felt” the other side of the pump for the adjusting “stud” and lock nut.

Go to MonacoWatts.com.  Get in touch with Mike Hughes.  He sells the Watts Link kits.  He would be the person to ask.

 

Thanks Tom and yes, I felt the top side of the pump and it is smooth, there is no adjusting stud or lock nut there.  So if this is a TRW, is it the first one you've seen without the ability to adjust it?

10 minutes ago, DavidL said:

Diagnosis comes first.

If there is steering play in the box, then look at all joints while moving wheel back / forth to find that play.  Might be a Joint, not the box.  Since the box has evidently been replaced, that is likely not the problem.

Define wandering:  You keep the wheel straight and the vehicle moves with the wind from passing trucks?  Or RV moves with road undulations?  Or you move the steering wheel and the RV keeps going straight?  Do bumps affect the issue?

The shocks look like they have been around as long as the RV...that's a wear item and good handling starts there.

Check tire pressures since that doesn't cost anything.  Ensure pressure is correct for the Axle weight as per the tire's spec chart.

 

Thanks David, and I've only driven it about 300 miles so far - most of which was on the (very straight) route 5 between Portland and Eugene - but in response to your questions: 

"You keep the wheel straight and the vehicle moves with the wind from passing trucks?" - YES, I found that I had to steer towards the passing trucks in order to stay in my lane.  

"Or RV moves with road undulations?" I'm not sure I can tell given my very limited experience so far

"Or you move the steering wheel and the RV keeps going straight?"  YES, there seems to be a lot of play in the steering

"Do bumps affect the issue?"  I'm not sure I can tell given my limited experience so far, but she's a handful.

Shocks: yes, they appear to be the Monroe's, I'll replace after addressing the steering box

Tire pressures: all were at 110 when I picked it up, and 115 while driving, I just doubled check that is correct for the FALKEN EcoRun RI150.

Thanks again!

5 minutes ago, Tom Cherry said:

Congratulations.  You have a TRW box.  The splined clamp with a locking nut is TRW.  The steering arm is the way you identify.  You can google Shepherd.  They have a PDF that lets you identify which steering sector you have, but it goes over a shaft with a tapped hole and there is a bracket or clamp or keeper that unscrews directly from the steering shaft.  Yours is clamped on….

No HELP on the model or anything else…but confident you have a TRW.  Read up on how to adjust it….not that hard….just GO EASY.  Those us that used to have to adjust play out of an 40/50/60’s car or truck with no power steering did that all the time,

Thank you very much Tom, this is wonderful news that I have a TRW!  

Hi all,

New owner of a 1991 Dynasty 31' here (Howdy!), and I've been reading up on how best to address the wandering woes of my rig and I understand I should start with the steering box.

It appears that a previous owner installed a new steering box but I can't determine which one it is, it doesn't say TRW or Sheppard on it as far as I can see and the only number on it is partially obscured, maybe 5686875?.  Also I can't find any adjustment knob (ruling out the TRW) but it doesn't look like the Sheppard pics I've seen either?

Please see the pics attached, and any feedback is appreciated!

Thank you,

Drew George

Southwest Oregon

(619) 818-3739