Steering gear, intermediate shaft and slip joint replacement

Don Jaksa

Don Jaksa

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Mar 27, 2022
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Started as a leak in the upper seal on my steering gear box leaking power-steering fluid.
The thread has now transmogrified into a rebuild of the steering mechanism

Can the seal be replaced without removing the steering gear? Never mind.

How difficult is it to swap out the steering gear box for a rebuilt one? I guess I'll find out.
Mine has 180k miles on it and a fresh one would be in order.

What else should I change while I'm in there?
Looks like new boots for the steer shaft as well

What say Ye?
 
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1. Yes. NAPA NPS7367. See https://www.gmcmotorhome.org/thread...eal-and-dust-cover-on-the-steering-box.73853/

2. To swap steering box, it can be difficult to remove the pitman arm from the tapered shaft but otherwise it's straightforward. Note, it's heavy. Important: The GMCMH box has special stops built into it to prevent interference with the control arms, so your best bet is to have it rebuilt by someone like Red Head Steering Gears. Don't just use an off-the-shelf steering box. Also, you can't install the stops in an off-the-shelf box without dissasembling/reassembling it, which is difficult.

3. The cause of upper steering box seal leaks is often because the slip shaft has seized. If yours is seized, Dave Lenzi is a good source for a better-than-factory replacement, or you can replace it with a Borgeson shaft (see https://www.gmcmotorhome.org/thread...ng-shaft-part-numbers-and-installation.93107/).

4. Yes, the boots protect the factory slip shaft. Boot solution: Dorman 614-001 and Duralast FA8082, both of which need to be cut to fit. Duralast should be cut so that there are 8 ribs on the wide end. Dorman should be cut to remove the widest section; it's the second section that fits the CV joint. When cutting the Dorman boot, leave the ridge on the "keep" part so that wire tie/hose clamp has something to grab.
 
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Thanks guys. Looks like a project

Looks like the Borgeson option is the way to go. Borgeson option now disgarded

Dave Lenzi machined replacement parts to be used
 
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Don Jaksa said:
Thanks guys. Looks like a project

Looks like the the Borgeson option is the way to go

What about the rebuilt steering gear offered by GMC Parts (Applied)? Should it be considered?
www.gmcrvparts.com

REBUILT Steering Gear - GMC Motorhome

We are a major supplier of GMC Motor Home, RV Parts. Serving GMC MOTORHOME owners everywhere.
www.gmcrvparts.com

and what is "Fixed ratio" all about?
Click to expand...

I have the Borgeson shaft in mine, it's a bit light duty. Lenzi has a refurbished shaft which is a thing of beauty, I'd recommend getting that instead of the Borgeson.

btw have you cleaned the filter on the windshield wiper motor? If this is plugged, it will put pressure on the seal and cause it to leak.
 
tmsnyder said:
I have the Borgeson shaft in mine, it's a bit light duty. Lenzi has a refurbished shaft which is a thing of beauty, I'd recommend getting that instead of the Borgeson.

btw have you cleaned the filter on the windshield wiper motor? If this is plugged, it will put pressure on the seal and cause it to leak.
Click to expand...
Where would I get the Dave Lenzi shaft?

I have not used the wipers nor driven the coach in a while, but I will look into the wiper filter.

I'll take pictures, its a mess down there
 
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Don Jaksa said:
Where would I get the Dave Lenzi shaft?

I have not used the wipers nor driven the coach in a while, but I will look into the wiper filter.

I'll take pictures, its a mess down there
Click to expand...

The wiper motor is hydraulically in series with the power steering gear box. When the filter plugs it puts pressure on the gear box (from what I've read on this forum and the old birdfeeder email listserve)

So it doesn't matter whether you've used your wipers lately or not, the pressure would be on the box regardless.

Contact Dave Lenzi here: mlenzi (at) charter (dot) net
 
Thanks for the information.

My steering gear, intermediate shaft and slip joint are original with 180,000 miles on them. They look well worn, the shaft has seized and there is play in the steering gear as well so I am going to replace them all including a Dave Lenzi shaft and boots.

With it all apart I will also pull the filter and replace it and new hoses.
All electric wipers could also be an option

The price of the steering gear has gone up by $85 bucks since I started this thread. I better order quick
I'm looking at about $2000 for everything with shipping
 
Don Jaksa said:
Just got off the phone with Dave Lenzi and we are going to do business
Click to expand...
Sounds like you're going to swap the box then?

How are your skills with paracord and sliding friction hitches? Suspending the box from above to take the weight was a lifesaver for me when I swapped the box on a more "put together" coach. It's tough getting the heavy box lined up so you can thread the bolts. One thing you could do is install removable studs into two of the holes in the box. Then slide it up into the frame and get the bolts started in the two other holes, then remove the two studs and replace with bolts.

Of course, mine had an extra dosage of struggle because the frame was slightly tweaked. The reason I was replacing the box was because it was snapped off in an accident. Maybe if things are correctly shaped, it's easier to just quickly bolt it in. I had to do some pounding, filing, guess and check--all while laying in a puddle of mud while sleet and snow came down. Probably my least favorite GMC moment to date.
 
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pvfjr said:
Sounds like you're going to swap the box then?

How are your skills with paracord and sliding friction hitches? Suspending the box from above to take the weight was a lifesaver for me when I swapped the box on a more "put together" coach. It's tough getting the heavy box lined up so you can thread the bolts. One thing you could do is install removable studs into two of the holes in the box. Then slide it up into the frame and get the bolts started in the two other holes, then remove the two studs and replace with bolts.

Of course, mine had an extra dosage of struggle because the frame was slightly tweaked. The reason I was replacing the box was because it was snapped off in an accident. Maybe if things are correctly shaped, it's easier to just quickly bolt it in. I had to do some pounding, filing, guess and check--all while laying in a puddle of mud while sleet and snow came down. Probably my least favorite GMC moment to date.
Click to expand...
Thanks for the ideas. I will use the power of mental thinking for sure.

One thing you could do is install removable studs into two of the holes in the box. Then slide it up into the frame and get the bolts started in the two other holes, then remove the two studs and replace with bolts.
Great idea!

I did a complete bogie swap all by myself and have a great set of tools. Maybe tie 3 dozen helium balloons to the box and float the new box into place...I'll figure it out somehow
 
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Don Jaksa said:
Here are the new parts I ordered
View attachment 17008

View attachment 17007
Everything Dave Lenzi advised me to get

First step is to spray all the bolts with BoShield to free up any nuts and bolts
View attachment 17009
Click to expand...
You made the Smart choice. Expensive, but smart and you will never have to worry about replacing those parts again.

To answer your original question…. Changing out the upper seal while the box is still installed in the gmc is not too hard. But I found out that success at stopping the leak varies. The issue is the top of the box constantly sees moisture, rain. The shaft itself can pit and rust over time and no new seal will stop the leak.

Many of those parts can have some slop. Dave makes sure his parts are to spec and will last longer the. Original.

Mark the pitman arm well. So you know what end goes up. What direction it goes on And such. It can confuse you when it is time to re-install. I had time. I sprayed and had the puller on it a few days. I think when I went to tighten it more on day 3. It popped off.
 
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Boeshield T-9 is some great stuff
boeshield.com

Boeshield T-9 | Rust Protection & Waterproof Lubricant

Shield your gear from rust and corrosion with Boeshield T-9®, the ultimate waterproof lubricant for bikes, boats, tools, and more.
boeshield.com boeshield.com
but I wouldn't use it to free up fasteners. A 50/50 mix (1 to 1 for the math challenged! 😜) of ATF (used or not) and acetone works better than the overpriced store bought stuff...all of them.

Another excellent aviation crossover product, developed by Boeing and Rolls Royce, is Hylomar Blue.

Enjoy Lenzi-izing your steering! Be forewarned, in future you'll have to concentrate on trying to stifle the big grin while you're driving.
 
Okay, T-9 says right on the can "Frees up rusty parts" but I am willing to give the 50/50 mix a try.

The stuff I can't stand is BLASTER

Thanks for the tip
 
Don Jaksa said:
Okay, T-9 says right on the can "Frees up rusty parts" but I am willing to give the 50/50 mix a try.

The stuff I can't stand is BLASTER

Thanks for the tip
Click to expand...
IMG_5611.webp

Soaking the fasteners in the home brew each day for a few days works well. To speed things up apply heat prior to each application of solvent.

BTW, everything is marketed as freeing rusted fasteners, even WD40 which doesn't!
 
Richard RV said:
BTW, everything is marketed as freeing rusted fasteners, even WD40 which doesn't!
Click to expand...
To be fair, it cut the required torque by 54% according to the cited test. That's not nothing, and it's readily available and cheap. I use a lot of PB and had given myself the impression it worked better than WD-40 and Liquid Wrench. Maybe I'll have to revisit Liquid Wrench for a while. IIRC it's cheaper than PB too. Spray cans certainly have value for portability and convenience, but I think a squirt can of ATF/Acetone warrants a prominent position in my shop.

Edit: Interestingly enough, there seem to be a lot of questions circulating as to the validity of that test. One thread even has someone claiming to be the original author stating he actually used PS fluid instead of ATF as he'd grabbed it by mistake at the auto parts store and didn't notice. Supposedly many readers had noticed the PS fluid in the article's photo and had been questioning this. That of course, leaves me with more questions.
 
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Another independent tester is Project Farm. You'll have to use your own judgement about the validity/applicability of his methods, but at least he gives full transparency on his methodology:


1761932309754.webp


 
Applied GMC

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