Replacing shocks inspecting bulkheads

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Replacing shocks inspecting bulkheads

August 22, 2019, 04:10:34 pm

One item on our list for this fall/winter visit to Nac is replacing the shocks. Any suggestions as to what to put on? Any guesses as to cost? Time?

I've been trying to follow the various discussions about Bilsteins vs Konis, and I'm confused. As I understand them, in order to test the shocks on our coaches they have to be removed, so it makes sense to me to put new ones on, rather than the old ones.

The other major item is inspecting and repairing the bulkheads. I'm guessing that the inspecting part doesn't take long. How long does the repair part take?

I understand that, in theory, I could do both of these myself, but I'd rather have those who know what they are doing do the work. That way, if something else breaks (hello, Mr. Murphy) it is already where it can be fixed.

Re: Replacing shocks inspecting bulkheads

Reply #1 – August 22, 2019, 05:28:23 pm

More than one shop I trust has recommended the Koni shocks.

Recently replaced 8 Bilstein with Koni, I am happy with the ride of the Koni shock.

Re: Replacing shocks inspecting bulkheads

Reply #2 – August 22, 2019, 06:45:38 pm

For shocks, Koni FSD's.

Absolutely no way to know either cost or length of repair of the bulkhead until it is opened up. You can get a very general idea by counting the number of broken Rolock bolts (though the heads may still be there), the separation of the joint itself and also how far forward (referring to rear bulkhead) of the joint the box beams are rust-jacked (pushing down the fiberglass underbody more significantly than further forward).

The repair also depends on your goal-- have it last a year or two or replace all the rusted metal for a long-term solution.

Re: Replacing shocks inspecting bulkheads

Reply #3 – August 22, 2019, 06:55:41 pm

Big telltales are looking at the engine compartment for corrosion. The same for the exposed electrical panel. Looking inside the propane/diesel compartment can also show some rust along with the generator compartment. How are the radiator fins? Any rot toward the bottom? Check brake calipers also for corrosion as many brake problems are related to the pins not allowing the caliper to move. If quite a few Roloks fail the torque test and there are signs of rust/corrosion in the spots indicated above, the damage is likely to be more extensive. A coach with northern history already has two strikes.

Pierce

Re: Replacing shocks inspecting bulkheads

Reply #4 – August 22, 2019, 08:20:32 pm

Hi David. We went to Koni FSDs and they made a significant difference over the OEM Bilsteins that we replaced. But those were in pretty bad shape.

We had the bulkhead done at MOT after Keith inspected. Mine was preventive with no rust jacking etc. and was done in about 6 hours or so as I recall.

Good luck

Re: Replacing shocks inspecting bulkheads

Reply #5 – August 22, 2019, 08:26:48 pm

Another vote for Koni. Replace and forget about shocks. Will outlast most ownerships. Same with airbags... plenty of other things to worry about. Much improved ride.

Bought our Konis online and delivered them to install.

Re: Replacing shocks inspecting bulkheads

Reply #6 – August 22, 2019, 08:50:29 pm

The Koni's have a lifetime warranty

Re: Replacing shocks inspecting bulkheads

Reply #7 – August 22, 2019, 09:43:14 pm

Thanks. Looks like Koni FSD shocks. We did the air bags a couple of years ago and noticed improved ride and no loss of level. Doing the shocks ought to improve the ride even more.

Brett, what do you mean by "...have it last a year or two or replace all the rusted metal for a long-term solution." While I expect to put the coach up for sale in January, I don't want to spend $2000 for a partial repair when for $2500 it can be done right. On the other hand, I don't really want to spend a ton of money that isn't going to (mostly) come back when I sell in six months.

Re: Replacing shocks inspecting bulkheads

Reply #8 – August 22, 2019, 10:23:53 pm

Until know bulkhead needs I cannot estimate cost but if needs are typical if major repair I doubt you would want to undertake it.

Get inspected st MOT. I recommend you go cautious on torque test. You can ruin some and even if they feel firm that is not absolute they are all good. I saw one bulkhead where all held but the square tubing was total rust.

Re: Replacing shocks inspecting bulkheads

Reply #9 – August 23, 2019, 12:13:44 am

Quote from: kb0zke – August 22, 2019, 09:43:14 pm

Brett, what do you mean by "...have it last a year or two or replace all the rusted metal for a long-term solution." While I expect to put the coach up for sale in January, I don't want to spend $2000 for a partial repair when for $2500 it can be done right. On the other hand, I don't really want to spend a ton of money that isn't going to (mostly) come back when I sell in six months.

The amount of rust in the structural box beams does not go from perfect to failed, except through a process of degradation-- it goes through a rusting process.

Once opened up (FG floor under the basement accessed), it is possible to determine to what degree the structural integrity of the beams has been compromised. There ARE conditions where this untreated metal is still strong enough to be used. But, unless the rust on the outside of the box beams AND inside the box beams are treated, it will continue to degrade. The longer one plans to keep a coach, the more important it is to replace rusted metal. Very common to replace metal from front of wet bay to rear bulkhead-- NOT that big a job for those who have experience doing it.

Re: Replacing shocks inspecting bulkheads

Reply #10 – August 23, 2019, 12:16:41 am

When I called Extreme in Nac recently, I was told they recommended NOT checking torque on the rollocks ( bulkhead ). In our case I had previously checked 3 on the driver side and guess what,, They broke and THEN began the separation.

We just finished peeling back the filon (if that's the word) and cleaning, painting, re insulation, over drilling for #8 3/8 bolts and
Gorilla glueing the filon back up. Fortunately no welding needed in that area. I'm still planning to have Extreme or MOT check out the remaining area this spring.

Re: Replacing shocks inspecting bulkheads

Reply #11 – August 23, 2019, 01:34:20 pm

My Grand Villa U300 bulkhead repair was around $16K but many have been north of $30K. This is for dismantling basement and completely replacing the corroded steel tube structure.

Re: Replacing shocks inspecting bulkheads

Reply #12 – August 23, 2019, 06:38:45 pm

Koni vote. Had 8 new ones put on at FT earlier this year with the 8 new firestone bags and two new ride height valves.

Re: Replacing shocks inspecting bulkheads

Reply #13 – August 23, 2019, 07:13:17 pm

Quote from: Bob & Sue – August 23, 2019, 12:16:41 am

When I called Extreme in Nac recently, I was told they recommended NOT checking torque on the rollocks ( bulkhead ). In our case I had previously checked 3 on the driver side and guess what,, They broke and THEN began the separation.

If that was all it took to start the separation, you really had a problem. I recall a forum member had his fail while driving. You can imagine the damage that could do. The Roloks usually fail right at the point they leave the big angle iron and start into the tubing. I like to back them off, look the the Rolok and then try a torque test. If you can't back a fastener off and then put it back, it's not doing much is it? Brett has inspected a lot of Foretravels through the years. How about it Brett?

Pierce

Re: Replacing shocks inspecting bulkheads

Reply #14 – August 23, 2019, 07:37:28 pm

Rance at Xtreme said that the Rolok could rust in the angle iron but still be holding on the tube and not to mess with them.

Re: Replacing shocks inspecting bulkheads

Reply #15 – August 24, 2019, 02:09:10 am

Basically the same thing they told me....

except I plan to have them all replaced with thru bolts to avoid future issues. Along with any necessary rust abatement.

Re: Replacing shocks inspecting bulkheads

Reply #16 – August 24, 2019, 03:32:03 am

Quote from: Pierce & Gaylie Stewart – August 23, 2019, 07:13:17 pm

If you can't back a fastener off and then put it back, it's not doing much is it? Brett has inspected a lot of Foretravels through the years. How about it Brett?

Pierce

What I do (as described in the Tech Talk section-- Bulkhead Repair, located at the top) is put an inch-pound torque wrench on the Rolocks. This is after lengthy discussion with the engineers at Rolock. The 250 INCH-lbs I use in the "tighten direction" will NEVER break these grade 8 bolts.

What you will find 90% of the time is that it will either not move with that torque (all OK) or it will keep turning with far less than that torque. If it turns, unscrew it. 90% of the time, the bolt will be broken 3 threads in-- where it starts into the first side of the box beam.

I have never understood those who say not to check the bolts. If they can't hold 250 inch-lbs, they sure are not going to hold your motorhome together! And, 250 inch-lbs is not capable of breaking those grade 8 bolt.

This is from both theory (from discussion with Rolock engineers) and practical experience from checking several thousand of them over the last 12 years.

Re: Replacing shocks inspecting bulkheads

Reply #17 – August 24, 2019, 03:34:28 am

Quote from: craneman – August 23, 2019, 07:37:28 pm

Rance at Xtreme said that the Rolok could rust in the angle iron but still be holding on the tube and not to mess with them.

I have only inspected ONE coach with that issue. Properly done, the angle is drilled LARGER than the diameter of the Rolock so that the Rolock (self tapping) only torques into the box beam. The design fails if the Rolock can torque into the angle, as that will not pull the angle into the box beam (which it must do).

Re: Replacing shocks inspecting bulkheads

Reply #18 – August 24, 2019, 10:26:58 am

If the hole in the angle iron were to be the same size as the box beam, the Rolok, since it is threaded the entire distance, would thread the angle iron and then the box beam and not pull the angle iron together with the box beam. So, if there were an initial gap of 1/8", after tightening, the gap would still be 1/8." The angle iron has to be drilled larger so the first threads cut by the Rolok are in the box beam and then the angle iron will be pulled together with the box beam.

If you can remove the Rolok, drill for a 3/8" corrosion resistive fastener and either with a channel or individual holes, place a nut/washer on the far end of the bolt. The Rolok was designed for quick construction in steel structures in dry conditions and is not suitable for the bulkhead application. I did a torque test for a 3/8" fastener and the box beam was not deformed in any way. With a 316 stainless fastener, a Nyloc could be used at the far end. A Nyloc is available for hot dipped galvanized fasteners but harder to find as most of locking nuts have a small locking piece at the top of the nut.

Pierce

Re: Replacing shocks inspecting bulkheads

Reply #19 – August 24, 2019, 11:06:35 am

Quote from: wolfe10 – August 24, 2019, 03:32:03 am

I have never understood those who say not to check the bolts. If they can't hold 250 inch-lbs, they sure are not going to hold your motorhome together! And, 250 inch-lbs is not capable of breaking those grade 8 bolt.

For sure, 250 inch lbs is not much torque. Put an inch lb torque wrench on them and know the truth. Be in a place and
position to replace before possibly snapping the majority of Rolock heads off. The torque capabilities of the bolts give a good indication of condition of bolts and threads they are inserted into. The tensile forces acting on the bulkheads are not entirely addressed by bolt torque, but while inertia, withdrawal resistance and the adhesive properties of rust probably come into play, rotten fasteners and framing will need to be addressed. It would be a tough beside the road job.

Re: Replacing shocks inspecting bulkheads

Reply #20 – August 24, 2019, 12:33:45 pm

8MM or 5/16 bolt has a 2000# plus shear value.
If I had Uni- coach that one rolllock would not torque up, I would drill between each one , along with access hole for nut, and install a 8MM bolt/ nyloc. and torque them to 15FT # .
If the 15# crushed the tubes, you have a problem and the lower tubes that hold the front to the rear, need replacing.

By not repairing this properly ,the bus value is almost for parts . Repaired well and documented, the bus has some value above parts.
IMHO .

Re: Replacing shocks inspecting bulkheads

Reply #21 – August 24, 2019, 07:40:52 pm

I first installed one 3/8"-16 grade 8 up by the fuel tank where I could access both sides. I used a flat fender washer and then torqued to 45 lbs. It didn't even start to damage the tubing. Hey, it's .125" thick on each side. My feeling is that if it even starts to damage the tubing, then it's time to open the coach up on the bottom and start replacing tubing. Tubing is really cheap, it's just the labor that costs.

Pierce

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