Rear Air Shocks

I saw a thread on rear shocks in the "old" forum, and kept up with it, since I was having the same issue. The issue is bottoming out the rear of the Goldwing while riding across any small dip/bump in the roads. Mine was hitting really HARD...enough to be very uncomfortable. It was mentioned that the centerstand may have been what was actually hitting, but not on mine...it was the rear shocks bottoming. Even with 50 psi of air, it would hit with just me on it. With Mama on it too...faggeddaboutit!!
So...I decided to replace the springs inside the airshocks with a set from Progressive, and do the seals too, since one of mine had some seepage.
Long story short, I did the swap, and couldn't be more pleased with the results. I am now able to run the rear shocks with about 10psi of air, and it has NOT bottomed out at all in any of the places it always did before. The ride is still super smooth, too!
I got my springs and seals from cheapcycleparts.com, for less than $100 total, including shipping. I had to come up with a make-shift press to get the shocks apart, but it wasn't that hard to do.
I have to get back to werk now, but I shall expand on this later. In the meantime, here's a few pics of my shocks, and the set-up I used to dis/re-assemble them.

Dan has my install write-up posted on the Manuals: 80-83 Shop Service and Parts manuals thread.
Unfortunately, cheapcycleparts apparently no longer sells the Progressive springs, tho they should be available from Progressive, or probably other places too.
I was going to add the link to the springs, but they just don't sell them any more, and they don't come up on their web-site. :Awe:

The Progressive springs are definitely stouter than the stock springs. The inner spring is shorter, but a lot thicker wire diameter, while the outer spring looks almost identical to the stocker. When installing the Progressive springs, they recommend not putting in as much fluid(automatic transmission fluid) as the service manual states, due to the thicker springs. The springs take up more room inside the shock cover, which leaves less room for the fluid. I messed up and put in the full 12 ounces of fluid, instead of the recommended 10 ounces. I didn't really think about it at the time, but later, when I did happen to think about it, I got scared. I wondered if the extra fluid would wind up popping the seals out of the shocks, or make them leak. I contacted Progressive and asked. They said it would be "advisable" to remove some of the fluid... :sensored: I wasn't going to tear back into them just to dump 2 ounces out. I took the air lines off, and bounced it up and down on the suspension, and no fluid came out, so I left it the way it was.(maybe my measuring cup is off a wee bit? That's my story, and I'm sticking to it!)
So far, I haven't had any problems with mine. They don't leak, which was my only real concern.
The fact that I can now lower the air in the rear shocks down to less than 10psi and it not bottom out is neat. It does ride smoother with the lower pressure, even when loaded.

It actually took me longer to get the dang shocks off the bike than it did to change the springs out. The first one took a little longer, as I had to figure out how to set up my press. The first one took me about 45 minutes to do, start to finish, once I had it off the bike. The second one took about 15 minutes! It's really not that hard of a job to do, but it is time consuming if you have a dresser. A naked 'Wing wouldn't be bad at all.
I highly recommend the Progressive springs...they are great!

Now we just have to find who sells them, maybe cheapcycle parts still does but not listed. I'll give them a call.

Another thing I just remembered...
To get the seals out, there are a couple of different methods recommended, either of which will leave a HUGE mess all over the place. One method is to remove the retaining snap-ring, then fill the shocks with oil, and then compress them, which is supposed to "pop" the seals loose....along with every drop of the fluid... :sensored:
The other method, is basically the same, except you use compressed air...the result is the same, tho...not a pretty sight!
I decided against either method. I simply drilled a small hole in the seal, and ran a small sheet metal screw into it. Then I could pull the seal out with pliers...and NOT have a massive oil spill all over my bench. That worked out perfectly for me. :clapping:

I was checking for rear springs and found them at www.bikebandit.com .

no doubt apple my rear shocks have progressive springs and the differense was amazing , if i can get the same result out of the front as the back ....im looking to get progressive springs for the front...i think this raises the safety and handleing way up on our wings of yesteryear!!!!!!!!

This forum is a great resource. I blew one of my air shock lines. I've got the hose fixed but when it blew there was a discharge of fluid, maybe 8 ounces. You mentioned the air shocks use automatic transmission fluid. Any particular type and how much per shock?

Any automatic trans fluid will work fine. I think the manual calls for 10 or 12 ounces per shock... :good:

Somewhere in my search of material on rebuilding the rear shock I found that you need to use Dextron II tranny fluid. I bought Dextron III, but I figured that was close enough. I wouldn't want to use Mercon or something. A lot of the new fluids are mulit-use. They can be used in place of Dextron or Mercon or soemthing. But I would be sure that it is Dextron II compatible.

The main differences in trans fluids are the additive packages. These are mostly for differences in friction materials used for the transmission clutches, as each manufacturer will specify a particular fluid composition that will have the best application/shifting characteristics for their vehicles. The actual hydraulic properties of the fluids are all pretty much the same, since they all basically use the same base stocks. That being said, Dextron is the most common, and popular of the trans fluids out there. Dextron II would have been the oil of choice in the '80s, when our 'Wings were new. Dex III is simply a more developed additive package for the same basic oils, due to the electronic advances in automatic transmissions. Dex III is more compatible with the smaller feed holes/orifices in the newer transmissions than Dex II.
I would think that there would be absolutely no functional differences in the shock applications of any Dextron, Mercon, or Mopar trans fluids for this particular application. I would, however, never recommend the use of a "reclaimed/re-refined" fluid, such as the generic branded, purple looking stuff that you can buy at a convenience store, or Wally World...even tho they claim it's as good as anything else. :good:

OK. So a couple days ago I finally got tired of bottoming out on my new (to me) Interstate. I grabbed the bicycle pump and put 35 lbs of air in the rear suspension. Going to work the next morning, the red warning light was on (it had never come on before). I figured that I must have overfilled it even though the manual says I can go to 57 lbs. After I got home I checked the air pressure. It was zero...zilch...nada! I grabbed the pump again and blew it up to 30 lbs. I waited about 30 seconds and it was back to zero! I did not hear any air escaping, so can I assume the lines aren't leaking, that it is the shocks?

Somewhere on this site I thought I read that there are shocks for an 81 Interstate that don't require air. If that is the case, does anyone know which ones they are? If I have to replace the shocks anyway, I might as well get (relatively) maintenance free units. I can change the shocks, but I don't think I am mechanic enough (nor have enough tools) to rebuild the existing ones.

I love the bike, but the ride is not what I expect from a Goldwing.

i think that progressive make some that dont require air ....416 i think there called ....just have to make sure you get the right ends on them so they hook up right....

From all that I have read here @ CGW, and from what I learned in doing my rear shocks, I have deduced that 99% of the time, bottoming out has more to do with the amount of oil(or lack there-of), in the shocks than the amount of air in them. Of course, if they won't hold air, then they probably won't hold oil either, depending on where the leak is, and how severe it is.
There are really only two places the rear shocks could leak...either from the seal at the bottom of the "air chamber", or the top, where the air lines go in. If the lines are not leaking, there are still two o-rings up there that could be leaking. The lower seal leaking would show obvious signs of a fluid/oil leak, providing there is still any oil in the shocks. My right side shock was definitely leaking from the lower seal, as there was always oil on the diff right under where the shock mounts to it. I could pump mine up to 57 psi and STILL bottom out with just me on it. Now, with the new springs, seals, and oil, I can run as little as 10psi in the rear, and not bottom at all, no matter how much weight I put on it. :good:
hth

I don't see any indication of fluid leak. of course, since I bought this used, there may not be any fluid in them, to leak out. :smilie_happy: :swoon:

I will visit the Progressive site and see what I can see. My wife suggested a 1200 Sportster instead. I will take the cheap route first. :music:

pasvorto":utvsjy96 said:

I will visit the Progressive site and see what I can see. My wife suggested a 1200 Sportster instead. I will take the cheap route first. :music:

Click to expand...

How far do you plan to ride? That Sportster will beat you to death if try to go very far.

Actually I was thinking of Route 66 next summer... She thinks they look cool.

I agree with the low on oil issue. A lot of goldwings are probably just low on oil. I did an analysis that showed the pressure vs. travel and with less oil the force doesn't increase much due to air pressure. With more oil it gets much higher as you get to more travel on the shock.

Now, on the other hand, on my GL1100 that I just put the progressive springs into, I measured the oil that I took out of them after I was done. Between the two shocks it was right at 20 oz. It is supposed to be 12.5 OZ each side. So at least in my case, it wasn't just the oil level, and the shocks held air pressure.

I'm thinking at least part of the problem was the dissovled bottom out bumper inside the shock. On the one side it was all down into the damper and made the damper hard to compress and retract. Perhaps it was sticking some?

Progressive's website is good. You can figure out what you need with or without air. Don't let their prices scare you. You can probably find it for 20% less somewhere else.

The advantage of the air is that you can easily adjust the ride height which will vary due to loading. You can do that on a non-air shock as well, but the saddle bags will block your access to the adjuster ring on the shock. If you don't mind setting it for two up and just riding higher and stiffer when 1 up then you are OK.

I put the progressive spring kit into my rear shocks and replaced the seals. That's about your cheapest option. Total cost was about $100. The job wasn't too hard. I had to make a spring compressor, but you can buy the progressive one for about $70 and that would make it even easier. The shock rebuild was a LOT easier than replacing the timing belts.

Had I the money, I would have just bought the progressive replacements with the air. Those are about $350-$400 I believe.

Take care,

Dennis

How does one know if the oil is low? Is there a way to check and/or add more?

You could just put the bike on the center stand. Take the shock off and disconnect the airline. Then turn it upside down over a container and shake it like a ketchup bottle. In about 5 minutes you will have the oil out. Putting it back in isn't as easy.

One guy on here left it on the bike and compressed the shock then slowly let it back up while using a syringe to squirt oil into the air hole on the top. You let that drain in for a second, then compress the shock again, and repeat. I think he even made a video of it. The shock actually sucks the oil in when you let it uncompress. He just kept going till it was spitting the oil back out when he pressed it down. I think I would measure it and not add more than the recomended amount myself. He reported that it fixed his bottoming out issue, and didn't replace anything, just added more oil.

It's about half way down page 2 of this topic.

https://classicgoldwings.com/forum/viewtopic.php?f=23&t=894&start=20



Good luck,

Dennis

I saw that video. I may have to try that this weekend if I can find any time.