• Ciao Guest - You’ve landed at the ultimate Guzzi site. NEW FORUM REGISTRATIONS REQUIRE EMAIL ACTIVATION - CHECK YOUR SPAM FOLDER - Use the CONTACT above if you need help. New to the forum? For all new members, we require ONE post in the Introductions section at the bottom, in order to post in most of the other sections. ALWAYS TRY A SEARCH BEFORE STARTING A NEW TOPIC - Most questions you may have, have likely been already answered. DON'T BE A DRIVE-BY POSTER: As a common courtesy, check back in and reply within 24 hours, or your post will be deleted. Note there's decades of heavily experienced Guzzi professionals on this site, all whom happily give endless amounts of their VALUABLE time for free; BE COURTEOUS AND RESPECTFUL!
  • There is ZERO tolerance on personal attacks and ANY HYPERLINKS to PRODUCT(S) or other competing website(s), including personal pages, social media or other Forums. This ALSO INCLUDES ECU DIAGnostic software, questions and mapping. We work very hard to offer commercially supported products and to keep info relevant here. First offense is a note, second is a warning, third time will get you banned from the site. We don't have the time to chase repeat (and ignorant) offenders. This is NOT a social media platform; It's an ad-free, privately funded website, in small help with user donations. Be sure to see the GTM STORE link above; ALL product purchases help support the site, or you can upgrade your Forum profile or DONATE via the link above.
  • Be sure to see the GTM STORE link also above for our 700+ product inventory, including OEM parts and many of our 100% Made-in-SoCal-USA GTM products and engine kits. In SoCal? Click the SERVICE tab above for the best in service, tires, tuning and installation of our products or custom work, and don't miss our GT MotoCycles® (not) art on the BUILDS tab above. WE'RE HERE ONLINE ONLY - NO PHONE CALLS MADE OR RECEIVED - DO NOT EMAIL AND ASK QUESTIONS OR ASK TO CALL YOU.
  • Like the new V100, GuzziTech is full throttle into the future! We're now running on an all-new server and we've updated our Forum software. The visual differences are obvious, but hopefully you'll notice the super-fast speed. If you notice any glitches or have any issues, please post on the Site Support section at the bottom. If you haven't yet, please upgrade your account which is covered in the Site Support section or via the DONATE tab above, which gives you full site access including the DOWNLOADS section. We really appreciate every $ and your support to keep this site ad-free. Create an account, sign in, upgrade your account, and enjoy. See you on the road in 2024.

Fork Oil Change problem

Markus H

Tuned and Synch'ed
Joined
Aug 11, 2013
Messages
32
Location
Somerville, AL
First, I hope this is the correct place to ask this question. I'm new to this.

I removed the forks from my 2014 NTX to change the oil, wound off the cap, but could barely get a wrench on the nut under the cap to separate it from the pumping member pin (as its called in the workshop manual). The nut is barely visible/accessible from under the cap. After grinding down a wrench to make it thinner (to fit above the jam nut), my first go at it slightly stripped the corner off of the nut. I've stopped to check here and see if there's a trick to this.
I've perused several forum to see if I could find a solution with no luck.
I've not had any problem getting the spring out of the way, just getting the darn wrench on the nut with sufficient purchase to remove the cap.
Any suggestions are much appreciated.

I attached a pic of the step from the manual. Capture
 
Last edited:
While on this topic, I'm wondering why it's really necessary to take the cap, rod, springs, etc out of the shock to get a good level of the oil. It would seem that the critical oil level would be with the "guts" IN the shock, versus out. I recognize it's a little tricky with the spring in the way, but it's a whole lot easier than getting that cap off.
The only problem then is establishing a new oil level with the guts in. I can check the existing level easy enough, but I'm not sure it's actually correct. Heck, both shocks currently have different levels. Hmm.
 
I've never had that type apart but if the spring is keeping tension on the nut I would try using a spring compressor to relieve it.
 
You have to take them apart to check the oil level as it is done by measurement rather than capacity.
That said, I worked out how much it took to do one leg a while ago and when I do the other one (ran out of time on the day) I am going to see if the capacity is the same (it should be of course but I might have miscalculated somewhere along the line). If so then I won't have to separate again.
 
The latest service man states 612cc of oil, doesn't have it all apart to measure air gap just the tube down in the leg is all it says. This is unlike the norm of spring off.
If you have the capacity then it's dump & pump.
 
I've never had that type apart but if the spring is keeping tension on the nut I would try using a spring compressor to relieve it.

Thanks for the reply Trout, but the spring tension doesn't appear to be the issue. At full extension, the spring has little tension on it. Actually, you have to manually compress the spring to gain access to the nut.
 
You don't have to take them apart to change the oil. Only to rebuild them.

Does this mean that you're not concerned with the level from the top of the tube, but just refill with the 650 cm3 as stated in the manual? I was nervous that I might overfill if there was some fluid still left in the fork that was not expelled through the pump and dump process. I've heard stories of blowing out seals from overfilling. (I don't imagine that I'm the sort of rider that uses forks that heavily to blow out a seal, but...)
 
Markus, give it plenty of time to drain. Also pump the fork a bit after it has drained and let it drain more. Some more oil may come out, or not. Main thing is to have an equal amount of oil in each leg. The air above the oil also acts somewhat as a spring as it resists compression. So long as the amount of oil in each leg is equal you should be good.
 
It usually takes 4 pumping sessions then drip an hr. You also pump it back in before measuring air. Clean the fork tube before pumping or dropping in in the leg. Then I coat it w/Dow Corning o-ring lube, it conditions the seals and you get no leaks.
 
Thanks guys for the help. I did as suggested and afterwards checked the oil levels to see how they looked and they came out within a 1/16 of and inch of each other. So all is good. I took it out for a ride and the clunk in the front end (that caused me to consider the oil change) disappeared. The bike seems to be handling much better again. Much appreciated.
I'm still going to search around the net to see how folks are addressing the removal of the cap just in case I ever need to change the fork seals. I've got about 18,000 miles with original seals in.
Thanks again for the help.

P.S. John Zibell, I see you're in Huntsville. I'm just across the river in Somerville. If you're game some time, maybe hook up and fetch a cup of coffee in the morning before the heat sets in. My wife and I often head over to the Brugger Bagel shop on Cecil Ashburn and Bailey Cove for a quick weekend ride.
 
Remove all the preload to decompress the spring. Normal wrench will fit without issue. Insert the wrench into the widest part of the spring. Crescent wrench will not fit. Needs to be a combination wrench.

Spring an preload tube needs to be removed to fill to a level. If you are filling to a volume then maybe but using that method does not really get rid of all the crap in the tube as it is difficult to flush out. Also, you need to stroke the dampers to make sure all the oil is out of them. Hard to do if the spring and cap are still installed.

If you are going to do it, best to do it right the first time. Removing the dampers is only one more bolt. That way you can make sure all the crap at the bottom is out.

As for the clunk, oil would not do that (unless you lost a lot of oil). Either you pre-load was backed out all the way or you have a bushing starting to go. I would keep an eye on that to see if it comes back.

Just my 2 cents.
 
Remove all the preload to decompress the spring. Normal wrench will fit without issue. Insert the wrench into the widest part of the spring. Crescent wrench will not fit. Needs to be a combination wrench.

Spring an preload tube needs to be removed to fill to a level. If you are filling to a volume then maybe but using that method does not really get rid of all the crap in the tube as it is difficult to flush out. Also, you need to stroke the dampers to make sure all the oil is out of them. Hard to do if the spring and cap are still installed.

If you are going to do it, best to do it right the first time. Removing the dampers is only one more bolt. That way you can make sure all the crap at the bottom is out.

As for the clunk, oil would not do that (unless you lost a lot of oil). Either you pre-load was backed out all the way or you have a bushing starting to go. I would keep an eye on that to see if it comes back.

Just my 2 cents.
 
Canuck, Thanks for the reply. There must be something different with my forks. I backed off of the preload before removing the forks. Under the spring was the nut I thought would be used to remove the cap. This nut turned out to be a 17mm jam nut. It was easy to get a wrench on and loosen, but the cap was still connected. Just up from it was a 15mm nut peeking out from under the cap. A combo wrench would not fit as there were not enough threads to back off the 17mm jam nut for the 15mm to fit in. So I ground down a 15mm to make it thinner so I could get it in. But as there was very little of the 15mm showing from under the cap for the wrench to hold on to, my first attempt to loosen the cap rounded the corner of the nut. As I didn't want to make a mess of the nut, I opted to change the fork oil using the drain-pump-drain process and fill with the oil amount stated in the manual. I wasn't happy, as I wanted to change the fork seals as well. I ended up cleaning the fork seal using a SealMate with some success.

As I think about this I am wondering, is what I perceive as the jam nut the nut that get loosened and run to the bottom of the threads on the rod at which point it bottoms on the end of the threads and the cap will spin off? I didn't try that as I was concerned with twisting the rod.

Your guidance is much appreciated!

Mark
 
Yes.........

You just put a wrench on nut between the springs (17mm) and a socket on the cap and twist. The 15mm nut you are seeing is part of the cap. The entire cap will spin off the damper rod and leave the 17mm nut on the rod. Once that 17mm nut is loose, the cap should just spin off. If not, then it is somehow jammed on the rod but I don't think that is the case.
 
Good God this sounds like a pain to do. I was always going to rely on Moto Guzzi dealer C&D Motorsports to do the routine fork work since they were pretty close to my location, but they shut down and now the closest dealer is three and half hours away. I don't really want to perform this myself !!
 
Good God this sounds like a pain to do. I was always going to rely on Moto Guzzi dealer C&D Motorsports to do the routine fork work since they were pretty close to my location, but they shut down and now the closest dealer is three and half hours away. I don't really want to perform this myself !!

It's actually rather easy. Especially if just changing the oil.
You could also just remove the forks and take them to another dealer that knows how to change fork oil which would save you some money and let them do the tricky part. They would just get refill specs from the internet.
I got confused about the jam nut on the damper rod thinking the cap was double nutted on. Thankfully Canuck set me straight.
Take your time and it's a piece of cake. And it feels good when you get it done!
 
You may want to call there, I think he is still doing service. I talked to someone there last week.

Best news I've heard all day, thanks for this. 6200 mile (10,000 km) service is due in about 2000 miles, would love to give him some business on at least the fork oil change and maybe also the throttle body balance check.
 
Back
Top