How hard are front shocks to rebuild / parts sourcing

[tdskip]

Hi folks / hope everyone is doing well (or well enough given the strange times).

How hard are the front shocks to rebuild them in 1975? I’ve got a bit soft and I’d like to get them sorted out before summer riding. I’m decent with a wrench but I’m not experienced working on motorcycles.

Any specific brand or parts source recommended?

Thanks!

[flyin900]

Not that hard if your handy and have some tools and a shop manual. There are Honda seals still available and aftermarket too. I personally use the Honda seals although it isn’t a must by any means and aftermarket are normally cheaper.
Check the Tech tips section for info on doing the job and also having a shop manual helps too.

From what I remember when doing a set on a 1976 the old ones were a bear to get out of the lower forks, yet with some heat and a seal puller I won out.

[jdvorchak]

If they aren't leaking don't bother to rebuild. You might just want to look into new springs and change the fork oil. ATF is the recommended fork oil to use.
Good luck.

[tdskip]

Thank you for the responses, and I apologize for the slow follow up. I missed that people were kind of to reply to my question. Sorry.

They are not leaking now, but feel soft so perhaps I’m incorrectly assuming that they need to be rebuilt. I’ll do some searching but is there a shock oil that people recommend to help firm things up a bit?

Thanks And hope you’re both having a good weekend.

[flyin900]

The oil maybe low or gone from the forks. Worth pulling the forks off the bike and taking the units apart to clean out the old fork oil. You will be able to see what condition the oil is in once you drain it and if you get a reasonable amount out or next to nothing.
I think the 1975 allows you to just remove the upper tube and lower slider easily once the bottom bolt is removed, while leaving the seal intact in the lower slider assembly. If that is the case then it is easy to take the tension off the upper section and remove the fork spring and clean out everything. Best to remove the lower bolt in the bottom of the slider first when the forks are off the bike with the spring still in the upper tube, as that will keep tension on the whole assembly to allow you to break the bolt free.
Then remove the top cap and take out the spring by first loosening the chrome large top cap while the forks are still in the triple trees, so you still have tension on the chrome tube to break the large chrome nut free first.
If you end up leaving the old seal in there if it looks fine then I suggest cleaning and refilling the fork tubes and fully assembling them. Then really giving them a good number of pumps then a rest and more pumps to test that the old seal is still oil tight. Saves reinstalling them on the bike, only then realizing the old seal is not a good as it seemed.

[rcmatt007]

the "too soft" may be that the 40+ year old springs are not as springy as hey used to be. Progressives are stiffer and some find them too stiff. You might also take out the springs and measure them, and someone might be able to compare them to what they have.

[flyin900]

Great idea Rodger. From the GL1000 service manual here are the free length specs for the fork springs, if you don't have manual handy. Tight wound section goes at the top of the fork and looser winding at the bottom.

FREE LENGTH
STANDARD: 519mm (20.4 in)
SERVICE LIMIT: 495mm (19.5 in)

Fork oil amount is specified as 170-180cc's in each leg or 5.8 to 6.1 oz.'s. Usually ATF can be used which is about 8 weight, so a little heavier 10W or possibly 15W fork oil will give you a different reaction to using the ATF fluid if the springs are in spec.

[pidjones]

Back in '04, the first thing (besides the belts!) that I did to my '77 was to rebuild the leaking forks. Getting the old seals out is a pain, but the rest is just work. An automotive seal puller hook will do it, but you have to be careful. Use of heat from a propane or MAP torch helps a lot. Since then, I've rebuilt four more sets for bikes I've rescued. While the lower legs are off, besides cleaning the inside REAL good, I polish up the lowers with my drill and buffers and sand the tubes with 2000 grit until they look like mirrors. The Allen comes right out of the bottom with an Allen hex socket on an impact driver. Do this BEFORE you take the spring cap nut off, and the spring will keep the inside from spinning.

[rcmatt007]

ditto on the bottom allen.... don't ask how I know

[gregforesi]

When I changed my 78 to a cafe style it moved my riding position way forward. The front was soft and the back hopped around curves. I installed lighter springs on the rear Progressive shocks and went to 15 weight fork oil in the front (ATF is about 7.5 wt) as the PO had already changed the front to Progressive springs. It's way better than it was before the changes.

[rcmatt007]

When I changed my 78 to a cafe style it moved my riding position way forward. The front was soft and the back hopped around curves. I installed lighter springs on the rear Progressive shocks and went to 15 weight fork oil in the front (ATF is about 7.5 wt) as the PO had already changed the front to Progressive springs. It's way better than it was before the changes.

nice to see you on the board

[Sidecar Bob]

I always recommend a full rebuild of the forks if you don't know when they were last done or whether they were cleaned out properly at that time. After that, assuming that they don't leak and the old fluid doesn't look too bad when you drain them you can just change the fluid every few years.

FWIW, my first bike's Owner's Manual specified a 50:50 mixture of engine oil and ATF for the forks. My first Honda didn't come with an Owner's Manual and it was before you could look these things up on the internet so I assumed it required the same and used that for years before I learned that Honda didn't recommend the same as Suzuki. Around the time I learned that Honda just specified "ATF" I also learned that there is quite a range of viscosities between the versions of ATF specified by various car manufacturers so saying "ATF" without specifying which type is like telling you to put "oil" in the engine without specifying whether that is heating oil, motor oil (of a specified viscosity), olive oil or bunker crude. So I continued using the 50:50 mix because it allows me to use different viscosities of motor oil to tailor the fork fluid to the conditions (in my case, I use ATF & 10W40 in my summer machine and ATF & 5W20 in the winter one).

[leonardhcross]

tdskip. I am working on a 1976 gl1000. The forks were leaking. I researched the rebuild first. Once I got the old seals out, everything was straightforward but getting those seals out was really tough. Here is a link to a Youtube video that I made showing how I was eventually able to get the seals out. Best of luck: https://www.youtube.com/watch?v=_MQmbLY ... Jy&index=2

[williwm]

I have had several gl1000s that had leaking seals. I built the tool and had some success, but had a few like yours that refused to come out. After struggling too much on the last one I decided to use heat and a lot of it. I removed all the rubber I could and heated the seal very hot, to the point of the heat burning the thin layer of rubber on the od of the seal. When that thin layer burned out the seal was easily pulled out with needle nose pliers. The metal of the seal was heated to a red heat to do this but that heat wasn’t transferred to the aluminum so no worries with damaging the fork.

I used a very small tip with a oxy-act rig but I’d think a small hand propane torch would work, just may take a little longer . This can produce soot so maybe do it outside. Worked well for me