Author Topic: Triumph Trophy Fork Seal Tales  (Read 1374 times)

Offline montmil

  • Posts: 8371
Triumph Trophy Fork Seal Tales
« on: September 17, 2016, 10:30:18 PM »
My 21-year old Tri Trophy 900 began weeping fork oil from both seals. Having done seals on a couple Airheads, I thought it wouldn't be a big deal. Wrong.

Lacking the official Triumph Special Tool to release the damper rod from the fork lowers, I had to make one. Cost me $21.00 of which twenty was for the tab at a welding shop. After a bit of a struggle, the forks were disassembled, new seals installed and ready to add fresh Bel-Ray 15wt. Lemme check the shop manual for the correct volume... What!

Nope, no actual figure for oil volume. I'm to add oil while the fork legs are off the bike and keep in a vertical position. Add the juice and measure the level until the fluid is exactly 117mm below the top of the open stanchion. Then drop in the spring, spring seat, spacer and screw on the top cap.

From a 1000cc jug, It took near 600cc to fill one leg. Naturally, I had to go fetch another jug to finish the job. Thirty bucks and I've got 800cc left over. Too bad the Triumph doesn't have three fork stanchions.

Bottom line, I need to determine a fluid height measurement with the forks installed as I don't relish the idea of removing the legs just to check fork oil levels.

What would be a simple afternoon chore on an Airhead has now, what wilth making tools and such, run to five days of chipping away at it. Have a Sunday morning motorcycle gathering for coffee on the village Square and hope to complete the seal job later in the day.

Yes, this is a modern Hinkley Triumph but I'm reminded why the British motorcycle industry went down the crapper. As Edward Turner once said, "Our customers enjoy fettling their bikes on the weekends." God save the Queen.
« Last Edit: September 17, 2016, 10:32:40 PM by montmil »
Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

Offline skippyc

  • Posts: 339
  • Shouldn't have sold them old bikes.
Re: Triumph Trophy Fork Seal Tales
« Reply #1 on: September 18, 2016, 05:25:09 PM »
You can tell me the factory doesn't have a quicker way of filling them on the assembly line.

Offline montmil

  • Posts: 8371
Re: Triumph Trophy Fork Seal Tales
« Reply #2 on: September 18, 2016, 06:19:14 PM »
Quote
You can tell me the factory doesn't have a quicker way of filling them on the assembly line.

Perhaps the complete and filled fork legs are slotted into the line just after Benny Hill gets the steering stem assembly snugged. Dunno. Do know it seems a silly, labor intensive chore for an owner.


Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

Online Bob_Roller

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Re: Triumph Trophy Fork Seal Tales
« Reply #3 on: September 18, 2016, 06:43:45 PM »
I replaced the left fork seal on the oihead today, been seeping for 6 months now, 40 minutes from start to finish .

One of the few things BMW improved upon with the newer bikes !!
'81 R65
'82 R65 LS ?
'84 R65 LS
'87 Moto Guzzi V65 Lario
'02 R1150R
Riding all year long since 1993 .
I'll give up my R65, when they pry my cold dead hands from the handlebars !!!!!

Offline montmil

  • Posts: 8371
Re: Triumph Trophy Fork Seal Tales
« Reply #4 on: September 19, 2016, 08:05:17 AM »
Quote
I replaced the left fork seal on the oihead today, been seeping for 6 months now, 40 minutes from start to finish...

That's OK, Bob. Rub it in. ;D

Drafted a neighborhood Oilhead owner to assist me in compressing those bloody strong fork springs far enough to get the fork's top caps back on. This chore has gone on for far too long. I'll throw the front wheel on today and call it done.

Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet

Offline Tony Smith

  • Posts: 2274
  • Graduate, Wallace and Gromit School of Engineering
Re: Triumph Trophy Fork Seal Tales
« Reply #5 on: September 21, 2016, 06:20:38 PM »
Quote
Drafted a neighborhood Oilhead owner to assist me in compressing those bloody strong fork springs far enough to get the fork's top caps back on.

I use my bearing separator kit, clamp the "base" lightly around the fork leg just below the top triple clamp and then use extensions as required until the extractor can be centred over the "plug" and used to gently ease it into the fork leg. I have been meaning to make a much simpler  device along the lines of a bottle-capper that will bolt to the triple clamps but I have not yet had to rebuild the forks often enough for the process to annoy me enough to get around to it - when I do I'll take lots of photos etc because it will cost pennies to make and in the long term useful enough to tuck in a drawer somewhere.
 
Actually, it might get made sooner than I thought - I discovered on the weekend that the K100 forks I bought use the came kind of top plug as the R65 and given that I expect to have to do some finagling to get the spring rate right when I fit the K100 front end to the R65 I may have to take those caps off and put them back on a few times before the end of that.

On the subject of the K100 front end, after carefully measuring up I believe it is going to be a very simple "bolt-on" affair, I may lose a trivial amount of turn lock, but on the plus side I reckon the steering lock will line up and the way K100s run their brake lines is just brilliant, BMW should have done that from the get-go. I am going to retain the stock instrument and headlight "plate" and will use simple brackets to allow me to bolt it to the triple clamps. Currently on the hunt for an LS rear wheel so that the spoke patterns will more or less mount.

My R65 is about to become a "frankenbike" - reverting to the older heavy flywheeel, R75 final drive (thanks again Wilcom), K100 front end and soon a Siebenrock 860cc kit. I would prefer if nobody points out that selling my R65 and buying a post 1985 R80 would get me most of what I want, I'm having fun which is the point of the process.
1978 R100RS| 1981 R100RS (JPS) | 1984 R65 | 1992 KLE500 | 2002 R1150GSA |

Offline montmil

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Re: Triumph Trophy Fork Seal Tales
« Reply #6 on: September 22, 2016, 02:09:47 PM »
Quote
Quote
Drafted a neighborhood Oilhead owner to assist me in compressing those bloody strong fork springs far enough to get the fork's top caps back on.

I use my bearing separator kit...

No gots me a bearing separator kit but did have the wrench for changing blades on my chop saw. 22mm socket, chop saw wrench (kind of a box spanner thing) 3-inch extension (provides room for three hands) and ratchet. We both press down and...Done. The second leg I did myownself as the proper tooling was at hand.

Next up was to fab brackets to mount a pair of LED driving lights. After the hassle of the fork seals, this job was cake.

Monte Miller
Denton, TEXAS
1978 BMW R100S
1981 BMW R65
1983 BMW R65
1995 Triumph Trophy
1986 VW Cabriolet