2.5 3R (GT) 30k Mile Forks Service (including seals)

[Journeyman]

The front forks are due for maintenance at 30k miles. I put mine off until 35K, but just finished and thought I’d share my notes for those who might be interested in saving some money.

The manual does a fair job, but as with many other projects in this manual it jumps around wildly from section to section rather than presenting the information in a linear manner. I’ll try to help with that and include some tips I found along the way...

Tools- nothing from Triumph (unless you want to). You’ll need a generic fork spring compression tool and a 47mm seal driver. There are hacks to avoid buying those, but they’re pretty inexpensive and make the job easier.

Parts - two seal kits from Triumph. ( 2X $80.51/each). This is OPTIONAL. It's easy to do while you're in there. If I didn't and it leaked later I'd have to repeat all the steps and spend another $50 on fork oil.

Fork Seals Kit​

Part Number: T2049310

Fork Fluid- the closest I could find that meets specs is Honda Pro HP Fork Oil SS-47 ($25) here at Amazon.

Download the users manual from our resources section. I uploaded one that can be searched by keyword, which saves a boatload of time. Here are the sections you’ll need- in order:

Forks Removal 898 - 900
Fork Renewal Draining 169 -172
Fork Disassembly 903 - 907
Fork Assembly 908 - 910
Fork Oil Renew - Refilling 173 - 177
Fork Installation 901-903

Fork Removal (898 - 900)
Pretty straightforward. Loosen, don’t remove, Top Cap. Clean the upper tubes really well and continue to do so as you slide them down. Dirt and grit around the triple clamps could scratch the tubes. I used WD-40 to help slip them out. If they resist coming out a large flathead screwdriver prying the lower clamp further open a will help. Also when reinstalling.

Fork Renewal Draining (169 -172)
After compressing springs and inserting spring holder mark the damper locknut with a sharpie- notice it’s position relative to the spring holder handle. Remove Top Cap and return locknut to that position (if it moved). Use calipers to measure from top of locknut to top of damper rod and note. Mine was 9.75mm
Between step 10 and 11 (this is left out) compress the spring again and remove the slotted bowl shaped washer- now you can remove the spring spacer and spring.

Drain all oil. Pumping damper rod will help

Mine wasn't terrible- it's going into my dirty motor oil pan.

Fork Disassembly 903 - 907
Repeating instructions here, Do Not Change The Fork Adjustment Settings (Flathead setting on Top Cap)
Have someone hold the fork while you work on it or strap it to something to hold it upright- no need for the fancy clamp Triumph shows
No need to remove the damper rod. Ignore step 1 & 2.
Note positions of seals and bushes
Do not remove the damper fixing from the bottom of the fork (#1 and #2 that follow immediately after step 6- I know )

Oil seal- spring side goes this direction ->

 

[Journeyman]

Fork Assembly 908 - 910
Skip 1 and 2- not installing damper
After step 3 use a piece of milk carton (I used Yogurt container) to wrap around the bottom of the inner tube where it is sharp around where the upper bush goes (you reuse that by the way) in order to make a plastic funnel. Coat this plastic on the outside (smooth side up) with rubber grease or fork oil. Slide seals, in order onto the tube using this “funnel” to help you get the two rubber seals safely past those sharp edges.

47 mm seal driver tool

The correct orientation of the oil seal is with the text facing the circlip (embedded spring facing the washer).

Fork Oil Renew - Refilling 173 - 177

The air gap is 94mm. Overfill slightly and suction out until you reach the proper level. You could do this with a caliper or straight edge. I made a took similar to one Motion Pro makes using a large fender washer, some copper tubing and a syringe. With the tube extending 94mm below the washer you just suck up the fluid until it starts drawing air.

Tip- drop the spring in carefully. Cut a long section of nylon string or fishing line and make a loop on one end. Pass this through the spring spacer (loop at bottom). Loop the nut and slowly (or it will squirt) pull the shaft up through the spacer as you drop it into the fork. Otherwise, the shaft will creep back down into the spacer. This way you don't have to push the spring compression tool down very far- the string helps you keep the shaft and nut fully extended.

Before putting the Top Cap back on readjust the locknut so that it is the correct height from the end of the rod (you got that measurement earlier). Once there use a sharpie again to make a mark on the nut that you can reference it in case it gets turned. When tightening the top cap make sure that nut stays in the correct position so that distance is maintained.
Wait to torque the cap until the next step

Fork Installation 901 - 903
Pretty straightforward. Use a screwdriver to pry the lower clamp further open while sliding in forks if they resist. Use caliper and a straightedge to get height of forks above top triple clamp correct according to the manual.

 

[Jagster]

Great post, as always.

 

[ciderbaby]

Great write up but can I just ask why you would change the seals unless they were leaking

 

[Journeyman]

Great write up but can I just ask why you would change the seals unless they were leaking

Fair question. I'd rather be preemptive. I'd rather just replace the seals while I'm there than take the chance that they won't leak sometime before the next 30k miles. If so, I'll have to pull the forks again (time) and replace the fluid again ($50). Kinda like replacing the water pump even though it's not leaking while you're getting your timing belt replaced on the car.

 

[Dr.D]

Wow again, very nice work and post.

 

[papanorm]

Great job as always and quite impressive. Thanks for taking the time for all of the details.

 

[ciderbaby]

Fair question. I'd rather be preemptive. I'd rather just replace the seals while I'm there than take the chance that they won't leak sometime before the next 30k miles. If so, I'll have to pull the forks again (time) and replace the fluid again ($50). Kinda like replacing the water pump even though it's not leaking while you're getting your timing belt replaced on the car.

Makes sense