Yamaha TRX850 Enthusiasts Forum

Was adjusting my chain today, L/H adjuster bolt works fine, R/H one is a bit stiff (maybe due to corrosion, I think). What would be the best thing to loosen it up? Did spray on INOX (kind of permanent WD40) and that freed it up enough for me to adjust the chain but its still a bit stiff. Was thinking of just spraying the bolt occasionally, and really fixing it next time I adjust the chain or change the tyre. Would a smear of Kopper - Kote do the trick? Eventually like to get a set of anodised bolts and nuts (like ProBolt). Am I on the right track with this?

Bob

PS what is the configuration on these bolts? I know they are a 12mm head, but what the pitch and length?

Bob,

Maybe too obvious to mention, but you di slackened the axle nut first before doing the chain tensioner bolts?

Also, are you sure it's the tensioner bolt thats stiff, and not what it's trying to push backwards? (i.e. wheel, axle etc)

Forgive me if this is all too basic!!

Dave.

Nah, Dave - checked all the boxes on all that. It seems to be corrosion on the threads inside the swingarm, the threads on the bolt are not damaged either.

Bob

Maybe a helicoil is the answer?

I've seen a few of the same bolts snapped off (not TRX, but other similar Yamaha adjusters...). A real bitch to get out if they do. I'd be generous with the lube, work it out slowly and replace it with a new bolt as soon as possible.

I'm pretty sure it's 1.25 pitch 8mm... But that's from my fading memory...

Thanks Max. It's alright as it is ,at the moment, but I know the more I use the adjuster the more it's gonna wear (can see the shiny tips on the threads of the bolt - probably caused by the corrosion). Not far off getting a new chain, so might do it all when the rear of the bike is off. Wouldn't mind some of those trick Gilles chain adjuster blocks,eh? Serious BLING!

Bob

I think what happens is it rusts inside the swingarm (exposed threads) making it a bugger to back out. Always a good idea to keep it lubed with some WD40 or slicone spray to keep the corrosion off.

This place is a fountain of useful information Thanks again Max

Bob

Exactly the same problem for me (right hand side)...except mine snapped when trying to work it in and out after replacing chain & sprockets. Drilled it and got an easy-out in but couldn't get the leverage on that to get the bolt end out. Going to take it to an engineer friend and see if he can do the trick. Then it'll be replaced by something a little less corrodable and will be lubed up properly
Trust me Wombat - sort it before it gets as bad as mine did

Yes, the adjuster screw is standard m8 x 1.25 pitch. I took the original bolts out and replaced them with stainless steel hex head screws and locknuts, available from any workshop supplier. Course I filed off any identification letters on the screw head to give a nice flat surface before I fitted them, with copper-slip grease, and have had no worries for over three years now.

Thanks guys, got next Wednesday off so I pop over to a little Nut & Bolt place a few kms from here. I got some great allen head bolts from there many moons ago for the old Guzzi and they were as cheap as.

Bob

Got some Hex head set screws today, all correct dimensions, but the hex head itself is 13mm not 12. Will this be a clearance issue inside the adjuster block, or will everything be sweet? Would I have to get 1mm shaved off it?

BTW look underneath your swingarm down near the adjusters. There's a small hole on either arm. I suspect its for drainage for the swingarm, but I think you're able to put an aerosol straw into it and lubricate your adjuster screws from the inside. Only saw it for the first time yesterday

Bob

Wombat wrote: BTW look underneath your swingarm down near the adjusters. There's a small hole on either arm. I suspect its for drainage for the swingarm, but I think you're able to put an aerosol straw into it and lubricate your adjuster screws from the inside. Only saw it for the first time yesterday

Bob

Yes, good tip! A few squirts of WD40 every now and then would be a good idea. Just make sure not to empty the can and let it drip out on the tire later.

I've found that most of 8mm bolts have 13mm heads. I hope you have enough room.

!3mm fits just fine !!! BTW the hole is most likely a vent hole needed to let out expanding gases during the welding process, but if it serves as a lubrication point .... WTF.

Thanks Red,

did you say you used nylocs as the locking nuts? If so, I'll go and get some tomorrow. All I got today was std M8 nuts. Have to look round for a metric Tap and die set in case I fook up the threads up or maybe even a helicoil set. I'll just take it nice and easy and use plenty of WD40.

Bob

Well the chain is definitely on it's way out, so a new set of sprockets and chain go on at Easter (have a few weeks off). While this is being done, I'll finally tackle this chain adjuster problem.

I was talking to a friend at work today who restores old Kawasaki Z1s, and he said that the way to do it is, as Max said use plenty of lubricant and take it slowly. He also said to do small turns (like a quarter) and then back it off, lube and then wait 5 mins and try again. His theory was that when turning the bolt when corroded you create a small amount of heat which causes the bolt to expand and jam therefore causing it to break.

If it does break, what is my best course of action?

Drill and Easy-Out?
Drill and re-tap?
or
Drill and Heli-Coil?

What would be nice would be a tasty JMC or MetaMachex shinny job.
But of course they don't do them for TRXs or do they?

Bob