Rear suspension bearings

[1675]

Just spent an enjoyable bank holiday monday afternoon in the garage servicing the rear suspension bearings. It seemed better than being in the garden, digging. All were in good order apart from the one above the exhaust pipe which was bone dry. I put this down to it beng dried out from the heat off the exhaust and the fact my dealer obviously hasn't touched it as the bolt couldn't be removed because of the centre stand recall modification. I replaced this bearing and sleeve, together with all of the other oil seals in the assembly, repacking everything with grease. The only other bearing sleeve showing signs of corrosion was the one at the rear of the forked linkage, which had a couple of areas of corrosion where it seems the grease had been washed out in the area between the alloy yoke and the shock. I think this is due to me using jizer in this area to clean dirt off, and it is also very good at disolving grease, so my fault. I will revert back to something less aggresive and keep clear of this area in future cleans. I also did some drawings for some tools to make the removal and replacement of the rest of the bearings easier which I will do at the end of this season. I plan to replace the 2 x 90mm bearing sleeves then as well, but seeing as they are about £50 a pair will make my own. I will post some pictures when I have made the tools and probably do a step by step guide.

[earthman]

Nice one,....looking forward to the pictures/guide.

[1675]

I have just finished the job and have detailed how it was done. Unfortunately I am better at making parts on my macinery than posting photos, so it may have the write up in 2 parts. Bear with me!!
I had dismantled the suspension yoke and its bearings some time ago, just to check how they were. I took this opportunity to replace all of the bolts so they can be removed/replaced from the right side of the machine as it makes it easier to get the front one out without having to take off the strengthened centre stand stop bracket.
I started by cleaning the bike then putting it on to the centre stand and removing the silencer and rear wheel. I laid the wheel directly under the rear drive and placed some wood onto the wheel to hold up the rear drive and swing arm when the links were removed. All 3 locknuts were removed from their bolts then the lower rear bolt removed. The top bolt, which goes through the swing arm was removed, allowing the links to come away. The lower rear bearing sleeve (2mm dia x 90mm long) can now be pushed out, allowing the yoke to be freed from the shock. The front bolt can also be removed, bit it is a bit tight against the right hand stand return spring. If the bolt is pulled out till it is touching the sring, the alloy sleeve on the right hand frame lug can be "teased out" to allow more clearance to allow the bolt to come away from the frame. (Teased in my case involved a pair of pliers to twist it out. Not reckoning on this I remade this in a piece of stainless due to scoring on the original). Once the yoke is removed, you can then examine the 3 needle roller bearings, together with the bearing in the lower shock and the 2 in the swing arm. Due to an incredible amount of foresight by the Triumph assembly team, this is very easy as there is no grease there to impede your inspection. Because my bike has suffered from some "enthusiastic owner fiddling", my bearings were still packed with grease, so not much wear. I found the front bearing dry and its pin worn out. The others were in good order, but the rear lower pin of the yoke was marked due to water ingress where the bike had been cleaned with Jizer, thereby washing any grease away. I believe the front bearing suffers the most, because it is directly above the exhaust and gets hot, melting what little grease is in there away.
I was a toolmaker many years ago and still have a well equipped workshop at home so made some drifts and a plastic ring to prevent any damage to the alloy yoke when I drifted the bearings out and the new ones back in. I also made a couple of drifts to remove and replace the needle bearings. All bearings and seals were obtained from a local bearing stockist at £5 for the bearing and £1 each for the seals, a little different from dealer prices. A couple of hours thinking, same for the tooling and 10 minutes to remove and replace the bearing. Bit cheaper than the £400 I was qouted. As the famous saying goes, "re assembly is a reversal of the dismantling process". The new oil seals wem=nt in easily enough with just finger pressure. Plenty of high quality bearing grease packed into the bearings and all nuts torqued up to spec. I didn't have to make any new bearing sleeves but will make some in the next couple of weeks (but did buy the 20mm x 30mm long front sleeve to save time). Any questions, please ask. Anyone in the UK who wishes to do their own overhaul can borrow the stuff I have made and if anyone else has access to a machinist who is willing to make them, I will send drawings.
First pic shows :-
No 1 is for removing 1 of the bearings from the swing arm
No 2 is for removing the other bearing from the swing arm as well as the lower shock, front and rear yoke bearings
No 3 is for replacing all bearings and is mabe from alluminium
No 4 is a centralising bush for No 3 to aid replacement
No 5 is a platic ring to be used to remove and replace the bearings without causing damage (plastic being softr than ally)
Second pic is grinding the steel removal drift to 19.93mm and 25.93mm respectively on a Jones and Shipman cylindrical grinder.
The eagle eyed amongst you may see other things in these shots, one being a batch of timing gears for a 1960s Italian bike which just need their mounting and lightening holes to be drilled

[1675]

Couple of more pictures
No 1 is the yoke with its new front bearing, alloy instalation drift and cenralising bush (not actually used in this location)
No 2 shows the needle roller bearing being fitted to the yoke. Note the plastic support ring in the vice.
No 3 shows a couple of cylinder barrels from a 1960s Italian bike. I got 20 alluminium castings made and machined them to replicate the originals. Some will be Nikasil plated, others will be fitted with spun cast iron liners. The barrel on the left is an original which had sustained damage when a con rod broke. I bored it to accept a cast liner. The machine the barrels are on is a Moore Jig Borer (google it) a very accurate American machine tool, though us Brits did have machines of similar accuracy. The wife blew a gasket when she got in from work as I had put the barrel in the oven at 220 deg celsius for half an hour to expand it to let the new liner in and she could still smell "someting strange" in the kitchen some 8 hours later. I denied all knowledge of course. She's just coming round 4 days later and our shephards pie for tonights tea had a metallic aftertaste. No sense of humour. Hope you fiind this interesting.

[Coconut]

Some excellent engineering work going on there 

I have a small ( Clarke ) Lathe / Milling Machine, but rarely get to play with it these days.

Cheers, and thanks for the great write up 

[silverstripes]

Great write up and good detail. I did do mine but could not get the front bearing out and the yoke off.

What did I do wrong as I removed and reversed the bolt but the yoke would not detach. 

[1675]

There is an alluminium sleeve which abuts to the front bearing sleeve from the right side of the frame. Difficult to see if the area is dirty. Also difficult to remove as there is only 3mm of it showing and it prevents the yoke coming out . I had to grip it with pliers to wriggle it out, then made a new one out of stainless.

[ZShyster]

1675 and Coconut,

Please weigh in.

1675 you are clearly 100 times more competent at mechanics and machining than I am.  That said, my bike is going in for the 20,000 mile maintenance in a couple weeks, should I have them check and lubricate these "rear suspension bearings"?  If so can you post the diagram from the manual with them highlighted so I can give it to the shop?

I know that an ounce of prevention is normally worth many pounds of repair dollars, so if this is a problem I want to address it before it becomes the kind of project you have described.

Thanks much.

ZShyster