greasing the universal joint

[Guest ratchethack]

How do you know if you've blown a seal? I thought you listened for the sticky fart sound and stopped. Also, what is the best way of greasing the front fitting? I can't even see it. I've read that loosening the rear shock bolt and letting the swingarm drop carefully will let you access it, has anyone done this? Thanks.

 

VR6Dave

Dave, I just greased the front U-joint again on Saturday. I'd previously been successful doing it as you described -- bevel drive out, rear shock bolt out, and carefully lowering the swingarm. This procedure had previously allowed access to the zerk (nipple) on the front U-joint cross. Inexplicably, this pass I couldn't get the angle fitting to pop onto the zerk! The driven trunnion was too close to the zerk, and wouldn't allow the fitting on there. So out comes the swingarm. While I was in there, I took off the "safety cage" around the U-joint, greased the joint, and wiped up the excess old grease.

 

NOTE: I'd had the "safety cage" off before when I had the swingarm out, with the idea of drilling an access hole for the zerk in it. I didn't do it the first time and couldn't remember why. (A remembry is a terrible thing to lose ) The reason that this wouldn't help became clear: The angle of the zerk on the cross points rearward enough that an access hole wouldn't help. Now if the front U-joint were assembled with the zerk facing FORWARD, drilling a hole for grease gun access through the cage would make sense, and allow easy servicing at any time without dismantling anything. But I wasn't up to rebuilding the U-joint on Saturday, and just put 'er back the way she was.

 

I don't think there's any danger of "blowing" a U-joint seal by greasing. A couple of pumps until the old grease starts coming out, clean up the excess, and you're done.

[Guzzi2Go]

Here is another silly one.

 

Would it be possible to just pull the "safety cage" over the shaft with everything still bolted on? Just to release the three screws holding it and then slide it backwards till the nipple is visible?

[Guest ratchethack]

I tried this once with the swingarm on the bike. Not only is access to the inboard screw a @#$%&!, but frustratingly enough, once the cage is loose, with the swingarm in the way (at the bottom of the cage, the clearance to the swingarm is only 8-10 mm), you can't do much of anything useful with it WRT access to the zerk!!

[dlaing]

There are forum threads discussing how to grind down the grease gun fitting fo a better fit.

My fitting barely wedges in there and is a pain to get off once fitted.

I don't disconnect the shock, perhaps I should.

Some use a 90º angle fitting, but I have not found one small enough.

Others have no problems what so ever <_>

For me, the cage is not a problem, but the swing arm is.

I think a 45º angle zerk is the solution. But I could be wrong

[Guest ratchethack]

There are forum threads discussing how to grind down the grease gun fitting fo a better fit.

I'd seen the photo(s) and remember them well. I was unwilling to compromise the integrity of the various fittings I have by grinding them down. The ones I have appear to be ~24 gauge sheet stampings. They're the threaded "adjustable clamping" type -- It wouldn't take much of any grinding at all to hole them. Though I've searched pretty extensively, I haven't found a smaller-diameter fitting anywhere.

 

I'd spent way way way too much time riding from auto parts store to store, to Sears, ad nauseum in search of the Holy Grail of long, small-diameter, angled grease nozzles, angle adaptors, etc. -- TO NO AVAIL. My last ditch effort to fab a needle-type "force it on and pray" nozzle out of tubing with a custom tip could not take the pressure of the grease pump and failed.

 

The U-joint trunnions are rough forgings, and I reckon the clearance between trunnion and zerk varies from joint to joint. With the trunnion angled down far enough, there's no problem -- unless it can't be angled down far enough. In my case, dropping the swingarm down isn't enough. I reckon I was "blessed" with a tight one. Somehow, I'd previously managed to jam mine on twice and yank it back off again (it took considerable effort both going on and coming off), but somehow couldn't get it jammed on a 3rd time.

 

The bottom line is that without some kinda intelligence breakthough here, I've about used up all the effort I'm willing to expend on grease gun attachments -- so I reckon I'm resigned to taking the swingarm off every 12K miles for that @$#%&! front U-joint zerk until either the U-joints or myself die of old age.

[VR6Dave]

I thought about unbolting that safety cage but figured that it too would be one or two bolts out easy and the final one a pain. Then find that you can't reach the zerk. When you say the bevel box out what do you mean? I've got the MG stand, will that give me enough clearance to drop the swingarm so I can access the frint zerk? BTW, from what side or angle do you get to the zerk? Thanks.

 

Dave

[Guest ratchethack]

When you say the bevel box out what do you mean? I've got the MG stand, will that give me enough clearance to drop the swingarm so I can access the frint zerk? BTW, from what side or angle do you get to the zerk? Thanks.

 

Dave

Dave, the bevel box (bevel drive) is that great walloping 20 lb casting full o' crownwheel and pinion gears (one each) swimming in gear lube, that splines the driveshaft up to the right-hand side of the rear wheel hub. It's also properly known as a hub transmission , and improperly (though commonly) referred to as a "differential" [sic]. But as any gear-head worthy of the name will be quick to point out, a differential is found only on cars and trucks, and splits power delivery between TWO driven wheels via planetary gears -- wot a bevel drive ain't got, and can't do.

 

Once you disconnect the torque arm at the top of the bevel box -- it's that long rod with rubber bushings that bolts up to the frame at the front -- and slide out the spindle (axle), carefully supporting that 20 lbs., the bevel box will pull straight back off the driveshaft. For re-assembly, note the alignment marks on either ends of the splined shaft. You'll want to make sure these splines have good lube on them, and don't neglect to apply grease SPARINGLY to the hub splines on the wheel before it goes back on.

 

The MG stand seems to be good for just about anything you need to do here, and SHOULD work perfectly well for this. I had my transmission out and back in with mine. With any luck, like many others, after getting the bevel drive out and disconnecting the aft shock eye by taking the bolt out, and gently lowering the swingarm, you should be able to gain enough access to come in with your grease gun from the back, over the top of the driveshaft, through the tunnel in the swingarm, and plug into the zerk fitting in the front U-J "cross" with a 45-degree end-fitting. Sounds easy, don't it? For some, evidently it is -- or pretty close. Per my comments above, I've been able to do this 2 out of 3 times myself. . .

 

Good luck. Any more Q's, put 'em here. Lots of Guys here have experience with this. Many more don't have any at all -- but they know they should , and their negligence of their Guzzi's stalks them in their darkest dreams, sure as death & taxes.

[VR6Dave]

Well I finally had the time to get to t front zerk today. What a pain in the ! Wheel off, bevel box out, shock unbolted and swingarm dropped. Then it took me an hour to get the cap off the zerk. Either there is a special tool or those Italians have very small hands. I made sure the marks lined up on the shaft before bolting everything back up. Tomorrow I'll go for a ride and see if I forgot something. Other than this everything else has been simple or easy to get to. I hope the new bikes are a little more forgiving when it comes to drive shaft maintenance. Thanks to everyone on here, if I can do just about anyone else can.

 

Dave

[grossohc]

I took my rear wheel off today as i thought i could here a whine from the rear (mg paranoia) . I need new tyres anyway and am putting on Z6,s. Anyway the bearings on the wheel seem fine also the needle roller one on the bevel box and the inner one also fine, cant feel any play so am now happy, but i did notice the thin washer between the swing arm and the bevel box had worn away some of the outer alloy on the box, are you meant to make sure that the washer sits on the inner race before tightening up the axle and will it make any difference , also tried to grease THAT nipple on the shaft but gave up.

Gary

[Guest ratchethack]

Gary, something seems a little out o' whack here.

 

Having just been thru the drill on this again (for the same reasons -- new Z6 just fully scrubbed-in! ) this is pretty fresh in my mind.

 

The washer you're concerned about between the bevel box and swingarm should NOT come into contact with the casting of the box at all, except at its outer diameter. Can't picture how wearing away of the casting could occur, since it fits into the bore in the casting that also contains the neoprene seal underneath it.

 

IIRC, I'd determined that this washer is NOT clamped in the "spindle stack" -- that is, it's not clamped up with the inner bearing race. It should align itself in the recess against the neoprene seal. Its function appears to be solely for the purpose of keeping the needle bearings in the outer bevel box clean, grease in & water out...

 

Makes me think the wrong washer might've got in there somehow.

 

In case this helps, I just put a caliper on the washer -- it's 40 mm OD.

[dlaing]

Makes me think the wrong washer might've got in there somehow.

That is what I was thinking.

The washer should be fairly snug around the axle, with no room to go off center.

Another possibility is that it is the wrong size needle bearing.

If my notes are correct, the bearing should say Torrington HK 2516 2RS.

And still another possibility is that the bearing seat was milled too deeply....assuming it sits in a milled seat. If it does not, then it must be held by the washer within, that is held in position by a bearing spacer loaded down by the case bolts that are visible when the wheel is removed. Could those bolts have come loose?

EDIT what was I thinking!!!????? The washer should be snug around the inner race, not the axle.

[grossohc]

Well, i have had another look and on closer inspection on the needle roller bearing there are a few flatspots so i have pulled the bearing only trouble is i have now definetly f%^&$d it . I have checked the washer and my one is meant to sit in a recess on the bevel drive . The I.D.of the washer is the same as the ouside of the inner ringwhich seems right as it would cover the bearing nicely. What I must have done is when putting the wheel on before the washer has fell off the inner ring rested on the axle and when i have tightened up the wheel it has ground down the bottom of the box , will order a new bearing and washer tomorrow or check local for a bearing hope its ok for friday. Also is there meant to be movement on the washer and spacer i can move them in and out ways a couple of mms, i dont think it matters but does anyone know.

Hope this makes sense, im off for a beer or 2

Gary

[Guest ratchethack]

Gary, wot seems to've happened here as you've described it makes sense to me up to the point where you've apparently got a few mm movement "in and out" of the washer and spacer. Can't imagine that part.

 

The spacer (which IIRC is the inner race for the needle bearing?) should clamp up in the stack under axial force from torque on the spindle nut. The washer should not have any lateral movement.

 

Best to always make sure that washer is home in its recess before doing up the spindle nut. I've always "stuck" mine in place with grease on the needle bearings, which seems to've held it in place just fine prior to torquing up the spindle.

[grossohc]

Thanks for the input Ratchet, the in and out bit i am on about is, if you have a diagram is no.5 and 32 in the rear trans diagram D3 thanks again

Gary

[Tom M]

I tried a few different grease gun tips and hoses and finally found a combination that reaches the front u-joint zerk without needing to remove the swingarm or disconnect the shock, although I did remove the rear wheel and bevel box. Someone else here recommended this fitting in another thread but since I can't find that thread now I'll add it here.

 

It's available at ACE hardware stores.

http://www.acehardware.com/product/index.j...hId=22788313823

 

I connected it to my grease gun with a 1/8" npt union from the plumbing section there.

 

I'm also replacing rear wheel bearings (left side is notchy) and servicing the cush drive while I'm at it. Luckily my cush drive retaining screws came out OK after a few shots from an impact driver, but I'll be replacing them with stainless screws to avoid the corrosion problems that others have had. FYI the screws are M6 x 20mm long button head. I ordered them along with some other stuff from McMaster-Carr, $7.74 for a box of 25. Part number 92095A240.

 

I'll be bleeding the clutch too since I find access to the bleeder best with the rear wheel out.

 

Hope this helps

 

edit: I got the wheel bearings from McMaster too. Part number 6661K105. They are SKF 6204-2RSH/C3 GJM (made in Argentina). $10.85 ea. The grease gun fitting is available from them too. 1090K47.