83 xj900r seca transmission problems?

I just bought a xj900r 83 and when in gear it seems like there is something holding the rear wheel back and I hear bad noises from the rear of the bike. Where so I begin on figureing this out. I think that the defferintal is the problem but how do I check this. Thanks Bryan

 

Shut her down.
Select Neutral.
Try to rotate the Real Wheel forward whilst on the Center Stand.
If the Rear Wheel fails to rotate fully ... the Final Drive is at fault.

 

I have tried that and it starts to hang up when you turn the wheel. How big a deal is this to fix? Thanks for the quick reply Rick

 

before going into the differential,I,d make sure that the rear brake caliper is not binding. Do that by removing the caliper from it's mounts, swinging it aside and try rotating the wheel in neutral again. It,s worth a try.

Cheers, Murray

 

Its not a brake problem I can hear the grinding back near the pumpkin. anyone got directions on how to do it.

 

You were absolutely right it has a broken ujoint right by the output shaft. How big a deal is it to change it? where can I get the part? I think this is going to be a bad bike when it is on the road again.

 

should be easy, i have an extra one if you need.

 

There's no rebuilding the U-Joint. New part.
There's a Splined female end the Drive Shaft joins to.
Once you clear the way of Brakes, stays, Rods and Rear Wheel ... the whole Rear End is supported by the Shocks and Swing Pins.

(It's worth buying a Socket that will fit the Hex Flats on the Swing Pins, ... even if you have to Machine or Grind the Socket's O.D. to enable the Socket to get on the Swing Pin. Getting loose won't be a problem.
Getting it Tight with the right amount of End Play.)

 

Be aware that the XJ900 cross-joint (U-joint) is different than the ones on the 650 an 750 models.....the 700 and 900 models use a much larger cross-joint (and driveshaft).

We do have good used ones and rebuilt ones available!

 

Is there anything else that I should replace while I have it apart?

Thanks to everyone that has responded, can't do it with out ya!

Bryan

 

I'd replace the swingarm bearings while you're this far in - they're pretty cheap to buy so you may as well.

 

How come I cant seem to find these parts online except in the uk? Is there something I I need to know about these 900s? Thanks anyone know what size the nut and bolt that hold the swingarm on are?

 

They're unique! And greatly sought after!!

And they were only imported for one year (1983) into North America, whereas the rest of the world got them (off and on) up until about 1994...........

 

Manual says the pivot arm shaft thread is 22mm x 1.5mm.

 

The Factory Book says: M22X1.5

The Left side is a Pivot Element.
The Left side is a Solid Pivot "Pin"
A short, shaft ... on the end of a threaded Hex-headed, SOLID Bolt -- Shorty Axle.

The Right side is a Modified Pivot Element.
The short shaft is threaded.
The Right Side is 2-Piece ... Not Solid.
The Pivot Element is "Adjustable". It's O.D. Threaded with a Hex Nut Locking feature.

The Threaded Element is Screwed into the Bearing on the Right Side of the Swing Arm and turned in to the Bearing until the Side-to-Side End Play is brought into Specs and then the Hex Nut Tightened and torqued to lock the Pivot in place within limits for travel without binding.

[900 Right Side Swing Element 2-Piece Hex-nut on O.D. of Pivot Element with Internal Allen Adjustment at Center. 26mm Hex]

 

Well I just got done tearing down the rearend and I am stuck. I cant seem to get either of the hex nuts free 27mm I broke a allen trying to losen it. What am I doing wrong? I don't have a manual yet but i have ordered one.

 

Are you using a socket on the nut or are you trying to remove them with the allen key?

 

Tried to remove it first with a socket and broke a 1/2" rachet then I thought that I might have to lossen that allen head first just afraid that I am gettting ready to break something

 

already broke a 6mm allen wrench

 

The nut is a locknut - and has to come off first. You might need an airgun to get it off by the sounds of it. Or try some heat.

 

I havent removed the final drive unit have to be taken off or can I leave it attached to the swingarm? I am going to get a BIG breaker bar tomorrow to get those nuts off. These aren't reverse threads are they?

 

From memory, they are RH thread (remove counter clockwise).

 

Those Hex Nuts are on there with 75 Foot-pounds of Torque.

It's not reverse thread.
Big torque for a Highly Critical Suspension Component.

I use a 6-Point Socket
A long 1/2 Inch Breaker bar
I put a Leather Work Glove on the end of the Breaker Bar
Hit the Glove a good whack with a Hammer or a Baseball Bat.

The Allen is there to allow you to remove the Pivot Pin AFTER the Hex Nut is off ...
>and, ...
To precisely fit the Pivot Pin back-in and "Feel" the Pivot Pin engage the SwingArm Bearing and position the Pivot with "Just Enough" Preload to engage the Bearing >> Eliminate Side to side Free Play, and then HOLD the Pivot Pin from moving while the Locking Hex Nut is Replaced, Tightened-up and Torque applied.

If the Pivot Shaft "Rotates" while the Torque is applied >> The movement will over-tighten the Pin and cause the Bearings to Bind.

Replace the Right Side Pivot Pin in Stages
Clean the Threads of the Bike and the Pin
Add High-Strength Thread-Locker (RED) to the Pivot and set the Pivot to the proper tightness to eliminate free-play without binding the bearings.
"Let it cure according to the instructions on the packaging"
Fast Forward to Hex-nut, ...
Thread-Lock again.
Tighten the Hex-nut down as tight as you can.

How do I expect you to Torque the Hex Nut with a Big Socket and a Torque Wrench and Hold the Pivot Bolt from moving with a Allen Wrench?

I don't!
Instead of playing "Phyque-phyque" with it ...
It's Thread-locked.
Put 72 Footpounds on the Hex-nut!

http://www.permatex.com/documents/Threa ... lector.pdf

 

I see oil in the drive-shaft boot along with the fragments of the u-joint it came apart in 2 pieces. Is it normal to have some oil in there or does that indicate another problem that I need to address?

 

If the Boot's Drain Hole is "Virgin" and never perforated; you can find Oil, Water and Goo.

Some PO's lube the U-Joint by lifting the Boot and using a Oil Time Squirt Oil Can.
(I lube mine like this)

If the Drain is Closed; nothing drains out.

Then, again ...
Look at the Output Shaft Seal behind the U-Joint.
If there is evidence that -- that is where the Oil is coming from; you may need to do that Seal.

 

It doesn't seem to be leaking from the rear output shaft so I guess I am ok there. Can I remove the drive shaft tube from the dif? There is a bunch of metal in it.