Broken Pinion Shaft....What now?

[latheboy]

Yup, I broke the pinion shaft, right where the nut holds it on. My main question is, what do I do now? I can get a whole new assembly for $775, (dealer buddy price, but ouch!) or should i pick up a used assembly from ebay with unknown milage, or should I roll up my sleeves and rebuild my own? I have the basic knowledge, but have never been in a final drive. Setting lash should not be a problem, as I have access to my whole machine shop.....

I would like to find a venture rearend for the gear ratio, but they could be hard to find. Can i rebuild mine with venture gearing?

 

[maleko89]

Same thing happened to me. I bought a used one from Ragingmain. Fargo, do you still have that spare Venture? Anyway, had one of those temporarily and top gear dropped 500 rpms. Interstate riding was very nice!

 

[one2dmax]

I've got 2 max diffs and 1 venture diff left. They are getting blasted and painted as we speak.

Sean

 

[latheboy]

I would like a price on the venture diff. I can send you mine as a core if you have a use for it. Please send me an email if you would like to quote a price that way. [email protected] I will need to get this thing going ASAP. What color are they getting painted? I would love a black one.....


Thanks!

Keith

 

[latheboy]

Also, does anyone know what causes this? Of course its has to be 120hp abusing every bit of the driveline during a wheelie, but....

Its hard for me to visualize an end load on the end of the pinion shaft unless there is a bad bearing, taking the driveshaft out of alignment? How else could a stub shaft be broken at the end? Sean, what else do you find bad when going thru a diff with a broken pinion shaft? anything?

 

[one2dmax]

Pretty much everything else survives just fine but it's not worth rebuilding so no real point in shipping it to me (I could use some of the internal stuff and outer case for the occassion where I chrome them).

$250 plus shipping. They are getting painted gloss black. I can get it satin black (or neon yellow, or whatever). Just need to let me know.

email me directly at [email protected]

These suckers are heavy so keep in mind shipping isn't cheap.

Sean

 

[fruit_nut]

read my thread headed "internal noise", (page 2) for a possible solution.

 

[Dan David]

I had the same problem with a 91 Vmax. The final gear drive assembly was making a horrible sound when decelerating. Somehow the nut holding the pinion gear was not punched in to lock it so in time it loosened stressed the gear and it finally sheared. I checked all over (I'm in the Philippines) but no one sells the final gear only, one has to buy the final gear drive assembly (used ,for about 350US$).

I took the final gear drive to my favorite machinist (the guy does excellent work) and he took the gear out (after fabricating a special tool) put the gear in the lathe, tapped in a thread into the final pinion gear and implanted a new bolt of the same size and machined to the original specs.

After reassembly, he made sure the nut was properly punched in.

I installed the implanted final drive to the VMax, added gear oil, presto problem solved. The machinist charged me 10US$. (Labor in fairly cheap here.) The machinist later told me he had done this procedure before with another VMax.

 

[Maxxer]

Mine broke too on my 93. I bought a used one from Sean Morley, excellent service. Item was shipped as he said, it arrived in good condition. I replaced the unit this winter, and filled it with fresh gear oil. I had my first spin this weekend with the new pumpkin, all is smooth and quiet now. Thanks a million Sean, you saved me a lot of money!

 

[gleno]

I had the same problem with a 91 Vmax. The final gear drive assembly was making a horrible sound when decelerating. Somehow the nut holding the pinion gear was not punched in to lock it so in time it loosened stressed the gear and it finally sheared. I checked all over (I'm in the Philippines) but no one sells the final gear only, one has to buy the final gear drive assembly (used ,for about 350US$).

I took the final gear drive to my favorite machinist (the guy does excellent work) and he took the gear out (after fabricating a special tool) put the gear in the lathe, tapped in a thread into the final pinion gear and implanted a new bolt of the same size and machined to the original specs.

After reassembly, he made sure the nut was properly punched in.

I installed the implanted final drive to the VMax, added gear oil, presto problem solved. The machinist charged me 10US$. (Labor in fairly cheap here.) The machinist later told me he had done this procedure before with another VMax.

This is an old post I'm replying to but it describes exactly what happened to me a couple of weeks ago.

Here are pics of the damage.

The loose retaining nut meant the bearing shell on the pinion gear was floating. This in turn chipped the pinion gear tooth . The metal shavings from the pinion gear chopped out the diff oil seal. The oil leaked all over the rear rim and the internal bearing got so hot the spacing shim (shown broken during disassembly) welded intself to the bearing shell.

This all happened at highway speeds following a rear wheel lock-up:surprise:

 

[one2dmax]

I'll take the old housing if you are going to trash it! I do have some good diffs if you need one.

Sean

 

[spursmech]

I would like a price on the venture diff. I can send you mine as a core if you have a use for it. Please send me an email if you would like to quote a price that way. [email protected] I will need to get this thing going ASAP. What color are they getting painted? I would love a black one.....


Thanks!

Keith

unk:Here's a nice one on Ebay. Just drill and tap for shock stud and plug speedometer opening. Good Luck, Spurs http://www.ebay.com/itm/99-11-Yam-X...Parts_Accessories&vxp=mtr&hash=item5890a6506d

 

[CaptainKyle]

unk:Here's a nice one on Ebay. Just drill and tap for shock stud and plug speedometer opening. Good Luck, Spurs http://www.ebay.com/itm/99-11-Yam-X...Parts_Accessories&vxp=mtr&hash=item5890a6506d

Thats a good deal ! I thought I sold them cheap but thats $ 15 bucks cheaper than I sell them.

 

[sdt354]

Since the post is revived (which is kool), Can we discuss the causes?.My guess is holeshots, wheelies, rolling burn outs. Worse with DD? I like a roll on in a race on the street if possible. It's much kinder to my drivetrain. Or, is there something about these parts when aged? A chain drive version would have been a great factory option. All the parts that would be available by now would make it affordable to convert.
Steve

This is an old post I'm replying to but it describes exactly what happened to me a couple of weeks ago.

Here are pics of the damage.

The loose retaining nut meant the bearing shell on the pinion gear was floating. This in turn chipped the pinion gear tooth . The metal shavings from the pinion gear chopped out the diff oil seal. The oil leaked all over the rear rim and the internal bearing got so hot the spacing shim (shown broken during disassembly) welded intself to the bearing shell.

This all happened at highway speeds following a rear wheel lock-up:surprise:

 

[gleno]

Since the post is revived (which is kool), Can we discuss the causes?.My guess is holeshots, wheelies, rolling burn outs. Worse with DD? I like a roll on in a race on the street if possible. It's much kinder to my drivetrain. Or, is there something about these parts when aged? A chain drive version would have been a great factory option. All the parts that would be available by now would make it affordable to convert.
Steve

Nearest I can determine is that I downshifted so fast that I locked up the rear wheel ( I nearly missed my off ramp from the freeway). Whether the bearing shell lock nut was floating before that I'm not sure.

The earliest indication that the lock nut was loose and the bearing was floating was a metalic grinding noise that is 'felt' on deceleration. You will hear it as it becomes worse.

I thought I had a bad bearing shell in the gearbox. You can't feel it on acceleration or coasting, only deceleration.

When you do a rear tyre change, check the tension on the bearing shell retaining nut shown in the picture.

 

[doud1987]

I have the grinding sound you are describing when decelerating so I think I should check that nut, but I am not sure about where to find it and how to access it: Should I remove the rear wheel and look on the shaft side?
Ed

 

[CaptainKyle]

I have the grinding sound you are describing when decelerating so I think I should check that nut, but I am not sure about where to find it and how to access it: Should I remove the rear wheel and look on the shaft side?
Ed

Remove the rear wheel & remove the 4 nuts that hold the differential in place & take the diff off pull the driveshaft out & look in the diff where the shaft seats & there is a nut in there & that would be the one.

 

[gleno]

I have the grinding sound you are describing when decelerating so I think I should check that nut, but I am not sure about where to find it and how to access it: Should I remove the rear wheel and look on the shaft side?
Ed

1) Take it to the Yamaha dealer and get a firm quote for checking and adjusting the bearing nut.

2)Yamaha dealers need a custom tool to do the adjustment (see maintenance manual)

If that fixes it, Great. BUT if it not...:ummm:

 

[latheboy]

If you have the ability, I would take the rear diff off and look and see if the pinion shaft is broken. If the pinion shaft is broken, the nut and the end of the shaft will fall off in your hand when you take the driveshaft out. It thats the case, talk to Morley.

 

[doud1987]

Ok I will try to check it by myself first, if it is loose I will go to Yamaha for adjustment, if it is broken I will look for a new diff... Thanks guys!