Driveline wear

[jpweeks173]

Stripped the splines off my driveshaft last summer. Replaced driveshaft and mid shaft. Reinstalled everything and lined up pump with cold fusion alignment tool. Pulled my pump to do some repairs the other day and found my splines completely worn out already. They seem to be worn evenly all the way down the spline, but worn for sure. Wanna figure this out before I start going through a shaft every season. Maybe midshaft was not lined up properly as I only shimmed the pump and not midshaft to bulkhead? Anybody have any input?

 

[Proformance1]

first off it looks like your shaft engagement is a bit short. What hull, what shaft, what pump, what midshaft, also looks as if oring wear is excessive for a new shaft. Did you check the shaft for shaft run out? first guess would be firewall shimming, but could be bent shaft??

 

[jpweeks173]

Rockered front and rear Blaster hull. Stock pump. Installed brand new stock drive shaft and mid shaft. Wouldn't think to check runout on a new shaft. Didn't even think about how far it was engaged. Maybe wrong length shaft as well?

 

[todc207]

My last B-1 was 100% stock when I bought it and the shaft spun and looked exactly like this pic. Is there a way to shim for more engagement? I know it was factory set up and had the same amount as this one

 

[Proformance1]

Was it a new midshaft or remanufactured? Were both midshaft and driveshaft OEM Yamaha parts or aftermarket?

If you wore the driveshaft the midshaft is shot also, they wear as a set. When you redo it with the new shaft, and midshaft, shim the pump, then put midshaft on about 1/4" away from firewall. Then use a dial indicator to check distance to firewall at all three hole locations, spin midshaft housing and recheck. Make sure they are all close to even.

 

[jpweeks173]

Checked the shaft and it is the correct length/part number. They were replace as a set. Sbt parts....

Don't know why it wouldn't be engaged enough if the shaft is the right length @todc207

 

[jd0g]

This looks exactly like my shafts , i now keep a spare set on the shelf, Someone needs to figure out a way of creating a longer mid shaft/driveshaft engagement. CHRIS- Jetmaniac you got yr ears on.

 

[smoofers]

I've seen quite a few blasters have this problem and I don't think anybody has really figured it out yet.... Some never shear splines, some just like to munch them immediately...

 

[High Speed Industries]

Checked the shaft and it is the correct length/part number. They were replace as a set. Sbt parts....

Don't know why it wouldn't be engaged enough if the shaft is the right length @todc207

I've noticed that oem shafts are the best. They seem to last longer than aftermarket. You might want to track down some oem parts when you do the repair.

 

[Quinc]

Did you shim your engine without the rubber coupler in place?

 

[jpweeks173]

Maybe when I go back I'll get @Sasquachcrap to cut me an oem one a little longer than stock. Seems like it could use another 3/4". Engine was shimmed with coupler removed.

 

[Sasquachcrap]

I can cut it longer or you can shim your midshaft back.

 

[jpweeks173]

Please elaborate @Sasquachcrap. Don't see how you can get 3/4" from shimming. How could you shim it back if it's pressed in from the front?

 

[Sasquachcrap]

I don't think you need 3/4 ". The shaft and mid-shaft don't need to bottom out. I would have to measure but you can press the midshaft further back into the housing and put a shim under the coupler before puting it on to make up the difference. But you may be right you may need more then you can shim out. And I would be glad to cut you one the right length.