WR 4th & 5th on a 10 YZ450f?

Use the bearing listed for the YZ and it will all just drop together. 

Clevochild, I have done the full swap on 2 different 2012 YZ450's, my bike then my friends bike about a year ago. All parts were ordered for a 2012 WR. Neither bike has had any issues since the swaps.

You will need all the gears, main axle, drive axle, the drive axle washer you already mentioned (it has teeth on the ID that match the coarse splines on the WR drive axle), and it would be a good idea to get a new lock tab washer for the balancer (clutch side only) as it does not like to be reused. All of the washers that fit between the gears are dimensionally the same so no need to get them. The snap rings that keep the gears in place should theoretically be replaced, but I found that they are very resilient to stretching out even after removing and reinstalling multiple times.

Yamaha sells a complete top end gasket kit for about the same price as just buying a base and head gasket. Replacing the head gasket is not optional.

I was able to re-use all of case cover gaskets with no problems.

Also, I used CRC engine break in lube (moly disulfide) from Napa on the head bolts and gear/shaft mating surfaces and it worked quite well.

 

Hi All, I'm looking at doing a full WR gearbox swap into 2010 YZ450, do we know of anyone that's done the full swap?

 

I've done some searching and apart from the actual gears and pinions and the main and driven shafts the only other differences in the part numbers between the 2012 WR450 and the 2010 YZ450 are nos 11 and 19 in the wr parts fiche Pt. No. 93306-00431-00 (the bearing on the gear shift side of the main shaft) and 90209-21332-00 (a washer that sits between 3rd and 5th gears).

 

The bearing may be an issue if the outer diameter is a miss match for the YZ case and I'm not certain on the actual dimensions of the main and driven shafts. Any help appreciated.
 
Thanks, Hayden

 

 

I have a 2010 YZ with full WR gearbox.

A couple of the Yamaha dealers here in South Africa do WR conversion on YZ's (at a reasonable price)

I would suggest that you email our dealer for a quote (this will provide a list of parts needed): shimwells@mweb.co.za

 

I really do like the taller 5th. Comapred to my CRFx, the YZ450wr is taller geared and makes for a better tool for multi-day adventure rides  :thumbsup:

yz_zpstvcxl21t.jpg

 

Taller gearing makes this easier:

index.php?action=dlattach;topic=134175.0

I have a 2010 YZ with full WR gearbox.

A couple of the Yamaha dealers here in South Africa do WR conversion on YZ's (at a reasonable price)

I would suggest that you email our dealer for a quote (this will provide a list of parts needed): shimwells@mweb.co.za

I really do like the taller 5th. Comapred to my CRFx, the YZ450wr is taller geared and makes for a better tool for multi-day adventure rides :thumbsup:

yz_zpstvcxl21t.jpg

Taller gearing makes this easier:

index.php?action=dlattach;topic=134175.0

What brand is that over size tank and was it hard to install on the bike? Im looking for over size tank for my 2013.

What brand is that over size tank and was it hard to install on the bike? Im looking for over size tank for my 2013.

That's an IMS 2.4Gal

 

Perfect fit.

Just be sure to tighten the fuel pump plate on correctly (the plate at the bottom of the tank which holds the pump in place)

If not, the O-ring will not seat properly and the tank will leak.

 

I found that, unlike with the stock tank, the IMS is not 100% flat at the bottom and this requires you to press down firmly on the pump's mounting plate, when tightening its screws.

Hi all and thanks everyone for the help and information. I just installed the whole 1 thru 5 2012 WR450 gearbox into my 2010 YZ450 going off the info in this thread with no issues or problems at all. Rides awesome and shifts smoothly. Hayden

OK, so I'm doing the bottom end on my 07 wr450 and I'm interested in this WR/yz hybrid gearbox. I ordered new 06 yz450 1st gear wheel,gear shaft, 2nd + 3rd gear sets. I'm hoping to run the yz 1-3 and the WR 4th and 5th in my bike. Looking at oem part schematics it looks like they share the same transmission shafts.

I have read on some other forums that some of the gear dogs won't mesh properly together when you mix and match. Is the 06-09 gearbox different? I already bought the parts but would like to know before I try to install them and risk not being able to get my money back for them.

Never herd of anyone taking that approach with a WR.  What exactly are you trying to accomplish by closing up the first 3 ratios?

 

Based on my experience with my Hybrid trans, there are no issues with mixing the YZ450 1-3 with the WR 4 & 5 in that year range.

Basically I do supermoto track days alot with the current WR transmission I'm constantly shifting between 2nd and 3rd, 1st is pretty much useless- I have to start in 2nd gear on holeshots. A buddy of mine has a YZ with a four speed and he runs pretty much the whole track in 2nd gear. Im not used to his bike but i ran 7/10thd of a second fasyer riding his. from what I have read the yz's actually have a little taller gearing in 1st through 3rd.

Edited by knuckleduster271

The first three are taller and closer.  Third is only very slightly taller, but they're so close to the same, it's not really worthwhile to change 3rd out:

 

WR:

2.417
1.733
1.312
1.050
0.840

YZ:

1.929
1.533
1.278
1.091
0.952
 

The attached image is a graphic comparison, shown as if they were a bicycle freewheel:

Ratios.png

Great info thank you for posting that, I just went ahead and bought all new gears, forks, main+ drive axles (had to buy one in order to run the yz 1st gear and the splines for my front sprocket were badly worn on the other) for the whole gearbox. I had 7,000 miles on it in motard trim, all pavement. these bikes are kind of known for gearbox failures so I just opted to replace every single gear. The gears and dogs looked perfectly fine on the set I took out but I didn't want to risk whipping a motor that had about $2000 worth of head, crank and piston upgrades in it.

I have a 2013 yz450 and would at a min like to do the 4th and5th gear wr switch. Does anyone have the parts numbers needed and the appropriate donor wr years.

Thanks

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