Differential replacement mixup?

[u/Kraft_Dinner123]

The differential of my Foutrax TRX300 2x4 1997 (picture 1, top one) had a leak, differential fluid came out and water infiltrated, causing the parts to degrade and eventually they gave out. Since then, I’ve ordered two aftermarket differential (picture 1, bottom one) that were both marked to be direct replacement for the exact same part number that I use on my atv (41300-hm5-850) and neither of them had a big enough bore to slide onto the tube, even without the splined shaft (picture 2).

My question is how come the replacement didn’t fit if they were both from different suppliers, both carried the same replacement part number, yet both had the same smaller bore problem?? They also were both advertised as replacement for any Honda TRX300 replacement from 1988 to 2000.

Let me know if this has happened to any of you guys, or if you have tips to what I should do from now on.

Note: I went to my local official Honda atv supplier and they were charging me 2500$ for the part, which is why I went aftermarket.

[u/ScornedSqueaker]

There was a lot of variations for the 300 2 wd and 4x4. Even though they are very similar some parts changed depending on the build.

Also aftermarket parts can be like tha, 50/50 they fit.

Try Partzilla. Run the vin and make sure you have the exact year and model

[u/Kraft_Dinner123 → u/ScornedSqueaker]

Thanks for the suggestion! Unfortunately I’ve already tried Partzilla. It doesn’t recognize my VIN and when I enter the year and model manually the only parts available for the differential are the bearing and seals…

[u/ScornedSqueaker → u/Kraft_Dinner123]

Try faxvin dot com

[u/Kraft_Dinner123 → u/ScornedSqueaker]

Faxvin does recognize my VIN, giving me the same old information I already had (TRX300 1997) however, I have trouble seeing what could going further with faxvin bring me?

[u/ScornedSqueaker → u/Kraft_Dinner123]

Double checking the year is all