250br rear diff in 250sx

[oldtrx]

will the 250BR rear differential bolt up in the 250sx swingarm without modification? or will the whole swing arm transfer?? need a quick answer thanks

[Tecate Karl]

. suposedly the gearing is a little diffrent but I dont know for sure on that but I'm pretty sure the swing arms will switch over if not the rears will I have an 85 br rear in my sx thats how I know they will

[Tecate Karl]

what year rears are u running and trying to switch too

[TheRealFatShady]

The gearing in the rear end is different, ring gear divided by pinion gear??? Maybe the opposite of that. But you supposedly cannot take one gear from an SX and one from an ES and make a new ratio. Won't work.

The swingarms mount to the frames differently, and the SX driveshaft has a spring on it. I don't know if they are the same length, but the ES feels longer.

I believe the differentials should bolt up to either one, but I don't believe the full assembly with swingarm/driveshaft/axle will swap, or at least not a 'bolt on' swap.

[oldtrx]

i know on trx300's a common thing to find is a trx350 foreman, 250sx, or 250BR rear end swap, it happens all the time on highlifter... there cant be that much of a different ratio, just throwin that out there

its an 85 250sx, my neighbor has a BR witha supposedly good rear end, i havent checked out its fluid or seals yet, i think its an 85 or 86

wish the swingarm would fit... gotta replace axle bearings also..

[oldtrx]

. suposedly the gearing is a little diffrent but I dont know for sure on that but I'm pretty sure the swing arms will switch over if not the rears will I have an 85 br rear in my sx thats how I know they will

so the diff swap is a for sure green light

[pirate122]

yes it is the same thing,but make sure it is the same year because 86 and 87 dont fit in a 1985 model the axle is 2 1/2 in longer . the big red gear ratio is 9:34 and the sx is 10:35 you wont see the difference.

[cattle-dog]

if its just the diff you are useing bolt it up direct fit just a little diffrent gearing, diffs need to be same year to swap.

[Thorpe]

the big red gear ratio is 9:34 and the sx is 10:35 you wont see the difference.

Um... Try your math again...

[jeswinehart]

I done the es to sx differential swap 3 maybe 4 years ago and it was exactly what i was looking for for a wee bit more top end speed on my 85 Bigred.
Big huge difference,,, no. But certainly noticeable.