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231 question

middleurb

NAXJA Forum User
Location
NC
i blew my 231 123 spline this weekend and i found a replacement but it is a 121 spline. is it possible to switch the splines from the old one to the new one and make the thing fit in my xj?
 
middleurb said:
i blew my 231 123 spline this weekend and i found a replacement but it is a 121 spline. is it possible to switch the splines from the old one to the new one and make the thing fit in my xj?


yes. but be prepared.


theres a hard way and an easy way.

you can rip apart both cases and press out the input gears and swap them, this will require complete tear down of both tcases mind you.


opotion two, depending on how thrashed your old tcase was you can reuse the rear section and graft the 23 spline identical front half to the rear half of the 21 spline case.

A friend of mine just did this exact same thing a few weeks ago.
 
I thought you could just change the planetary assemble? Its been awhile since I have been in one though.
 
be careful on the years... there aparently was a different planatart gear cut in different years...
 
middleurb said:
i blew my 231 123 spline this weekend and i found a replacement but it is a 121 spline. is it possible to switch the splines from the old one to the new one and make the thing fit in my xj?

Should be able to just swap the input/planetary. The 231 is easy to work on, so as long as you pay close attention to how things come apart, you shouldn't have any problems putting it back together. Like was said, there are some slight differences from early years to later years, so look close at the parts to make sure they'll be right. Odds are they will be. You didn't say what broke, but there should be good parts in the busted t-case that you can re-use if needed.
 
XJ_ranger said:
be careful on the years... there aparently was a different planatart gear cut in different years...

Yes, just make sure it matches the ring gear, the older ones are cut different than the newer style (I think 87 plus). They fit but make a HORRIBLE noise when you spin it.
 
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