tranny questions....

1989 xj 4.0 i6 aw4 & np242j.

just after thanksgiving i had to replace the t-case, so i dont think this should be part of the problem.

onto the problems/ questions.... pardon me if this sounds like a newbie problem.

a slight shake between shifts. 2nd to 3rd & 3rd to 4th (D). then around 50 mph it does it again. (it's making the driver, my girlfriend, nervous when she goes to work & such)

is this due to bein so old (has over 260k on it) and wearing out?

is it less expensive to "rebuild" the transmission or just replace it with one from a j/y?

i have not yet had to rebuild a transmission, so i REALY don't want to mess it up if i end up rebuilding it.

any tips or suggestions? or if anyone has the time/parts to give me a hand in this would be GREATLY appriciated!!
we need to keep this xj running as it is our daily driver (no other vehicle yet).


thanks & keep them muddy!!!

ok just got off the phone with both, the parts store & the yard.
seams that there is only like $100 diferance in priceing. rebuild or replace.


oh and thanks for the help. :cheers:

Your first post says it was three days ago, but I hadn't seen it until just now? Server issues?

Anyway, is your power/comfort switch working? When was the last time you adjusted the throttle body pressure cable? What is the reference voltage of your TPS? What is the output voltage of your TPS? What fluid are you running, how many miles since the last flush and fill?

power/comfort switch? never used it.
havent adjusted the throttle body cable. (wasn't aware it could effect teh tranny this way)
not sure, not sure, don't have voltage reader.

fluid in the tranny? red. lol just kidding. she stopped at o'reily's on the way home & put in (either valvoline or pennzoil, she can't recall atm)

last flush -n- fill? not since i've owned it. due to that by doing this on such an old vehicle COULD start causing problems like this.(by washin away th e"gunk" that is keeping it together, lol) now that i am having these problems.. i need to deal with it, and fast.


may be able to get my hands on a wrecked xj, just not sure what tranny/t-case it has, or the year of it. still waiting on the guy to call us.

Put the switch in power mode. Adjust your throttle body pressure cable. Have your TPS checked. Service the dang tranny. It's an old wive's tale, kinda like things you might do could cause blindness, that servicing it now will cause problems.

cruiser54 said:

Put the switch in power mode. Adjust your throttle body pressure cable. Have your TPS checked. Service the dang tranny. It's an old wive's tale, kinda like things you might do could cause blindness, that servicing it now will cause problems.

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LMAO but agree with everything Cruiser54 said.

Search "poor mans flush" and do it. Also, odds are that the O'Reilly's parts counter Dude may have sold your wife the wrong fluid.

Joe, I was just agreeing with everything you said.............just a little firmer in my presentation. I would certainly perform the maintenance diagnostics we suggested before running out and buying some unknown replacement trans.

cruiser54 said:

Joe, I was just agreeing with everything you said.............just a little firmer in my presentation. I would certainly perform the maintenance diagnostics we suggested before running out and buying some unknown replacement trans.

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Yep, check, test, clean, adjust!

I was LMAO about what you said concerning blindness!

Joe, I'll bet you wear glasses as I do, huh? I missed that earlier.ROFLMAO

cruiser54 said:

Joe, I'll bet you wear glasses as I do, huh? I missed that earlier.ROFLMAO

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Yep, progressive bi-focals! :looney:

glasses? what are those? they don't make them STRONG enough for me! lol

no seriously though, the tranny fluid is dexron merc , as OEM recomendations. that much i do know. this much i know she knows as i have had her buy it before.
just never realy thought about doin the flush -n- fill, it wasn't giving us any problems, so i didn't think about it. (i know, stupid. also why i had to replace the t-case after thanksgiving).

tonight while we were driving home from the store it occured to me that there COULD still be some mud stuck somewhere. she drove through some realy sticky mud a few weeks ago & this is when it all started. (i know, smack me on the back of the head now, but i though we had gottten rid of all the mud).
but the TPS & other sensors will get checked as it isn't goin over 1500 RPM now, not sure when it was shifting but it shifts between 1000 & 1500 now.

Don't forget to adjust the throttle pressure cable--easiest to do: http://naxja.org/forum/showthread.php?t=1015963