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Transmission issues

F

fsj-earl

NAXJA Forum User
Location
Middletown, PA
Picked up a 92 XJ for my daughter. has about 158,000 on it. Straight 6 with auto tranny. Doing basic maint on it. Changed all the filters and fluids. Did tranny filter and fluid and now it shifts weird. Runs 1st gear up to about 30 - 35 mph and then shifts, runs 2nd gear up pretty high as well. Did not do this before the tranny filter change and fluid fill. Any suggestions or ideas? Did not spend much on the XJ and don't want to spend too much on the fix either. Thoughts? Thanks.
 
Did you use Dex III transmission fluid? If not, that is the problem.

If yes, go buy a pint of Trans-X and add it to the fluid. Then run it through the gears, forward and reverse and in neutral for 10-20 minutes in the driveway. Then drive it some to let the Trans-X soak in and clean sticking valves (removes / dissolves, dried up vanish from old burnt transmission fluid) in the valve body. May need to drain 2-3 quarts, and repeat the Trans-X, 2-3 times for a permanent fix. But it should improve with each treatment.

But check the fluid level on a flat driveway first, engine hot, and running in park after a short drive. Make sure it is not low or overfilled.
 
The AW4 jeep transmission is easy and cheap to fix. If you still have a problem it is probably a loose wire connection, bad fuse or an easy to reach and swap solenoid valve. Don't panic as the AW4 Jeep transmission itself is bullet proof.

The shifting is actually controlled electrically with solenoid valves. :sunshine:

And the only other issue can be varnish that came loose changing the fluid and the clean fluid is loosing varnish and making the shift valves stick. But if you used the from fluid that has been reported to cause erratic shifting too. Must use DEX-III/Merc only.
 
Not sure what I used for tranny fluid. I thought it was DexIII. I will check and I will try the TRANS - X fix that you suggest. How do I know if it is a solenoid, loose wire, fuse, etc. Auto trans scare me. All kinds of fairly dust and magic to make them work. Give me a good old manual any day! Thanks!
 
I used the Valvoline Max-Life - Dex/Merc. Should I not have used that? Where do I find DexIII? My local AutoZone and Advance Auto don't carry it.
 
THat's the same stuff I use. Have you adjusted your kickdown cable yet? Unless you messed with it, I doubt that it would help, but it's not a bad idea to do first. If that was out of adjustment, it would cause the same symptoms.
 
fsj-earl said:
I used the Valvoline Max-Life - Dex/Merc. Should I not have used that? Where do I find DexIII? My local AutoZone and Advance Auto don't carry it.
Click to expand...

It needs to say Dex III. IF it says Dex IV or Dex V or Dex VI, Or Mercon V, or synthetic on the label, it ain't the same stuff, and it will cause problems in the old AW4s, according to many.

I use the Walmart Supertech Dex III/Merc, under $13/gallon. I don't see it online in gallons. I buy it at a local retail walmart.

https://www.walmart.com/ip/16213433...75035&wl11=online&wl12=16213433&wl13=&veh=sem
 
dan1977p said:
THat's the same stuff I use. Have you adjusted your kickdown cable yet? Unless you messed with it, I doubt that it would help, but it's not a bad idea to do first. If that was out of adjustment, it would cause the same symptoms.
Click to expand...

I think Valvoline makes more than one, synthetic and non synthetic, Dex III-Merc-non-synthetic and Mercon V, Dex IV-VI synthetic? Not the same stuff.

He said he used Max Life. Sounds like synthetic to me?

I would not go near an older transmission that used Dex III with this stuff

https://www.walmart.com/ip/Valvolin...75035&wl11=online&wl12=15125768&wl13=&veh=sem
 
That's exactly what I use and it works great. I know some folks hate it but I also won't use the overpriced stuff just because of a name or a million mile guarantee that can never actually be claimed on.

Top line on the back says it's compatible with DexIII transmissions. I would recommend a full flush and 100% new fluid on anything I haven't done the PM to myself, though.
 
dan1977p said:
That's exactly what I use and it works great. I know some folks hate it but I also won't use the overpriced stuff just because of a name or a million mile guarantee that can never actually be claimed on.

Top line on the back says it's compatible with DexIII transmissions. I would recommend a full flush and 100% new fluid on anything I haven't done the PM to myself, though.
Click to expand...

Compatible is not the same as DEX III.

Too many people have reported trashed transmissions that were working before they died right after they they switched or did a flush.

Also every one I know and trust, including myself knows and says that a flush of an unknown condition transmission is surest way to kill it.

In my 45 years the best path has proven to be slow frequent 3 quart transfusions. Never a 100% change out, unless it has been 100% rebuilt, which of course gets pure new fluid.

If too much fresh fluid is used it can free up chunks of varnish, like paint chips that plug up ports and hang up the valves, in the valve body, and fork up the friction clutch plates, and they you have no choice but to pull it and rebuild it.
 
Last edited:
Ecomike said:
If too much fresh fluid is used it can free up chunks of varnish, like paint chips that plug up ports and hang up the valves, in the valve body, and fork up the friction clutch plates, and they you have no choice but to pull it and rebuild it.
Click to expand...

I'll agree with this part and and bet that's why the ones fail that used a DexIII compatible fluid and not just because it's synthetic or not 'real' DexIII. I'd bet it was due to any fresh fluid doing exactly what you say above.

It feels like a lot of the same folks who say 'Buy American because we have ANSI/ISO/etc certified facilities' are the same folks who say 'Use only "true" DexIII' even though the compatible fluids go through the same certification process DexIII does by ANSI/ISO/etc.

I don't do transmissions unless I have to and totally forgot that flushing a good known working transmission is asking for failure.
 
Synthetic is a much better cleaner-solvent like fluid than older Dex III peanut based oil Trans-fluids (or engine oils). That super strong cleaning ability is way too aggressive on older used transmissions that have not always been using synthetic fluid, and frees up cooked gunk way too fast thus clogging tight tolerance moving parts (engines or transmissions) and it also cleans up old seals and by doing so can make them leak where they had not leaked before.

dan1977p said:
I'll agree with this part and and bet that's why the ones fail that used a DexIII compatible fluid and not just because it's synthetic or not 'real' DexIII. I'd bet it was due to any fresh fluid doing exactly what you say above.

It feels like a lot of the same folks who say 'Buy American because we have ANSI/ISO/etc certified facilities' are the same folks who say 'Use only "true" DexIII' even though the compatible fluids go through the same certification process DexIII does by ANSI/ISO/etc.

I don't do transmissions unless I have to and totally forgot that flushing a good known working transmission is asking for failure.
Click to expand...
 
Ok, so am I screwed here or what? Do I drain and refill with the proper DEXIII, if I can find it, new filter, run some TRANS X or Lucas or something else through it? Thanks in advance!
 
fsj-earl said:
Ok, so am I screwed here or what? Do I drain and refill with the proper DEXIII, if I can find it, new filter, run some TRANS X or Lucas or something else through it? Thanks in advance!
Click to expand...

No need to change the filter. Did you drain and add 10 quarts, or 3 quarts?

No you are not screwed (yet). Verdict is out, as some have simply switched to Dex III and the problem went away.
 
I just added about 3 quarts. Just replaced what was lost when I pulled the pan and swapped the filter a few weeks ago.

Ok. I will do the pan drain and top off with the DEXIII. Wish me luck.
 
fsj-earl said:
I just added about 3 quarts. Just replaced what was lost when I pulled the pan and swapped the filter a few weeks ago.

Ok. I will do the pan drain and top off with the DEXIII. Wish me luck.
Click to expand...

If that fails to get all back to normal try adding a 1/2 pint of Trans-X next.

good luck
 
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