AMC Eagle Den Forum

The Shop => Transmission Shop => Topic started by: kalve on February 16, 2013, 08:07:45 AM

Title: 4 speed auto trans fit 85 Eagle 258
Post by: kalve on February 16, 2013, 08:07:45 AM
Hey guys I got a 85 Eagle wagon with factory 258 engine an 3 speed auto trans. I got a guy who says he found a 4 speed auto trans with overdrive from a 95-98 jeep cherokee with the 4.0 engine. Will this trans fit the eagle an is it a direct bolt up or do I have to change some things? I am planning later on to go with the 5 speed manual from the jeep wranglers probably by next year or so but this guy said he could get me this trans for like $100-$200 an its got 90K miles on it vs 181K on my engine an trans.
Title: Re: 4 speed auto trans fit 85 Eagle 258
Post by: Bird-o-Prey on February 16, 2013, 11:10:52 AM
I believe the most important issue is the the output shaft from the engine.  The Eagle has a 23 spline shaft (I believe).  The bell housing might be adaptable or changeable.  I believe that there is a 4 speed transmission that is a direct bolt up for our engines.  Possible an AX4 ( I may be getting my numbers crossed here).  Others here may be able to point out the correct transmission model.

Cheers
Title: Re: 4 speed auto trans fit 85 Eagle 258
Post by: carnuck on February 18, 2013, 04:08:45 AM
If the trans is from a Cherokee, then it's an AW4. If it's from a Grand Cherokee, it's a 42RE and I would RUN away from it! There is no direct swap (same size, etc) 4 speed auto to fit the Eagle.
  The AW4 is 3.5" longer than the 998 or 727 (from a Grand Wagoneer '84 to '91) You need a 1" spacer/clocking ring to use the Eagle tcase and it will only work if the trans is '91 or newer. (23 spline. They are 21 spline before that) Somewhere around '96 they twisted the 23 spline outputs as well to make them quieter.
  You will need a custom trans crossbar and driveshafts.
   You will need the 4.0L flexplate and starter too. And add the TPS (throttle position sensor) and computer as well as the TVS cable.
   I forget the name of the company that makes a manual controller for the AW4, but unless you swap in the EFI and harness from an XJ (with auto) the trans won't shift on it's own (neither would the 42RE)

The 4.0, 258 (4.2L) and 232 are the same bell pattern ('71 and newer), same balance (zero) and many things interchange externally.
Title: Re: 4 speed auto trans fit 85 Eagle 258
Post by: kalve on February 18, 2013, 06:42:32 AM
ok so pass on the trans swap to much work if i am going to put a 5 speed manual in it later. The reason why I asked because the 3 speed auto factory trans that is in this 85 Eagle is acting up. The guy I got the car from hit a snow bank with it in the 90's an then parked it in 04 till I got it in Nov 2012. You do normal driving an reverse on flat ground its fine but you put it in reverse an go to back it up a hill giving it gas or even flat ground in reverse an try to back over something giving it some gas in reverse reverse will act like it is trying to kick out of gear or its not went into gear yet. I think either the shift linkage is in a bind or band bad in the trans or something were he hit the snow bank with the car. I had the trans fluid  an filter changed an it shifts better than before but still acts up. I am looking to probably do the 5 speed swap come next year.
Title: Re: 4 speed auto trans fit 85 Eagle 258
Post by: kalve on February 18, 2013, 07:09:34 AM
So what trans would be a direct bolt in for this car if I have to have this trans replaced?
Title: Re: 4 speed auto trans fit 85 Eagle 258
Post by: carnuck on February 18, 2013, 01:19:19 PM
Eagle, Wrangler till '90 with 4.2L, 84-91 Grand Wagoneer (not '93-94. They are ZJs) 727 or 999 off 4.2L 6 cyl or AMC V8, '80 to '83 Jeep pickup, Cherokee or Wagoneer limited. NOT the small Cherokee and not '79 or older (look underneath. Drive shaft is same side as Eagle if correct)

Too bad you're not close to Seattle. I'm selling a '97 Wrangler AX-15 (with external slave bell) and NC231 for $500 obo. I had the EFI flywheel, but it seems to have disappeared along with the good clutch. I think I still have a regular flywheel with worn clutch.
Title: Re: 4 speed auto trans fit 85 Eagle 258
Post by: HawkenEagle on May 28, 2013, 08:57:10 PM
So if you want overdrive in an automatic transmission you would need to swap the engine and trans together? Wouldnt be a bad idea if you had a good doner EFI engine as well. So assuming I did that, what's the consideration with the transfer case or mounts??
Title: Re: 4 speed auto trans fit 85 Eagle 258
Post by: eaglefreek on May 28, 2013, 09:56:30 PM
Quote from: HawkenEagle on May 28, 2013, 08:57:10 PM
So if you want overdrive in an automatic transmission you would need to swap the engine and trans together? Wouldnt be a bad idea if you had a good doner EFI engine as well. So assuming I did that, what's the consideration with the transfer case or mounts??

No, the AW4 from a Cherokee will bolt right up to the 258. 91-96 AW4 will work best. You will need a Flexplate, torque converter and starter from an XJ. To bolt up the stock transfer case, you'll either need to have a spacer made or you might be able to cut the input shaft of the transfer case. I think it's 7/8" longer. I haven't got that far yet. You will need to move or modify the transmission crossmember. The front drive shaft will need to be lengthened and the rear shortened. The AW4 uses a stand alone computer that only needs a few inputs. You'll have to weed the harness for it from a XJ. You will have to install a TPS (throttle posiition sensor) to the carb. If you get a TCU (transmission control unit) from a 87-90 XJ, it will provide the 5v needed for the TPS. Then you just need 12v, ground, signal from the brake switch (unlocks converter), signal from TPS and everything else plugs into the transmission.
Title: Re: 4 speed auto trans fit 85 Eagle 258
Post by: carnuck on May 29, 2013, 03:15:48 AM
Quote from: eaglefreek on May 28, 2013, 09:56:30 PM
Quote from: HawkenEagle on May 28, 2013, 08:57:10 PM
So if you want overdrive in an automatic transmission you would need to swap the engine and trans together? Wouldnt be a bad idea if you had a good doner EFI engine as well. So assuming I did that, what's the consideration with the transfer case or mounts??

No, the AW4 from a Cherokee will bolt right up to the 258. 91-96 AW4 will work best. You will need a Flexplate, torque converter and starter from an XJ. To bolt up the stock transfer case, you'll either need to have a spacer made or you might be able to cut the input shaft of the transfer case. I think it's 7/8" longer. I haven't got that far yet. You will need to move or modify the transmission crossmember. The front drive shaft will need to be lengthened and the rear shortened. The AW4 uses a stand alone computer that only needs a few inputs. You'll have to weed the harness for it from a XJ. You will have to install a TPS (throttle posiition sensor) to the carb. If you get a TCU (transmission control unit) from a 87-90 XJ, it will provide the 5v needed for the TPS. Then you just need 12v, ground, signal from the brake switch (unlocks converter), signal from TPS and everything else plugs into the transmission.

The output shaft of the AW4 is a little over 7/8" longer than the input gear of the Eagle or FSJ tcases. What they call a 1" spacer is about $100. You need a custom trans crossbar, different rear shaft (we used an SX4 rear shaft with XJ yoke on it for SOTE so it has 2 slipjoints but it has a NP242 tcase)