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Author Topic: Eagle Automatic Transmission  (Read 31866 times)

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Offline captspillane

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Re: Eagle Automatic Transmission
« Reply #75 on: September 01, 2011, 02:26:39 AM »
I've also read thru this post, and I'm not sure about a few things:

the 998, 999 and the 727 will all fit on a SX/4 258 I6??  Just bolt 'em on, and away we go?

Someone also posted the bells are all the same?  Well, let's say I have an SX/4 with a 998 tranny.  Can you have it rebuilt with 727 parts?  Is something like that possible, or do you just go out and scrounge for a 727?  What if you can't find a 727 and you're stuck rebuilding the bell you've got?   Can you turn a 998 or a 999 tranny into a 727? 

Am I babbling again??


A 904, 998, and 727 all have different aluminum casings. They have the same number of components in the same place inside, but some of the internal assemblies are bigger and heavier in one model than another. The 727 is by far the strongest and the 998 is slightly stronger than a 904. The pan, valve body, linkages, plugs, bellhousing, and 4WD adaptor are all identical. It’s just the area right above valve body that’s dramatically fatter on the TF727 than the TF998. I wish I was home to take a picture of the two next to each other since it’s neat to see how only one area of the casing is puffed out. After upgrading your Eagle with the TF727 there will be less room between the floorpan and top of the transmission but otherwise all the important dimensions and linkages don’t change. Most rebuild kits are just a big pack of gaskets without any steel parts, so it’s very common to see one generic kit that works for all three models.  Most of the gaskets are identical but you need to get the correct bands, friction plates, and other metal parts to match the model you’re working on.

Keep in mind that the available manual transmissions for your Eagle are rated between 265 ft/lbs for a T5 and 300 ft/lbs for an NV3550. The TF727 is rated at 450 ft/lbs and the 998 is at least 300 ft/lbs. The NV3550 is very robust and hard to break, yet it is still weaker than the 998. This should make it obvious that automatic transmissions will not fail because of applied engine torque. Even excessive heat is usually not an issue. They fail because they are totally controlled by pressurized fluid. As soon as one of the antique gaskets inside the transmission gives out the hydraulic pressure on the back of the servo decreases, which in turn decreases the amount of force being applied to the friction band, which allows it to slip and heat up until eventually you are no longer able to drive. A freshly rebuilt TF998 is much more reliable than a TF727 that has never been rebuilt.
Currently Inspected and Insured as of Jan 2013:
-1985 Eagle Station Wagon 258 T5 Stickshift
-1980 Eagle Station Wagon 258 Auto Fuel-injected with GM TBI

Minor Repairs Underway:
-1982 Eagle SX4 258 T5
-1981 Kammback 2.5L Iron Duke T5

Restoration Efforts Near Completion:
-1982 SX4- 401 NV3550
-1983 SX4- 4.5 MPI NSG370 (6 Speed)

Restoration Efforts Underway:
-1985 SW- 4.0 MPI AX15
-1982 SX4- 4.0 AW4
-1981 SX4- SD33T NV4500 (Turbodiesel 5 speed)

Future Rescue Efforts- '85 Maroon SW, '87 Limited SW, '84 Limited SW, '87 4 door Sedan, '81 2 door Sedan, '88 White SW, '77 4 door Hornet, '74 2 door Hornet, '79 Spirit AMX, '81 Kammback.

RIP- Red '81 SX4, '84 4dr Sedan, '84 SW, '81 SW, '80 Spirit, '83 SW, '83 4dr Sedan

Offline captspillane

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Re: Eagle Automatic Transmission
« Reply #76 on: October 25, 2011, 01:12:14 PM »
Here are some pictures comparing a 727 and a 998. The 727 is obviously fatter and has heavy parts, including a fatter input shaft. The throttle body, 4wd adaptor, and relative position and shape of all the components are identical however. The linkages are all the same as well. They are a direct bolt in exchange. They use different torque converters along with the different input shafts.







Currently Inspected and Insured as of Jan 2013:
-1985 Eagle Station Wagon 258 T5 Stickshift
-1980 Eagle Station Wagon 258 Auto Fuel-injected with GM TBI

Minor Repairs Underway:
-1982 Eagle SX4 258 T5
-1981 Kammback 2.5L Iron Duke T5

Restoration Efforts Near Completion:
-1982 SX4- 401 NV3550
-1983 SX4- 4.5 MPI NSG370 (6 Speed)

Restoration Efforts Underway:
-1985 SW- 4.0 MPI AX15
-1982 SX4- 4.0 AW4
-1981 SX4- SD33T NV4500 (Turbodiesel 5 speed)

Future Rescue Efforts- '85 Maroon SW, '87 Limited SW, '84 Limited SW, '87 4 door Sedan, '81 2 door Sedan, '88 White SW, '77 4 door Hornet, '74 2 door Hornet, '79 Spirit AMX, '81 Kammback.

RIP- Red '81 SX4, '84 4dr Sedan, '84 SW, '81 SW, '80 Spirit, '83 SW, '83 4dr Sedan

Offline dredevil

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Re: Eagle Automatic Transmission
« Reply #77 on: April 04, 2013, 05:25:56 PM »
I saw alot of posts saying to use a 727 out of a jeep with a 258.
Will a trans out of a 1986 Wagoneer with a 360 work?

Offline carnuck

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Re: Eagle Automatic Transmission
« Reply #78 on: April 05, 2013, 12:51:41 AM »
I saw alot of posts saying to use a 727 out of a jeep with a 258.
Will a trans out of a 1986 Wagoneer with a 360 work?
Grand Wagoneer, yes. Tcase as well. '80 to '91. Some 6 cyls used the 999. Usually Cherokees
FOR SALE
'87 Comanche 4.0L AW4/NP242 3.73 gears, lifted 5" on near new 33" tires $3500 obo
'82 Eagle Wagon (Brown Betty) 4.2L/727/NP229 and soon 8.25 rear axle and non-vacuum 3.08 front to match. 235/75/15 tires. It's down to minor body work (someone creamed my driver's door but I have another in good shape) almost rust free and interior work (seats are worn and carpet torn). $2000 but about to go up due to more work being done.

Pics of my other for sale stuff http://tinyurl.com/jimsclads

 

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