904 versus 998 Pix and info wanted

[401 Pacer]

Found a rebuildable 998 for sale, haven't seen it yet though and before I check it out I want to find some pix of one in order to identify it over a 904 (the seller may either not know for sure or could even be trying to get over on me!)

I know what a 904 looks like, just not familiar enough with 998's to be sure. Also, what, if any, differences were there between V8 trannys and 6 bangers? I realize that stall speeds (and lockup) varied. They did indeed use 904s behind some year 304 engines.

Thanks in advance!

[AMX69PHATTY]

For the 998, on the pass side, in the back, above the pan's corner, there is a round shape in the casting which is the servo bore, and the 998 has 2 "gusset ribs" above this "servo
cylinder" visible on the outside of the case. The 904's lack these "gusset ribs". Understanding is the 998's have a 4 gear planetary, where the 904's only have a 3 gear, and the 999's I beleive have a 5 gear planetary. I'm not completely clear, but there were lower first gears in some or all 904/998/999's that the 727's, 9xx's have a first gear ratio of 2.74 I think, instead of the 2.45 first gear of the 727's, 2nd is also diff, 1.54 vs 1.45. Believe that hard parts for any version of the 9xx's can be purchased and installed into any 9xx series case.

Have yet to get together a document that captures all these specifics, applicatons, and years.

[401 Pacer]

Is that all you have to give me? LOL! Thank you very much!!!

[AMX69PHATTY]

Info from ---> gremlinx.com web page - http://www.gremlinx.com/AMC-Transmissions.htm

TF-904 - alum case - 3spd - oil/water - '72-'87 (121/150/232/25
TF-998 - alum case - 3spd - oil/water - '72-'87 (258/304)
TF-999 - alum case - 3spd - oil/water - '80-'87 (J232/J25
TF-727 - alum case - 3spd - oil/water - '72-'87 (J258/X360/X401)
"J" in front of the cid means JEEP tranny.
"X" in front of the cid means both passenger and JEEPs.

TF-904/998/727 are Chrysler trannies that were used for many years in all Chrysler products.
The internals exchance easily, but the exterior is AMC only.
TF-904 is light duty and was originally used with Chrysler 4 and 6 cyl engines starting 1960,
some early 273 V8s also got this tranny. Also some mid-size Chryslers with 318's got this tranny.
TF-998 was originally used with Chrysler small V8s (31 and was the original lock up converter tranny.
Note that you can identify a lockup 727 transmission because
it has about 5/8" of the end of the smaller input shaft machined smooth.
If it's a non lock up transmission the splines go to the end of the shaft (except for about a 1/8" bevel).
TF-904 has 3 pinion planetaries and a single wrap rear band.
TF-904 was available in 2 ratios, wide ratio with 4 cylinders, standard ratio with 6 cylinders.
TF-904 was used in all cars behind the 258s, except the Eagle which used the TF-998.
TF-904 uses the same output shaft and seal as the T-4 and T-5.
TF-909 used in Jeeps, is a 904 with a lock-up torque converter.
----> ( what were the ratios in a TF-904 ?
TF-998 was used behind the 258 only in the Eagle.
TF-998 has a larger front servo, 4 pinion planetaries, and a double wrap rear band.
TF-998 was used in all 304s in cars starting from '72, except some HD applications which got the 727.
----> ( what were the ratios in a TF-998 ?
TF-999 was originally used with 360 Chryslers, possibly also in later FSJs.
TF-999 is same as TF-998 except for 5 plate front clutch, and a wider front band.
TF-998/9 can be indentified from the TF-904 by the two external ribs on the case above the rear servo.
----> ( what were the ratios in a TF-999 ? )
----> ( TF-999's had a 2.74:1 first gear )
TF-727 is a very heavy duty transmission, can hold almost anything,
but on the downside is very heavy, and this way inappropriate for drag racing use.
TF-727 was also available as a hd option in big cars with a 6 cyl. and Wagoneers with 6 cyl '80-'83,
and Grand Wagoneers from '84-'87. TF-727 was used in Jeeps from '80 - '92.
TF-727 case is 16" long and 14 bolts hold in the pan.
TF-727 Gear Ratios are 2.45(1st) 1.45(2nd)) 1.00(third).


Info From ---> http://www.allpar.com/mopar/torqueflite.html -

AMC moved to the Torqueflite in 1972 for cars, and
around 1979-80 for Jeeps, which had used Hydramatics before then.
The TF-998 / 999 was a 904 built inside a 727 case.
Torqueflites first appeared in 1956, as an option, in Imperials and 300Bs.
This unit had a cast iron body with an aluminum converter housing and aluminum tail shaft housing.
The gear ratios were the same in the forward gears as they are now; 2.45:1 1st, 1.45:1 2nd, 1.00:1 3rd.
Reverse was 2.21:1 in the early units and 2.20:1 in all models since 1962.
The various Torqueflites had the same internal ratios, despite their other differences.
Until 1980, they were relatively narrow, in and after 1980, a wide-ratio gearset was introduced
and used in most of the 998 and 999 transmissions (see Tom Hand's detailed article).
This wide ratio was 2.54 1st, 1.54 2nd, and 1.00 3rd (as with 3rd in the earlier Torqueflites).
This gearset, which uses a welded-steel planet cage, is noisier and less durable
than the original-ratio gearset with its machined-aluminum planet cage,
but the lower first and second gears helped cope with the tall rear axle ratios needed for gas mileage.

The differences between the 904, 998/999, and 727 was largely in the materials and the amount of 'beef', and in the torque converters.
The 904 uses different kickdown bands to hold the front clutch retainer drum during second gear.
Most 904s have a single width band, but some 998 and 999 versions of the 904 have a drum
with five clutches, and need a wider band to hold it.
Some 904s use what is called a "flex band" that performs identical functions to the standard cast band but will not retain the circular shape of the cast band when it is removed from the transmission.
Some 727's also use the flex band in later model years.
A double wrap band (also called Hemi or 440-6pack band) was used with five clutch retainer drums that were used in the maximum performance 727s. This band was wider and could produce much greater holding power than the single width cast or flex band found on most other 727 units. One might think it wise to use the Hemi-band with the standard 727 drums but it will not work because of the width difference between the four and five clutch drums. I will explain various tricks that can be done with bands, apply levers and drums in the modification section.
TF-904 has 3 pinion planetaries and a single wrap rear band.
TF-998 has 4 pinion planetaries, a larger front servo, and a double wrap rear band.
TF-999 is same as TF-998 except for 5 plate front clutch, and a wider double wrap front band.

In 1962 the aluminum case was introduced. It had the code name of "727" and together with the torque converter, it weighed about 160 pounds. The original 727 was basically unchanged through 1965. Certain items were altered in the 1965 model year and these included enlarging of the torque converter splines on some 1965 models, elimination of their flanged output shaft, and changing the shift mechanism from two cables to one rod-and-lever arrangement. All of these changes have been incorporated on 904s and 727s since 1966.

Info from ---> http://www.allpar.com/mopar/transmis...queflites.html
The following might prove useful to people looking for information on their RWD Torqueflite trannys.
I know that it applies to Chrysler application transmissions,
but I don't know it applies to the Torqueflites that were sold to AMC or other OEMs.

A-727 transmissions from their inception until 1966 have 19 splines on the input shaft.
A-727 Non-lockup transmissions from 1967 onward have 24 splines.
A-727 Lockup transmissions appeared in 1978 and have 23 splines.
Not all A-727's made after '78 were lockup, specifically towing pkg A-727's commonly were non-lockup,
and would have the '67-onward 24 spline input shaft.
A-518 overdrive also has 23 splines.
A-727's ?? --> The Output Shaft has 29 splines.

A-904 transmissions from their inception until 1967 have 18 splines on the input shaft.
A-904 Non-lockup transmissions from 1968 onward have 27 splines.
A-904 Lockup transmissions appeared in 1978, and have 26 splines.
A-500 overdrive transmissions also have 26 splines.
A-904 's ?? --> The Output Shaft has 25 splines.

If in doubt, count the splines. It saves a lot of headache and stress later on when you might otherwise discover that you have the wrong torque converter or drive shaft yoke.
The 904 and 727 don't have a common dust shield.
The 904 uses a 10.75" converter. The 727 used either a 10.75" or an 11.75" converter,
so the bell housing is larger at the bottom and deeper at both the top and the bottom.
The starter ring gear is also larger. The starter itself mounts in a slightly different position as well, so things like headers might work on one and not work on the other.
If you're converting from a 904 to a 727, at the time this was written,
the dealer carried 727 dust shields for around $25.

For small blocks, 360 engines and some 318 engines of the LA family are externally balanced. They use specific balance weights on the torque converter, and are not the same between the 318 and the 360. The 340 engines in 1972 and 1973 used cast cranks, and thus used their own unique externally-balanced torque converters also. (Allan) The 5.9 Magnum engines are also externally balanced, but don't use the same balance weights as their pre-Magnum counterpart, so torque converters from the late seventies and eighties 360 will hook up but not balance properly on the Magnum motors. For big blocks, the 400 is externally balanced as well, so it should have its own particular set of balance weights.
Rick Ehrenberg wrote: “All 318 (5.2l) engines - Magnum, SMPI, or carbureted - are internally balanced, therefore there are no torque-converter / flex plate swap problems.”






Info from ----> gremlinx.com web page - http://www.gremlinx.com/AMC-Transmissions.htm

model type spd cooling used years -------------------------------------------

Hydramatic iron 4 oil/water (6 cyls) '50-'56
Flash-away iron 4 oil/water (250/327) '56-'57
Ultramatic iron 2 oil/water (320) '55-'56
M-35 alum 3 air (196) '57-'65
M-34 alum 3 air (232) '57-'65
M-36 alum 3 air (199) '66-'69
M-37 alum 3 air (232) '66-'69
M-42 alum 3 oil/water (199) '70-'71
M-43 alum 3 oil/water (232) '70-'71
M-40 alum 3 oil/water (290+2) '67-'69
M-44 alum 3 oil/water (304) '70-'71
M-8 iron 3 oil/water (196/250/287) '57-'66
M-10 iron 3 oil/water (327) '57-'66
M-11A iron 3 oil/water (290+4) '67-'71
M-11 iron 3 oil/water (343/360) '67-'71
M-11B iron 3 oil/water (304/360) '70-'71
M-12 iron 3 oil/water (360/390/401) '68-'71
TF-904 alum 3 oil/water (121/150/232/25 '72-'87
TF-998 alum 3 oil/water (258/304) '72-'87
TF-999 alum 3 oil/water (J232/J25 '80-'87
TF-727 alum 3 oil/water (J258/X360/X401) '72-'87
TH-400 alum 3 oil/water (J232/J258/J304) '65-'79
(J401/J360/Buick J350) (Toronado OHC J230)'65
"J" in front of the cid means JEEP tranny. "X" in front of the cid means both passenger and JEEPs.

BELLHOUSING NOTES
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The bolt pattern for the 196 is the same as the 64 -71 199 & 232, difference was that the 196 had different dowel pin sizes . AMC V8's emerged with the 290cid in '66 and the bellhousing was changed as well when the old rambler V8's were dropped from production. Starting '66 V8 bells (290-401) are all the same. Bellhousing for all engines changed '72 when AMC went from BW to Chrysler transmissions.
The bell for 6 cyls changed in '72 to match the V8.
The flywheel also went up in '72 from 153 teeth ( btw a common chevy size ) to 164 teeth ( btw a common ford size ).

TH-400 is a GM transmission used in various GM V8s. Gear Ratios: 2.48 1.48 1.00 2.08(r).
TH-400 has two variations in output. Some were built to bolt to the Dana 20 transfer case and some were built to bolt to the BW 13-39 "Quadra-Trac" transfer case used during the 70s. These two versions are not compatible. TH-400 factory adapter used on the Dana 20 version is light and prone to failure. The drive gear used with Dana 20 is not 6 spline, so you cannot bolt a Dana 18 to this transmission. The case is 24 1/2" long and 13 bolts hold in the pan. TH-400 was used in CJs with the BW 13-39 transfer case from 1976-1979. TH-400 was used in full sized Jeeps (SJs and J series pickups) from the late 60s until 1979. TH-400s used in CJs and later SJ had the AMC engine bolt pattern. TH-400 was used in late 60s SJs w/Buick 350, it had the BOP/BOC (Buick, Olds, Pontiac, Cadillac) pattern.
TH-400 used early with the AMC engines used an engine to transmission adapter.
TH-400 was used in all AMC Wagoneers.


Notes: Hydramatic transmission was called Dual Range Hydramatic and it was available only on 6cyl Nash, Hudson, and Rambler cars 50-56. Hydramatic was called the Flash-away starting '56. Gear ratios were: 3.96:1 - 2.55:1 - 1.55:1 - 1:1 & 4.30:1(R). Hydramatic was built by GM and was used in 6 cyls for '54-'56 and during '57 this dual coupling automatic was available only on the 250/327 V-8 equipped cars. '57 6 cyl Ramblers had begun using B/W automatic tranny called Flash-o-Matic. The 250-v8 was introduced in 1956 & the 327-v8 in 1957. Hydramatic had the oil dipstick under the floor until 1954 and for '55-'57 it was moved under the hood. Hydramatic was used in almost everything American car in the early '50s - even GMC M135 army trucks used in Korea. It was virtually the only automatic available back then. A disastrous fire in the factory forced makers to develop their own autos and ended its reign. Hydramatic copy was used by Rolls Royce into the mid '60s when they switched to the TH-400. Ultramatic was built by Packard and used in Packard powered Hudsons, 2 speed with lock up torque convertor, water cooled, propably the worst transmission ever built. All BW air-cooled trannies, the cooling is supplied by a "shroud" made onto the torque convertor. The air inlet is on the passenger side of the bellhousing. Don't mess with this or remove any parts, as the tranny will overheat without this system working properly. >From '57 to '67 the BW automatic was called "Flash-O-Matic" and from '68-'71 it was called "Shift Command". There was a change in the way the trans shifted that led to the later name change. Flash-O-Matic has L, D1, D2, N, R, P. D1 starts in first gear, D2 starts in second gear. They can also be manually shifted. Shift Command has the capability of manually shifting each gear, and is the now traditional L, 2, D, N, R, P. The idea of starting in second was to prevent excess wheel spin on slippery surfaces. These trannies could be manually shifted as well. Most earlier transmissions were single range, L,D,N,R,P. None of the BW trannies will shift down into Low unless speed is 25 MPH or less, so there no real danger in manually shifting the tranny. Cast Iron trannies are heavier and more heavy duty than their aluminium counterparts. Borg-Warner alum. automatics and the T-96 manual have the same spline and are the same length M-3X transmissions are all air cooled via torque convertor. M-34/35 both have cable shift. M-34/35 is also known in the industry as T35. M-35 is prone to cable shift jamming, the cable should easily move with low force in and out an inch or so, or it won't shift right. M-35 has both front and rear pump so it can be push/pull started (driveshaft turn the pump) M-35 is prone to the rear band partially applying when it's not supposed to and wearing out the rear band. The fix for this is to drill a small hole (.020") thru the rear servo piston. This might work on other M-3X series trannies as well. M-35 planetary gearset is a Ravigneaux type with primary and secondary sun gears, primary and secondary planet pinions and a ring gear. M-35 rear servo is a pressure apply / spring release type. M-35 front servo is a pressure apply / pressure release type with unequal piston areas. M-35 the clutch is oneway and located between the center support and the planet carrier. M-35 front clutch is a multi-plate type which is engaged in all forward gears. M-35 The rear clutch is similar in construction to the front clutch but with a large diamerter opiston and a coil type return spring. M-35 can be beefed up by using BW-51 (Aussie Ford Falcon XF) valve body, which changes the shift pattern to start in first gear and allows a partial-throttle change-down. Also hd clutch plates, hd clutch spring and hd raybestos bands are available for the same car. Also the 3rd and reverse drum can be replaced with a larger fitting unit from a late model BW-35/BW-65 and fitting flexibrake rather than fixed band (gives a much smoother shift) M-37 and manual T-96 have the same number of splines. M-35 and manual T-96 also have identical universal yokes. M-37 has bosses on the case for oil cooler lines. These same ones are on the later oil/water-cooled trans. Inside there is a boss with a blind hole that accepts a tube that goes to the pump. The tube from the M-40 should fit the M-37 (and the fittings from the outside of the case.) On the M-37 the tube is straight and goes to the valve body where there is a ball and spring valve, and then right out into the pan. On the M-40 it pumps it through the cooler, then back to the inlet to the rear of the trans, which is just an open drain. The cooler is enough to stop passive draining. M-37 the rear pump hole is just blocked off with an adapter plate. M-40 case might not be this way as it was recast and has a different dipstick location that is IN the case. The M-37 tube is hooked to the oil pan. M-4X series were basically heavy-duty versions of M-37 with new oil/water cooling. Which means the oil flows thru the radiator and water cools the oil, and the oil cools the trannny. M-8/10/11/12 series trans are all very similar to the Fordomatic, especially the M8/10. M-8/10 were also used behind the 6 cyl prior to 62. M-1X has cast iron case which is the trick to being much stronger than the other series. The servo arms that hold the bands push againts the case. The inards in the cast iron units are much larger and stronger than those used in the aluminum case trannies and nothing interchanges. M-11B has an oval shaped tag and the M12 is more square. Both have the model number stamped on them. M-12 was used in '71 with 360cid but only along with 3:54:1 rear. All other ratios with 360cids got the M-11B.

INTERCHANGE - BORG-WARNER

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Other BW/AW trannies include: M-35 Volvo (air cooled, '65-'75) M-55 Volvo (same as M-35 but oil/water cooled, '75-'84) M-3X Saab 900 (pre '85) M-3X Datsun Bluebird (pre '77) M-3X; M-6X series Rover (V8, '70-'87) M-51; M-6X Ford Australia Falcon XF V8 ('70s) M-1X Jaguar (air cooled, pre '6 M-12 Jaguar XJ12/XKE ('68-'75) M-65 Jaguar XJ6 ('74-'82) M-55 Isuzu/LUV ('81-'87) M-35 Mitsubishi/Hyundai ('71-'74) M-65 BMW ('74-'77) M-4X Triumph (early '70s to early '80s) M-1X Willys Jeep ('50s-'65) M-1X (iron warners) IH ('50s-'71) M-1X (iron warners); M-3X Postal Jeeps ('50s-'70s) M-5X is the improved version of the M-3X series (oil-water cooled,etc.) M-3X, M-5X, most internal parts (bands...)/ repair kits interchange. M-3X used by Saab is FWD, so none of the exterior parts interchange M-12 used by Jaguar should be the same tranny used by AMC, some exterior differences. M-65 used by Jaguar should is basically the same as M-4X used by AMC with some exterior differences. Borg-Warner's Aisin-Warner (Japanese/European) division supplied most non-US manufacturers with trannies that were the same or very similar as the US counterparts. So most parts interchange, though externals may differ. M-1X was used in IH with AMC 6 cylinder engines as well.

SHIFTER NOTES
----------------------------------------------------------------------
Different shifters were available in different setups, but all of them being AMC parts. (with both BWs and TFs) The shift lever is the same for all the m-35 based trannies. There is a difference on the outside where the shift lever goes. The earlier ones I have seen have a larger hole and shows in a '64 exploded pic. The later cars have a smaller hole but that should not really be a problem to rig.

Collected and posted by Antti-Ville Nauha (Pori, Finland) AMC CLUB FINLAND (AMCCF) Any corrections/additions -> contact me at antti-ville.nauha@kemira.com

[401 Pacer]

You left out mention of the Packard Twin Ultramatic and the kitchen sink LOL!!

Thanks to all your cut and pasting I now have to crack open ANOTHER 6 pack....thanks once again!

Several reasons I'm stuck on a 998 (or 999) is because it's a direct bolt in replacement for a 904 and offers nearly the same strength as a 727 but doesn't weigh anywhere near as much and has less internal power loss.

Check out this morphadite: