Overdrive transmission choices for AMC 401

[caionneach]

Situation: 1982 Jeep Cherokee Wide-Track restoration---

Components: Stock 258 cid engine and T-5 transmission;

purchased AMC 401 V8 :lo1l: (without intake and exhaust manifolds, carburetor, alternator, and a lot more :smile: ).

Problem: Choosing a transmission, preferably one with *overdrive* capability, to mate to the AMC 401 V8. 111!!!

Options: NV4500 manual 5 speed (fifth gear is overdrive);
GM 700R4 automatic overdrive (fourth gear is overdrive).

Additional considerations: NV4500 adapts to 401 with a bellhousing kit and an adapter from Advance Adapters or Novak Conversions and mates to the stock NP208 transfer case via the 23 spline output shaft.

Not clear about the 700R4---> Novak Conversions lists a kit for the 304 and 360 engines, but not the 401. Novak Conversions has replied that I will need a flex plate for a 401 that they can take and modify that will then work with their adapter.

Both transmissions appear to be tough, truck transmissions when the 700R4 is beefed up for heavy duty and 4X4. NV4500 is heavy duty by design.

Both are comparable in price. Which to choose? Which is easiest to install? Which will provide better gas mileage? :mrgreen:

Kenneth Smith
Monroe, Louisiana

[caionneach]

Many views, no help! :-|

[jeepsr4ever]

I will post up a little later...have to ship a boat load of AMC parts....I also have been thinking on this and will let you in on pt#'s ect.

[caionneach]

You're a God-send!

[["Avatar-send" for you ACLU types]] :laughing5:

I'm inclined to choose the NV4500 just because there's no doubt about the adapters to make it work. A buddy of mine says I should install the 700R4 because it will make drinking coffee while driving during rush hour traffic a lot easier! :razz:

[Dusty]

thats how i drive and drink, :razz: left knee on steering wheel, enough movement to hit the clutch left hand for shifting and right hand for drinking the cold .... or hot .... and head tilted to the side talking ont he cell phone propped between shoulder and ear.

yes i am the CHP poster child of what not to do. :lo1l: my friend jim is doing a 700r4 into his 401 cherokee. i vote manual though, drove a t-176 360 power cherokee once loved it 5 spd would have been just that much more

[BRAD ARTHUR]

good question and both equally good trannys. please post your outcome along with cost of conversion. both could be kinda pricey from what i see?

[Atransman]

It really depends on what you plan on doing with the vehicle. If you plan on rock crawling go with the NV4500. The NV4500 has either a 6.34:1 or 5.61:1 first gear (depending on the transmission) and the 700 has a 3.06:1 first gear.

[jeepsr4ever]

Paul I will let you deal with this one as I am really busy here tonight

[pyagid]

It really depends on what you plan on doing with the vehicle. If you plan on rock crawling go with the NV4500. The NV4500 has either a 6.34:1 or 5.61:1 first gear (depending on the transmission) and the 700 has a 3.06:1 first gear.

I agree with this 100% but, with the auto dont you factor in the slippage of the Torque converter as well? which multiplies the gear ratio?


Also the 700r4 will take more power to run than the nv4500. I believe. I think i remember seeing that a th400 takes close to 40hp from the motor to operate

-Paul

[Dusty]

It really depends on what you plan on doing with the vehicle. If you plan on rock crawling go with the NV4500. The NV4500 has either a 6.34:1 or 5.61:1 first gear (depending on the transmission) and the 700 has a 3.06:1 first gear.


The downside to the 6.34:1 chevy nv4500 is it was only made for 2 years and 1st and reverse are not syncronized.

Depending on what route you go with adapters the dodge NV4500 uses a 9 1/4" long input that is 1 1/4" in diameter and the Chevy input is 7" long and 1 1/8" in diameter. on your long wheel base vehicle this doesnt mean much but it is something to keep in mind as the dodge input is significantly stronger.

also the dodge tranny's up to 97 or 98 in gas powered vehicles had a 23 spline output. The dodge diesel's use a large 29 spline The chevy's use a 32 spline output.

The later 96 and up chevy nv4500's use the same gear ratio as the dodges but require a input bearing retainer with a collar as they are designed w/o :!: IIRC. as it was not a big problem. also the early chevy nv4500's have a different bolt pattern for marrying to the bellhousing than the later ones. the later ones share the same pattern as the dodges.

I vote for the nv4500 just be aware that with a dodge input you will have to order a special clutch with a different hub to match. easily done just specify. and if you have the linkage and bellhousing i would do a dodge NV4500 matched to a T176 or T18 bellhousing using your existing linkage etc. If you dont have the linkage i would get the AA bellhousing and either the chevy or dodge nv4500 and then you will have to put the chevy input into the dodge and machine down the input collar. and run a hydraulic clutch. the benifit here is a t-18 clutch for a J truck works

i changed the output in my dodge nv4500 from the big 29 spline to a 23 spline output this also requires a different OD gear both parts were not that expensive and eaily had through inland truck parts up in missoula mt.

As to the 700R4 Paul is right the torque converter does compound the ratio and the 700R4 has a low 1st gear to begin with lower than some other auto's out there. and i believe the number is 20%-25% of the power is lost to parasitic drag correct me if im wrong here. but it is a nice easyt o come by setup. the build up that is necessary to make it last with the torque of the 401 is expensive but well worth the investment if you choose to go that route. dont trust most run of the mill kits nor shops. the 401 shreds these things just like a 454 does when they arent done right

[Mudrat]

... left hand for shifting and right hand for drinking ....

UMMmmmm Dusty ??? Are you in a right hand drive Jeep that you can use your left hand to shift??? I haven't had to do that since the Moris-Mini in Scotland :razz:

Mud

[Lifted79CJ7]

On a right hand drive car - are the pedals reversed as well???

Always wondered.... :-|

[Mudrat]

On a right hand drive car - are the pedals reversed as well???

Always wondered.... :-|
Not in the UK Mini's anyway.

[Dusty]

... left hand for shifting and right hand for drinking ....

UMMmmmm Dusty ??? Are you in a right hand drive Jeep that you can use your left hand to shift??? I haven't had to do that since the Moris-Mini in Scotland :razz:

Mud


Left hand drive, its an art form that takes lots of practice

[Mudrat]

... left hand for shifting and right hand for drinking ....
UMMmmmm Dusty ??? Are you in a right hand drive Jeep that you can use your left hand to shift??? I haven't had to do that since the Moris-Mini in Scotland :razz:
Mud
Left hand drive, its an art form that takes lots of practice
Has anybody told you lately your 8) crazy??

Just thought I'd ask :wink:

[Dusty]

:?: 8) of course all the time but being called crazy is only a matter of perspective or just raising the bar :razz: :sa:

Isnt that what Chevy guys always say to us AMCr's anyways "you're crazy to rebuild that boat anchor" as you spank em downt he line

[jeepsr4ever]

The one I love is...AMC ....aint that ford? 111!!!

[caionneach]

Depending on what route you go with adapters the dodge NV4500 uses a 9 1/4" long input that is 1 1/4" in diameter and the Chevy input is 7" long and 1 1/8" in diameter. on your long wheel base vehicle this doesnt mean much but it is something to keep in mind as the dodge input is significantly stronger.

also the dodge tranny's up to 97 or 98 in gas powered vehicles had a 23 spline output. The dodge diesel's use a large 29 spline The chevy's use a 32 spline output.

[........]

I vote for the nv4500 just be aware that with a dodge input you will have to order a special clutch with a different hub to match. easily done just specify. and if you have the linkage and bellhousing i would do a dodge NV4500 matched to a T176 or T18 bellhousing using your existing linkage etc. If you dont have the linkage i would get the AA bellhousing and either the chevy or dodge nv4500 and then you will have to put the chevy input into the dodge and machine down the input collar. and run a hydraulic clutch. the benifit here is a t-18 clutch for a J truck works

i changed the output in my dodge nv4500 from the big 29 spline to a 23 spline output this also requires a different OD gear both parts were not that expensive and eaily had through inland truck parts up in missoula mt.

As to the 700R4 Paul is right the torque converter does compound the ratio and the 700R4 has a low 1st gear to begin with lower than some other auto's out there. and i believe the number is 20%-25% of the power is lost to parasitic drag correct me if im wrong here. but it is a nice easyt o come by setup. the build up that is necessary to make it last with the torque of the 401 is expensive but well worth the investment if you choose to go that route. dont trust most run of the mill kits nor shops. the 401 shreds these things just like a 454 does when they arent done right

This is very good information. I forgot to mention that I'm keeping the stock NP208 transfer case--no reason not to-- :sa: but that makes adapting the 700R4 a little hairy. My goal is to install the 401 with a compatible overdrive tranny and minimize modifying the existing drivetrain. I could do the T-18, the TF727, or the TH400, but my goal is *overdrive.* The NV4500 from a late 90s Dodge looks to be the best route. Unless the output shaft of the 700R4 can be switched out or modified from 27 spline to 23 spline for the NP208, then the NV4500 is the logical best choice.

I'm not planning on rock crawling (kinda hard to do here in lowzy-anna :laughing5: and I'm not building a racing engine. But I am installing some things like a crank scraper and, much later, a radiator with an electric fan to minimize parasaitic drag. I've done a little looking around, and a beefed up 700R4 is every bit as pricey as a NV4500 if not more so when you specify that the tranny be able to accommodate 400 horsepower.

[KEV]

:idea: Thinking about the 700R4, check the bottem half of the bolt pattern.
If the alinement pins and first bolt are indexted the same in reference to the crank, then section in the top half of the bellhousing. I was thing about doing this so I can run one in my J20 with a 455 buick.

But then again I've lost a few marbles over the years 111!!!

[Dusty]

dodges with the 208's came with 23 splines also behind the np435s for a few years the 700R4 came married to the 208 so i dont think it should be too hairy. probably just a matter of swapping the inputs ordering the correct one.

I am a strong advocate of manual tranny's
:lo1l:

The nv4500's can be had used for $600-900 in great shape, i have bought a couple for that price range and run them. even bought a couple with sheered off inputs from dodge diesels, replaced the input and ran them worked great.

being able to hold 400HP is hard with the 700R4 without alot of cash. its not the hp as much as it is the torque from the 401 that kills trannys manual and automatics. DONT lug the nv4500 below 1500-1600 in OD rumor has it that is what is hardest on the OD gear and the bearings and typically leads to thiewr failure. nice thing though is if OD fails it falls off into the tail housing not the rest of the gear cluster

my whole NV4500 combo bellhousing hydraulic clutch tranny and t-case is sitting somewhere around $2500 with the HD output on the t-case and everything new/rebuilt from flywheel to rear t-case yoke. and i had to put a new input, output/mainshaft, OD gear and bearings in my tranny then the t-case got the HD output, clocking ring and longer input and a rebuild, then the new clutch, AA bellhousing, hydraulic system and flywheel. so it adds up quick but i was aiming for all out rebuilt and new.


I love these ones too
"AMC 360 is the same motor as a dodge 5.9 360"
"401 that motor is a turd my (mildly built) 350 chevy would run circles around my buddy's 77 gagoneer with a stock 401"
"Get rid of that AMC Crap it costs too much to build one and convert to a chevy small or big block"
"the 401 is an aneamic POS dont waste your money" :?:

and then you educate them :wink: with taillights and tire smoke when the light turns green. :t:

[ol' school power]

"AMC 360 is the same motor as a dodge 5.9 360"
"401 that motor is a turd my (mildly built) 350 chevy would run circles around my buddy's 77 gagoneer with a stock 401"
"Get rid of that AMC Crap it costs too much to build one and convert to a chevy small or big block"
"the 401 is an aneamic POS dont waste your money" :?:

and then you educate them :wink: with taillights and tire smoke when the light turns green. :t:
Sure,AMC same as the Magnum 5.9. That's why in the 87 Service manual the AMC 360 is referred to as a 6.0 litre to avoid issues.

[eight]

It should be alot cheaper to buy a chevy 208 that bolts up than to adapt to a jeep 208.

[The PIG Smith]

Automatic Overdrive Transmissions are long standing discussion over at the IFSJA's forum.
Different folks have approached installing a OD Tranny in a FSJ from several ways.
The same logic applies to AMC Go-Fast Cars.

1. Use a GM OD tranny, 700R4, 4L60 or 4L80.
This would require an expensive adapter to go between the engine and transmission.

2. Use a 42RH from behind a 4.0L Jeep.
This model OD Trannys have the AMC bell-housing bolt pattern the we need to mount to our AMC 360/401 V8.
The 42RH is basically a Chrysler A500 OD Tranny which is based on the TF904/999.
These trannys are light to medium duty transmissions and are weak in stock form.
BUT, these OD transmissions can be built to accept the HP output of a V8 but at a considerable cost.

3. One IFSJA member, Ristow, has taken a A518 OD tranny, a close cousin of the TF727,
cut the Mopar bellhousing off and is welding a AMC TF727 in its place.
Check out his posting and his progress:
My Overdrive Transmission Project (http://www.ifsja.org/forums/vb/showthread.php?t=51307&highlight=42RH)

4. There is an on going debate about the idea of taking the rear half of a A518, which is the OD unit of this tranny and mate it to a TF727.
While is appears that it will bolt up, I do not know if it will work.
Some say positively not, some say maybe, some say, why not?


Some issues that will need to worked out with type of OD tranny swap in a FSJ would include:
Rear cross member mounting, stand alone computer for the modern trannys, TV cable or kickdown linkages,
both the transmission and transfercase shifters and speedometer connections.
Larger issues would be transfercase options, driveshafts lengths.

Purpose:
If you performing this swap to save $$$ at the pump, I serious doubt your ever recoup your investment of both time and money in the swap.
If you are performing this swap as a hobbits adventure, and solving all the technical issues are more important to you
than the time and money spend, then I say it is a worth while project