NP435/445 to 2.5litre 200TDI

[Dave64]

Hi Guys,

Had a bit of a look and took a few measurements on this. Having a 10mm thick adapter plate (8.5-9mm after machining flat) whose inner circle bolts to existing Range Rover 200 TDI 2.5 diesel fixed with socket head cap screws in existing location. Standard Ford F100 cast iron bell housing will attach to another ring of bolts OUTSIDE that circle. Had to use the DODGE truck version of the input shaft, bit over 8.5 inch. Ford, Dodge and even International harvester versions of NP435 input shafts interchangeable, bearing retainers are NOT, so bit of machining required to fit either Inter or Dodge retainer to Ford bell indexing hole. Had to have a spigot bush turned up to size for R/Rover crankshaft bore and Dodge input shaft tip.

Gave machinist the original alloy R/R bell, the Ford cast iron bell, plus a sheet of 500 X 600 X 10mm thick mild steel plate, already pre drilled to the 200 TDI housing bolt holes and dowell pin locators.

A few little pieces of machining, drilled the clutch throwout lever fulcrum rivets out, install a 10mm flat plate between the fulcrum and the back of the bellhousing wall, to correct both travel and angle of throw.

I used the original R/R pressure plate (9.5") with a 1971-1981 Chrysler 9.5" clutch plate (23 spline X 1"), but had a longer female spline made into the new plate (twice the normal depth). The original set up used a flat face clutch throwout bearing, which I (and my clutch man considered incorrect), so we substituted the bearing with one with the raised face on it. Pressed it and an extended collar onto the original Ford throwout bearing carrier plate.

This may seem like a lot of excessive ginning around, BUT it does have a few advantages. Can use std off the shelf parts for most things, pressure plate, throwout bearing, Ford bearing retainer etc. One added advantage is I can also directly bolt the NP445 all synchro close ratio box to the Ford bellhousing (445 has added lugs which were drilled out to suit the Ford bell at the bottom, top holes were simply sleeved with dowells from 9/16" down to 7/16"). I can also simply by changing the bellhousing to each gearbox, revert to putting a Dodge box behind a Ford engine, or vice versa, simply by changing the input shafts).

Anyone contemplating having a play with these NP435 boxes, just be wary of a few things. The Ford F truck is the best to work with as they are so common here in Oz. I actually swapped the last one for spares, cost me a carton of stubbies (beer, approx cost $45). Second most readily available is the Dodge box (couple of different versions, I used the one from behind the 6 cylinder HD hemi engine, every second farmer has had one at one stage, cost, one large bottle of Bundy Rum). The Inter can also be obtained reasonable easy but are a bit trickier because although all internals are the same, have different cases, input set ups as well as different outputs.

Although the NP445 will bolt up to anything, anywhere the 435 will, the box itself is getting extremely hard to get hold of, and very few internals available, if at all. I think you SHOULD be able to get seals and bearings, gaskets etc, but hard parts may be a different story. I bought the box from the US, payed for it in April this year, arrived and cleared by customs only a week ago.

Way I figure it, going to install the 445 behind the 200TDI. If the box has a hemorrhage, simply reswap the bellhousing onto the 435 and drop it in.

I haven't added anything about the output side of the transmissions, as there are half a dozen mobs who can pull conversion kits off the shelf, e.g. Novak, Advance Adapters, plus a few smaller outfits who make adapters to any number/style of transfer cases. My project calls for a simple engine swap to transmission.

Why go to all the trouble? First off, I am a 'tinkerer', can't help myself, someone says it can't be done, makes me all that more determined. Secondly, these NP435 boxes are legendary for toughness, can be very easily obtained, are extremely simple to work on.had been used by just about every manufacturer since 1960 odd, still installing them in certain applications up until the 90's

Drawbacks? NOT an overdrive box, 4th is still direct. They are a very heavy box, quite large, someone once described them as a mass of huge gears encased in cast iron!. Sure, you can break them, break anything doing something ridiculous, but matched to the right engine/T.C, setup properly, they really are almost 'bulletproof'.

Bloke in the US even tinkered around with changing the input tooth/ countershaft tooth count thereby altering internal ratios ending up with 3rd gear as an overdrive ratio, direct 4th as normal, 2nd gear as an underdive. Interesting concept, ended up with almost the same ratios as the Chrysler A833 truck transmission, maybe a future project? got plenty of spare 435's laying around.

Cheers, Dave

[Dave64]

Just a bit of an update re that cobbling of 2.5L TDI 200 engine to the NP gear box. I ended up using the NP445 version (close ratio, all_synchro) instead of the standard NP435, although the Ford bellhousing has been machined to accept either the Ford OR Dodge, even Inter. variations.

Pretty straightforward, no great unexpected dramatics. Had the old 5 speed R/Rover manual box for sale for a while now, only asked $50 for it, never even got any enquiries. Probably understandable, didn't have the transfer case with it. I don't know Jack about these transmissions, but to my eye, they look pretty light duty, wouldn't like to be dumping too much torque into them. Put me in mind of when Jeep got away from heavy duty light truck transmissions and started putting tinkle alloy car boxes in them. I do stand to be corrected on the ability of those R/Rover transmissions, no doubt someone will have a story of how they pulled a D9 out of a bog with one!

Cheers, and all the best for the silly season, Dave64

[Carloz]

In my Dodge WC62 sits a NP420(??), like in all of the Dodge WC-series. Looks generally the same but that one is a sliding gear non synchro crashbox with strait cut gears: a very "basic" gearbox with a super wide ratio. ,

[Dave64]

NP420?? Man, that's gotta be an early girl, I thought they went the way of button-up boots!

Have to be pre-1960? 435's first came out early to mid sixties, did they not?

Dave

[Carloz]

Hahaha, never heard about the Dodge WC-series? It's from WW2! :-)

[Carloz]

NP420?? Man, that's gotta be an early girl, I thought they went the way of button-up boots!

Have to be pre-1960? 435's first came out early to mid sixties, did they not?

Dave

Hello Dave,

Well... just learned a bit more about these New Process boxes..

NP420's where used in the Dodge M37 miltary trucks for example... In my Dodge WC62 is an even earlier version!

NP420 has synchro on 3th & 4th gear and even helical cut gears on 2,3&4th!! :-P

I am looking for a Dodge close ratio NP435 with suffix "A". "A" means it is a Dodge or GM close ratio version (1st gear 4,56 : 1).

Maybe you can help me with some measurements (Dodge version)?

- I am looking for the mounting holes to the bellhousing

(in my bellhousing it seems to be right: Horizontal two holes above the inputshaft, 9" from eachother and 2 just under the inputshaft, seems to be 8 3/4" from eachother. Vertical left side 2 1/2" and right side 3" from eachother)

- the outside diameter of the bearingretainer which lines up the box with the crankshaft (I expect it to be 5,125")

- Is it possible to machine down to 4,75"? (the actual diamter in my Mopar Flathead 6, 230ci)

- Length&diameter of clutch release guide

- Length of splined part of inputshaft

- Length & diamter of pilot tip

- Total length of Input shaft to mounting fase (I think it is 8 3/8" for NP435? And it is 8" for my Dodge WC one)

- Length of box

- Distance between mounting face to the hart of drive shaft yoke

Pff... sorry.. a lot of questions.. But it would help me a lot! :-)

A close ratio NP435 would make life a lot better in my old truck. But still keeps the original apeariance as much as possible. :-)

[Dave64]

Carloz,

I too had a bit of trouble with the close ratio version of the NP435A.

My close ratio box has the tag NP445 on the case, but all my paperwork will say that it's a NP435 and they are interchangeable. A few blokes on the forums in the states seem to be at odds with this.

I can tell you that of both the boxes I have here (3 actually, 2 in pieces) they all accept the same bellhousing patterns and input shaft retainers.

The bellhousing I have is the cast 318 version out of a campervan, I will have to have a fossick around out in the garage loft and take a few measurements, again I can tell you that the 'ears' on my Dodge version NP435 are the same as the NP445, but without confusing the issue, I used the Ford version bell as it suited my application better, simply redrilled the holes on the lower two 'ears' Early boxes may not have these ears, but if you are simply swapping Dodge to Dodge, shouldn't be an issue.

I'll copy your measurements down on paper and get the Dodge bell out and measure it, hopefully later today.

I have no idea which engine/bell you are currently running, flathead six(?), but Chrysler did confuse the issue a bit with their NP435's, I have an early NP435 bell at a mates place, from behind a slant six 225 has one style, have another sitting in an Oz built D5N 200 behind the 245 Hemi HD has another style, one from behind the 318 different again. Probably going to have to work off those measurements you have posted.

As to availability of earlier NP435A's in the G.M. version, I hunted around for quite some time, posted on several GM as well as Dodge sites. Couldn't locate one. Did find a few Dodge versions, but getting a bit hard to get. I had to import mine from the states.

Leave it with me and I'll see what I can come up with in relation to your measurements. Sorry, read your post again, 230 flathead!

Can answer a couple of questions off the top of my head, if you are going UP in bearing retainer size, you can either have the index hole machined out, OR, you can do what I did and have the outer diameter of the input shaft REDUCED. We are only talking a very small amount. I have had the pilot tip on one shaft shortened, again if it's only a small amount, you have plenty to play with. All these ones I have here are the later hydraulic throwout bearing type, again, if you have to shorten/lengthen the actual sleeve that the carrier slides on, no great drama, I had mine done. Any good lathe man can turn one up. Thought about your spigot shaft bush/bearing? Again, a lathe can turn one up out of sintered bronze.

Just one little thing to watch for Carloz, Dodge (Chrysler) used these NP435's across a very large range of models and also for nearly thirty years in many slight variations. Some input shafts ran rollers, some had tapered rollers and I have heard, but not seen a version with needle rollers.There are several different length/spline count/ shaft diameters on the input side. Also on the back of the box again, several differing lengths/splines, not to mentionthe difference between 2WD and 4WD versions with and without the handbrake drum set up, but that's an easy one to work around.

Cheers, Dave

[Dave64]

OK, Carloz, try these for size, and remember I am taking the measurements from MY NP445, or as it is sometimes called, NP4350. Whether it differs from the NP435 close ratio, I can't tell.

Maybe you can help me with some measurements (Dodge version)?

- I am looking for the mounting holes to the bellhousing

(in my bellhousing it seems to be right: Horizontal two holes above the inputshaft, 9" from eachother and 2 just under the inputshaft, seems to be 8 3/4" from eachother. Vertical left side 2 1/2" and right side 3" from eachother) Taken with a digital vernier, I came up with these:- Top two holes=8+9/16". Bottom two holes 8 +3/4". Vertical LEFT side=2.958" Vertical RIGHT side= 2.903" .ALL MEASUREMENTS TAKEN WITH VERNIER TO CENTRES OF HOLES! You'll have to convert decimal to fractions.

- the outside diameter of the bearingretainer which lines up the box with the crankshaft (I expect it to be 5,125") CORRECT! 5.125"

- Is it possible to machine down to 4,75"? (the actual diameter in my Mopar Flathead 6, 230ci). You may be better off either machining a "collar" to press fit OVER the smaller bearing retainer, or size your retainer down FROM 5.125 TO 4.75. You would have to check whether you would still have enough "Meat" around the retainer so as it won't leak, but still retain it's strength.

- Length&diameter of clutch release guide. :- Sleeve from face of bearing retainer to end of guide (sleeve)is 3.087" X 1.255 O.D. X 1.0255" I.D.

- Length of splined part of inputshaft:- 1.650"

- Length & diameter of pilot tip:- 2.150" X 0.750"

- Total length of Input shaft to mounting fase (I think it is 8 3/8" for NP435? And it is 8" for my Dodge WC one):- Again, pretty close, 8+9/16" * see below

- Length of box NP435 std box, face to face of case :- 10 +13/16" MY NP445 (NP4350) :- 13.00" ** see note below

- Distance between mounting face to the hart of drive shaft yoke on MY unit, :- 5 +1/16" *** see note below

Note * You say 8 3/8", mine is 8 9/16" difference of 3/16". HOWEVER, there are as previously stated, quite a few variations when it comes to both input and output shafts, even on Dodge. Early Dodge used 10 spline inch and a sixteenth coarse spline depending on size of engine and truck fitted to, normally pick then by the parking brake drum on rear of gearbox, have been a few variations though. Everything I have here has the LATER one inch diameter X 23 spline common Chrysler/Dodge for smaller trucks!

Note ** I cannot with any honesty tell you if the early GM/Dodge NP435A gearcase is the same as other NP435's. I have always thought that the extra length in the case was to accommodate the extra syncro set up, plus the modified input bearing from flat roller to tapered roller and throw in the fact that they reworked the location and position of reverse gear inside the box itself, BUT had retained exactly the same shift pattern.

Note *** Again, a few variations when it comes to your output shaft measurements. I have two here have identical lengths, yet one has the speedo drive on one side, the other box has it on the other side. Also have differing output bearings and seals in the actual housings, yet use the same yoke. Can't tell you why.

Hope all this waffle is of some use to you. Personally, having two NP boxes side by side, I would opt for the close ratio all-synchro every time, UNLESS I were switching to a very low (higher road speed) diff. As both trucks have reasonable existing gearing, (4.10 on the tray truck with 7.50 X 16 tyres) and the Postal has 3.73 ratio on roughly the same overall diameter tyres (31 X 10.5 X 15") with NO more body weight than the WW2 Jeeps, For me I can't see it being an issue.

If I can be of any more help, don't hesitate to drop a line. BTW, two questions, are you running a transfer case? If so, I am surmising it is the island or divorced style, if so you will possibly have to shorten the jack shaft between the main gearbox and the transfer case because of the extra length (2 3/16"). If like mine a simple 2WD, it won't worry you, just shorten the main tailshaft.

The other query, roughly what size is your jigger? Certainly the all-synchro option is highly desirable for driveability, you obviously have nutted out your tyre sizes as well as final drive (diff) ratios.

Cheers for now, Dave

[Carloz]

WOWW!! That's a lot of useful information!

Thanks a lot! And sorry for Hi-Jacking your topic!!

I am going to verify and make new measurements on the stuff overhere: all is taken appart because the engine died on our last trip, all crankshaft bearings are gone... So now its a good time for an power and gearbox upgrade... well... I mean... lets keep looking at sunny side of this..

Regarding your questions:

The original crash-box has (about) the same ratios as a wide ratio NP435. We have changed the diff ratio from 1:5,83 to 1:4,89 with the original 9,00x16 tires (35"/36"-ish = 90cm).

With the old diff ratio I could drive away easily in second gear, 1st was useless on the road. Sometimes handy for use in ww2 commeraration parades. With the new, taller, final drive we can cruise 80km/h / 50mph with a resonable engine rpm (around 2350rpm) but, off course, its now getting hard to depart in second gear and 1st is still super short. Also when down shifting from 4th to 3th its a much to big step: 3th is 1:1,7! So when you shift down to early the engine will explode..

So a close ratio NP435 ("A"-version) is very desirable indeed!

There is a, also ancient, divorced transfercase: NP200. It's the 1:1 Hi and 1:1,5 Low version. The later M37 version is 1:1,97 i Low. There is an quite short driveshaft in between which can made even shorter.

The size of my jigger... hmm... I am not sure of what you mean with this.. :-) Maybe you mean this: It's weighs almost 3tons and has six wheel drive.

[Dave64]

Carloz,

Don't sweat about "hijacking" my post! I am now a bit interested in your own jigger. If your rebuild is going to take some time, can I suggest that you take progressive photo's? I either use a small pocket camera (or the iPhone and snap away as each component is assembled). When you get to my age, it's the only way I can remember the correct order things go back together!

If you don't wish to post photo's here, you can always send me a personal message. Best of luck with the rebuild, particularly interested to see just how your upgrade transmission adapts to an early girl engine. Maybe you could send a few details about your own Dodge?

Cheers for now, Dave