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NP 435 Trans Conversion

6K views 104 replies 7 participants last post by  Jafo220 
#1 ·
I have seen some posts on here with some members doing this conversion. I went with the Novac kit to a D300. I have the trans rebuilt and pulled the t150/D20 out this weekend and ran into an issue. It appears the input shaft on the np435 is 3/4" shorter than the input shaft length of my t150 trans. I measured the entire length of the 435 i put shaft at 8 1/4 inches end to end. I went on Novac and found a new replacement according to their specs it is 9 inches end to end. I know I need to just call, but are there any here that has ran into this issue. I did plenty of research before going this route and never seen anything mentioned anywhere about the input shaft length being to short on certain applications.
 
#4 ·
I believe it is the Ford version. According to the person I bought it from, it came out of a 1 ton ford truck. It was a 4x4 version. I had to order the specific 4x4 pattern for the adapter to the D300. I put the stock t150 bellhousing on the t150 and you can see the input shaft sticking out from a side view. I then put it on the 435 and the shaft is slightly recessed inside the housing. There is no way it can reach the pilot bushing.
 
#5 ·
Yes, I ordered the specific pilot bushing for this conversion. The pilot bushing Novak sent was roughly the same depth as the stock one. Or it appeared to me to be the same length. When I get home I will look again. I will also try and figure out how to post some pics of what I have.
 
#6 ·
I had time to glance at the pilot bushings out last night. The bushing that came with the clutch kit is pretty close to the pilot bushing that Novak sent me for the conversion. The conversion bushing might seat a hair deeper but not much. They look pretty identical.
 
#7 ·
Called Novak and confirmed the input shaft for that trans is 9". Mine is 8 1/4". No idea why. Maybe a different engine application, dunno. But I decided to go ahead and purchase the correct input shaft and install it.

I also talked to him about the pilot bushing. I have been looking at the wrong one. The conversion pilot bushing is installed into the outer bore of the crankshaft, not the inner bore where the stock bushing goes. Don't know how much that will bring the pilot bushing back, but I aim to find out. I will install the special bushing, mock up the bell housing and see what it measures.
 
#8 ·
Called Novak and confirmed the input shaft for that trans is 9". Mine is 8 1/4". No idea why. Maybe a different engine application, dunno. But I decided to go ahead and purchase the correct input shaft and install it.

I also talked to him about the pilot bushing. I have been looking at the wrong one. The conversion pilot bushing is installed into the outer bore of the crankshaft, not the inner bore where the stock bushing goes. Don't know how much that will bring the pilot bushing back, but I aim to find out. I will install the special bushing, mock up the bell housing and see what it measures.
I have mine installed now so I can't measure but basically the back of the conversion bushing will be at or near the front of the original bushing. My original bushing is about 5/8" long so the input shaft can be roughly that much shorter. That's the case with my original 304 anyway (78 CJ5).

On another note, have you decided how to handle the transmission/transfer case mount? This seems to be a relatively common conversion but I haven't found much about mounting. Here is what I am planning to do, I'll use the Barnes4WD skid (3" drop) and bolt it to the 3 rear holes in the frame. This puts the skid kind of far back and leaves the NP435 exposed. I'm thinking about adding an extension that will bolt to the forward most hole in the frame and also bolt it to the Barnes skid so it can be easily removed for servicing the NP435.
 

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#10 ·
I'm also using the Novak poly mount, my adaptor is for the Dana 20 but the mount looks similar to the 300 adaptor. The crossmember I'm using is dropped 3" below the frame, same as stock.

In the pictures I have a 3/4" spacer under the poly mount and with the crossmember bolted to the frame my engine is angled to the rear 3 degrees below horizontal (factory service manual shows 5 degrees). With the 3 degree engine angle the mounting surface on the intake for the carburetor is very close to level (my understanding is that the carburetor should be close to level with wheels on ground normal load, etc) but I'm doing a frame off so it's going to be a bit before I have the body on and can make final adjustments. I do plan to do a double cardan in the rear and I will have to rotate the Model 20 significantly, just not sure how much yet.

Hope I'm not getting too far off your original topic.
 
#11 ·
Don't mind at all, good conversation. It's all relevant to the conversion.

I get what you're saying. I couldn't remember the angle. You seem to be doing it the right way though. Some I have heard didn't. That's why I mentioned those things I did.

The trans mount either way should be about the same between the two. I wouldn't think they're not that far apart other than maybe diameter if that. I have both out on the floor right now. Only reasons I went with the 300 over the 20 was I got this one at a good price and the gear ratio is slightly lower than the 20. The 4:1 kits were a little cheaper for the 300 at the time as well. This 300 was in excellent shape other than some seal seepage. The 20 is just as good a tranfercase as the 300 though. I wouldn't have argued if I had to go that route. That's why I am keeping both my T150 and dana 20 setup. I'll rebuild them and shelve'm for backups or i may find a cj5 that needs a drive train. 🤙

Just hoping I can sneak by and not have to replace this input shaft.😁
 
#12 ·
Good luck with the input shaft. My NP435 came out of a 1978 Ford 3/4 ton 2WD pickup. The swap to my original 304 bell housing worked as advertised with the large pilot bushing. I put in a new diaphram style Luk clutch from NAPA, the clutch was the OEM application and everything fit perfectly so it was a relatively easy swap. This is my first time doing this so I don't know about any differing input shaft lengths, I've been relying on Novak's info and this forum.

Post up what you find out.
 
#13 ·
That was going to be my next enquiry. Mine came with a three finger style clutch. I ordered and got the same Luk clutch kit you have which is a diaphram style. I would hope to think that I should be able to use either one. So I'll try the diaphram and see what happens as well. I mean all other components are the same between the two as far as I know.
 
#14 ·
To confirm, I'm using NAPA part # NCF 1101015. It appears Novak only sells the diaphragm style for the conversion but they also say a stock clutch from 76-79 CJ's will work and that these are typically 3 finger style. In this thread https://www.jeepforum.com/forum/f8/np435-31434/ a couple of guys are saying that the release bearing for 3 finger style will not fit over the NP435 bearing retainer. Doesn't make sense to me, the outside diameters of the T150 and NP435 bearing retainers seem exactly the same to me. In any event, the diaphragm style seems to be the safe bet.
 
#15 ·
To confirm, I'm using NAPA part # NCF 1101015. It appears Novak only sells the diaphragm style for the conversion but they also say a stock clutch from 76-79 CJ's will work and that these are typically 3 finger style. In this thread http://www.jeepforum.com/forum/f8/np435-31434/ a couple of guys are saying that the release bearing for 3 finger style will not fit over the NP435 bearing retainer. Doesn't make sense to me, the outside diameters of the T150 and NP435 bearing retainers seem exactly the same to me. In any event, the diaphragm style seems to be the safe bet.
Hmm. I have both out on the floor right now. Should be an easy check. I have digital calipers as well. We'll find out pretty soon. Both throwout bearings look the exact same to me as does the bearing retainers. Both forks look the same too. I bought a used bellhousing sometime back due to mine breaking where the clutch linkage braket bolts to it. I fabricated a reinforcement bracket that has held up well. It will be going on the new bellhousing. I got a fork with the bellhousing.The only difference I seen, at a glance, between the two clutch types is the diaphram style is not at tall as the 3 finger style.

I bought mine off Rockauto. My part number is 01-015.
 
#16 ·
I measured the outside of both the T150 and NP435 bearing retainer O.D. They are pretty close, so close that I would say they are the same size O.D. I also slid my new throwout bearing over the NP 435 retainer and it's a good fit.

I also got the old pilot bearing out finally. It was slightly wallered out so using my clutch alignment tool didn't quite work. I use the wet paper method. So I kept stuffing wet paper in the hole and wrapped the tip of the tool with electrical tape to make up the I.D. and it finally pushed out. Got the bell housing mocked up and measured from the high ridge on the end of the of the crankshaft back to the outside surface of the bellhousing that mates to the face of the trans. It was right at 6". So there should be enough left on the end of the NP 435 input shaft to go into the pilot bushing. I am still going to double check it after I install the bushing, but it's looking like the input shaft I have now should work. I had no idea the pilot bushing would outset that far but looks like it does and designed to.
 
#22 ·
Thanks.

Got the trans in yesterday. I don't know why, but I had a heck of a time getting that sucker in. I have had my T150 out and back in before with little issue. This NP435 was much different. It was tough. It had less than a 1/4 inch to go all the way in and just stopped. I had to walk in the rest of the way with the mounting bolts. I know it was the bearing retainer bolt heads. Ran into that issue mocking it up with other bolts with shoulders. Went with straight bolts and still was tight.went in though.

I decided to try my original hump cover pan just to see where things line up. It's not like I have heard, where it sets further forward. It looks to me like it comes through the floor in about the same spot as my T150. The case top is different and won't fit through the hole in the cover pan, but it's about the same spot. I think it'll work with a little trimming and the right shifter boot. I'll post a pic bellow.

Well on the the transfer case today.
 

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#23 ·
Yes, those retaining cover bolts are right at the edge of cover, the bolts on mine had a special kind of smaller head. Mine went in OK but I have the body off so obviously that makes it easier. I did have some trouble though and I found a thread here on the forum with some tips on how to precisely center the clutch plate (basically don't trust the pilot tool alone but also inspect visually and by feel all around the disc and make slight adjustments as needed), after that went fairly easy.

Here's a pic of mine bolted to my original 304, looks to be located about like yours. I do think I will have mine sitting in a higher position than is shown in your picture. I've been thinking I would need a whole new tunnel cover. This pic was taken when I bolted it up over a year ago when I was just getting started just to be sure how it fit, this was without the conversion pilot bushing in place so it went in really easy!
 

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#24 ·
Looks like the same position. Mine looks to be a little higher.

I got it all in and now it's a matter of some adjustments. I actually used the original skid plate. It took some fitting and I need to do some more modifications on the passenger side. I had to drill new holes on that side and two holes were not on flat areas. So I'll get some longer bolts and I will fashion some small pipe and weld it onto the skid plate so that the bolts will have a flat area to tighten down on. No biggy though.

I actually started the jeep up and ran it through all gears and checked my reverse lights. All seemed good. I do need to pull my shifter out and bend it back about an inch and half. In first gear, the shifter is right up on the dash. I also have to move my dual transfer case shifter back to the middle hole on the bracket. I can't get either one into low, hits the dash. Then I'll start to modify my stock hump pan and find a shift boot.

I called Tom Woods drive shafts today and have my front and rear drive shaft coming. Should have them by next Thursday. Then we'll really see if it's all going to work and work good.

Um, I seen in your pic that you still have the NP435 reverse light switch. Do you have a connector for that? I put my old one in out of my T150 and it works great.
 
#27 ·
I'm sorry, thinking, no holes lined up on the passenger side. I had to drill new ones. The front and back holes I had to trim out because the holes lined up where the plate started it's downward angle to the middle. Those two I will have to modify later. Right now they have bolts in them but not what I like.
 
#29 ·
That looks like it worked out very well, hopefully this thread will be helpful to others swapping in a 435. Your Jeep is a CJ-7?

I'll be bolting my Barnes4WD skid into a semi-permanent position this weekend. I'll post up a picture. My jeep is a CJ-5 and to start with I'm bolting the skid in place without any spacers but it's very likely I will need some, with no weight on the frame it looks like there is no way the rear drive shaft will work but it's been done before by lots of others so a combination of double cardon shaft, rotating the axle and lowering the skid a bit must work.
 
#34 ·
Should help in really spelling out what you can get away with.

I wouldn't mind having one of those Barnes skids. I decided to put that money into driveshafts at this point. I wouldn't mind upgrading later. Yes post some pics, I'd like to see that in place. It has the removable plate right?

Yes, to clarify, my jeep is a CJ7.

If you would take some friendly advice. I would call Tom Woods and talk to them about your driveshafts. They can help you along with what will work and what won't. I had a good 20 minute conversation unhurried. Learned a few things too. With the Cardon shaft ends it required me to swap my output shaft yoke on the transfer case etc. They can tell you exactly what you'll need.

I had looked in the recent past at some CJ5's. I wouldn't mind having one down the road.
 
#37 ·
I'm using the original torque bar. I guess that Novak poly mount can be bolted in place with the three holes in the poly mount up or down, I have it mounted opposite from you but my Novak adapter only has bolt holes on the wider spacing. I'm using that torque arm as the "preload" plate for the poly mount.

All comments and suggestions welcome as I have not attempted a project like this before.
 

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#38 ·
Finally, here is pic of my rear output and rear yoke. This is with my model 20 axle in about the stock position, it is rotated up about 6.6 degrees. The engine and transmission/transfer case are tilted about 3 degrees below horizontal. The distance from the floor to the center of the rear yoke is about 14" and from the floor to the center of the transfer case yoke is about 24". So vertically the distance between the yokes about 10", horizontally the distance between is about 13". A driveshaft between the two as they now sit would be about 16" long.
 

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#40 ·
I just measured mine. It measured 5" drop from bottom of frame to bottom of skid. But, being it's a stock skid, the mount sits up from the bottom of the skid about 2.5". So taking that, unless my math is wrong, I actually have about a 2.5" drop on the drive train from the bottom of the frame if that makes sense.

I also used the protractor on my phone against the bottom of my trans case and it told me 4.3 degrees.
 
#45 ·
Just an update. Received my drive shafts last night. Had to put off the install until tonight after work. But we'll be putting them in tonight bar nothing else comes up.

The drive shafts look pretty good. But they'll look better on the CJ.😁
 
#46 ·
I may not have much to update for awhile on the conversion. I've got some work to do on the front axle, then moving back to the body to finish some metal repairs before painting. I'm basically happy with how I have the skid, just need final adjustments after I have the body back on it. I will post up how it works out when I get there.

Interested to hear how yours works out when you try it out.
 
#47 ·
I may not have much to update for awhile on the conversion. I've got some work to do on the front axle, then moving back to the body to finish some metal repairs before painting. I'm basically happy with how I have the skid, just need final adjustments after I have the body back on it. I will post up how it works out when I get there.

Interested to hear how yours works out when you try it out.
Ok. So, one thing you will need to consider when you get to that point. Dust shield for rear output yoke. The yoke that you will be getting probably won't have a new dust shield on it. This is what I ran into last night. So how do I get the old dust shield off without major damage to it? Had no idea. So being they are just lightly pressed on, with the yoke setting on it's spline side shaft, I applied some very good penetrating fluid around the base, let it soak for a few hours. I got me a medium size punch, got as close to the the neck area as possible and firmly hit one hit using four points around the neck and it came off! I reinstalled it on the new yoke, and this is where I learned that the bolts supplied with the new yoke are to long to go in the holes with the dust shield installed. 🙂 So, before you put your dust shield on the new yoke, put your mounting bolts in their holes. Then put the shield in place. Then install the yoke on the output shaft of the transfer case.

So with that done, I just got it all together this morning. I had to adjust the clutch out some more. Super sensitive. I have drove a washed out, worn out clutch so long, this is a whole new feel for me. There is a stark contrast between the feel of a 3 finger and diaphram style clutch. The diaphram doesn't feel any easier, just more touchy. I can adapt though.

With the clutch adjusted, tried it out in the driveway, then took it around the block. I am happy to say, the all around lower gearing suited my 2.54 gear ratios. Didn't seem to here any noises that wasn't normal. My first and reverse make some noise when I really push on the gas, but I think that is somewhat normal. But all in all, so far, I like it. I'm taking it out for a little longer drive in a few minutes.

One other issue, I new would be an issue is my front drive shaft to Y-pipe clearance. Bout a 1/4 inch between before the touch. I have an exhaust leak on the passenger side manifold to address also. I will try an post some picks later.
 
#48 ·
Thanks for the dust shield tips.

I had already gone to a diaphragm style clutch a few years back and I too noticed a stark difference in the feel of the pedal. It seemed quite a bit softer to me than the 3 finger style and it was harder to feel the engagement point. I liked the feel of the 3 finger style better but even though the diaphragm clutch felt soft it never let me down.

I assume you meant 3.54 gears, instead of 2.54? I have 3.54 as well.
 
#49 ·
Yeah 3.54. Lol. I missed the three and hit two. Probably spend more time correcting typos, missed that one. 😁

Pretty accurate description on the clutch feel. Spot on. I drove it quite a few miles yesterday. Clutchwise, it didn't take too long to get the feel for it. It is softer. The engagement point is quick. Not much slippage there without the extra rpms. Tried out the 4 hi and 4 low yesterday as well. All that is good.

One thing I had was a vibration between 50 and 55ish mph. The instructions with the drive shafts said that the driveshaft using the CV joint should be straight with the pinion. Well mine isn't. I seen it when I put it in. But the angle wasn't too bad. So I took all my measurements and call Tom Woods again yesterday. Looks like I'll be shiming my rear diff as well. He recommended 6deg shims. So those are on the way. It was not bad, but you could feel it coming up through the seat and had a low deep resonating vibration sound. He said he thinks that the shims should fix the problem.

Of course, I decided to mess with my passenger side exhaust manifold yesterday. A while back, I decided to replace the bolts and wound up breaking one off in the last cylinder passenger side. I used anti-seize compound thank goodness. So I thought, meh, I'll just pop the manifold off and get the broken bolt out. That back bolt is a nightmare. But got it out. In the process, the gasket between the damper part and the manifold disintegrated on me so now I have a bigger leak.😏 Of course no one has a gasket. Had to order them. I am just going to pull both manifolds and replace the studs and new gaskets all around. So I haven't been able to drive it after the shakedown cruise. I did get my broken bolt out. Everytime I touch one thing, it creates another project. You may have to wait a while longer because of doing your resto, but it'll be worth it because you won't have to deal with stuff like what I am.
 
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