The Stovebolt Site Forums The Parking Lot Big Bolts New Process 540 application? will it swap?

Im looking at a NP 540 transmission to purchase but the guy doesnt know what it fits and Im unsure as well. The tag states, ratio 606...Serial # 9 8 72. Case casting # C92581AG. Questions are, is this a GM application trans.? Is this a 5 speed with overdrive? Is the serial number the date of manufacture, if not what is the date? Might this bolt up or be easily adapted to my 1955 6500? (original 261, 4spd, 2spd).
Thanks, Patrick

GM used a lot of New Process transmissions. It was what we call a vendor transmission. I'm not sure who else used it, but they were common from the mid 50's through the 70's. It could have been built in 1972, They usually had a suffix of CD, CL or OD. CD had the deep 1st gear, CL had the close 4th and 5th ratios that we called a "working 5th" and the OD denoted 5th over. They had a larger input shaft than a 4 speed and usually were used with a 13" clutch. I remember guys putting the OD models in their 55 2nd series trucks, but I'm not sure if the 1st series has enough room for the larger clutch housing. And if its a 5th direct, you wouldn't gain anything. NP 540 have 4 shift positions toward the dash and 2 toward the seat. Put it in the gear that would be away from the driver toward the seat and turn the input shaft. If the output shaft turns the same speed, its a direct. If it turns faster, it would be an OD.

I have one of these in my 72 C50 and I love it. So much better gear spacing than my SM420s have had and potential for dual PTOs. Mine is 1:1 5th gear. I've been over 18000 lbs going over one of the steepest grades in the PNW and sure appreciate the tighter 3-4-5 spacing. I have a spare setting in the garage, but I doubt I'll need to put it to use when you look @ how it seems to be built.

I'd really love an NP540 with a GMC 302 in my 49 COE if the 235 or SM420 ever gives up.

I wonder what kind of luck others have had with this trans.

The bolt pattern on the front of the trans. is GM, or Ford, or IHC, or Dodge, etc. They come w/ large, long input shafts(not very useful), and short input shafts. Parts are getting hard to find. An excellent, close ratio trans, OD ones are rare. I mated one to a Dana 20 in an early Bronco, and Dana 241. Look in 1.5 ton trucks, never came in pickups. Most yards don't know what they are, don't bother asking, just look. Al top cover w/ 4 shift rails, two steel pins in top of Al housing shift ball rotates on get loose, wear item.

I ended up with the trans., it is Dodge. It was part of a package deal which included a rebuilt 57 Desoto Hemi, a 56 Dodge medium duty bellhousing with 13" flywheel and pressure plate. Also various spare parts. My guess is that sometime back the original engine went sour in the Dodge and someone snuck in the Desoto Hemi. I havnt 100% verified that the trans is 1:1 but Im pretty sure it is. I know this is Bowtie/GMC country but if anyone has a line on a clutch for this please let me know.

Thanks

Some photos... http://www.flickr.com/photos/17087539@N07/

You probably need to get the clutch rebuilt. What does the tag on the transmission say? Or put it in 5th gear and see if the input and output turn the same. What are your plans for the hemi?

As far as the clutch goes Im missing the throwout bearing and clutch disc. The tag reads- NP 540, Ratio 606, serial #9 8 72, assm #3458638D052. I havnt completely decided where the hemi is going to reside. We do have a 58 Morris Minor that I originally bought to build into a street driven 60s style straight axle gasser, I have a 327 and a M22 that was going in it but that hemi would look wild in that tiny car. What ever the hemi ends up in Im leaning pretty heavy to selling the NP540 and components to help fund the project. I was up till midnite last nite looking at all the different transmission adapters available for this engine and may end up going against my grain with a 350TH automatic. Out of all the vehicles we own, 55.1 6500, 59 Bel Air, 58 Morris, 46 Dodge/40 Chevy "Johnny Cash Special" truck, the only automatic we have is our 77 Ford Pinto Station wagon, and my wife only drives automatics. Plans for the hemi will be on hold for awhile, Im trying to stay focused on the 59 and hope to get it finished this year. At the same time Ill be keeping my eyes glued to the internet looking for hemi parts.

1955first6500,

You sure do have a nice collection of small engines...

The COE looks pretty good also!

Mike B

The number of photos on my Flickr page doesnt even begin to show the number of small air cooled engines I now have since those were posted, that and old walk behind mowers and tractors, I may be having a big sale in the spring to liquidate some of them, its gotten a bit out of hand but I do love the old stuff. The COE I sold to a local guy a few years back, he still has it, of course I still kick myself for letting that one go. Thanks for your nice comments.

This is a sickness with no cure!!!

I know a man that collected big antique car from the teens and 20's along with gas and auto memorabilla. He auctioned it all off a few years back for over $1 Million just so he could start all over again, he just loves the "hunt".

Mike B

You lucked out on the 540, it looks like it has the short(about 6") input shaft. Can bolt to just about anything, just drill and tap the bellhousing for this bolt pattern. Bottom holes may be taped already for mounting bolts to be inserted from inside bellhousing. A good, close ratio trans., not stong enough for a 6BT, fine for a 4BT, 4-53, etc.

Probably won't get more than scrap price for it, save for appropriate project w/ diesel for you or one of your buddies. Easy to adapt to transfer case w/ stock Ford adapter off 435.

The numbers are probably Dodge numbers which mean nothing to me. However, most of the New Process had a 6.06 first gear. They could either be a close ratio between 4th and 5th or a wide ratio with a .81 overdrive. If it is an overdrive, someone is probably looking for it. The best way to find out is to put it 5th gear and see if the output turns the same speed or faster than the input. They are tougher than one might think. There were literally hundreds of them behind 409 Chevs that hauled grain from the Texas High Plains to the port in the 60's and they took a lot of abuse and stayed together. I ran a NP541 behind a GMC 370 V8 and grossed 80,000 and never did tear it up.

Do you mean to say that I could mate this trans. up with my 6cyl Chevy bell housing, drill and tap the mounting bolt pattern and be good to go? And if so I use the Chevy flywheel and clutch? From the transmissions bell housing mating surface to the end of the input shaft it measures 9-1/4". To the end of the spline it measures 7". The diameter of the end of the shaft is 1/2". The diameter of the spline is 1-1/2". The transmission in length, bell housing mating surface to roughly center line of u-joint is 18", how does this compare in length to the SM420?

1955,

The SM 420 has a 10-1/2" long case. The Input Shaft is 10-spline, 1-1/8" diameter with a 19/32" pilot tip and it sticks out 6-1/2" from the face of the case.

The output shaft can have a single band brake drum, a 2-shoe drum brake or no brake drum.

Mike B

Thanks Mike, I appreciate the info.

It took making a few marks and a number of turns of the input shaft but I did determine that its an overdrive. What confused me was an earlier mention of the shift pattern, but today I found out that on an overdrive 540, 4th and 5th gear shift positions are swapped (4th to the right and down and 5th(OD)straight up(top right). Im tickled, but to bad this trans. isnt meant for my Chevrolet.

I have a NP541 OD in a 600 GMC and it is a real goofy thing to drive. 1,2 OD and reverse are towards the dash, and 3 and 4 are towards the seat. There is no other transmission like it and it takes some breaking of old habits to drive it. The direct close ratio takes some learning too because the sequence is 4th low axle, 5th low axle and then back to 4th hi axle and then 5th hi axle. It took some learning, but the close ratios in the top 4 gears were boss on the Texas high plains.

So, I was mistaken if the input is 9.25" long. You can still use it, however, just make an appropriate(about 3") spacer to take up the extra space. Must register the retainer correctly, or, search parts places for a short input shaft w/ the correct # of drive teeth for the cluster gear.
The trouble with making an OD 5th, is they take away 3rd. gear to make OD, thus leaving a large gap if there is no 2 speed rear.

Im seriously considering the swap. I have a spare bellhousing I could mate up with the trans. to see how the new holes might lay out. I would try to locate a GM input shaft. I would also need to locate a PTO to keep the hoist bed in operation. And yes my truck has its original 2 speed rear, after having one I couldnt imagine not having one. The NP is longer than the SM so shorten the driveshaft. The NP has the same type of emergency brake set up that the SM has but Ill probably have to lengthen the bracket. Im sure Ive missed some things, Ill know better once I start digging into it, probably closer to spring.

A Chevy input shaft may work OK, however, it is important that the gear that drives the cluster, is the same as you have now. I would remove the existing input shaft to carry around w/ you to see if it matches up with one you might find. I have seen different input bearings also, that should be easy to fix.

I looked at the 2 Chrysler 540's I have, both input shafts stick out from the front of the trans about 7.5", 1.5" spline, 17 teeth on the cluster drive gear(about 3.25" O D), Px if you wish. Easy to get clutch disc w/ variety of spline counts from clutch rebuilder; 1" +/_ thick adapter should be easy to make, take care of Chrysler shift rail stick out. Chrysler is only one w/ this stickout, so, if it is a problem, a top shifter cover from other make will fit, however, there are at least 2 styles of shift covers that are hard to tell apart, so make sure to get a guarantee that another one will fit before you purchase it. Make sure pins at top of shiftcover are tight.

I have been looking for a PTO for a NP540 anyone know which will fit and where to locate one?

I bought my np540 pto from a truck wrecking yard in Colorado, found it using google.

I have a large 10 spline input np542gl that may be up for grabs if one of you are interested. Right now it is behind a 4-53 Detroit in my 61 k20. I have both the standard shift knob and a NOS shift knob with the electric 2 speed axle switch built in.

Off topic sort of, i hate to hijack a thread, but Ed Pruss could you please elaborate on how you swapped an np540 into an early bronco. I am trying to do this and you are the only reference of a successful swap I can find on the internet. An help would be great! Thanks if replying here is inappropriate please PM me.

Does anyone know if the NO 540 short shaft and long shaft are the same diameter?

Are you referring to the input shaft?

Nevadasmith,

I used stock GM bolt pattern 540 with short input shaft. Stock 6 cyl. Bronco transfer case adapter(shorter than V8 one), bore front of adapter to same as rear brg. of 540, drill and tap holes in rear of 540 to match adapter, including oil circ. holes. Victory gear welded output shaft of 540 to transfer case input gear. That is the easy part. Since there is no longer the rear nut on the 540 output shaft, must keep it tight. I had threads ground(common exercise) on output shaft of 540 next to rear bearing, and made a split locking nut to fit those threads. Made for a very handy operation, up to 14,000. Loads.

Optional application for NP-241C(etc.) transfer case, use stock transfer case from an NP-435 4 speed trans, same bearing as 540 output, drill and tap holes, etc., get powerglide adapter set from Mark Williams(Louisville, CO), one to fit 35 spline, 90 degree output of 540, tighten with stock nut, other half to fit whatever input splines of transfer case. Might have to use additional splined shaft to make up correct length.

Ed

Yes my question is about the input shaft. You say there is a short input shaft that will allow swap to pretty much anything without much modification. Do you know the diameter number of splines and length of that short input shaft? I’m looking to put a NP540 in my Chevy that has a L6 261 / SM420.
Thank you