Finally caught a break NP440 / MY 6

[par4tom]

After 3 months, forty or fifty phone calls, three false starts and numerous disappointments, I was finally able to piece together an NP 440 / MY6 transmission.

One of the guys here on the forum got me started on this venture and I think I'm really going to appreciate the fact that he did.

First, this transmission if a 4 speed overdrive unit that allows me to still have some fun working a manual transmission. Captain Fab hooked me up on the brake booster bracket for the hydraulic clutch and the quality was first notch. Not to mention, his pricing is really, really affordable for what you get. Those of you sitting on the fence, get hooked up with him. He's a wealth of knowledge!

For those guys that are looking to find one of these trannies, all I can say is good luck! The Car-Parts website is basically a huge misprint, as a lot of the yards say they have this tranny, but what they really end up having is something completely different.

For somebody who is looking, Hon's in SC has a complete unit with rods but no shifter. It includes the bell housing.

Also, S-K Speed on the east coast, has a slew of these transmissions complete and ready to go. I think he said he had 10 of them. He also has the shifters. Just be ready to cough up about $2,200 to $2,500 for the complete unit rebuilt.

As for me, I found the transmission I was looking for in Oregon, Music Man had a nice shifter and two sets of rods in Chino Hills (Thanks Music!) and I found a third set of rods in Montana that will work with the forward/offset bracket like mine.

All in all, I spent about $700 for the complete unit and that included having the tranny serviced with new seals, turning down the front bearing and complete tuneup of the rods and shifters.

It shifts really nice...can't wait to get it into the truck and running here soon.

Thanks to the forum, Music and Captain for the help...my wallet hurts a little bit more but I'm having a blast pulling this whole thing together. The sense of accomplishment is the best part...

If somebody else is looking for this tranny, hit me up as I'll try and help you out. I feel I owe the forum a favor after all the help you've given me.

I do have a couple of sets of rods but each set is for a certain type of mounting bracket. Music Man can tell you about that...









Here's a few before and after pics...good luck on this! And don't wait to find one...they have all but disappeared!

[par4tom]

And here are a few before photos...and a bit better after photos. Just goes to show you can't judge a book by its cover...a pressure washer, degreaser and about 4 hours of scrubbing didn't hurt either.

T

[Rich 5150 69]

I`ve been searching as well. got a few leads I need to check out, two of them a good promise...

[LEEVON]

Yours looks great! We're a small group that's for sure. I have one in my '50 chevy truck, behind a 5.3L. Can't wait to try it. I saw three at a swap meet recently, one from a rebuilder. I guess I should buy those next year LOL. I got my bellhousing from a guy through www.car-part.com I guess I was lucky because he knew EXACTLY what I was looking for. I think his info is in my "Popeye" build thread.

[par4tom]

Rich...Hon's in GA has a complete unit with the bellhousing (not the one like I have). I think she wanted $350. Sorry, no shifter! I have a picture is you want it...just PM me and I'll send it across.

If someone has the shifter...they are worth something because where else can you go for an overdrive without having to deal with an electronic speedo issue?

With the shifter, I'd say if you can get them for $300 to $350...a good cleaning and you should be able to sell them all day long for about $550 to $600. Or, if you need one...I'd say $600 to $700 is about the bottom of the market price wise.

You're right...we need to start a MY6 club...Music Man has a ton of good info on this thing. Someday, it would be nice to collaborate on a FAQ for this tranny. There's really nothing else like em!

Cast iron trans are pretty easy to find, and so are the aluminum ones with the Chrysler/GM bolt patter. Its the ones with the t-10?? / Saginaw pattern that I had trouble finding. I'd like to find another one just so that I have it...

BTW - What fluid are you using inside? There was a thread saying gear oil, DEXRON II, 30 weight...what's worked for you? OEM said DEXRON...

[Blue666]

I have one behind a 350 in my 66 Short bed Fleetside. Mine has the clutch fork on the driver side. I have had trouble finding shifter rods but recently picked up some straight rods at the pick & pull. I might try to bend them up into something usable.

I'll get to Captain Fab for the brake clutch set up.

[Rich 5150 69]

Did you get the bell housing with it......you may not have the right bell housing, they are bell housing specific...

http://www.chevelles.com/forums/showthread.php?t=349891

[Blue666]

Rich 5150, That is the bellhousing that I have.
I purchased a complete unit; flywheel, clutch, pressure plate, throw out bearing, fork, bell house trans, shifter, output stub of drive shaft.
Two of the three rods were lost during shipping. I have been struggling ever since to build or convert some decent rods. I drove the trans for about four years with flimsy rods.

I am currently working to get my rust issues fixed and some other things complete before getting back on the road.

[Rich 5150 69]

Originally Posted by Blue666

Rich 5150, That is the bellhousing that I have.
I purchased a complete unit; flywheel, clutch, pressure plate, throw out bearing, fork, bell house trans, shifter, output stub of drive shaft.
Two of the three rods were lost during shipping. I have been struggling ever since to build or convert some decent rods. I drove the trans for about four years with flimsy rods.

I am currently working to get my rust issues fixed and some other things complete before getting back on the road.

Actually meant this for Par4tom, his does not look like it...just curious if they had more than one bell housing for GM...

[MusicMan70]

Par4Tom, That tranny looks great all cleaned up and ready to go! Thanks for posting the photos and the compliment. I was happy to help with the shifter.

Now you have become an an expert on this too; as far as the hunting and disseminating which parts are correct and what will work.

I used this Amsoil product in mine; forgot the capacity, but at least two quarts I think. It was referenced in the Classic trucks article as well.

[MusicMan70]

Rich 5150 69 Re: Finally caught a break NP440 / MY 6

Actually meant this for Par4tom, his does not look like it...just curious if they had more than one bell housing for GM...

Rich 5150 69, yes I think there are two style bell housings for these. If you look at the pic you can see the dual pattern used; it just has plugs in them.

[gimmy 64]

so my question is why don't you go with the modern 5spd? if these things are so hard to find, just asking

[Rich 5150 69]

These have a torque rating just below the muncie....

[par4tom]

Gimmy maybe in hindsight I should have. I kinda liked the "old school" aspect of this tranny.

As far as the bell housing, this tranny bolted right up. Mine has the mounts on the bellhousing and quite honestly, I wasn't all that excited about cutting the existing crossmember as it had one of the brake lines attached to it. Plus, I would have had to move the clutch to the drivers side, cut the hydraulic clutch hose down, weld in a new crossmember, rebleed all the brakes and the clutch.

Maybe I m just getting old.

Got the tranny mounted on the bell housing and into the truck. It was really easy...one person job even.

Message me on the rods if you need them. I have two complete sets and owe the forum a favor...

Rich, the bell housing you see in the picture above is the one I had in the truck already. It was bolted up to the original SM 420 Granny Tranny. It's the same bolt pattern that all the Muncies used. I have the "horseshoe" motor mount on the front of a sbc 350.

Old school...old school sound with about 350 hp!!!
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[rcbildr]

Is there a write up somewhere here on this transmission????

[MusicMan70]

Some reference articles

http://www.classicjunkyard.com/new_process_a833.htm

http://www.customclassictrucks.com/t...n/viewall.html

[Brad54]

I wrote that story for Custom Classic Trucks.
I've got one in my '61 Suburban, and drive it daily. Honking down the road in OD with 3.42 gears is great.
I've put around 50,000 miles on mine since having everything rebuilt, and it's never given me the least bit of trouble.

I found an exploded one at Charlotte last year, with a destroyed case... I need a tail housing for my spare. I also found one with an iron case--I'd like to get that, just because they're even tougher. In the Mopar world, the aluminum case has proven not to like high horsepower, as the counter shaft registers right in the aluminum case, without a bushing. After some serious abuse, that shaft will start to wallow out the hole in the case, and then things go very poorly, as the shafts pry themselves away from one another, etc.

The iron case would definitely fix that.

But the aluminum trans has been awesome for me... the reason I'm looking at that iron one is because I REALLY like this set-up, and would consider the iron case a "LifeTime Part."

-Brad

[Rich 5150 69]

As I understand it the iron case is the old style A-833 four speed, they are not idenntifiable from the standard mopar four speed other than the linkage that is hopefully still attached, the 3/4 shift linkage is upside down...it also came in three differant tail shaft housings a-body, E-body, b and c body....still researching this.

[MusicMan70]

Brad54

I wrote that story for Custom Classic Trucks.

Well then Brad54, THANK YOU!

That article was the reason I chose to go with that transmission. I always reference it when I get the chance. Aside from the challenge of acquiring all the right parts, that article made the changeover so easy.

I have 3:92's in my 61 Burb and the overdrive is perfectly matched with my GMC V-6. My hat's off to you.

[par4tom]

Me too! I liked the article and hope to enjoy the transmission as well.

Hey Brad, how much horsepower is too much for the aluminum case version.

BTW, the cast iron versions are relatively easy to find.

Tom
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[BLK65K10]

Brad54 thank you for the article. It started me on the hunt for one years ago when I had my 66 SWB. I ended up buying a couple of different trannys but never go to finish the install and had to sell the project to pay doctor bills. I had the cast iron case one out of a 83 gmc pickup with a diesel. It excepted the standard chevy bellhousing.

[par4tom]

Here are a few photos of the installation...it was simple and aside from someone holding up the tailhousing while I set the bellhousing mounts, easy!

As far as fluid went, I've heard more opinions on this matter than I can shake a stick at. In the end , I went with the Dexron III fluid as was in the original GM service manual. I'll let you know if there is any whine once I'm done. It took just shy of 4 quarts to fill...

[kieth]

What is the OD ratio in 4th gear, what is the torque rating of the transmission. ?????


ok i found it , it is a .73 in 4th gear. I think one could find a later model 5 speed and be happier with it. nv3500 or 4500, they are readily available and cheap......and have a taller OD ratio. If they are inexpensive enough they could be worth it. JMO Kieth

[Rich 5150 69]

Kieth any of the other two would be a viable option for an overdrive, the 3500 actually was replaced with the NV-3550 it only has a torgue rating of 300 ft lbs, same as the t-5 trans, the NV-4500 is a very tough trans, also very heavy trans, at 200 lbs, if you decide to get either of these two trans, get one from the GM line up as the input shafts are differant from the mopar version, also one not thought of by many is the Asin-ax-15, used in the jeep from 92 to 99 5-speed, though the MFG never gave the torque ratings the jeep owners that have them say they believe its in the 375 to 400 ft lb ratings these trans were used in both four wheel and two wheel applications if found in a two wheel model you wouldn`t have to find a tailshaft housing for it, all these trans can be installed in our trucks in one of two ways, either by adapter to chevy bellhousing, or by specific bellhousing sold by Novak or thru Summit, and or Advance adpters. Novak website list all the trans specs and adapters/bellhousings....happy reading...http://www.novak-adapt.com/catalog/a...s_adapters.htm

[par4tom]

He's got me curious...what is the torque rating of the NP440/MY6? Not that it matters, I'm not going to be drag racing. Mainly bought this transmission for better freeway manners...

Plus...my neighbors laughed at the old SM420 I had...I had it in first and it sounded like I was going a hundred...he turned around and I was doing like 4 mph!!! HAHAHA...

Big Hat, No Cattle!