Cummins 4BT & Diesel Conversions Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
131 Posts
Discussion Starter · #1 · (Edited)
Somewhere on here I read that some of the NV4500s were stronger than others. Which ones are the best to get? I tried using the search, but the shear volume of info about this particular tranny made it hard to find. Also will a 203/205 doubler w/DS drop work behind it?

Thanx York
 

·
Registered
Joined
·
159 Posts
What are the major design changes?

The NV4500 series transmissions have undergone many minor and major design changes since 1992. The minor changes, while important for durability and shifting ease, are not easily identifiable to the layman trying to determine the features of a particular transmission. The following list shows the major changes we have identified. To precisely identify a particular transmission by part number, get the numbers off the build tag on the left PTO cover and the decals on top of the top cover.


The light duty 1" 19 spline input shaft used in 1992-93 was changed to 1 1/8" 10 spline in 1994.

1992-93 models had a coarse thread shift stub. This was replaced by a square stub that accepted a press on shift lever for 1994-1997. A metric threaded shift stub was introduced for 1998.

1992-1996 had an interlock mechanism built into the 1-2 syncro to prevent high speed downshifts into 1st or second gear. This feature was dropped during the 1996 model year

In 1997, New Venture changed the design of reverse gear from a dual plane to a single plane. The reverse gear ratio was changed from 5.61:1 to 5.04:1.

For 1998, the shift tower and shift handle were redesigned. 2WD models no longer had a speedometer drive (the speedo works off the rear axle). 4x4 tailshaft housings were changed to eliminate mountings for the transfer case shift lever. Also, with HD models, the mainshaft nut was redesigned late in 1998. This change first showed up on transmissions with an AD suffix on the Dodge part number (ex: 52108131AD)
 

·
Registered
Joined
·
131 Posts
Discussion Starter · #3 ·
Thank you, that answered my strength question. Where the rear output shaft and bolt patterns different between different years and applications?
 

·
Registered
Joined
·
33 Posts
I wonder when they started using the updated fifth gear nut on these? That would be another thing to keep in mind when looking for an NV4500. It is a realativly cheap part but 270-280ft.lbs. to put the darn thing back on.
 

·
Registered
Joined
·
808 Posts
I wonder when they started using the updated fifth gear nut on these? That would be another thing to keep in mind when looking for an NV4500. It is a realativly cheap part but 270-280ft.lbs. to put the darn thing back on.
The 'stronger' NV-4500's were NV-4500HD. They were used behind the 5.9 diesel and V10 gas. The input shaft size was increased to 1.250" x 10 spline. The output shaft was changed to 29 spline. I use the NV-4500HD on my trucks.

In answer to Alaskan Wheeler's question on the new nut introduction; The following is the complete email I received from New Venture Gear, Sustomer Support on January 2, 2003.

Paul

Cut and paste of email from NVG;
"

_____________________________________________

From: "John Malone" <[email protected]>



Sent: January 2, 2003

Subject: NV 4500 Manditory Repair



Paul;



The NV 4500 Transmission as used in General Motors, Chevy and Dodge Trucks form its introduction to 1995 suffer a design problem in the 5th gear lock nut retainer. It is probable that during the life of the NV 4500 Transmission, the 5th gear retainer nut will loosen and allow the final 5th Overdrive Gear to fall off the shaft. When this happens SERIOUS damage will happen to the Overdrive. The more miles the transmission has, the more apt the fail to occur.



The update to eliminate this problem is a new 5th gear Nut with a newly designed retainer. The retro fit requires special tools and can not be done properly without the special tools. All Authorized New Venture Transmission stations can make the retro fit. The cost which includes a modification to the output shaft is $250.00, Two Hundred Fifty Dollars.



All transmissions modified by New Venture Transmissions will have the words "NEW NUT" stamped into the case by the top left Overdrive mounting bolt. If these words are not there, consider the transmission as unmodified and a serious threat of failure. Transmissions built after January 1st, 1999 feature a completely new 5th gear retention system eliminating the 5th gear nut problem.



I hope this answers your question on the 5th gear nut failures.



Sincerely

John Malone

NV 4500 Customer Support

New Venture Transmissions

Syracuse, NY"
 

·
Registered
Joined
·
61 Posts
as to the dubbler sit i have been doing reserch on the same topic. i got a nv4500hd out of a 99 dodge diesel. wanting to do the same thing. i have found you kneed to get one or convert one to a 32 spline output and find a gm np203 or convert one to a 32 spline female input. then find a ford np205 to get the drivers side drop. then you kneed the adaptor kit to work with the ford 205 as 99% of np203 gear sections are identical.as for the nv4500 to np203 adaptor i herd it done two ways. one is to have the case redrilled and mount directly to the trans and use a short input shaft on the tcase or 2 use a longer input shaft on tcase and i think advanced adaptors used to make a np203/nv4500 adaptor plate.


here is a bit from offroaddesign.com http://offroaddesign.com/catalog/doubler.htm
NV4500 5 speed Manual Transmission:
The NV4500 came in Dodge and GM output configurations and the one that's used to mate to the NP203 is the GM 4wd NV4500. This uses a 32 spline output shaft and an adapter housing that's approximately 7" long. The 203 will need a 32 spline input gear and the front face will be re-drilled to match the GM round bolt pattern on the factory adapter housing. This makes maximum use of commonly available parts and uses the desirable 32 spline shaft connection.
 

·
Registered
Joined
·
1,462 Posts
No, you don't need all that crap.

Here's the recipe-

Cummins/V10 NV4500 HD 4x4 version. Throw the mainshaft away, if it's used it will be junk anyway.

Buy a new 2wd dodge cummins mainshaft, 5th gear and nut. Buy good, OE stuff.

Cut the 2wd mainshaft off so the end extends 1.375" past the mating flange of the 4x4 rear housing. Take the mainshaft to a shop that resplines like Dutchmans or Moser. Dutchmans does better work, they post heat treat. Moser does not. Have the shaft resplined for Ford 31 spline.

Assemble the tranny and you can bolt up any Ford 203, 205, 1356, 1345, whatever you want and you don't end up with a bunch of oddball expensive parts.

Guys have used the dodge 4x4 mainshaft and resplined it to 31 spline. Don't do this!!!!!! The dodge mainshafts don't engage a Ford transfercase enough. If someone tells you they do, they don't know how to use a tapemeasure.
 
1 - 8 of 8 Posts
Top