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This is a brief look at some five and six speed transmission swap possiblities that exist for 1960's and 1970's RWD Chrysler products. For the most part, these are nightmarish swaps and are discussed only for the point of dissuasion. On several Internet car forums ideas of Dakota five speed swaps are bantied about and this article hopefully will serve as a shot of reality. Even the swaps that are highly regarded by the popular press not as easy or as "drop in" as they the manufacturer and press may lead you to believe.
Installing a Five speed or a Six speed is an extremely challenging proposition. The first hurdle to over come is that no factory transmissions or bellhousings can be used without modification. There are real possiblities for five and six speed swaps that are practical and we'll look at those swaps first, but it was already stated, these are not simple and they do require significant modifications.
With any transmission swap be very careful to ensure that the installed pinion angle and the driveshaft u-joint angles are acceptable! Driveshaft shops should be able to fill you in on this topic, or even a reference like the MP Mopar Chassis Book.
TREMEC builds manual transmissions that have been OEM tranmissions for many manufacturers including Ford and Chrysler. TREMEC, which stands for Transmisiones y Equipos Mecanicos was originally financed by Clark transmissions along with other investors in Mexico in the mid 1960's. It was established as a transmission manufacturer that supplied nearly 100% of the manual transmission requirements for Mexico's domestic automobile market at the time, and during the 1980's it began supplying transmissions to the US. TREMEC was acquired by DESC, a Mexican component supplier. In the US, TTC (Transmission Technologies Corp) was established as a joint venture between DESC and Dana, and US facilities were opened up in Michigan, Ohio, and Knoxville, Tennesee.
Today, apart from manufacturing some excellent TREMEC designed units, TREMEC also manufactures the T-5, T-45, and T-56 transmissions (TREMEC purchased these designs from Borg-Warner).
There are several companies that make and sell "kits" to install The TREMEC TKO's in Mopars. Among them are Keisler, Forte, and Darkhorse. Initially, it appeared that Keisler Automotive Engineering & Electric seemed to have had the most advanced kit. The Keisler "kits" appears to be a bolt in swap and it is heralded as exactly that by several popular MOPAR magazines, however, mopar related bulletin boards and mailinglists have been routinely busy with compliants of poor fit, kits coming with the wrong parts, and some buyers waiting months while Keisler sorts things out. E-body, A-body, and B-body problems range from incorrect drivetrain angle, cross member fit problems, and driveshaft length issues.
Plus, it is not as stock appearing or as technically simple for all applications and it is commonly described by magazines such as MOPAR ACTION.
A drawback of the TKO is its super wide ratio gearing. The TKO has a 3.29 first gear and a 1.98 second. Thats a serious drop. Thats even wider than the wide-ratio A-833 first to second jump of 3.09:1 to 1.98:1. The same magazines that frowned upon the 833-OD's wide ratios for racing applications don't seem to be phased by the TKO's super-sized ratio changes. With a 3.23 or lower rear gear you'd be shifting to 2nd gear at the other side of the intersection or sooner!
A really nice five speed to bolt into a RWD mopar is the T-56. It is a strong, (not as strong as the 833, but strong nonetheless) lightweight, close-ratio five speed used in Trans Ams and Camaros during the 1990's. Here is a chart comparing the gear ratios:
| Transmission | 1st | 2nd | 3rd | 4th | 5th | 6th |
|---|---|---|---|---|---|---|
| TKO | 3.29 | 1.98 | 1.34 | 1.00 | 0.83 | |
| T-56 | 2.66 | 1.78 | 1.30 | 1.00 | 0.80 | 0.62 |
The T-56 is not a simple bolt-in, and nobody seems to be advertising a bolt-in kit. A MOPAX reader was able to preform such a swap using an Mopar LA to Chevrolet trans adapter, a master and slave GM hydraulic throwout bearing, and a custom input shaft adapter. Talk about easier said than done!
Doug Nash began building his own five speeds in the 1970s. Originally, these were designed to replace GM Muncie 4-speeds, but DNE (Doug Nash Engineering) expanded to Ford and Mopar applications. DNE was bought by Richmond Gear and, currently, Richmond Gear sells the old DNE 5-speeds as well as a couple six speed designs. Price tags on these units are not for the faint of heart, but there is a large selection of gear ratios available, and they are build soley with high performance applications in mind.
The stock bellhousings only line up 3 of the 4 mounting holes, so an aftermarket bellhousing is most likely required. Richmond Gear sells their five and six speeds with a length and mount orientation that is best suited for B and E bodies, however it is very unlikely that the shifter will appear stock or exit the floor in a stock location. For any mopar application, a cross-member and driveshaft modification will be required.
The great thing about using a Richmond Gear transmission is the wide array of gear ratios that can be used. a nice close ratio transmission can be spec'ed out to make any Chrysler engine a barrel of joy to shift.
The biggest disavantage of any Dakota/RAM transmission being swapped into an A/B/C/E body mopar is the super wide gearing. These transmissions are truck transmissions and shift like truck transmissions. First gears are quite often "granny lows" that are not even used unless your pulling a horse trailer out of a ditch! Even when first gears aren't in the 4:1 and 5:1 range, the ratios are spaced apart such that every shift would drop your RPMs well below the point where you are making good power.
Here is a brief listing of Dakota/RAM transmissions and why you would NOT want one in your passenger car:
The Aisin Warner AX15 was an aluminum case five speed that, unlike passenger car transmissions, the AX15 uses a center support mount design. Used in 2x4 and 4x4 Dakotas starting in 1992. Swap problems: 3.83:1 first gear! No aftermarket performance shifters, low torque capacity, wide ratio gearing.
The New Venture NV3500 five speed with a integral bellhousing was used in 1994 and up Dodge Dakota V8 Ram truck (this started life in 1988 as the GM HM290 ). For a truck transmission, the 3.49:1 1st gear isn't too low, but its still super wide. Swap problems: integral bellhousing requires a hydraulic clutch, from the stand point of it actually fitting in a RWD passenger car, it has a very tall main case, super wide truck gear ratios. no performance shifters.
The New Venture NV4500 was a big heavy 200 lb. five speed that did not have an integral bellhousing. The NV4500 was used in V10 and diesel RAM applications starting in 1994. The NV4500 replaced the Getrag G360 that was used 1989-93 behind Cummins Dodge trucks (the Getrag is incredibly expensive to repair). Swap problems: first gear 5.61:1, nuff said... this is what 4x4 guys are talking about when they discuss "crawl ratios".
Starting in 1998, Dodge used the New Venture NV5600 which is a extremely heavy-duty 6 speed used in heavy-duty Dodge trucks from 1998 on. Despite its use of an aluminum bell housing, the entire unit cast with its cast iron main case tips the scales at 360lbs (can handle vehicles with a gross combined weight of 26,000 lbs). Swap problems: 360lbs!!!! 5.63:1 first gear !!!