5-Speed to 6-Speed AWD Conversion for the 3000GT/Stealth

by Jeff Lucius

In the Mitsubishi 3000GT VR4 and Dodge Stealth R/T Twin Turbo, the 6-speed transaxle offers many advantages over the 5-speed version.

The gear ratios are more evenly spaced.
All final gear ratios are higher for better acceleration in all gears.
The possible top speed is increased to 200 mph.
There is a potential for better gas mileage using the 6th speed.
The output shaft and transfer case are stronger.

For more information on our AWD system including all gear reduction ratios look at my web page 2-AWD.htm. The 6-speed drivetrain was introduced with the 1994 model year and continued until the end of 3000GT/Stealth production.

Listed below are the parts required to convert the 1991 to 1993 5-speed AWD drivetrain to a 1994+ 6-speed AWD drivetrain. Though the clutch is the same, you might as well install a new one and resurface or replace the flywheel if necessary. The front driveshafts are the same so do not need to be replaced. Problems may arise with the 6-speed cable brackets and levers hitting the BOV (especially the aftermarket GReddy Type S) and the lower radiator hose, so these two items may need updated or modified somehow. Some owners report that the 6-spd shifter assembly inside the cabin should also be used, rather than the 5-spd shifter assembly. You can re-use the all-wheel steering pump on the rear differential. Note that some later model Stealths Twin Turbos do not have the AWS feature and so their rear diffs are designed differently. The 6-spd drive gears (ring and pinions) can be transferred to your 5-spd rear diff - but this can be a major hassle and expensive. The major pieces are bolt on replacements and require no modification or extra brackets, etc.

6-spd transaxle and 6-spd transfer case ($1500-$7500, depending on used condition or if new).
6-spd propeller shaft ($700-$1200, depending on used condition or if new) - or lengthen the front piece ($50-$100) because of the 1" shorter transfer case - or use an aftermarket propeller shaft such as the 2-piece carbon fiber shaft manufactured by ACPT for about $1000.
6-spd rear differential (~$2000 new, as low as ~$400 used) - Note if you need AWS pump access or not. Also, it should be possible to switch just the drive pinion (13 teeth for the 6-spd, 11 for the 5-spd) and drive gear (43 teeth for the 6-spd, 39 for the 5-spd).
6-spd shifter cables (~$140 new) - 5-speed cables may not allow enough travel however some people (See Neil's post to the 3SI messsage board below for example) have been able to re-use the 5-speed cables.

Below are shops that may be able to help you repair, replace, or find drivetrain components.

Kormex Transmission Parts 2020 S. Vineyard Ave. Ontario, CA 91761 800-429-5464; 909-947-0569 ask for Frank Martin info@kormextrans.com New and rebuilt Getrag transmissions and transfer cases Synchros, output shafts, posi front diff!	Pampena Motrosports 1743 Julia Goldbach Ave. Ronkonkoma, NY 631-738-0303 info@pampenamotorsports.com Services 3S Getrag transaxles.	Auto Sports Unlimited 200 N. Franklin, Suite 100 Zeeland, MI 49464 800-624-3876 Rebuilt Getrag transmissions and transfer cases hardened output shafts
Autocraft Industries, formerly Component Remanufacturing Specialists, Inc. (CRS) Oklahoma City, OK Autcraft no longer sells Getrag parts!	Mentor Mitsubishi 9090 Mentor Avenue Mentor, OH 440-953-1000 Willing to order Getrag parts from Japan.	Shepherd Racing 2446 Manchester Rd. NW North Lawrence, OH 330-832-2366 jshepherd@sssnet.com Rebuilds 3S Getrag transaxles.
Supercar Engineering Troy, MI 48083 ask for Philip Glazatov sales@supercar-engineering.com Many parts available	Drivetrain Specialists 3852 Pioneer Ave. Las Vegas, NV 89102 800-216-1632 702-876-3100 ujoints@intermind.net Some parts available.	Southern Gear 4369 West Atlanta Road Smyrna, GA 30080 800-289-7432 770-435-1461 Some parts available.
Standard Transmission & Gear 1000 N.E. 29th Fort Worth, TX 76106 800-783-8726 817-625-7109 Some parts available.	Transmission Depot 460 E Copans Rd. Pompano Beach, FL 33064 954-781-5500	ManTrans LLC 4920 Woodlane Circle Tallahassee, FL 32303 877-626-8726 850-222-6993 Rebuilds 3S AWD and FWD
Based on reports from 3S owners, it is strongly recommended that the transmission shops below be avoided! Standard Transmission (Kingsville, MD) Transmission Mart (Winter Haven, FL) MD Auto (Alpine, CA) Gilarno's (Freedom, PA)		Getrag parts might be available from some Mitsubishi dealers in Australia. Check there also for Japan-only parts. Let me know of specific dealers that will work with us in the USA.

Acknowledgments

Some of the information presented here was gathered from various email lists, message boards, and vendor web sites. I would like to particularly thank Brian Woodrell, Rob Green , Brad Bedell , Neil , and Chris Umber for their contributions.

Back

Home

Forward

Except for the small gif and jpg images, the content, images, photographs, text, and multimedia displayed are Copyright ©2000-2005 by Jeff Lucius and K2 Software. All rights reserved. No part, section, image, photo, article, or whole of this site may be reposted or redisplayed without permission of the author.
Page last updated August 26, 2005.