TheAMCForum.com Homepage
Forum Home Forum Home > The Garage > Transmission & Drivetrain
  New Posts New Posts RSS Feed - 3 speed to 4 or 5 speed swap?
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Click for TheAMCForum Rules / Click for PDF version of Forum Rules
Your donations help keep this valuable resource free and growing. Thank you.

3 speed to 4 or 5 speed swap?
 Post Reply Post Reply Page  <1 345
Author
Message
  Topic Search Topic Search  Topic Options Topic Options
Midnight Rambler View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jan/17/2011
Location: SoCT
Status: Offline
Points: 1670 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Midnight Rambler Quote  Post ReplyReply Direct Link To This Post Posted: Oct/16/2022 at 7:43am
Originally posted by Buzzman72 Buzzman72 wrote:

Originally posted by FSJunkie FSJunkie wrote:

5-speed is the only way to go as far as I am concerned, or perhaps a wide ratio 4-speed, but no T10 was ever wide enough. The best 1st gear they ever had was like 2.50:1. 

Actually, it was 2.64 in an AMC. But point taken.


I agree! I'm currently doing a T-5 with a '87 Ford: 3.35, 1.93, 1.29, 1, .68.  My American has a 290, 3.15 rear, and 205/70/R14 tires (25.3").  It should be goldilocks for a cruiser:

1st gear @ 4000rpm is 28.5mph
5th gear @ 2000rpm is 70.3mph

'66 American 440 Convertible 290/M-40/AMC 20 3.15/PS/PB
'04 Jeep Wrangler X Rocky Mountain Edition 4.0 5sp
Back to Top
jpnjim View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Nov/25/2007
Location: New England
Status: Offline
Points: 2752 		Post Options Post Options   Thanks (0) Thanks(0)   Quote jpnjim Quote  Post ReplyReply Direct Link To This Post Posted: Oct/16/2022 at 8:17am
^^
That will be a sweet setup, and a sweet ride!

You'll have a perfect first gear for pulling away from lights effort free (10.55),
a great highway pulling gear (2700@65 in 4th),
& a great highway cruising gear (2300@80 in 5th).

I wouldn't want to lug it in 5th too much at low speed, in 5th, especially if there's hills,
but that's why there's a 4th gear.

Would be a great car to drive cross country Thumbs Up

How is the 290 set up? Stockish, with a 4bbl?
71 P-code 4spd Javelin/AMX
some Jeeps and some Fords
Back to Top
Midnight Rambler View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Jan/17/2011
Location: SoCT
Status: Offline
Points: 1670 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Midnight Rambler Quote  Post ReplyReply Direct Link To This Post Posted: Oct/16/2022 at 1:39pm
Originally posted by jpnjim jpnjim wrote:

^^
That will be a sweet setup, and a sweet ride!

You'll have a perfect first gear for pulling away from lights effort free (10.55),
a great highway pulling gear (2700@65 in 4th),
& a great highway cruising gear (2300@80 in 5th).

I wouldn't want to lug it in 5th too much at low speed, in 5th, especially if there's hills,
but that's why there's a 4th gear.

Would be a great car to drive cross country Thumbs Up

How is the 290 set up? Stockish, with a 4bbl?


Lower compression 290, stock 2bbl replaced with Offy 360DP and Edlebrock 500cfm. The engine loves it, I can't wait to lose the drag from the automatic.

'66 American 440 Convertible 290/M-40/AMC 20 3.15/PS/PB
'04 Jeep Wrangler X Rocky Mountain Edition 4.0 5sp
Back to Top
farna View Drop Down
Supporter of TheAMCForum
Supporter of TheAMCForum
Avatar
Moderator Lost Dealership Project

Joined: Jul/08/2007
Location: South Carolina
Status: Offline
Points: 19672 		Post Options Post Options   Thanks (0) Thanks(0)   Quote farna Quote  Post ReplyReply Direct Link To This Post Posted: Oct/18/2022 at 8:00am
It will be fine as long as you don't try to use 5th gear BELOW 70 mph. For most driving you have a great four speed though, and then fifth for high speed interstate cruising! Really needs a 3.31 rear axle, that would be the "sweet spot". I'm running 3.55s with my AW4 and 4.0L. OD is 0.705 (88 model... 87-90 had 0.705, 90.5+ had 0.753 OD), so close to yours. It does great, but I would like a little more speed for cruising. Right now it's ~2250 rpm @ 70 mph. With 3.31 gears 2250 would be 75 mph. Since first is 2.804:1 it needs a little more gearing than yours does. I ran it with 3.08 gears at first, and it would pull them, but take-off wasn't nearly as good and pulling 4th under 65 mph put a load on the engine. Not lugging or anything, but it was definitely working harder and only turning 1800 rpm. When I switched to 3.55 gears (standard for an XJ Cherokee with 4.0L and AW4) average gas mileage actually went UP by 2 mpg! 
Frank Swygert
Back to Top
Eddiebell View Drop Down
AMC Apprentice
AMC Apprentice
Avatar

Joined: Jan/11/2020
Location: Cleveland Ohio
Status: Offline
Points: 152 		Post Options Post Options   Thanks (0) Thanks(0)   Quote Eddiebell Quote  Post ReplyReply Direct Link To This Post Posted: Oct/18/2022 at 6:21pm
This is a beautiful transmission nice detent smooth shifting short shifting even I was very impressed with that transmission when i saw you guys at the car ahow and he let me try it out .  When i get rid of my t10 this will be the trans's i get . TKX in Wooster Kevin's ride 

Edited by Eddiebell - Oct/19/2022 at 5:12pm
Back to Top
cone View Drop Down
AMC Addicted
AMC Addicted
Avatar

Joined: Apr/17/2010
Location: pennslyvania
Status: Offline
Points: 568 		Post Options Post Options   Thanks (0) Thanks(0)   Quote cone Quote  Post ReplyReply Direct Link To This Post Posted: Oct/19/2022 at 6:05am
I installed a Tremec TKO 3550 in my 70 AMX years ago and it was the best mod I did to the car. It has a 3.31 rear and turn at about 2000 RPM at seventy. Drove it to the west coast and back and it made the trip a lot nicer, especially on the Interstate. I only wish AMC had the money back in the day to do this, they would have sold a lot more cars.
1987 J20, 87 Grand Wagoneer,70AMX,
Back to Top
 Post Reply Post Reply Page  <1 345
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.03
Copyright ©2001-2019 Web Wiz Ltd.

This page was generated in 0.453 seconds.
All content of this site Copyright © 2018 TheAMCForum unless otherwise noted, all rights reserved.
PROBLEMS LOGGING IN or REGISTERING:
If you have problems logging in or registering, then please contact a Moderator or