Cummins 4BT & Diesel Conversions Forums banner

1 - 8 of 8 Posts

·
Registered
Joined
·
2 Posts
Discussion Starter #1
evening -

i have an '89 dodge CTD with a spent 727 3-speed auto.....don't really have the spare cash on hand to do a 4500 5-speed swap, but was wondering if the totally rebuilt sm465 i have under wraps would hold the torque of the CTD?

also, with the 727, 3.07/3.08 gearing i was averaging around 22mpg, any speculation on how different the mpg reading would be with a 4-speed manual?
 

·
Administrator
Joined
·
4,171 Posts
evening -

i have an '89 dodge CTD with a spent 727 3-speed auto.....don't really have the spare cash on hand to do a 4500 5-speed swap, but was wondering if the totally rebuilt sm465 i have under wraps would hold the torque of the CTD?

also, with the 727, 3.07/3.08 gearing i was averaging around 22mpg, any speculation on how different the mpg reading would be with a 4-speed manual?
I think the cost would far outweigh the benefits. The SM465 is a strong transmission but gathering the related parts to install it would be a real money pit.
 

·
Registered
Joined
·
2 Posts
Discussion Starter #4
thanx guys for all the info.....i had done a search a few months ago when i 1st joined the site, but couldn't remember finding much. must have done the search wrong as i found TONS of information this time around.

Again, thanx guys, and i apologize for the repeat question :rasta:
 

·
Registered
Joined
·
92 Posts
727 is a 3 speed final is 1:1. There is a replacement that is a 4 speed (4th is OD). Real nice for Diesels. You don't have to touch the Diff ratio, otherwise with the 727, you'll need to change the Diff ratio. Check the forum under transmissions. It'll have the 727 and the newer version with the OD.
 

·
Premium Member
1989 Jeep Wagoneer, 360v8, 727, stock for now,
Joined
·
2,667 Posts
evening -

i have an '89 dodge CTD with a spent 727 3-speed auto.....don't really have the spare cash on hand to do a 4500 5-speed swap, but was wondering if the totally rebuilt sm465 i have under wraps would hold the torque of the CTD?

also, with the 727, 3.07/3.08 gearing i was averaging around 22mpg, any speculation on how different the mpg reading would be with a 4-speed manual?
Because you have 3.08 gears you do not want or need an overdrive. The SM465 was put behind the 4BT would probably work, but I think it would be better for you to rebuild the 727 cost wise.
Right off hand to change to the Sm465 you would need a chevy trans adapter, flywheel, bell housing, starter motor, clutch assembly, cheaper to rebuild.
 

·
Registered
Joined
·
92 Posts
You may wish to also look into the A500 / A518 Chrysler Transmissions. These have Lock-up torque converters. You wire the lock-up switch via the brake pedal, the lock-up will increase your MPG, hands down. Check with a "ratio" calculator and see what difference an overdrive makes vs. what you have right now. You want to be within the 1400 - 1800 RPM range. If you're towing, you'll want to be near the 1800 range, if you won't be towing, getting nearer the 1400 range will give you more MPG, while taking advantage of the max torque right there. These trannys, including the A727, are very inexpensive to rebuild (about $200, or less for the kit). Add a shift kit, if not included, and you have a VERY Heavy Duty transmission for your diesel. Remember, if these can handle drag-strips, they'll handle your diesel. :D
 
1 - 8 of 8 Posts
Top