Go Back   Great Lakes 4x4. The largest offroad forum in the Midwest > 4x4 Talk > Chevy Tech
GL4x4 Live! GL4x4 Casino







Search
Reply
 
Thread Tools
Old September 22nd, 2009, 06:36 PM   #1
dlackore
Newbie
 
Join Date: 09-22-09
Location: Duluth
Posts: 4
iTrader: (0)
Mentioned: 0 Post(s)
Default CUCV Gearing Transmission

Hello Everyone,
I have some questions! I am looking at an M1028a3 cucv (1.5ton dually) with a 6.2 diesel, 4.56 gearing, and a 3 speed auto. However, I am looking to replace my daily driver with this vehicle, which is where my problem arises. Currently, the truck has a top speed of roughly 45-55 mph, which makes it tough to drive on the highway. I was wondering if anyone knew of maybe a different transmission (700r4?) that would work with this set up? The truck has posi front and rear which are Dana 70's. Also, does anyone know of possibly a 2 speed transfer case that would work, or what gears from another truck I could swap out? Thank you in advance for any help!

~D
dlackore is offline   Reply With Quote
Old September 22nd, 2009, 08:19 PM   #2
Disturban
Senior Member
 
Disturban's Avatar
 
Join Date: 02-27-08
Location: Lowell, MI
Posts: 2,794
iTrader: (2)
Mentioned: 0 Post(s)
Default

Re-gearing the axles would be your best bet 4.11's maybe 3.73's if you are not going to add bigger tires or tow/haul heavy loads with it. Are you sure it has a Dana 70 in the front? It should have a Dana 60. Nice find though those trucks are cool
Disturban is offline   Reply With Quote
Old September 23rd, 2009, 12:00 PM   #3
dlackore
Newbie
 
Join Date: 09-22-09
Location: Duluth
Posts: 4
iTrader: (0)
Mentioned: 0 Post(s)
Default

ok, so it turns out the person selling the truck, has 3.54 gears for a Dana 70 from a Dodge, and the same gearing for a Dana 60 from the same Dodge. I was wrong, by the way, it DOES have a Dana 60 front end. So, my question now is, will those gears just bolt right in? I mean will everything line up? will I need anything else? will I lose the posi? etc . . .
dlackore is offline   Reply With Quote
Old September 23rd, 2009, 03:37 PM   #4
Hoss Blazer
!SPARTY ON!
 
Hoss Blazer's Avatar
 
Join Date: 08-25-07
Location: Boyne City Michigan
Posts: 2,579
iTrader: (15)
Mentioned: 0 Post(s)
Default

So what gears are in the truck right now, still the 4.56's? What tranny and t-case are in it? I kinda find it hard to believe that the max speed would be 45-55mph......by putting it into the website. I'm gonna be running a TH350/NP205 combo, Dana 60/14bolt w/4.56 gears and 35" boggers. It says @ 65mph it's gonna be turning just over 3000rpm. At 75mph it's just over 3400rpms.

http://www.grimmjeeper.com/gears.html
Hoss Blazer is offline   Reply With Quote
Old September 23rd, 2009, 03:48 PM   #5
blownexploder94
Todd
 
blownexploder94's Avatar
 
Join Date: 11-22-07
Location: South Lyon
Posts: 1,074
iTrader: (6)
Mentioned: 0 Post(s)
Default

except the 6.2L red lines @ 3600RPM
blownexploder94 is offline   Reply With Quote
Old September 23rd, 2009, 04:32 PM   #6
Hoss Blazer
!SPARTY ON!
 
Hoss Blazer's Avatar
 
Join Date: 08-25-07
Location: Boyne City Michigan
Posts: 2,579
iTrader: (15)
Mentioned: 0 Post(s)
Default

Well we kinda need all the variables also! I forgot tire size in my last post also sorry
Hoss Blazer is offline   Reply With Quote
Old September 23rd, 2009, 04:36 PM   #7
ojsdna744
Resident Slasher
 
ojsdna744's Avatar
 
Join Date: 11-05-05
Location: Durand
Posts: 284
iTrader: (9)
Mentioned: 0 Post(s)
Default

Re-gearing the axles is your best bet. That truck will hit 60-65 on the open road the way it sits........one way to re-gear is bolt on 33 inch tires. I went that route and it's decent on the e-way @ 70mph. (It is kinda loud however! )

Last edited by ojsdna744; September 23rd, 2009 at 04:50 PM.
ojsdna744 is offline   Reply With Quote
Old September 30th, 2009, 06:40 PM   #8
dlackore
Newbie
 
Join Date: 09-22-09
Location: Duluth
Posts: 4
iTrader: (0)
Mentioned: 0 Post(s)
Default

Currently, there are 4.56 gears, and relative small tires, (235, 70 15;s maybe?). The truck is a 3 speed auto, and according to the speedo, I was only going 45 with the pedal to the floor. Perhaps the speedo was off? I can tell you this, that ol 6.2 was screamin. There is no Tach, so I can't tell you what the rpms were.
dlackore is offline   Reply With Quote
Old September 30th, 2009, 06:42 PM   #9
dlackore
Newbie
 
Join Date: 09-22-09
Location: Duluth
Posts: 4
iTrader: (0)
Mentioned: 0 Post(s)
Default

I forgot to add. It is a Dana 70 rear, and a dana 60 front with th 300 tranny and np208 t-case.
dlackore is offline   Reply With Quote
Old September 30th, 2009, 06:48 PM   #10
samurai2240
Adrenaline my drug choice
 
samurai2240's Avatar
 
Join Date: 12-06-05
Location: muskegon
Posts: 1,035
iTrader: (6)
Mentioned: 0 Post(s)
Default

http://www.steelsoldiers.com/cucv/
samurai2240 is offline   Reply With Quote
Old October 1st, 2009, 12:09 AM   #11
Ebrown
Senior Member
 
Ebrown's Avatar
 
Join Date: 06-28-06
Location: Saginaw Mich
Posts: 480
iTrader: (23)
Mentioned: 0 Post(s)
Default

You have a J-code 6.2, Th-400 trans, and a np-205 or np-208 t-case... You problem is that you don't have a over drive trans ( 4 speed: 700r4 auto, 4L80E auto

Here are you options

1) I wouldn't regear your axle, Waste of money ( if you have to pay someone to to the work for you.. You will have to get 2 new or used ring and pinion and more probley new 2 new or used carriers

2) Gear Vender over drive unit (Very expensive)

3) swap in a 700r4 diesel trans

4) Swap in a 4L80 diesel trans (Found in 1992-1994 chevy diesel truck) These trans are computer controlled and were found behind 6.2 and 6.5 diesel. These trucks usd a stand alone tranny control computer (IIRC): Same as the th-400 but with over drive
5) Swap in a NV-4500 standard trans

6) IIRC changing tires size will help some (You shoulds have 245X75X16) moving up to 33X10.50X16, 33X12.5016 or 34X10.50X16 this will help in droping your RPM's....

7) find a front Dana 44 or corp 10 bolt and a FF 14 bolt or Sf 14 bolt rear and swap axle to 3.73, 3.42, 3.08 gearing, and sell or store you axle with 4.56 gears but however you will still have poor fuel milage because you don't have a overdrive trans

It all comes down to what you plan to use the truck for (Hauling, towing, offroading, winter driving, etc and how much your willing to spend...


If it was me I would find a diesel 700r4 (1991)! The 700r4 was found in 1/2 chevy pickups, blazer and burbins and would be almost direct swapif you found the correct donor truck ( 1/2 chevy pickup truck)( trans, shifter linkages, drive shafts) the only problem might be U-joints (But you should be able to find a conversion u-joint)


Hope this helps
Ebrown is offline   Reply With Quote
Reply
Great Lakes 4x4. The largest offroad forum in the Midwest > 4x4 Talk > Chevy Tech
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump



All times are GMT -5. The time now is 03:45 PM.


Powered by: vBulletin, Copyright 2000 - 2012, Jelsoft Enterprises Ltd.
User Alert System provided by Advanced User Tagging (Lite) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd. Runs best on HiVelocity Hosting.
Copyright 2005 - 2012 Cracker Enterprises - Powered by Linux
vB Ad Management by =RedTyger=
Page generated in 0.14639 seconds with 32 queries