Gear Swap/ Pump Mods
#1
08-17-2008, 02:21 PM
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Gear Swap/ Pump Mods
Alrite I have a 1992 1 ton dually 5 spd 4.10 gears pretty stock except for the straight pipe and i turned the injector pump up. Im not doing much hauling anymore and the low gears are killing my highway mileage not to mention top end. I would like to swap them for some 3.55s or something around there. Where can i find replacement gears and would this be a costly change? I have also heard that if you can find a tranny from like a 95 or so it will mount up the same and they have overdrive?? Also does turning the full load delivery up really affect mpg? I know it just raises the pressure and helps atomization but is that all? I love this truck and hope for it to be my daily driver for years to come so any helpfull advice will be greatly appreciated. i want some of this 20+ mpg i've heard so much about! Thanks
#2
08-17-2008, 02:56 PM
Getting a shop to go a gear swap will be about $500/axle. Yuo can get the stuff to do it for ALOT less but it takes some skill and alot of special tools to set them up.
As for the tranny... I found this on another site
1.) The 94-02 bellhousing adaptor which is about 1" thicker than your current one.
2.) Get the starter that goes with adaptor and your going to want to bend (trust me your going to want to after the starter hitting the frame drives you nuts) the frame up slightly where the starter is.
3.) Transmission 47RH from a 94 or 95 truck, diesel prefered, but a V10 unit can be made to work by changing the governer weights in the OD unit if you can't find a diesel setup unit. Not going into that here.
4.) Get the 2nd gen flexplate, either when you get all the other parts or ge a new one.
5.) 3 pin connector for lockup/OD functions, get from the junkyard or from these guys if you really can't find one http://www.transmissionsone.com/, just a friendly warning, the page is huge and the connector is at the bottom. At $39 I consider this a last resort, junk yard ones are alot cheaper.
6.) You need to decide at this point what kind of $$$ you can spend on this, can you afford some aftermarket stuff, throw a master rebuild kit at it, a good torque converter and a full valve body and a billet front lever (one that lets you lockup in any forward gear )
Installation:
Is it 4 wheel drive or 2 wheel? 2 wheel drive is simplier, no transfer case. On the 4 wheel drive transmissions the T-case from a 94-95 seals with a seal on the T-case input shaft. NP205's have a coupler between the trans and itself and it seals on the flange. I find the easiest thing to do is to pull the seal out and use RTV to seal the flange up. Be aware that there is a drain of sorts on the OD unit that is why you should use RTV a gasket won't seal it.
Trans mount:
It's going to have to modified slightly, if you or a buddy has a milling machine then its a piece of cake and it will turn out looking pretty decent. If you don't you can use a cutting torch to do it also, won't look as nice, but then again who's going to see it. The slots in trans mount plate need to be lengthed the amount the trans moved back which is about an 1".
Drive shafts:
Depending on the wheel base, you may or may not have to shorten/lengthen the drive shafts, I didn't have to on a club cab. I did have to move the carrier bearing mount rearward an 1" with 1/4" x 2" flat stock.
TV bellcrank lever:
This is VERY important, the 94-95 lever is incorrect for the 1st gen application, won't travel correctly and the trans won't shift right. You will need to take the one off of your current A518 or 727 and put it on the trans going in the truck.
The best thing I can tell you for milage is to bump the timing about an 1/8 of an inch.
Oh and I see this is your first post...
As for the tranny... I found this on another site
1.) The 94-02 bellhousing adaptor which is about 1" thicker than your current one.
2.) Get the starter that goes with adaptor and your going to want to bend (trust me your going to want to after the starter hitting the frame drives you nuts) the frame up slightly where the starter is.
3.) Transmission 47RH from a 94 or 95 truck, diesel prefered, but a V10 unit can be made to work by changing the governer weights in the OD unit if you can't find a diesel setup unit. Not going into that here.
4.) Get the 2nd gen flexplate, either when you get all the other parts or ge a new one.
5.) 3 pin connector for lockup/OD functions, get from the junkyard or from these guys if you really can't find one http://www.transmissionsone.com/, just a friendly warning, the page is huge and the connector is at the bottom. At $39 I consider this a last resort, junk yard ones are alot cheaper.
6.) You need to decide at this point what kind of $$$ you can spend on this, can you afford some aftermarket stuff, throw a master rebuild kit at it, a good torque converter and a full valve body and a billet front lever (one that lets you lockup in any forward gear )
Installation:
Is it 4 wheel drive or 2 wheel? 2 wheel drive is simplier, no transfer case. On the 4 wheel drive transmissions the T-case from a 94-95 seals with a seal on the T-case input shaft. NP205's have a coupler between the trans and itself and it seals on the flange. I find the easiest thing to do is to pull the seal out and use RTV to seal the flange up. Be aware that there is a drain of sorts on the OD unit that is why you should use RTV a gasket won't seal it.
Trans mount:
It's going to have to modified slightly, if you or a buddy has a milling machine then its a piece of cake and it will turn out looking pretty decent. If you don't you can use a cutting torch to do it also, won't look as nice, but then again who's going to see it. The slots in trans mount plate need to be lengthed the amount the trans moved back which is about an 1".
Drive shafts:
Depending on the wheel base, you may or may not have to shorten/lengthen the drive shafts, I didn't have to on a club cab. I did have to move the carrier bearing mount rearward an 1" with 1/4" x 2" flat stock.
TV bellcrank lever:
This is VERY important, the 94-95 lever is incorrect for the 1st gen application, won't travel correctly and the trans won't shift right. You will need to take the one off of your current A518 or 727 and put it on the trans going in the truck.
The best thing I can tell you for milage is to bump the timing about an 1/8 of an inch.
Oh and I see this is your first post...
Last edited by RSWORDS; 08-17-2008 at 03:02 PM.
#3
08-17-2008, 05:36 PM
Diesel Enthusiast
if ur talkin bout a 94 and up 5spd its the nv4500. 5th is 0.73:1 if u have ur stock trany its the getrag 360 witch also has overdrive with a ratio of 0.77:1. in my opinion this alone is not enough reason to swap. to install the 4500 u will need most everything between the engine and transfere case including the starter and clutch cylinder unless u get the special conversion belhousing that lets u keep the original starter, engine adapter plate, and clutch cylinder at any rate u still have to do somethin with the trany mount but not a big deal
#4
08-17-2008, 06:27 PM
if ur talkin bout a 94 and up 5spd its the nv4500. 5th is 0.73:1 if u have ur stock trany its the getrag 360 witch also has overdrive with a ratio of 0.77:1. in my opinion this alone is not enough reason to swap. to install the 4500 u will need most everything between the engine and transfere case including the starter and clutch cylinder unless u get the special conversion belhousing that lets u keep the original starter, engine adapter plate, and clutch cylinder at any rate u still have to do somethin with the trany mount but not a big deal
---AutoMerged DoublePost---
if ur talkin bout a 94 and up 5spd its the nv4500. 5th is 0.73:1 if u have ur stock trany its the getrag 360 witch also has overdrive with a ratio of 0.77:1. in my opinion this alone is not enough reason to swap. to install the 4500 u will need most everything between the engine and transfere case including the starter and clutch cylinder unless u get the special conversion belhousing that lets u keep the original starter, engine adapter plate, and clutch cylinder at any rate u still have to do somethin with the trany mount but not a big deal
I totaly missed teh 5 spd part
Leave the getrag in. It truly is a good tranny that gets as bad rap. Just overfill it a little and dont tow in to high a gear and it will be a kick *** tarnny.
Last edited by RSWORDS; 08-17-2008 at 06:27 PM. Reason: Automerged Doublepost
#5
08-20-2008, 09:38 AM
Diesel Fan
if ur truck tops out @ 60 mph like my 1990 the getrag 5spd u'll need to do gear swaps 
. I need some 3.55's or 3.73's. My 1992 1/2 ton has 3.55's and a NV4500 and they're too high for the passes here in Montana. to bad the 9.25 wont hold up to the Cummins for long
. I need some 3.55's or 3.73's. My 1992 1/2 ton has 3.55's and a NV4500 and they're too high for the passes here in Montana. to bad the 9.25 wont hold up to the Cummins for long
#6
08-31-2008, 11:50 AM
I had a 91 nonIC that got 20-22mpg with 4.10s. Straigt pipe at 65mph got OLD after about 100mi, though. My 92 hasnt seen 20mpg since I brought it home from Houston TX.
W150CTDproject- The 2 4.10 trucks I've had did 60-65 in 4th. Check under the hood for slack in the throttle linkage.
W150CTDproject- The 2 4.10 trucks I've had did 60-65 in 4th. Check under the hood for slack in the throttle linkage.
#7
09-01-2008, 04:35 PM
Diesel Fan
i did check for slack the day i bought it, i adjusted it and still 60-65 in 5TH (over drive) cruising speed, fueled out to the wood 75-80ish mph. 
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