blazinbg
Registered Member
how interchangeable is a np241 to np208 in 1983 k5 700r4 trans.?
CK5
Register an account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members.
transfer case swap
- Thread starter blazinbg
- Start date
skidog1us
1/2 ton status
I'm thinking you meant to swap from a NP208 to a NP241...right. I just did this so that I could install a JB Conversions SYE. Since my rig is a 1987 which uses a mechanical speedometer and is a passenger side drop I had to make sure to obtain a NP241 from a 1989. Pretty straight swap.
xsmokey11499x
1/2 ton status
if you dont mean what the guy above me stated..
I have a 208 in SoCal.
I have a 208 in SoCal.
lol and I'll take the 241 
straight forward swap, same linkage, same bolt pattern, check the spline count, same tail shaft length I believe too. I've found some burb 400/241 combos, but the spline count is different from a 700/241.
straight forward swap, same linkage, same bolt pattern, check the spline count, same tail shaft length I believe too. I've found some burb 400/241 combos, but the spline count is different from a 700/241.
It's a direct swap BUT you have to find a one year only (1989) NP241 as that's the only year for a mechanical speedo.
Could you tell me more about this swap, I realy want to do this.
a one year only 1989,
Do you mean I can only get a 241 from a 89 K-5 Blazer for a direct swap?
How does the NP 241 compare in strength to the NP 208?
I have a 88, 208 with a mechanical speedo.
thank you.
Ed
You'll only be able to get a mechanical speedometer drive NP241 with the same spline count as your 27 spline NP208 from a 89 Suburban, Crewcab or K5 with a 700r4 as well. That said, you can also get them from the 3/4 tons and 1 tons with manual transmissions and 4l80es and trade someone here for their 27 spline input shaft.
The NP241 has a slightly larger chain than the 208 does, and IMO, is more than strong enough for anything you can throw at it. Same goes for the 208, only real weakness is that aluminum housing...
Also keep in mind that it isn't impossible to purchase the parts needed to switch an electric speedometer NP241 over to mechanical, nor is it impossible to install an electric speedometer in your K5.
I am personally running a 32 spline NP241 behind an NV3500 with an electric speedometer from a 91 all installed and playing nice together in my 1985
The NP241 has a slightly larger chain than the 208 does, and IMO, is more than strong enough for anything you can throw at it. Same goes for the 208, only real weakness is that aluminum housing...
Also keep in mind that it isn't impossible to purchase the parts needed to switch an electric speedometer NP241 over to mechanical, nor is it impossible to install an electric speedometer in your K5.
I am personally running a 32 spline NP241 behind an NV3500 with an electric speedometer from a 91 all installed and playing nice together in my 1985
1989 was the first year for the NP241 and the only year for mechanical speedo however you can use an NP241 from any blazer/burb/crewcab up until 1991 but you will either have to convert it to a mechanical speedo or deal without a working speedo and VSS. 1992 and later NP241's will be a driver drop case and WILL NOT work unless you swap in a HP D60 from a Ford.
what would it take to switch from an electric to mechanical speedo?
From what i've heard you have to swap the output shaft and everything that goes along with it including the tail housing.
I was just looking over JB conversions and since I want to convert to slip yoke elimination kit, I think it comes with what I need.
Thank you for your help,
Ed
I have a JB SYE on my t-case and it DOES NOT come with any portion of speedo stuff at all.
Ok, good to know. I guess the hole in the JB bearing housing is just for the speedo cable part.
There is some one here in hawaii with a 241 from a 90 K-5 Blazer, I was thinking of getting that and finding the parts for the mechanical speedo conversion. This might be easier then to look for a 89 only vehicle.
you continue to educate me, you've been a big help.
Thanks,
Ed
As mentioned, you can go to an aftermarket speedometer to work with the electric VSS (Vehicle Speed Sensor). Basically every vehicle made in the last 20 years uses them and they are VERY easy/cheap to find aftermarket.
The 241 is basically the NP208 version 2.0. All of the concepts are the same, aluminum case, chain drive, planetary gear set, 2WD/4WD with a low range etc.
The 241 got a stronger gear set (varied based on application but almost always better than the 208 stuff), better oiling, things like that. Think of it as the improved version of the 208.
Where can I find the after market parts to make the VSS work with my speedometer cable?
Thanks,
Ed
JagsthatRun.com carries such a device, but I would not reccomend one... That little electric motor cannot be trusted to accurately translate the speed forever...
You'd be far better off swapping to an electronic speedometer to match the VSS no matter which way you look at it. I don't know for sure about the 241, but I know it is getting tough to find different combination of the speedometer drive gears for the 208 these days, so getting your speedometer accurate if you change tire sizes or gears could be a challenge. While I know that it doesn't get cold where you live, speedometer cables eventually wear and start to bind causing the needle to jump around at slower speeds (usually made worse by cold temperatures).
The 90 speedometer is an easy install. Two wires run down to the VSS on the transfer case, one wire goes to ground, one wire goes to 12V ignition, and one wire goes to the electronic speedometer. The speedometer is grounded and powered by the instrument cluster. While the cluster does require you to re-pin your wiring at the cluster, it is easily done, and well documented online.
By modifying the DRAC you install to control the speedometer with a simple DIP switch, you can calibrate it for virtually any gearing / tire size combination possible with just a basic calculation and setting of said DIP switches to match a pre-determined chart.
You'd be far better off swapping to an electronic speedometer to match the VSS no matter which way you look at it. I don't know for sure about the 241, but I know it is getting tough to find different combination of the speedometer drive gears for the 208 these days, so getting your speedometer accurate if you change tire sizes or gears could be a challenge. While I know that it doesn't get cold where you live, speedometer cables eventually wear and start to bind causing the needle to jump around at slower speeds (usually made worse by cold temperatures).
The 90 speedometer is an easy install. Two wires run down to the VSS on the transfer case, one wire goes to ground, one wire goes to 12V ignition, and one wire goes to the electronic speedometer. The speedometer is grounded and powered by the instrument cluster. While the cluster does require you to re-pin your wiring at the cluster, it is easily done, and well documented online.
By modifying the DRAC you install to control the speedometer with a simple DIP switch, you can calibrate it for virtually any gearing / tire size combination possible with just a basic calculation and setting of said DIP switches to match a pre-determined chart.
Becides the transfer case, what would I have to remove from the dooner vehicle?
Would the 90 speedometer be a direct swap?
What else would I need from the instrement panel?
Thanks for all your help,
Ed
Vss 241
I dont have the TBI set up any more, I went with Mass Flo, will this be a broblem with the VSS system?
Becides the transfer case, what else would I have to remove from the dooner vehicle?
Would the 90 speedometer be a direct swap?
What else would I need from the instrement panel?
what is the DRAC?
Thanks for all your help,
Ed
I dont have the TBI set up any more, I went with Mass Flo, will this be a broblem with the VSS system?
Becides the transfer case, what else would I have to remove from the dooner vehicle?
Would the 90 speedometer be a direct swap?
What else would I need from the instrement panel?
what is the DRAC?
Thanks for all your help,
Ed
could you tell me were I can get the infromation need to re-pin the wiring cluster?
Also, is the VSS controled in anyway by the TBI ECM, becasue I installed an after market FI system.
Thank you,
Ed
