Transfer Case input gear swap question

[DaveB]

I am swapping a chevy NP241 input gear into a Dodge NP241 case to get the slip yoke eliminator which the 241D case has. The input gear assembly meshes with a large spiral gear for low range operation. Should I swap the gears as a set like you would a ring and pinion ? or would there be a problem mixing the two sets ?
The gears and shift collars also have painted spots on them which I presume is to line things up. However everything turns so I'm not sure why they have the paint dots. Any ideas ?

 

[ichi-san]

I ignored the "dots" when re-assembling a Jeep NP231 without any problems after years of use. Lately, I've been invesigating swapping the Input Gear in a NP231 and nothing I've run across seems to be concerned with matched gear sets - only that the tooth count and pitch on the Input matches the rest of the internal gearing. And the Input gears are sold stand alone, not in sets like a R&P.



Richard

 

[utah340six]

Ben at intermountain trasmision did mine.
install 241 planatary and heavy chain in one for me.
dave if you want his number he probly could help.
call my son zac he will have it 801 599 6068

 

[Tacoma]

On a related note, Dave-- are you having any issues? do these cases mesh together like buttah or what? I'd love to ditch the slip yoke in the Burb... but not for $300.

 

[mbryson]

I intend to do similar to a 208. I did swap in a correct splined input shaft into my 242 (used case to used case) and put about 50K miles or so on it after that.

 

[neagtea]

I have a custom built SYE for a 241 still on a case. The case is trash but the internals have very little wear. Be back Mon and can post a photo. Probably would trade or sell cheap.

 

[bryson]

I'd swap the whole planetary assembly as a unit. May not have any issues if you just swap inputs, but what is stopping you from just swapping the whole planetary? It's more work to pull the input out of the assembly anyways.

The dots are there because the planetary gears (the small ones that turn around the "sun" gear on the input... get it?) are timed (theoretically...) but I've never seen an issue with the gears being timed improperly unless you are working with a low-range gear set - because the low-range gears usually use a 2-stage planetary.

To be on the safe side, I'd swap the assembly, because you never know if the angle of the gear-cut, or the angle of the gear face are the same. Cheap insurance if you ask me.

 

[DaveB]

On a related note, Dave-- are you having any issues? do these cases mesh together like buttah or what? I'd love to ditch the slip yoke in the Burb... but not for $300.

Thanks everyone for the information. I put the two cases together (Chevy input gear into the Dodge case) and it went very well. I haven't swapped the larger outer gear yet but will do it when I take it apart for the final clean and re-seal. I slapped it together so I could determine how it was going to fit under the tub. I found that the Dodge 241 has a different clocking pattern but that if I removed one bolt of the six the case will clock level using the chevy adapter and no clocking rings required. I'll have to decide if I will rework the factory adapter to pick up the last hole. One weird thing was that the chevy case had ATF in it and the Dodge case had gear lube in it. I thought these always used ATF.

 

[Tacoma]

Someone might have put the wrong lube in the Dodge case?

Thanks for the info, Dave. I'm going to the yards today.

 

[bryson]

Someone might have put the wrong lube in the Dodge case?

x2. As far as I know, all chain driven NVG/NP cases take ATF.