Sprag modification to Manuel Lock-In

[HASSON1911]

So as i crawled under Isabell greasing the zerts and just checking the p-brake and etc. etc. I was looking at the front drive shaft. It is a sprag unit,( but doesn't drive due to a snapped shire pin in the front axle gear box, not important or related it on the list to get fixed). As I started to look at the engaging system the only difference I can tell from a sprag to an air lock-in is instead of going into the tranny it goes to an air operated switch. So my question is can a guy modify a Sprag to just disconnect it from the tranny and run a lever into the cab that would essentially be your lock-in lever for AWD instead of waiting for your rears to slip. Also, has anyone ever attempted this? Thanks for any help in advance!

 

[ODdave]

Sprage cases have different ratios for the front and rear output. Air shift is the best option, sorry.

 

[HASSON1911]

Dave you seem to confuse and intrigue me, when you say go to air shift does that mean I will have to go change gears, something I wouldn't have noticed just crawling under and comparing my sprage to an air shift truck i had next to it. Also, I wouldn't be changing any gears in the sprage, just simply telling it to engage when i tell it to, so essentially the same thing an air shift does without the air!

 

[ODdave]

When I say go air, I ment change the whole case out.

If you where to "lock" the sprag the driveline would bind up untill something broke if all wheels had equal traction. I do not remeber the exact percentage but the rear output on the sprag case turns faster than the front. This is needed to keep the front from engaging before rear wheel slip.

With an air case both front and rear outputs turn at the same speed to prevent bind because there is no ovverrun cluth like a sprag.

 

[Katahdin]

The internal differences between sprag and airshift transfer cases are more than meets the eye. Changing the linkages to a manual lever will not change how the sprag clutch works.

 

[ODdave]

Also, What "shear pin" is causeing the front not to drive? You shure your t-case isnt broke?

 

[m16ty]

The only thing the same between a sprag and a air-shift is the high/low and the case. The only practical way is to swap out the whole case.

 

[HASSON1911]

Well, thats a bummer but atleast i know not to do it. lol! Also, Dave when i was talking to a mechanic who worked on them in Vietnam, He said that right after the drive shaft in that gear box on top the axle that drives the power down into the axle there is a shear pin that will prevent the damage from happening in the T-case. you can see the box if you stand on the passenger fender and look at the top of the axle you can see the box I'm talking about.

 

[ODdave]

Pretty shure the guy was talking about the winch, Not the front axle....There is no shear pin in the driveline

 

[HASSON1911]

I guess i should get that sprage operating so i at least got AWD when i slip, personally i think its to late then and would like to have AWD before i slip, but i guess better late than never!! Also, an Air-shift from what i hear is out of my price range, if the lever would have worked i would have just fab. a lever together.

 

[ODdave]

bet if you looked you could find an air case for $2-300, the rest you could sorce real cheep.

 

[porkysplace]

The following TM shows differential carrier
TM 9-2320-361-34 page 10-7 shows the DIFFERENTIAL CARRIER picture exposed.


TM9-2320-361-34.pdf

 

[HASSON1911]

Thanks to ApopkaFL for the pics to help. Under those panels is where the shear pin is located, I haven't tore into mine yet but when i do i will be sure to post pics, No he wasn't talking about the winch since him and i were both under the truck, and he pointed out i should be able to jack it up enough to get the plate off and work in it.

 

[bjsmith]

dont beleive there is a shear pin in the axle under that cover is your ring and pinion gears

 

[gringeltaube]

........... Under those panels is where the shear pin is located, I haven't tore into mine yet but when i do i will be sure to post pics, No he wasn't talking about the winch since him and i were both under the truck, and he pointed out i should be able to jack it up enough to get the plate off and work in it.

I've been following your thread quietly... it seems you are the type of guy who prefers to find out and learn things by himself instead of listening to more experienced members... ?
FYI, all this is covered in the TMs; every single detail, every nut and washer, from every component. You can of course, but really don't have to tear into a diff to try to find a SHEAR pin there...
As for the sprag-TC conversion; I would recommend searching for REB KIT in the Deuce Mod. Forum. Maybe start reading this one and see what others have done long time ago: http://www.steelsoldiers.com/deuce-modification-hot-rodding/13496-reb-kit.html


Happy New Year!

G.

 

[ODdave]

I was trying to be polite (hard for me) by not busting his balls twice in the same theread. G is correct, There is NO shear pin in there. Now I dont feel bad because somone else said it.

 

[porkysplace]

I was trying to be polite (hard for me) by not busting his balls twice in the same theread. G is correct, There is NO shear pin in there. Now I dont feel bad because somone else said it.

I gave him a link to the TM and the page number of the exposed veiw with a parts list , think he bothered to look at it ?

 

[Ridgerunner]

I would replace this, said shear pin, with a bolt. That way you will have the utmost traction, that only a bolt will provide. Shear pins are for pu$$ies

 

[ODdave]

Its off topic but do you have any luck googling TM's? My computer dosnt want to download them from jatonka. I have the paper ones but didnt feel like going to the garage last night and had zero luck just using a search engine. Is there a website that dose not require downloading?

 

[tie6044]

ODdave is right, you can get the setup you need for reasonable, in fact, i could set you up with the case and everything else you need for $350 if you want to make a drive south