sprag transfer case or not?

[Westex]

I've read as much as I can on the sprag versus airshift transfer cases, but my question is can you have a manual lever shift transfer case that does not have the "wind-up" issue. Reason I ask is that mine is a 1971 M35A2 hardtop, and I crawled underneath it today and do not see the 'linkage' that the TM talks about between my transfer case and the tranny. Only connections I see are the jackshaft and then the front driveshaft running out of the transfer to the front axle. My transfer case is a lever shift. ???

 

[Heavysteven]

Mines a 1971 and yes the high low on the transfer case is lever. The one that's always in the way. Also, mines air operated switchbsays in out under cluster

 

[503m715]

The sprag type t-case has a piece of linkage between the trans and t-case. If you were to remove the floor section over the trans you could see it. If you have a lever switch mounted under the dash marked In and Out for front axle, you have an air switched t-case. It has no linkage between the trans. and t-case. Both have a shifter for high and low range.

 

[Westex]

The sprag type t-case has a piece of linkage between the trans and t-case. If you were to remove the floor section over the trans you could see it. If you have a lever switch mounted under the dash marked In and Out for front axle, you have an air switched t-case. It has no linkage between the trans. and t-case. Both have a shifter for high and low range.

This answered my question. I have an airshift transfer case. Thank you sir!

 

[PackRatWrecker]

Mine is a sprag t-case. Since I'm installing a slushbox, instead of a handshaker, I'm considering using the clutch pedal to push in the sprag lock shaft. Since the sprag automatically locks the front when moving forward(and a rear tire loses traction), I can only see a need to lock it occasionally, when backing up. I'd use a solenoid to engage it, when the backup light switch is activated, but the sprag shaft has a pretty healthy detent spring behind it.

Please tell me, If I'm understanding t-case operation incorrectly.

 

[1970amgeneral]

m35a2 TC

i have a 1970 am general and i cannot find how to engage my front axle. its a sprag style. i could not find anything on how to adjust it. could someone please help me on this. i put my rear tires on pavement and my front tires in gravel and my rear axles left blackmarks but no front action......any suggestions?

 

[gringeltaube]

....................... its a sprag style. i could not find anything on how to adjust it. ..................any suggestions?

No, you could not... because you did not click on "Search" and simply type in "sprag adjustment" ... (?)
Now, IF you did... lots of useful threads would pop up!

Or start with this post and also click on the links; which will take you to other posts with even more links, etc, etc......


G.

 

[InfiniteFoamies]

I have a 65' duece... It has been cannibalised so I do not know if there should be an In/Out switch on the dash. How can I determine? There is a manual lever I imagine for Hi/Lo

Thanks guys...

 

[tobyS]

Wow...another thread that gives a small tidbit of information about sprag. But G did give up "sprag adjustment" to search, which for some reason did not come to mind even after searching 20 other items for T138 adjustment. I'm glad to finally find it now that I've finished the assembly. I am on the shops schedule and do not have the luxury or stamina to read until it all blends together more than a couple of times. I made the mistake of thinking that at least one of the professionals at SS would help. That didn't happen. Since I had a difficult time with re-installing the sprag, I'll see if the referenced thread gives info I needed. I'm glad to find it now that I struggled and may or not have it right.

On a side note...can an air shift section of a T1138 be put upon a T138, replacing the sprag?

 

[WillWagner]

You DO realise that the OP was like 4 years ago and the one after G's post was a year and a half? This is a dead thread man.

 

[RAYZER]

On a side note...can an air shift section of a T1138 be put upon a T138, replacing the sprag?

No, they are totally different.

 

[tobyS]

Yeh...sorry, but after reading thread after thread and not finding hardly anything, I commented anyway. I share the mans frustration on finding information about transfer cases, about the insides of the Rockwell T 138 and T1138...of which the sprag unit is a major component in the older trucks.

If you notice Gribgletaube scolds 70amgeneral and a worthwhile thread was cut short and not completed. I like to read, but the lack of completed subjects on these threads makes research nearly impossible in reasonable time.

 

[tobyS]

No, they are totally different.

RAYZER would you go to the thread I started (M817 transfer case output bearing) and answer a few questions? You seem to be familiar with both T138 and T1138.

I'll make a post that bumps it up. Thanks Toby

 

[41cl8m5]

One thing that is not be said on this thread is on the sprag unit the ratio is different between the front drive and the rear. If you did a manual engagement lever for the front drive and you are on a hard surface all kind of things can go wrong and break. The two cases air/sprag are the same it is the front that is different and the internals for the front drive ( including the gearing). On the air case the gearing is the same front and rear so it acts about the same as a 4x4 truck on the road.

if you changed the gearing on the front drive so both are turning the same rate then a engagement lever would work. Eastern surpluses had a kit called REB I think to change the gearing and to remove the sprag. They no longer offer the kit due to how available the air transfer case are.

 

[tobyS]

One thing that is not be said on this thread is on the sprag unit the ratio is different between the front drive and the rear. If you did a manual engagement lever for the front drive and you are on a hard surface all kind of things can go wrong and break. The two cases air/sprag are the same it is the front that is different and the internals for the front drive ( including the gearing). On the air case the gearing is the same front and rear so it acts about the same as a 4x4 truck on the road.

if you changed the gearing on the front drive so both are turning the same rate then a engagement lever would work. Eastern surpluses had a kit called REB I think to change the gearing and to remove the sprag. They no longer offer the kit due to how available the air transfer case are.

On the thread I started a man said his 16.00's were making that gearing an issue and going back to the 1/1 (T138 high ratio) as opposed to .73/1 (T1138 high ratio) would make his rpm at highway speed correct. Yes it would...but both of us agree we would like to eliminate the sprag.

I understand what you are saying about the difference on the T138, as the front ratio and the rear are different. That surely would cause a problem without the clutch.

If one wanted more speed from an 809 series, going to the T1138 makes sense with the air engagement (and I assume equal gear ratio on front and rear).

 

[porkysplace]

Wow...another thread that gives a small tidbit of information about sprag. But G did give up "sprag adjustment" to search, which for some reason did not come to mind even after searching 20 other items for T138 adjustment. I'm glad to finally find it now that I've finished the assembly. I am on the shops schedule and do not have the luxury or stamina to read until it all blends together more than a couple of times. I made the mistake of thinking that at least one of the professionals at SS would help. That didn't happen. Since I had a difficult time with re-installing the sprag, I'll see if the referenced thread gives info I needed. I'm glad to find it now that I struggled and may or not have it right.

On a side note...can an air shift section of a T1138 be put upon a T138, replacing the sprag?

Isn't this the transfer case your working on ? [h=3]m817 transfer case output bearing[/h]This is the DEUCE form . The transfer cases in a deuce and a 5 ton are different , so what good does it do to hi-jack a thread in the deuce form , then complain about the thread ?

 

[tobyS]

Isn't this the transfer case your working on ? m817 transfer case output bearing

This is the DEUCE form . The transfer cases in a deuce and a 5 ton are different , so what good does it do to hi-jack a thread in the deuce form , then complain about the thread ?

I'm sorry about that. I've been looking at the subject and didn't see it was the deuce forum. My mistake. The topic of sprag seems to have application in both deuce and 5 ton, none of which are very complete.

 

[Recovry4x4]

T138-21 is the M34 series transfer case with the overrunning clutch. T138-27 is the air shift version and the 1138 is one I'm not familiar with.