Tranfer case hodgepodge

[joshs1ofakindxj]

In my quest for the conversion from the sprag to the air shift, I have acquired two air shift cases with their own unique problems at a fair price.

In the pictures, you'll see that the one on the left has a broken mount. I assume this was broken when the truck that it was in was rear ended and totaled.

The other case was replaced by the now broken case because it was having trouble shifting between ranges, would not shift on the fly, and when the oil was taken out, some "pieces" came out.

Now, I can attempt to weld what appears to be a cast iron mount, or I can make one case out of two.

I have downloaded and printed the TM for the transfer case but I haven't read it thoroughly yet to know what I can do.

If it would be cheap, fast and dirty to put the internals from the broken mount case into the good case of the other transfer case, then I just might tackle that.

If I'm going to have to replace a lot of parts just by tearing down the case, then I will attempt to weld the cast iron with some inconel or high nickel rod, but I'm worried about preheat and post heat on that big case.

Thoughts?

 

[ODdave]

One case from 2. Not worth the effort & risk to weld. You have a good case, use it.

 

[DieselBob]

I would also think this would let you give the gears and bearings a once over for defects.

 

[tgarrisoniv]

are a sprag and airlock interchangable? i want to switch but opposite from you. i want the sprag

 

[joshs1ofakindxj]

I would sell you mine but you're kind of far away!

Why do you want to switch to the sprag?

From my research, the only difference is one of the mounts uses studs and not bolts or something of that sort, but for the most part they are a direct swap.

I started tearing down one of the airshift cases the other weekend. What a project!

 

[poppop]

A question for those of you working on both types of cases? Is the synchronizer on the top shaft the same in both types???

 

[tgarrisoniv]

i hear that!
reasons:
1) my air compressor knocks
2) i have a power steering pump that could really use the mount that the air compressor sits on
3) i want more cool shifting devices in my cab

how much would you sell it for (just for local hunting purposes)

 

[joshs1ofakindxj]

i hear that!
reasons:
1) my air compressor knocks
2) i have a power steering pump that could really use the mount that the air compressor sits on
3) i want more cool shifting devices in my cab

how much would you sell it for (just for local hunting purposes)

If you're using stock brakes then you need to keep that air compressor. The air pack that acts as the brake booster is supplied with air by the compressor.

It would be cheaper and A LOT less work to replace just the air compressor.

There is plenty of room above the alternator on the passenger side of the motor to mount the power steering pump.

The sprag doesn't offer any more shifting options. You loose one by removing the air shift lever on the dash with the air shift case. The sprag is an automatically engaging transfer case, that works when it feels like it. You still have the same hi/low lever.

I would sell mine for $200 I guess. I'll probably just keep it around for parts.

 

[tgarrisoniv]

gotcha. i dont have stock brakes or axles. i have 5 tons with a pinion brake and a chevy 2500 booster. i just would rather shift manually but i have seen that alot of people have issues with these sprag cases and not too many with the airlocks

 

[joshs1ofakindxj]

Gotcha, I thought I could see a pinion brake kind of in your avatar picture.

Going from air shift to sprag is really unheard of. Everyone would rather have an air shift. Reliable engagement at the flip of a switch. The sprag engages when it senses slipping unless it is worn or out of adjustment.

 

[tgarrisoniv]

oh so no in/out lever?? thats pointless. i want to make my airlock a manual then. there has to be a way. ever seen it done?

 

[joshs1ofakindxj]

No lever on the sprag.

The air lock is a manual already, air actuated, you want to convert it to mechanical engagement. I would search the forum to see if it has been done.

 

[gringeltaube]

....... i just would rather shift manually but i have seen that alot of people have issues with these sprag cases and not too many with the airlocks

For a possible "manually shifted" airshift T136-27 I just replied this to Gimpy's post, here


G.

 

[robert c neth]

i hear that!
reasons:
1) my air compressor knocks
2) i have a power steering pump that could really use the mount that the air compressor sits on
3) i want more cool shifting devices in my cab

we have the same setup you have in our big mud truck and the sprauges didnt last long.ive been tempted to pull the air shift off and see if if a manual stick can be made.right now the sprauges are welded and we have 2 air shift for spares to play with.good luck on your quest.

 

[RAYZER]

are a sprag and airlock interchangable? i want to switch but opposite from you. i want the sprag

I have a good sprag that im about to take out,trade you!

 

[tgarrisoniv]

i hear that!
reasons:
1) my air compressor knocks
2) i have a power steering pump that could really use the mount that the air compressor sits on
3) i want more cool shifting devices in my cab

we have the same setup you have in our big mud truck and the sprauges didnt last long.ive been tempted to pull the air shift off and see if if a manual stick can be made.right now the sprauges are welded and we have 2 air shift for spares to play with.good luck on your quest.

thanks.... i talked to a good friend of mine that builds alot of big trucks with 2.5 airlocks w/o the "airlocks" he said he would show me how to weld it up. i will post pics when complete.

 

[joshs1ofakindxj]

Ok, so I tore down the air shift case with the bad internals. I found 30% of a bearing race and a beat up ball bearing, so I assume the previous owner pulled out the other parts. I can't see where the bearing came from, so it must be from inside the shifting mechanism. The case did have shifting problems....

Anyways, now that I'm familiar with disassembly and the internals I'll be tearing down my air shift case with the good internals and bad mount this weekend to combine the two to make a good transfer case

Questions:

1. What thickness should the gaskets be? 1/32"? 1/16"? I have access to rolls to make my own, I just need to know the size. TM 9-2520-246-34 hasn't helped me out with that. I believe it is critical because of question 2...

2. I'm not sure how to check the shaft end play for the counter shaft and output shaft. I see how to make shim adjustments with the end covers, but not where to inspect it. The TM is pretty vague about it. My guess would be that it is checked after the case is assembled with the shafts inside, and then place a dial indicator on the shaft end and wiggle it back and forth. Knowing the thickness of the gasket for the case will help me get this closer to spec before shimming.

I guess there is no end play or other critical measurements for the input shaft.

Any other pitfalls I should be aware of?

Thanks.

 

[spicergear]

i hear that!
reasons:
1) my air compressor knocks
2) i have a power steering pump that could really use the mount that the air compressor sits on
3) i want more cool shifting devices in my cab

how much would you sell it for (just for local hunting purposes)

GET A UNIMOG!!!

 

[spicergear]

When I sell my deuce crane truck, I am going to REALLY miss my REB kitted, manual shift T-case.

 

[gringeltaube]

..... I found 30% of a bearing race and a beat up ball bearing, so I assume the previous owner pulled out the other parts. I can't see where the bearing came from, so it must be from inside the shifting mechanism. The case did have shifting problems....

Prolly pieces of a bearing cage, not the race...? There is a total of 6 ball bearings on the input shaft. (see bearing numbers here)

1. What thickness should the gaskets be? 1/32"? 1/16"? ............... I believe it is critical because of question 2...

Go for 1/32"... or just 518 Loctite alone, after well cleaning/checking both surfaces (use flat file). Gasket thickness is NOT critical since you have to readjust bearing end play of counter- AND rear output shafts, anyways! You might need some extra shims to compensate.

2. I'm not sure how to check the shaft end play for the counter shaft and output shaft. I see how to make shim adjustments with the end covers, but not where to inspect it. The TM is pretty vague about it. My guess would be that it is checked after the case is assembled with the shafts inside, and then place a dial indicator on the shaft end and wiggle it back and forth. Knowing the thickness of the gasket for the case will help me get this closer to spec before shimming.

Yes, that's the safest method, although with some practice you can achieve that by hand-feel. Zero play, that is almost NO preload is correct.

I guess there is no end play or other critical measurements for the input shaft.

There will be just as much play as new or good ball bearings will allow.



Keep us posted with your progress!


G.