Dana/Spicer Transfer Case Guapo

So then I am assuming the intermediate shaft should measure out at 1.25"?? I'll take it to work and double check it with some mics that I know are calibrated and accurate.

There were 2 shims under the rear cap. Maybe I'll get lucky and won't need any, but plan on bringing yours anyway. I'll let you know if I don't need them, but with the rat race at work I May not get back to this project real soon.

Thanks,

lyle
 
lyle wiese said:
so then I am assuming the intermediate shaft should measure out at 1.25"?? I'll take it to work and double check it with some mics that I know are calibrated and accurate.

There were 2 shims under the rear cap. Maybe I'll get lucky and won't need any, but plan on bringing yours anyway. I'll let you know if I don't need them, but with the rat race at work I May not get back to this project real soon.

Thanks,

lyle
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Yes, seems there is no +/- diameter spec for the idler shaft od, but all six of the shafts I have that are usable measure 1.250" exactly on the bearing surfaces that are easily discerned.

I've pulled the box with all the small parts/shims/thimbles/extra gaskets/etc. Out so I'll bring it with me!
 
michael mayben said:
yes, seems there is no +/- diameter spec for the idler shaft od, but all six of the shafts I have that are usable measure 1.250" exactly on the bearing surfaces that are easily discerned.

I've pulled the box with all the small parts/shims/thimbles/extra gaskets/etc. Out so I'll bring it with me!
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What is the spec for the bore on the intermediate gear set? Since that is the outer race, I will take it in to have it mearsured as well.

Thanks for bringing the parts.

Lyle
 
lyle wiese said:
what is the spec for the bore on the intermediate gear set? Since that is the outer race, I will take it in to have it mearsured as well.

Thanks for bringing the parts.

Lyle
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I'm likin' 1.625 for the nominal oem bore diameter. All the samples I have (n=5) show 1.6255>1.626". A portion of the bore untouched by the bearings shows 1.625".
 
I took the intermediate gear and shaft into work and checked them with a calibrated mic and a cmm. The shaft shows maybe .0002" of wear and the id of the gear .0002-.0003". Not bad for 47+ years. If I was going to actually "wheel" this rig, I would replace the gear and shaft, but since this is only going to see some street use, I'm going to run what I have.

The gasket/seal kit and new yoke nuts and washers are due in on Friday from our good friends who so generously let us use this very informative site.

Lyle
 
lyle wiese said:
I took the intermediate gear and shaft into work and checked them with a calibrated mic and a cmm. The shaft shows maybe .0002" of wear and the id of the gear .0002-.0003". Not bad for 47+ years. If I was going to actually "wheel" this rig, I would replace the gear and shaft, but since this is only going to see some street use, I'm going to run what I have.

The gasket/seal kit and new yoke nuts and washers are due in on Friday from our good friends who so generously let us use this very informative site.

Lyle
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You win...again!

Jes' for the hail of it...what is the part number on that intermediate gear you have? Lemme see if I can beat it! I know what it is supposed to be, but after 47+ years let's verify!
 
Reassembled the tc as far as I could today. Looks like the replacement front cap gasket is thinner than the original. I need another .020" of shims under the rear cap to maintain the output shaft axial clearance of .002"-.006". With the two .030" shims, I have less than zero. I pulled the shims out of another t-18 I had on the shelf; it also had 2-.030" shims. Must be the factory standard.

This is the first time I have seen gaskets under lip seals. These gaskets were included in the kit from ihon. I'm impressed!

Lyle
 
lyle wiese said:
reassembled the tc as far as I could today. Looks like the replacement front cap gasket is thinner than the original. I need another .020" of shims under the rear cap to maintain the output shaft axial clearance of .002"-.006". With the two .030" shims, I have less than zero. I pulled the shims out of another t-18 I had on the shelf; it also had 2-.030" shims. Must be the factory standard.

This is the first time I have seen gaskets under lip seals. These gaskets were included in the kit from ihon. I'm impressed!

Lyle
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My "theory" about those seals...

Back in the mid-30's (1900's not 1800's!!!) when that case was developed, sealing elements as you know were rawhide, elastomers were unknown at that point as far as being used in seals and such. The steel seal "case" was also just a simple stamping and not very precisely done.

So the seal "gaskets" were used to reduce fluid migration around the case of the seal, kinda like the more modern encapsulated seals that are prevalent today.

And...because when those rawhide seals leaked (and they did so terribly!), resulting saturation of the seal lip embedded with grime ate the groove in the rotating member (the yokes). So then a replacement seal could not "seal". That's where we sometimes use the speedee sleeve overlay which are super expensive. So by using the gaskets as shims for the seal itself, it can be re-located slightly within reason) in it's bore so that the lip can ride on a undisturbed surface on the yoke shank.

These gasket/seal sets we market (along with many other sources) are assembled by aftermarket suppliers (actually one in particular!), spicer/Dana has not done these parts since the late-80's. So no doubt there are many variations in the gasket paper thickness, that's not a problem since when rebuilding, one should do exactly what you are doing...shim it up correctly!

You are also going to see that the "texas-pattern" gasket between the trans and the case May not be cut correctly for the IH stuff. No big deal, just whoop out the scissors and have at it! And you will have quite a few gaskets left over.
 
lyle wiese said:
I win??? Good!! What did I win?

How does 1859p2t2 sound?

Lyle
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That intermediate gear is actually spicer p/n 18-5-9. It should have a tooth count of 39 x 18 and a helix angle of 20* and was used in some d20 cases.

Unfortunately, I have none of that part number in my stash here for comparison to see if we have a better one!
 
It's reassembled with a new coat of paint. Looks a lot different than when I took it out.

I added two .010" shims to the two .030" already on the tc. Gave me an axial clearance of .0025".

Didn't need any of the thimbles; all this tc has is 1 cast "thimble" supporting the 2/4wd shift rod (I think), well, the longer of the two shift rods.

I'll get it put back in the truck this week.

Thanks for the shims Mike.

Lyle
 
Good deal!

Go through that box of "stuff" and remove anything you think you May need for doing another 18 or a 20 in the future. Keep an assortment of all the shims like we discussed the other night. Keep two of the new thimbles for future use on something else.

Also keep that 1-1/4" intermediate shaft for future use and if ya wanna mess with it, you can pick out a full set of roller bearings from that cup, I believe those are all new, just mixed up, you are bound to have a d20 around there someday that needs help?

I think that sealed bag roller bearing kit is for a np203/205, not a d18/20.
 
michael mayben said:
good deal!

Go through that box of "stuff" and remove anything you think you May need for doing another 18 or a 20 in the future. Keep an assortment of all the shims like we discussed the other night. Keep two of the new thimbles for future use on something else.

Also keep that 1-1/4" intermediate shaft for future use and if ya wanna mess with it, you can pick out a full set of roller bearings from that cup, I believe those are all new, just mixed up, you are bound to have a d20 around there someday that needs help?

I think that sealed bag roller bearing kit is for a np203/205, not a d18/20.
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Ok, thanks Mike, I will.

Lyle
 
Anyone know a good way to get this allen screw to loosen up? Since it has been constantly covered in oil it can't be rusted. I have tried to tap it with a mallet and with a hammer, but it doesn't want to budge. It's not a reverse thread or anything is it?
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I use a high quality long-pattern tee handle hex wrench to access those set screws. Also sometimes I use a hex wrench socket that has had the bit cut down so I can fit a breaker bar in there to break the screw loose.

If someone has been into the case before, they May have used loctite on the screw threads (common practice). If that is the case, you May need to use either a heat gun or a small propane torch and gently heat the boss where the screw threads into the fork in a very local manner to aid in breaking the loctite bond.

The only secret is having a high quality, tool steel hex wrench, not the typical chinee shit found at the discount house.
 
Well, I've heated it with a propane torch for a while, didn't work. I tried a longer allen key, didn't work. (the allen wrench would flex too much before I run out of space to turn.) I've tried a chapman wrench which attaches an allen key head to a small socket wrench-type thing, and I can't get enough leverage to break it free. This thing is really starting to annoy me. Any more thoughts?
 
Small diameter (just fits over allen wrench) long, strong steel tube? Maybe with a bend in it to give you more room to turn...
 
Get the fork material itself right at the threaded boss a dull red, it has to be expanded significantly for the set screw to break loose.

Grind a hex socket down so that just the stub engages the screw completely so you are not twisting the entire tool, then rig a cheater on whatever you are using to turn it with.

If all else fails, then use the gas axe and cut it off and extract the rail and fork in pieces, it's not worth aggravating the hemorrhoids over. I have plenty of excellent used ones in the stash here.
 
Okay after heating it for a longer period pf time I finally was able to break it free. Now I am debating whether I want to remove the interlock pin or to leave it in. I already have the Dana 20 set up with twin sticks and I use a chain to an eyebolt to keep the rear in 4lo (it has the tendency to pop out at inopportune times). Is it worth removing the interlock?
 
I'd remove the interlock myself since you have the twin stick setup. That is a nanny-state deal anyway.

Since the unit is down for rebuild (I'm assuming), then now is the time to correct the issue with popping out of low range under load. That is normally the result of the poppet springs having collapsed partially, worn detent slots, and worn poppets. If the shift forks show any sign of extreme wear/galling on one side, that is the consequences and should also be replaced.
 
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