Transfer case blues

[JohnnyC]

I have been tearing down my 727 and Dana 20 to do a reseal and im at a snag.

For some reason im struggling with seperating the front part of the transfer case--(which I believe is called the front bearing retainer, I know you'll correct me if im wrong)--with the the transfer case housing. It will not slide off of the left shift bar.

Please tell me it's just being a pain and that there isn't more to undo. Iv'e been using the manual but it's somewhat vague and I was born in the south.

 

[Michael Mayben]

Very common dude!

No doubt the shift rails are pretty rusty and mungy. Ya need to clean the rails best ya can before sliding the front retainer over the rails, the crap is creating interference since the holes in the retainer are actually guide bushings for the rails, fairly tight fit.

Scotchbrite pads work well for cleaning the rails as ya can wrap it around and see-saw back and forth. Then lubricate the rails with some kinda penetrant or light lube as ya work it back and forth.

There May be some distinct burrs on the rails also where the stick(s) pivot engages in the rail slots, those need to be removed with a file or dremel

in one rebuild I did, I found the shift rail to be significantly "bent" for some reason??? Most likely, the case had been dropped on the floor after it was assembled or during installation and not repaired. That one was a bitch to get apart!

 

[JohnnyC]

Well after two days of messing with the transfer case I finally got the front bearing retainer removed. Thanks for your help mayben.

Is there a tool to help with the reasembly of the idler gear shaft. As soon as I pulled the shaft tons of long bearings fell out of the gear set. Any advice???
Also I noticed some of the teeth on the idler gear set were chiped. I'm guessing that should be replaced. Whats that gonna run me? Do you guys have some good used one s on hand?

 

[Michael Mayben]

Can you post some pics of the idler gear along with the part number stamped on it? If Jeff doesn't have a used one at his location, I prolly do, but I need the part number. Sometimes the gear teeth can be reworked using a grinding stone inna dremel.

As for a line-up tool for the loose bearings, I use a dowel of the approximate diameter, the bearings themselves are stuck in place with transemble or you can use vaseline. I won't use grease for that install as it will "stick" the rollers and prevent 'em from rolling, they will "skid" instead and flatspot the shaft or bearing immediately. Use the same material to stick the thrust washers in place during reassembly.

See this thread for part number match of the intermediate gear to the bull gear, starts around post #29:

http://www.forums.IHPartsAmerica.com/basic-tech-questions/3638-driveline-noise-please-help.html

 

[JohnnyC]

Copy that. I'll try to get those pics posted on Tuesday. Thanks for that thread.

 

[JohnnyC]

can you post some pics of the idler gear along with the part number stamped on it? If Jeff doesn't have a used one at his location, I prolly do, but I need the part number. Sometimes the gear teeth can be reworked using a grinding stone inna dremel.

http://www.forums.IHPartsAmerica.com/basic-tech-questions/3638-driveline-noise-please-help.html

Hopefully this is what your looking for.

http://www.http://gallery.IHPartsAmerica.com/gallery/albums/userpics/10067/normal_dana_20_005.jpg
http://www.http://gallery.IHPartsAmerica.com/gallery/albums/userpics/10067/normal_dana_20_014.jpg
http://www.http://gallery.IHPartsAmerica.com/gallery/albums/userpics/10067/normal_dana_20_015.jpg
http://www.http://gallery.IHPartsAmerica.com/gallery/albums/userpics/10067/normal_dana_20_016.jpg
http://www.http://gallery.IHPartsAmerica.com/gallery/albums/userpics/10067/normal_dana_20_019.jpg

Here's a pic of the thrust washer. Should these be replaced???

http://www.http://gallery.IHPartsAmerica.com/gallery/albums/userpics/10067/normal_dana_20_020.jpg

Here is a few others:

http://www.http://gallery.IHPartsAmerica.com/gallery/albums/userpics/10067/normal_dana_20_022.jpg
http://www.http://gallery.IHPartsAmerica.com/gallery/albums/userpics/10067/normal_dana_20_028.jpg

 

[Michael Mayben]

Great pics dude, that tells the story!

Last pic first, that p/n is for the d20 bare "case" casting only, it's not the unit p/n.

The steel tag however is the primary identifier for that d20, 421769c91 is the IH p/n for the assembly, the other number is the spicer bom (bill or materials) number for parts lookup purposes by a spicer service center.

The 18-5-16 spicer number tells us that intermediate gear is a 17.5* pitch angle used behind a tf 727/t-407 bull gear inna Scout II and also in a few later Jeep vehicles.

The "entry" profile on all those gear teeth does not look bad enough for me to replace 'em unless I have some perfect ones that are available.

Ya know that "grinding" sound ya git when ya can't get the tc to shift easily due to internal parasitic rotation or oil drag when the engine is running and the tranny is in neutral? Over much time, that is what results, those square cut gears are real crude (but very durable!!) and simply not designed to "mesh" while any rotation is occurring (like when shifting on the fly).

However...if ya got plenty time on your hands and a dremel or die grinder with small sanding drums or consumable mounted grinding wheels, you can carefully use those to return the "profile" of the worn end of each gear tooth to an approximation of it's original shape which was kind of a "blunt" triangle if ya can follow me here!

I do the same on the dogs on the bull gears in order to salvage 'em.

This does take time and mucho patience, but once you have done a few teeth you will see it's easy!

As for those thrust washers, I'd replace 'em. And, if the inside of the intermediate gear and it's shaft aren't perfect, then replacing the roller bearings will be kind of a waste, the shaft surface and the id of the gear are the "races" for the roller bearings.