Teraflex Manufacturing Dana 20 Low Range Kit
Part 2 of the Uber-20 project (Building the ultimate low geared transfer case at home)
By BillaVista
Page 6 - Installing the kit, part 2
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Reassembling the case - part 2
Install front output housing bolts and torque to 30 ft lbs.
Install poppet ball caps.
Check front output shaft end-play by prying the shaft alternately to the rear and then to the front of the case. The proper method is to measure the end-play with a dial indicator. I must admit - I went by "feel". End-play should be between .001 and .003 inch. If it needs to be adjusted, you do so by adding or subtracting the shims under the front output shaft rear bearing cap. Note that there are no extra shims in the kit, so if you need them, you will have to source them separately.
Install the needle bearings in the intermediate gear with grease. Note that there is a row of needle bearings on each side of the gear, with a bearing spacer / washer separating the 2 rows in the centre of the gear, as well as one on each side.
Install the intermediate gear thrust washers in the case with heavy grease, being sure to align the tangs with the slots in the case.
The installed thrust washers should look like this.
Carefully drop the intermediate gear into place, being careful not to knock the needle bearings, bearing spacer washers or thrust washers out of place or alignment. It can be quite tricky and may take a few tries. I found it helpful to rotate the gear a little as I lowered it into place.
Start intermediate gear shaft into case by hand.
Once it begins to get tight, make sure the groove in the shaft faces the lock plate bolt hole.
Then drive the shaft home with a brass or other soft drift.
Install the lock plate...
...and the transfer case tag and then install and tighten the lock plate bolt to 14 ft lbs.
Check for clearance between the intermediate gear and the rear shift rod.
Rotate the gear. If there is any contact seen, heard, or felt between the gear and the front shift rod, you will have to remove the shift rod and grind a little for clearance.
The area in question that will need to be clearanced is shown here between my fingers.
The red arrows show the are where I ground my shift rod slightly for clearance.
Coat rear output housing with RTV and install, tightening bolts to 30 ft lbs.
Install front output thrust washer and yoke.
Apply thread locking compound.
Tighten front output shaft yoke nut to 225-250 ft lbs.
In my installation, the next thing I needed to do was install the doubler adapter with the main drive gear installed on it, back on the transfer case so I could turn the gears and check the case assembly and shifting operation before sealing up the case.
This shot shows the poor, worthless quality of the Crown Automotive gaskets. Useless!!
I'm not a big fan of gaskets anyway, and prefer a good, high quality RTV sealant / gasket making compound - but it's pretty poor when the bolt holes don't even line up. Like I said at the beginning - might as well just throw them out.
This is the stuff you want to use - either The Right Stuff, or the factory GM RTV - they are the best two gasketing products I have used.
The last thing to do before bolting the lower cover back on and filling the case with 80w90 gear oil is to check the operation.
Go to -->
Contact Info:
Tera Manufacturing, Inc.
5251 South Commerce Dr.
Murray, UT 84107-4711
phone/801.288.2585
fax/801.288.2571
TeraFlex
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Part 2 of the Uber-20 project (Building the ultimate low geared transfer case at home)
By BillaVista
Page 6 - Installing the kit, part 2
Go to -->
- Page 1 - Introduction - The What And Why Of The Project?
- Page 2 - Dana 20 Teardown Part 1
- Page 3 - Dana 20 Teardown Part 2
- Page 4 - Teraflex Low20 Kit and Case Grinding
- Page 5 - Installing the Teraflex Low20 Kit, Part 1
- Page 6 - Installing the Teraflex Low20 Kit, Part 2
- Page 7 - Checking Transfer Case Operation, Testing, Results and Contact Info
Reassembling the case - part 2
Install front output housing bolts and torque to 30 ft lbs.
Install poppet ball caps.
Check front output shaft end-play by prying the shaft alternately to the rear and then to the front of the case. The proper method is to measure the end-play with a dial indicator. I must admit - I went by "feel". End-play should be between .001 and .003 inch. If it needs to be adjusted, you do so by adding or subtracting the shims under the front output shaft rear bearing cap. Note that there are no extra shims in the kit, so if you need them, you will have to source them separately.
Install the needle bearings in the intermediate gear with grease. Note that there is a row of needle bearings on each side of the gear, with a bearing spacer / washer separating the 2 rows in the centre of the gear, as well as one on each side.
Install the intermediate gear thrust washers in the case with heavy grease, being sure to align the tangs with the slots in the case.
The installed thrust washers should look like this.
Carefully drop the intermediate gear into place, being careful not to knock the needle bearings, bearing spacer washers or thrust washers out of place or alignment. It can be quite tricky and may take a few tries. I found it helpful to rotate the gear a little as I lowered it into place.
Start intermediate gear shaft into case by hand.
Once it begins to get tight, make sure the groove in the shaft faces the lock plate bolt hole.
Then drive the shaft home with a brass or other soft drift.
Install the lock plate...
...and the transfer case tag and then install and tighten the lock plate bolt to 14 ft lbs.
Check for clearance between the intermediate gear and the rear shift rod.
Rotate the gear. If there is any contact seen, heard, or felt between the gear and the front shift rod, you will have to remove the shift rod and grind a little for clearance.
The area in question that will need to be clearanced is shown here between my fingers.
The red arrows show the are where I ground my shift rod slightly for clearance.
Coat rear output housing with RTV and install, tightening bolts to 30 ft lbs.
Install front output thrust washer and yoke.
Apply thread locking compound.
Tighten front output shaft yoke nut to 225-250 ft lbs.
In my installation, the next thing I needed to do was install the doubler adapter with the main drive gear installed on it, back on the transfer case so I could turn the gears and check the case assembly and shifting operation before sealing up the case.
This shot shows the poor, worthless quality of the Crown Automotive gaskets. Useless!!
I'm not a big fan of gaskets anyway, and prefer a good, high quality RTV sealant / gasket making compound - but it's pretty poor when the bolt holes don't even line up. Like I said at the beginning - might as well just throw them out.
This is the stuff you want to use - either The Right Stuff, or the factory GM RTV - they are the best two gasketing products I have used.
The last thing to do before bolting the lower cover back on and filling the case with 80w90 gear oil is to check the operation.
Go to -->
- Page 1 - Introduction - The What And Why Of The Project?
- Page 2 - Dana 20 Teardown Part 1
- Page 3 - Dana 20 Teardown Part 2
- Page 4 - Teraflex Low20 Kit and Case Grinding
- Page 5 - Installing the Teraflex Low20 Kit, Part 1
- Page 6 - Installing the Teraflex Low20 Kit, Part 2
- Page 7 - Checking Transfer Case Operation, Testing, Results and Contact Info
Contact Info:
Tera Manufacturing, Inc.
5251 South Commerce Dr.
Murray, UT 84107-4711
phone/801.288.2585
fax/801.288.2571
TeraFlex
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