TeraLow D20 Twin pops out

[bigjhoov]

Have you checked to see if your shifter fork is loose?

 

[707Bronk]

Hello my tcase started popping out of gear after I installed the heavy duty rear output assembly from WH, I have replaced the detent balls and springs and it still will pop out. I dont really want to sound like a dummy but could someone post a step by step procedure on how to set the preload on the rear output.

Thanks John

Checking the preload is easy. You are measuring rotational drag. You have to have an in-lb torque wrench though.

For the rear output, you remove the entire output assembly, put the housing in a vice and measure the preload by turning the yoke nut with the torque wrench. The drag will indicated on the torque wrench.

If you want more preload, add more shims. If you want less preload, remove shims. To add or remove shims though you have to dissassemble the entire output assembly. I have seen 5-9 in-lbs range (I think). I had mine set at 5in-lbs forward rotation and 7in-lbs backwards.

I checked my preload without the seal installed and the yoke nut not torqued to its final spec. You could probably get detailed instructions from WH or from whoever you bought the output assembly/shaft from.

I hope those are the right instructions as that was what I did and it seems to be working fine...hopefully someone else can confirm.

 

[Viperwolf1]

If you want more preload, add more shims. If you want less preload, remove shims.

It's the other way around, more shim thickness=more bearing clearance=less preload.

 

[707Bronk]

It's the other way around, more shim thickness=more bearing clearance=less preload.

I thought that was for the front output. Guess I got the front/rear shimming backwards in my thick head.

 

[Viperwolf1]

I thought that was for the front output. Guess I got the front/rear shimming backwards in my thick head.

It's true for both front and rear.

 

[707Bronk]

It's true for both front and rear.

I could have sworn that when I added shims to the front output that it decreased the bearing preload because the shims were adding space between the rear cap and the rear bearing race.

When I put mine back together, the front originally had 1 shim and its preload was about 25-30in-lbs, which was way too much. I ordered a shim pack and installed three more shims until it got down to 5-8in-lbs.

Then again, in the 60 days between finishing the rebuild and today there has been dozens and dozens of beers, so at this point I'm not sure if I actually did rebuild the xcase to begin with. lol

 

[Viperwolf1]

I could have sworn that when I added shims to the front output that it decreased the bearing preload because the shims were adding space between the rear cap and the rear bearing race.

When I put mine back together, the front originally had 1 shim and its preload was about 25-30in-lbs, which was way too much. I ordered a shim pack and installed three more shims until it got down to 5-8in-lbs.

Then again, in the 60 days between finishing the rebuild and today there has been dozens and dozens of beers, so at this point I'm not sure if I actually did rebuild the xcase to begin with. lol

Yes, exactly like I said, more shim thickness=more bearing clearance=less preload. Same for front and rear shafts.

On the rear shaft adding shims will move the outer bearing cone away from the cup, increasing clearance. On the front shaft adding shims moves the rear bearing cup rearward away from the bearing cone, increasing clearance.

 

[707Bronk]

You are exactly right viper. Just looked at the drawings again. I think the confusing part for me is on the rear shaft the bearings are trapping the races between the two bearings. Whereas on the front shaft the bearings are pushing the races outwards. Hence, my confusion. Thanks for setting me straight!