Dana 20 With Teralow kit advice

After many moons (20) the Jeep is on the road. During the build I had a 3.15 Teralow kit installed in the Dana 20. When in 3rd gear and 2 hi, under a load at 30-45 I am getting a whine from the transfer-case. It has always made it's whine in 4-lo but it never did it in 2 hi until now. Should I be concerned? Or is the noise the trade off for bigger and different gears? What do you think?

 

In the Dana 20, high range is a direct drive. Unless the front is engaged there should not be any gear whine. Are you sure the front is not engaged?

And are you sure its from the t-case and not the tranny?

And as a third, you did put oil in the t-case? I know people who have not after doing work.

I have the terra lows and the only time mine ever whines is when in 4-hi or low range.

 

In response...

No the front it not engaged

It is for sure the transfer case...

And yes is has fluid in it.

Any advice on how to proceed, been long enough not sure the installer will do anything for me. I have not had the Jeep over 50 as I am nervous about the whine I don't want to damage anything.

 

I would check to make sure that you are really in 2WD. See if you can turn the front driveshaft by hand. As mentioned above, the intermediate shaft of the D20 does not turn when in 2WD, so it should not whine in 2WD, regardless of the condition of the intermediate gear and shaft.

The entire rear output housing will come off of the Dana 20 without removing the transfer case. You could remove it and inspect the bearings. It should not engage with any gear in 2WD or neutral.

 

OK, front axle turns by hand. I have my trannny cover off too, I can see that the front shaft is not turning as I go down the road. My hubs are also unlocked too.

Anything else to try before I drain the fluid and start pulling things apart? It is Easter Sunday the wife will let me mess around, but I can't come in from the garage smellin' like gear lube today. But what you are saying is making sense... got to be in the direct drive parts...

 

Check the oil in your axles?

 

Front is good, back is low! I will top it off and report back in a few...

Sure hope this is the cause.

 

Thanks Tim, you just saved me a days work. Rear-end was low, topping it off has quieted it right down.

 

Just a quick follow up on this...

Noise is still present. Not as bad, but still there. I am thinking of pulling the rear yoke off and having a look at the assembly. Anything I should check for? What causes gear whine? gears not syncing? not lining up right? I looked at the exploded views, no shimming no crush sleeves, I can't see anything to even adjust.

 

Try pulling the rear driveshaft, drive it around in 4wd a bit and see if the whine is still there. Whining can be caused by a bad pinion bearing. If your rear gear oil was really low, the pinion bearing would not have gotten enough oil during operation, and may need to be replaced.

 

It is a very good idea to remove the driveline, I will do that.

I am about a week from getting my OX locker installed. I also have a master rebuild kit to install replacing all the bearings and the seals. Then I can remove the Dana 44 as a suspect...

 

I am going to pull my rear output housing today. After doing a lot of reading... I suspect the end play is too tight. Any thoughts?

 

My intermediate gear is turning in 2wd. I need to figure out why. So far I have not drained the fluid yet. Probably need to pull the bottom cover to figure this out.

 

Just a quick follow up, Jeep was in the Shop last night...

My pinion bearing was shot and had heated up to a point that the pinion changed to a blue color. Pinion is also chipped and shows signs of damage. (none of this is from the lack of oil) My OX installer suggested a new Ring and Pinion, he tells me whomever set the rear end up last time did not do me any favors. So in conclusion gear whine was coming from rear end. Also just a quick note in response to an older post... the intermediate shaft on my Dana 20 always turns no matter what gear you are in unless it is neutral. The whole dana 20 gear set turns in 2hi or 2lo.