Prolly a stupid question but...T-case slippage.

[SquareRoot]

Newly rebuilt th400 with a np208.

On three occasions, I have felt a distinct slip then clunk taking off from a stop in 1st gear.

I know for a fact it's not the rear end or
U-joints. That said, is it possible the stock 153k mile 208 case can slip? I know it has a chain inside but I assume that only matters when in 4wd?

 

[DoubleDingo]

My th400 has done that. Wouldn't rule out the transmission.

 

[SquareRoot]

That's my suspicion, I just wanted to rule out the t case.

It kinda felt like the chain jumped a few teeth, that's why I asked about the t case chain.

The first time it happened, I took off from an intersection making a right hand turn and I got on the throttle pretty hard. I got some serious vibration/banging that I thought was wheelhop. But I have a 14 ff with a Detroit locker. I never was able to recreate it.

 

[gotyourgoat]

Replacing everything piece by piece to source the vibration @Frankenchevy is the only true way to go.

 

[eskimomann209]

Chain is disengaged in 2wd. Even if it’s loose it’ll only be an issue in 4wd

 

[84 M1008]

That's my suspicion, I just wanted to rule out the t case.

It kinda felt like the chain jumped a few teeth, that's why I asked about the t case chain.

The first time it happened, I took off from an intersection making a right hand turn and I got on the throttle pretty hard. I got some serious vibration/banging that I thought was wheelhop. But I have a 14 ff with a Detroit locker. I never was able to recreate it.

 

[84 M1008]

Both my M1031 and my M1008 did this also. The locker gets grumpy when you make a sharp turn and get into the throttle. It happened more doing right hand turns though. It's perfectly normal, don't worry about it.

 

[Arkansas_V8]

Mine did that when the adapter cracked. Check that also.

 

[Vbb199]

I'll ask a simple question for you to look into.
Is the transmission low on fluid?

 

[Turbo4whl]

Both my M1031 and my M1008 did this also. The locker gets grumpy when you make a sharp turn and get into the throttle. It happened more doing right hand turns though. It's perfectly normal, don't worry about it.

Just like @84 M1008 said, perfectly normal for the Detroit Locker to bang on tight turns on a hard dry surface. The Detroit Truetrac is much more street truck friendly.

Here is a link to the Eaton site. Click the Locker and halfway down that page is a video that shows how the Locker works. While you are there, go back a page and click the Truetrac and see the difference.

https://www.eaton.com/us/en-us/prod...action-control/aftermarket-differentials.html

 

[SquareRoot]

Chain is disengaged in 2wd. Even if it’s loose it’ll only be an issue in 4wd

Thank you. That's what I figured. That leaves the trans or the locker.