Topic: Noise coming from my drivetrain when off the throttle

[toyotaman83]

I'm just finishing up the longest build ever.  I have a 1990 Toyota 4runner, I have swapped in a 4.3 Vortec.  This build has been a budget build when it can be.  So the drive train is as follows.  4.3 Vortec, AA bellhousing adapter, Stock R150, AA T-case adapter, Reduction box, Trail-gear adapter, 4.0 Marlin rear case and gears.  I have swapped in a solid axle, running 37" Iroks, near 10" of lift.  So i've been driving it up the street working out the bugs.  No noise when i'm on the throttle, when i get off I'm experiencing a clicky gear noise.  When i get back on it goes away.  I have listened with a stethoscope and it seems to be near the back of the tranny/reduction T-case but its hard to say.  Could a C-clip have come off? Do I have a gear floating?  Anybody else experience this?  I did clearance the back case for the Marlin gears. 

[toyotaman83 [OP]]

If I push in the clutch and unload the drive-train while coasting thats when i hear the clicky gear noise.

[2manytoys]

I have nowhere near the mods you do but, I had drive train noise at part throttle or coasting after lifting my truck. Sounded like trans or t-case about to eat a bearing.

Long story short....CV in the rear drive line cured it.

[Nimyad]

Yeah, you need a cv joint in the rear.

[toyotaman83 [OP]]

I have a Solid Axle CV on the Front and a IFS CV on the rear, I'll look into the rear CV.  Maybe its still not enough?  I have the stock Axle in the rear still running coils.  5.5 Fj80 coils, 2" spacers, allpro links and other misc brackets.  Pinion angle isn't the best. Maybe i'll pull the rear driveshaft and try running just the front and see if it does it?

[HogCanyonHopper]

you need a double cardan joint behind the transfer case and point your pinion on rear diff right at the t-case 

[OOPS]

  Pinion angle isn't the best.

This is where I would start.

[toyotaman83 [OP]]

Okay, I will look into the driveshaft being the issue.  Like I said I do have a CV also known and double cardan joint.  It is however a IFS version with less degrees of movement.  Also the rear axle is pretty fixed with all the brackets in place. (Stock Linked)  I was under the assumtion the 4runner driveshaft had major degrees of flex at the diff end?