Just picked up this 03 RCSCB 4.8/5-Speed from a member here. Great truck! Of course with 135k on the clock it needs some mechanical TLC to be perfect.



I've read about the NV3500 just being a truckish transmission and anytime this truck was clutched in normal accelerating or decelerating it would make an annoying CLANK! metallic noise. Many guys reported this at under 50k miles!

It would also make a Screech-Screech-Screech! sound under heavy acceleration. A shot of WD40 on the rear u-joint reduced the screech so off the O-Reilly for a u-joint.

New greaseable U-Joint = Screech gone and the entire drive train feels tight and connected much more like an LS1 car.

Also, since I yanked the drive shaft without raising the rear enough I was greeted with about a quart of Syncromesh on the garage floor. Went ahead and changed out the fluid with new Pennzoil Syncromesh and noticed a bit less whine.

I've owned C5s and a GTO with MN6 and all felt connected. I had been so bummed about how this thing shifted and the difference is amazing.

Old U-Joint, Roller Bearings? What Roller Bearings?

 

Wow, they were toast, must be a huge difference!

 

Do submarines have U-joints? That's where that one looks like it came from!

 

LOL - no kidding

I'm a FL boy whose been in TX for 18 yrs, never seen anything like that. This truck came from 100 W of Kansas City, must have been snowy from 2003-2010.

Truck has ZERO body corrosion and just a little frame surface rust here and there...but little things like this I am taking care of one by one. All new to me.

 

Careful with those greasable U's...there def weaker than what u had and if ur gonna be launching, might wanna be careful...

 

Hmm - suggest going back to OE ? Assume the greaseable is weaker as it is hollow ?

 

Thats correct. Check for a Spicer part...try a search on here or call them up, but when I blew my G-80 to bits everyone was screaming not to go with the greaseable joints as they couldnt take any power. Now I just blow up R&Ps

 

my nv3500 sucks whines makes all sorts of noise probably be its rated for 300ft tq and im putting down close to 600 so yeah swap the nv3500 do a auto swap or a t56 swap make it s 6sp

 

Until I replaced the U - and probably will put in a beefier one shortly, I was reading all the T56 swap threads. I'll live with it for now, no plans to go past any minor upgrades or bolt ons for now.

 

I went with greaseable u-joints in my 4.3 Blazer since they were the cheapest, but spent the extra coin on factory replacements for my truck for the durability