Solved reg cab driveshaft vibrations after lift

after i swapped my stock 3-leaf springs with a 4-leaf se t from a 2016 TRD and added a wheeler's progressive AAL, i noticed i had the dreaded grinding from my driveshaft. it sounded awful...like something would snap at any time.

i read some options on here such as flipping the driveshaft or adding shims or adding a driveline spacer. the last one made the most sense to me so that's what i tried. i ordered a 3/4" spacer from 4crawler.com, installed it in about 15 minutes and it worked! smooth as silk now.
i suspect the splines were not making optimal contact after the lift. they do now and seem to have plenty of play in either direction for rear axle travel.

not that there are a lot of regular cabs out there with the same problem, just passing this info along in case anyone has the same issue.

 

Strange, your drive shaft looks totally different from mine.
So this spacer goes between the differential and the drive shaft?

 

in my case, yes. the transmission side had studs that would've had to have been removed and longer ones pressed in

 

Interesting...wonder if this is a fix for other models also? Most complaints are vibrations after lift. Yours was more of a grinding?

 

i'd say this is a fix if your slip yoke has separated after you lift the truck and the driveshaft needs to be longer. what i experienced was both vibration and an awful metallic grinding noise, mostly on deceleration.

 

Would you say that "odd bouncing" or "strange thuds" would be explained by these issues?

 

hmmm, i don't remember anything like that. i'd probably look at u joints first if i were you. or maybe it's out of phase? apparently there are many more issues to chase down also if it's a two piece shaft. good luck!

 

Yeah it's hard to figure out what is the engine vs the driveline vs the tranny.

 

Any idea if this fixes the coasting noise at highway speeds?

 

yes, it did for me. whatever you do, don't shim your diff with a single piece driveshaft. you don't want to mess with the front/rear angle relationship
https://youtu.be/Idk3BVDVHq4

 

I don't understand why they do not just use a true constant velocity joint.

 

price

 

I'd gladly pay more

 

When I first joined in 2011 I found all the threads on TW about the regular cab "grinding"noise on deceleration, which I had. After much trial and error, I also came to the same conclusion that the slip joint was too loose like the OP. You can actually feel this if you crawl under and shake the driveshaft back and forth there's a slight "clunk". Spacer is worth it in my opinion, but just be careful about how much reduction in travel the slip joint has after installation.

 

I am going to do this asap as I too have the deceleration vibes after my lift.

 

I had the deceleration vibe thing, too, and it really bugged me. I just had my frame replacement done, and in the process had the rusty old after-market 4-leaf springs (I bought my truck used) replaced with the stock ones - I felt it was overly lifted in the rear and I wanted it reduced. Got my truck back - no noise. FWIW.

 

Kinda old thread but what size did you get? Was thinking 65mm x 65mm?

 

I'v got a silver reg cab with 2" lift and add a leafs in the rear. It makes the whirling sound when decelerating on high way.
If you move the drive shaft with your hand back and forth couldnt you tell if it was the drive shaft thats now too short? Would removing the add a leaf springs solve the problem?