Banged up my driveshaft. Buy replacement or retube original?

Two weeks out while wheeling I managed to hit my driveshaft. It's scraped up and has a very small dent towards the back. It's giving off some subtle vibes and I had it checked by a shop who lifted the rear and put the truck in gear and the shaft has an obvious wobble to it. The shop said he can retube what I have reusing my existing u-joints and make a thicker walled shaft for ~$400 if I take if off and bring it to him to save labor.

I am seeing new replacements online for $580. I'm wondering if I should buy a new replacement and keep mine as a spare. It is certainly usable enough to get me off the trail and back home if I was to ever really damage the new one to the point of immobilizing the truck while on the trail. However, the retubed shaft would be stronger. Is it worth the extra $180 to have a whole new shaft and not cannibalize my existing shaft?

Pictures of the damage. It doesn't look like much, and I'm really surprised at how little damage it took to throw it out of balance.

 

I'd go with the thicker/stronger option

 

Wow you can actually see the dent at the very far right in the top pic. I didnt notice that when you posted a few weeks ago.

A spare would be cool, but will you really have room to carry that around with you? Food for thought

 

Yeah I honestly didn't know it was dented until another member on here saw that picture and pointed it out. The vibes are so subtle I might not have ever noticed until things got worse, but I definitely don't want to mess up any bearings with time. A spare would be a pain, but on trip where hard wheeling is expected, I could know to bring it. But again I'm probably learning towards building a stronger one and learning from my mistakes and picking better lines.

The only concern in the back of my mind is that the shaft is fine, and the wobble is caused by my rear lift and the pinion angle being out of sorts. I didn't install shims because the truck didn't have vibes after the install of the lift, but I have no comparison of watching the driveshaft from before the damage. So I can only assume the wobble is induced from the damage. I guess if it still wobbles after the new shaft, it means I need shims. But the vibes I can feel now were not there post lift, I think. I think I'm overthinking it too much now though.

Does anyone know if driveline vibes from improper pinon angles post lift can be seen in the driveshaft with the wheels spinning if the rear of the truck is lifted off the ground? I don't want to buy a new shaft if that isn't the cause of the wobble.

 

Personally, I would go with a new shaft. Having the current one rebuilt and retuned sounds great, but unless he has a shaft balancer, it won’t ever be any better. Just as well, if he had a shaft balancer, he could balance the minor dent out if your current shaft.
I would look into a heavy duty one made to take a little more abuse.
Good luck bro.

 

The one he said he'd make me is a of heavier tube. He said he would mill down the old joints and weld them into the new tube and balance that. How is that different from what you say when you mean have a heavy duty one made?

 

No I dont think you would see those types of vibrations. They are caused from the small differences in angular velocity due to the u-joints. Theres some good short animations on youtube about it. Also, this why CV shafts (Constant Velocity) are a thing vs regular U-joint type axle shafts.

The best way to check things after a lift is to get a small magnetic angle finder. Basically you want the angle of each ujoint to be close to its neighbor. So a combo of shims and CB drop will line everything up. Another thing I learned from personal experience (though this shouldn't apply to you with a new truck) is a worn out carrier bearing will cause vibrations due to extra slop in the rubber support.
https://smile.amazon.com/gp/product/B07P6ZD8KT/ref=ppx_yo_dt_b_asin_image_o00_s00?ie=UTF8&psc=1

Back to the driveshaft. Personally I would be less worried about vibrations and more worried about strength. Its a pretty small dent, but Im not sure what that will do under a lot of torque. Probably nothing..

 

Yes I am familiar with the angles. I didn't think too much beyond them because post lift I don't think I had any vibes (but now I'm starting to question myself). Before the lift I took measurements using instructions on a thread I found on here. I put the angle finder on the flat spot of the transfer case and zeroed it out. First section of the shaft was 4.3*. The second part of the shaft was 4.7*. Next I zeroed it out while on there placed it on the flat spot of the rear diff and it read 3.4*. Following the install of the lift my angles were 3.4*, 2.0*, and 0.8* respectively. However, I didn't track this down any more because I didn't feel any vibes.

 

But I think you're right. I don't think the driveshaft angles being out of sorts would cause the wobble to appear. It was visible even at low speeds with the shaft spinning slow, you could see it wasn't spinning true.

I think I'm going to take the shaft off today after work and bring it to him. He said it would only be a day or two once he gets to it before I get it back.

 

Get a 14mm swivel socket if you dont have one already

 

It’s not, depending on how skilled he is. If he has a shaft balancer, you could just have the stock one rebalanced for next to nothing. He never mentioned that as an option?

 

He said it wasn’t possible because the stock one is compromised, which I never really wanted to accept. I think I might call him again tomorrow and ask why he can’t do that. From the damage I did, I really don’t think the integrity of the shaft is compromised. You make a good point. Problem is he’s the only guy for hundreds of miles. I’ve called all over and asked guys who work as mechanics and they all don’t have any leads on anyone who does driveshafts. So this guy probably knows he’s got me in a tight spot so to speak.

 

That would immediately put me into “screw you and you thinking you have me in a tight spot” mode. I would end up buying one from a trusted vendor online.

But I’m old, jaded, and stubborn as a damn mule.

 

I like driveshaft specialists in San Antonio. I went with a one piece with a double cardan joint on my super duty with a tuned 6.4 that made the torque of 5 Tacoma's and had no issues. I put a one piece aluminum from them on my 7.3obs truck and again no problems. If I had to get a new shaft for the taco I'd see if they could make a double cardan, I had no vibration with that at all. They ship too.

 

Build a stronger one. Pull the current one, put the truck in 4wheel drive hi and drive back to drop it off.

 

FYI- To check if it’s really “compromised” (ie: bent??) put the rear on jack stands, have someone put it in drive while you use a bit of chalk taped to a stick (hockey sticks work great) to touch the spinning shaft at various points. Just slide the stick slowly along the bottom of your truck to keep it steady until it touches the shaft. Turn the truck off and check the chalk rings. Cheap and easy. Always works for me.
-If it’s a small dent and not bent, it can prob just be re-balanced. Try calling a few auto machine shops.
-If your guy rebuilds it with a thicker tube, he’ll use parts from your old shaft so you won’t have a spare for wheelin.
-If you buy a new shaft, you’ll also have to buy new U-joints if you wanna keep your old shaft for a spare.

 

With this method, if the shaft is the bent how do the chalk rings look? They’d be crooked I assume?

 

What are you looking for here, runout? So a perfect shaft would have a solid ring all the way around wherever the chalk touches, but a bent driveshaft would only touch the chalk on the high side?

 

I just called the driveshaft guy I'm dealing with locally. He said that the shaft is bent and that's why it can't be re-balanced. I don't know if he's yanking my chain or not, but it might be true for this reason: With the truck in drive while looking at the shaft, the wobble was noticeable with the shaft spinning at very low speeds. To me, I would think that if it was a balance reason it would become apparent as speed increased. The variance can be seen as soon as the shaft started spinning.

I've been talking with Ron from Driveshaft Super Store. Debating having him build me a new shaft with a double cardon joint behind the carrier bearing. Price for that is right around the same as what the local guy is quoting me...

 

If you are seeing wobble at low speeds I'd think the shaft is definitely bent. If you can get a better product from DSS for about the same price I'd go with that.