Discovered the Front Driveshaft Out of Phase (Intentionally)

[iron.head]

I don't think the recall mentioned above is related to this. Seems that one is for CV axles that can break and cause full time 4WD vehicles (Limited Hybrid) to roll away.

What issues are you having?

2025 TRD OR long bed. seems vibrations in 4 High are excessive.

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[maxx075]

2025 TRD OR long bed. seems vibrations in 4 High are excessive.

Seems like the 6' beds have an issue with the 2-piece driveshaft that has been covered here quite a few times. Dunno if there's actually a TSB/recall out on those, but I know a few members have had them replaced once the dealer took the driveshaft out and the vibration disappeared.

 

[BLtheP]

2025 TRD OR long bed. seems vibrations in 4 High are excessive.

Good deal. Or bad deal really, but it contributes to the theme of the thread which is good. I ordered a 3rd gen V6 MT front driveshaft (37140-04053) due to some pretty good OEM parts sales going on near me, so I will report back how that turns out once received.

I had the same exact driveshaft in my 3rd gen spinning all the time with the ADD deleted, and it was smooth as silk. Unless we have some angle mismatches between the transfer case front output and the front diff, I think this will solve the problem (barring any unforeseen issues like the length actually being wrong, etc).

 

[Will721]

I have noticed a slight vibration in 4h at speed, but having never owned a brand new truck with zero miles I chalked it up to break in. Mainly because the first time I used it, I was on the interstate caught in a blizzard out of town. After the first 50 or so miles it did diminish significantly. I'll have to have a look at the front shaft.

It could be just an assembly issue. The slip joint has a spline, and that first pic does look as though it could be off by just one tooth. But then if you correct it, the shaft would likely require rebalanced.

 

[BLtheP]

I have noticed a slight vibration in 4h at speed, but having never owned a brand new truck with zero miles I chalked it up to break in. Mainly because the first time I used it, I was on the interstate caught in a blizzard out of town. After the first 50 or so miles it did diminish significantly. I'll have to have a look at the front shaft.

It could be just an assembly issue. The slip joint has a spline, and that first pic does look as though it could be off by just one tooth. But then if you correct it, the shaft would likely require rebalanced.

I've noticed it on mine since the first time I engaged 4H with any meaningful speed, and sadly after the 60 or so miles in the winter storm, it didn't get any better.

I agree it's probably off by a tooth, but it's not just mine - it's every single front driveshaft for the 4th gen that I could find on eBay. Whereas previous gen had them perfectly in phase as expected.

I'm not sure how the 4G driveshaft could even pass a balance test unless there is no angle on the balancer machine. Spicer typically knows what they're doing very well, I'm amazed to see them be the builder of this shaft unless Toyota specs told them to do this for some unknown reason.

I don't lean on AI very much but ChatGPT does tend to agree that there are zero functional reasons why someone would want a 2 joint shaft to not be in phase.

 

[Robb_D]

I decided to pop out and take a look at my front drive shaft August 2025 MY25 TRD Off Road Hybrid.
My driveshaft appears to be 90 degrees out of phase.
Have not noticed any vibrations to speak of, though generally don't use the truck at freeway speeds in 4wd, rarely did with my 3rd gen as well.

 

[BLtheP]

While phasing probably contributes in some way, it seems to be an intentional choice regardless. I received the new driveshaft today and installed it. Before doing so took a comparison photo. The two are practical identical besides the phasing.

Old on top, new on bottom:

Unfortunately the vibes are now worse, so this is a failed experiment. That’s disappointing.

I’m going to measure the angles of the flanges and shaft upon removal to see what the actual environment is like for these 2-joint shafts.

 

[BLtheP]

Swapped back to stock. During that time, I measured everything.

Driveshaft: 0° slope
T-case flange: 6° pointing up
Front diff flange: 0° pointing straight back

Obviously that isn’t ideal. Those flanges should be parallel to run correctly.

There is also a lateral front driveshaft offset of probably 2.5-3” which also adds to the angles. The front diff is several inches to the left compared to the transfer case. However, IF the flanges were perfectly angled and parallel, the lateral part probably wouldn’t matter. But since the flanges are not parallel, the lateral offset is likely contributing to the issues as well.

My assumption on what’s going on here and what could even explain why some have vibes and others don’t is that Toyota probably had to compromise to offer all the different drivetrain combos.

They are offering a lot on this platform:

• Manual/auto
• SWB/LWB
• 4WD/2WD
• Hybrid/gas
• 4wd full-time/part-time

To be able to do that and not design a bunch of different frames and front/rear diff housings, this is likely the best compromise they could get.

It is certainly surprising to see the drivetrain angled down 6° for my gas MT. I do have a super short front section on the 2 piece rear driveshaft, so likely what they did was try to make that work perfectly which messed up the front.

Oh well, no eventual deletion of the ADD or full time 4WD conversion for me I guess…bummer.

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