Front driveshaft with 2-3" OME (1 Viewer)

[Spook50]

I have the heavy/heavy OME on my 62 (haven't added any extra weight yet) with 4* caster shims, but am trying to chase down a heavy vibration/growl in my front drivetrain when at light throttle and with the clutch in in high range 4WD, at all speeds about 30 MPH. I know some vibration is to be expected given uneven wear of tires between front and rear and just the nature of the 60 series drivetrain's design, but what I've been chasing is beyond what should be considered normal. I had it before the H55F conversion and never got it solved. It's about the same after the conversion, which of course involved replacement drive shafts front and rear due to the tcase being shifted about 6" forward. The U joints in both are aligned correctly in phase, but all four look pretty old (possibly original to the driveshafts?) so I figure, like my original driveshafts replacing the U joints with new (getting Matsuba from Cruiser Outfitters) and properly maintaining them from the get go certainly won't hurt at all. I also intend to find a local shop and have them balanced properly for peace of mind.

A question I have though, given I'm sitting at about 3" of lift, plus the front drive shaft angle being steeper due to the tcase being shifted forward for the H55F swap: Am I still good with the stock driveshaft, or should I be looking to source a dual cardan front shaft? I have a lot of other things to be spending money on, so if sticking with the stock front shaft will do me just fine, I'll stay with it. I'm of the impression that a dual cardan front shaft for a 60 series costs a pretty penny, plus involves the work of drilling the flanges on the tcase output and the differential to accommodate the rectangular bolt pattern. Something I'd rather not go to the work of.

 

[cruisermatt]

Any particular reason are you using 4wd on the street at those speeds?

There's this neat thing you can do called measuring that will tell you whether you need a DC driveshaft or not

And if you do need one (you shouldn't though), you don't have to get one for a 60 (the only option there is a 81-84 front shaft and have it lengthened), there are plenty of Tacoma's, Tundra's, and 4runners with DC driveshafts that you could pick up for next to nothing at the pick-n-pull and changed the length.
I always shorten or length front driveshafts myself, and never balance them, but i never run 4wd on the street like that

 

[Spook50]

Any particular reason are you using 4wd on the street at those speeds?

There's this neat thing you can do called measuring that will tell you whether you need a DC driveshaft or not

And if you do need one (you shouldn't though), you don't have to get one for a 60 (the only option there is a 81-84 front shaft and have it lengthened), there are plenty of Tacoma's, Tundra's, and 4runners with DC driveshafts that you could pick up for next to nothing at the pick-n-pull and changed the length.
I always shorten or length front driveshafts myself, and never balance them, but i never run 4wd on the street like that

View attachment 2554727

It's rare that I drive faster than 45MPH in 4hi, but it's not uncommon to go about that speed either. Road conditions around here in the winter are enough that on straight roads it's done a lot. Shifting winds during light snowfall on the open highway are a big reason for it here in the late winter and early spring. Although I will say that since the H55F and addition of twin sticks to my tcase, it's much easier to shift into and out of 4WD on a whim as long as the hubs are locked.

I'm pretty sure my tcase and diff flanges are parallel, but now need to double check since I'm not 100% on that one. I do have the 4* caster shims, but since I'm still SUA they've tilted the pinion down after the OME install. Not even sure if 4* off of parallel is enough to make a difference in drive train vibration, but I'd believe it if someone told me it does. Especially with the difference it makes in bump steer (mine was atrocious before the shims).

 

[cruisermatt]

Measure your angles. you can get away with pinion/T-case flanges not being perfectly parallel, but there's a limit obviously