New lift, driveline vibes. Double Cardan Rear shaft? (1 Viewer)

[reklund5]

Been hemorrhaging money on this old Landcruiser lately, what's a little more?

Vehicle is a 1995 80 series with ~350k miles. Currently has ARB front bumper, ComeUp 9.5 winch, and MetalTech sliders. Rear bumper is stock, no cargo drawers or anything at the moment.

As for me, I've been building and wheeling Toyota pickups and 4Runners for 20 years. Not new to this stuff, but this one is fighting me.

Just got done installing 3.5"F/2"R Dobinsons springs, BP51 shocks, Delta radius arms and rear panhard bracket, OME trailing arms (adjustable uppers, fixed lowers) OME Panhard bars F/R, 4.88 gears and ARB lockers, and a whole bunch of small parts.

Chasing driveline vibrations as anticipated. Custom front driveshaft with double cardan, all is good up front. Still have pretty good vibrations from the rear from 35-50mph, and more noise than vibration at 65-75mph. Confirmed by removing the shafts one at a time and driving with the center diff locked. On front shaft only, smooth as glass to 80mph. Rear shakes your fillings loose.

Rear tcase output and pinion flange within 1.5° of each other to start. Adjusted to 0° with the upper trailing arms, no change in vibration. Replaced both rear shaft u-joints with Matsuba parts, very slight improvement. Had rear shaft balanced and trued. No real change. Suspect worn slip spline, tried another used/borrowed driveshaft- no change. Worse if anything as it was a high mileage unit.

Had a great conversation with Jess at High Angle Driveline today, who suspects that I'm outside the operating range of the standard rear shaft. Rear shaft is 11° in relation to the tcase or pinion flange. His recommendation is to go to a Double Cardan rear shaft. I'm all for it, but my concern is that in order to run one properly the pinion needs to be clocked up so it points more or less straight at the Tcase flange. Been down that road on my mini truck years ago....

So my question is: Is anyone running a double cardan/CV rear shaft in an 80, and were you able to sufficiently adjust your pinion angle via adjustable trailing arms without other modifications to the axle? (Coil spring seats, panhard bar mount, shock mount, etc?).

Any feedback or input is appreciated!

 

[BILT4ME]

I'm curious why you went 2" in front and 3-1/2" in back. Most people hate the stinkbug, not to mention the difference from front to rear angle of the transfer case to differentials.

Usually, the problem is only the front due to it being the shorter of the two shafts, but equal height front to rear.

Also, is the rear shaft correctly in phase and the slip yoke at the transfer case?

 

[reklund5]

I'm curious why you went 2" in front and 3-1/2" in back. Most people hate the stinkbug, not to mention the difference from front to rear angle of the transfer case to differentials.

Usually, the problem is only the front due to it being the shorter of the two shafts, but equal height front to rear.

Also, is the rear shaft correctly in phase and the slip yoke at the transfer case?

Lift sizing was based on recommendation from Cruiser Outfitters. It sets almost level -only a little stink bug currently. When the eventual rear bumper and drawers get added it'll be dead level I think. I threw ~450 lbs in the back today to see if bringing it down would make any difference, and it did not.

I *did* have front DS issues, hence the double cardan front shaft. It's good now tho.

Yes, rear shaft is indeed in phase and the slip spline is at the transfer case end.

 

[BILT4ME]

Lift sizing was based on recommendation from Cruiser Outfitters. It sets almost level -only a little stink bug currently. When the eventual rear bumper and drawers get added it'll be dead level I think. I threw ~450 lbs in the back today to see if bringing it down would make any difference, and it did not.

I *did* have front DS issues, hence the double cardan front shaft. It's good now tho.

Yes, rear shaft is indeed in phase and the slip spline is at the transfer case end.

Have you checked or changed you engine and transmission mounts?

 

[beatle_bayly]

I believe 80 series shafts should be OUT of phase. Though I'd say your rear shaft simply has too much angle. If you are going to the trouble to clock the rear pinion, it might work with the stock shaft.

 

[reklund5]

Have you checked or changed you engine and transmission mounts?

They're definitely due for replacement, however I had zero vibration prior to the lift.

 

[BILT4ME]

I believe 80 series shafts should be OUT of phase. Though I'd say your rear shaft simply has too much angle. If you are going to the trouble to clock the rear pinion, it might work with the stock shaft.

Only the front shaft. Rear is supposed to be in phase.

 

[reklund5]

I believe 80 series shafts should be OUT of phase. Though I'd say your rear shaft simply has too much angle. If you are going to the trouble to clock the rear pinion, it might work with the stock shaft.

Only the front OE shaft should be out of phase. The rear is always run in phase. Clocking the pinion with the stock shaft does me no good- tried it a few degrees either way and the vibration persists.

 

[baldilocks]

An operating angle over 6-7 degrees is very likely not going to run perfectly smooth despite the companion flanges being parallel. I fought the fight your in several years ago when my rear shaft was operating at 13 degrees. Been running double DC shafts several years now. Adjusting the pinion up is not a problem with adjustable links but the rear coils will be bowed somewhat.

The bow in mine hasn’t been a detriment running Slee 4” heavy progressive coils and 37’s loading pretty heavy and crawling boulders. At first the bow bugged me because, muditis dominated my cerebrum but I forced myself to just run it that way and at some point I forgot about it until I wrote this post…….

 

[LandCruiser65]

I'll bet the farm all you need to do is point your rear pinion up more. I just went thru this battle myself. I ordered a tom woods dc shaft after installing 37's and i got a noise. the slight lift increase was binding the aft u-joints. i installed the new shaft and still had a noise. I was pissed. I thought maybe the pinion bearing was going out at first. Basically I wasted 500 bucks on a shaft when all i needed to do was lengthen my upper control arms! noise went away! Try this first before shot gunning more parts on her!

 

[NorCalFJ100]

An operating angle over 6-7 degrees is very likely not going to run perfectly smooth despite the companion flanges being parallel. I fought the fight your in several years ago when my rear shaft was operating at 13 degrees. Been running double DC shafts several years now. Adjusting the pinion up is not a problem with adjustable links but the rear coils will be bowed somewhat.

The bow in mine hasn’t been a detriment running Slee 4” heavy progressive coils and 37’s loading pretty heavy and crawling boulders. At first the bow bugged me because, muditis dominated my cerebrum but I forced myself to just run it that way and at some point I forgot about it until I wrote this post…….

I'm following this thread for education! I am curious though what is another way to adjust pinion without those links and bowing the springs? I know you haven't experienced any negatives. Just wondering what the options are.

 

[reklund5]

I'm following this thread for education! I am curious though what is another way to adjust pinion without those links and bowing the springs? I know you haven't experienced any negatives. Just wondering what the options are.

The other way is to cut all the spring seats off the axle and re weld them in a different position so that the springs remain straight after the pinion is clocked up.
While I'm not opposed to the idea, if I can avoid it I’d like to...

 

[NorCalFJ100]

The other way is to cut all the spring seats off the axle and re weld them in a different position so that the springs remain straight after the pinion is clocked up.
While I'm not opposed to the idea, if I can avoid it I’d like to...

I see. So you adjust with the upper arms and then rework the seats.

Can you make any further adjustments to your upper arms to see if that helps? It's my understanding that the lower adjustable arms won't help, is that correct?

 

[baldilocks]

The other way is to cut all the spring seats off the axle and re weld them in a different position so that the springs remain straight after the pinion is clocked up.
While I'm not opposed to the idea, if I can avoid it I’d like to...

What deterred me from clocking the spring perches is the fact that the track bar bracket is integral with the drivers side perch and looked like it would be a pain to deal with. And, maybe I’m older than you, but when I get tired of pulling myself up into an 80 that’s lifted 5”+, going down to low lift won’t require any cutting and welding.

 

[baldilocks]

I see. So you adjust with the upper arms and then rework the seats.

Can you make any further adjustments to your upper arms to see if that helps? It's my understanding that the lower adjustable arms won't help, is that correct?

Adjusting the length of the lower links would rotate the axle house because the bushing bolt is not centered on the housing. However, you would also move the forward or aft depending on if you made the link longer or shorter in your effort to rotate the house.

Adjust lowers to move the housing fore and aft. Adjust the uppers to move the pinion up or down.

 

[b16]

I'm on a 4" lift with DC front and just had my rear shaft rebuilt. I had vibes in the rear also; was due to old u-joints now operating at an angle they were not used to. I bet simply replacing the ujoints will fix the issue.

 

[reklund5]

I'm on a 4" lift with DC front and just had my rear shaft rebuilt. I had vibes in the rear also; was due to old u-joints now operating at an angle they were not used to. I bet simply replacing the ujoints will fix the issue.

I've already got brand new Matsuba U-Joints in the rear shaft and the noise/vibration persists. Hence the consideration of the DC rear shaft.

 

[reklund5]

I see. So you adjust with the upper arms and then rework the seats.

Can you make any further adjustments to your upper arms to see if that helps? It's my understanding that the lower adjustable arms won't help, is that correct?

I can adjust the uppers more, yes. The lowers that I got are not adjustable (OME upper and lower arms)

At this point im thinking the next step is the DC shaft, I'm just looking to see if I can rotate the pinion up enough to make it work without relocating the spring seats and Panhard bar mount.

 

[landtank]

What’s the hub center to flare measurement in the rear?

 

[reklund5]

What’s the hub center to flare measurement in the rear?

I'll have to get that when I get home on Friday. I'm traveling for work this week.