Drive Without Rear Driveshaft?

[GrapeApe9]

I’m trying to isolate a vibration, felt more in seat but also in steering, on my 1999 LC. On both driveshafts I had the ujoints replaced and shafts balanced at a machine shop. After which the vibration decreased but is still present. Before I would notice vibration at 35mph and up, after the driveshaft balance and new ujoints it became less noticeable, starting around 55mph, and then clearly present by low 60s and up. Took it to mechanic who balanced the wheels and looked it over to no resolve. Mechanic took it to transmission shop and they believe it’s in the drivetrain and toward the rear. Unfortunately I couldn’t leave it with them as it was needed for vacation.
Could I remove the rear shaft and drive it? If so, are there limits? Also, any ideas as to what might be causing this issue?
Thank you!

 

[gatormark91]

I’m trying to isolate a vibration, felt more in seat but also in steering, on my 1999 LC. On both driveshafts I had the ujoints replaced and shafts balanced at a machine shop. After which the vibration decreased but is still present. Before I would notice vibration at 35mph and up, after the driveshaft balance and new ujoints it became less noticeable, starting around 55mph, and then clearly present by low 60s and up. Took it to mechanic who balanced the wheels and looked it over to no resolve. Mechanic took it to transmission shop and they believe it’s in the drivetrain and toward the rear. Unfortunately I couldn’t leave it with them as it was needed for vacation.
Could I remove the rear shaft and drive it? If so, are there limits? Also, any ideas as to what might be causing this issue?
Thank you!

Is your truck lifted?

 

[cmck]

I’m trying to isolate a vibration, felt more in seat but also in steering, on my 1999 LC. On both driveshafts I had the ujoints replaced and shafts balanced at a machine shop. After which the vibration decreased but is still present. Before I would notice vibration at 35mph and up, after the driveshaft balance and new ujoints it became less noticeable, starting around 55mph, and then clearly present by low 60s and up. Took it to mechanic who balanced the wheels and looked it over to no resolve. Mechanic took it to transmission shop and they believe it’s in the drivetrain and toward the rear. Unfortunately I couldn’t leave it with them as it was needed for vacation.
Could I remove the rear shaft and drive it? If so, are there limits? Also, any ideas as to what might be causing this issue?
Thank you!

Can you remove the rear drive shaft and drive it. Yes...... I have bent the rear DS and dropped it and gotten home just fine.

I feel @gatormark91 is going for possible pinion angle being too much because of a lift.

I also had a small vibration on a 3.5” rear lift and went to TrailTailor adjustable upper control arms to get the angle back and take out the vibration.

 

[MongooseGA]

I just drove around in FWD this weekend while having the same DS service done. It felt weird. Terrible torque steer.

Did you do the front shaft as well? My vibrations were reduced a lot but I still feel a little after doing just the rear. I've read rear control arms can be suspect, too.

 

[GrapeApe9]

Is your truck lifted?
[/QUOT

Is your truck lifted?

Unfortunately it’s not lifted.

Thanks.

 

[GrapeApe9]

Can you remove the rear drive shaft and drive it. Yes...... I have bent the rear DS and dropped it and gotten home just fine.

I feel @gatormark91 is going for possible pinion angle being too much because of a lift.

I also had a small vibration on a 3.5” rear lift and went to TrailTailor adjustable upper control arms to get the angle back and take out the vibration.

Good to know, thank you!

 

[GrapeApe9]

I just drove around in FWD this weekend while having the same DS service done. It felt weird. Terrible torque steer.

Did you do the front shaft as well? My vibrations were reduced a lot but I still feel a little after doing just the rear. I've read rear control arms can be suspect, too.

I did work on both shafts, then drove without the front DS. But had same issue. I hadn’t tried driving without the rear yet b/c I wasn’t able to find any definitive answer by google searches...

I’ll give it a try - appreciate the help, thank you!

 

[MongooseGA]

Fwiw, I locked the center diff when I drove it 2wd.

 

[fe sus]

Going to bring this thread back from the dead. I shipped my 99 lx470 across country to run the NEBDR. Plans were delayed due to storms but eventually I made it and did at least some of the NEBDR. I've also run the UTBDR in this rig and drove from Seattle to UT and back with no problems. Noticed vibrations on the trip back from VT, from VT to LAS and then up to Seattle. Vibrations at 60-65, not above or below.

Truck has SPC uppers in front and new tie rods. OME shocks. Bilstein shocks all around. Alignment is good. New bfg ta/ko3s. 18" wheels from newer 100. Height at rear wheel well is 35 1/4", 36 3/8" at the front. Not sure what that equates to vs stock. I noticed while doing the shocks that the U joint at the rear was toast. I'm trying to decide if I want to replace that joint and reinstall or swap out the rear driveline altogether.

Planning to take it out tomorrow in FWD and see if the vibration remains. What could I screw up by trying that out at highway speeds?

That line in the picture is a crack. The sleeve there is out of shape where the metal is missing.

 

[MongooseGA]

No, lock the CDL and it'll be fine. It'll torque steer like a mofo though, so be aware of that coming away from a light.

 

[kevgentile]

Going to bring this thread back from the dead. I shipped my 99 lx470 across country to run the NEBDR. Plans were delayed due to storms but eventually I made it and did at least some of the NEBDR. I've also run the UTBDR in this rig and drove from Seattle to UT and back with no problems. Noticed vibrations on the trip back from VT, from VT to LAS and then up to Seattle. Vibrations at 60-65, not above or below.

Truck has SPC uppers in front and new tie rods. OME shocks. Bilstein shocks all around. Alignment is good. New bfg ta/ko3s. 18" wheels from newer 100. Height at rear wheel well is 35 1/4", 36 3/8" at the front. Not sure what that equates to vs stock. I noticed while doing the shocks that the U joint at the rear was toast. I'm trying to decide if I want to replace that joint and reinstall or swap out the rear driveline altogether.

Planning to take it out tomorrow in FWD and see if the vibration remains. What could I screw up by trying that out at highway speeds?

That line in the picture is a crack. The sleeve there is out of shape where the metal is missing.
View attachment 3846774

I've been driving mine in FWD for 3 weeks now.
Took out the rear ds to rebuild the beat-up ujoints causing a horrendous vibration. Have been building my Tcase up with
10% ud, 3:1 lr and a part-time kit so decided to leave the shaft out until i install the completed tcase.

Like Goose stated, it'll be fine. my lx hasn't driven this smooth in a long time

 

[fe sus]

Thanks. I'm comfortable doing a run tomorrow to see if I've at least isolated the cause of the vibration.

Related note, my driveshaft is ~46 1/2" flange to flange. How does this compare with any of your rigs? Cleaning and inspecting to try and decide on u joint vs full replacement/modification.

 

[fe sus]

Nm about length. I've tried to keep the geometry close to stock and 46.5" looks good.