Rear end strange feeling (1 Viewer)

[ruggedrudgate]

Hello all.

So I’ve read every thump and bump thread on the 100 series forum and have yet to come across a similar issue. Maybe I’m not inputting proper terms during my search but I think I’ve tried every description I could.

06 LC 230k

Issue:
At mile 1.5 from home, and mile 0.3 from work I have a rear end stutter at acceleration from the street light, and also a bump type feeling coming from the rear end on rare occasions. The bump comes upward from the rear end. The rear end stutter happens when I stop at the same lights every day since they are timed. Then it is gone. I can give it the beans with a quick heavy pump if the accelerator and it typically goes away. Or if I slowly accelerate it will stutter for 2-3 seconds then it is over. Driveshaft does not wiggle, and has been properly lubed. All new fluids in diffs and transfer case. Tranny fluid looks immaculate. No grinding or noises. No vibrations. No grinding in turns. New calipers. Not sticking. It’s always from the rear and it is driving me crazy. Any good place to start? Or experience with this? Much appreciated!

 

[Trapper50cal]

Are your tires cupping or wearing in a weird or uneven way? Brake pads look okay?

 

[ruggedrudgate]

Are your tires cupping or wearing in a weird or uneven way? Brake pads look okay?

Hard to tell since the tires are only 6 months old so very little wear. New pads as well. It feels rotational if that makes sense. I’m thinking drive shaft or rear diff but I don’t know if there is an order of operations to track it down like pull drive shaft or open up rear diff or if I should start with the transfer case and move back from there. I don’t have any leaks and I didn’t have any shaving or metal when I changed my fluids.

 

[Fairgame]

Worn splines on drive shaft?

 

[zgfiredude]

How have you checked for driveshaft play? I sort of am thinking either splines, u-joints, or bearings. It sounds like there is just enough play to cause the shudder, but not yet bad enough to be more identifiable. I am feeling like pinion bearing may be a place to look.

 

[2000UZJ]

Inspect the upper and lower rear control arms. When the bushings wear out it can cause the axle to rotate. Typically the passenger side upper control arm gets trashed sooner due to the heat from the exhaust. This may not be easy to inspect while on the vehicle, as the bushings are somewhat difficult to see. They are easy to remove, and the uppers can be tested with a long screw driver and testing if they flex easily. Any cracks/tears they should be replaced.

 

[Exiled]

I recently had my truck up on a lift and had a chance to inspect the bushings on the upper and lower control arms. I've been feeling a bit of "wiggle" while switching lanes at highway speed and was curious to check them out (I also have a bent rear control arm). It was pretty easy to spot that the bushings (OEM and the original ones, as far as I can remember) are shot and definitely need to be replaced. I will use this as an excuse to order new upgraded control arms (Metal Tech or Trail Tailor) and then replace all the bushings, will report back on whether this solves the "wiggle".

I will try to convince the boss lady that I should also order new bump stops for the rear axle to install while I'm under the truck!

 

[GerLC100]

I will try to convince the boss lady that I should also order new bump stops for the rear axle to install while I'm under the truck!

I thought all that comes together in one box and doing one you have to do the other isn't that what Toyota states as mandatory?

 

[Exiled]

I thought all that comes together in one box and doing one you have to do the other isn't that what Toyota states as mandatory?

Being the long-suffering wife of an incorrigible Cruiserhead, she's developed an immunity to the standard tactics that may work on more naive spouses... she's on to me!

 

[ruggedrudgate]

How have you checked for driveshaft play? I sort of am thinking either splines, u-joints, or bearings. It sounds like there is just enough play to cause the shudder, but not yet bad enough to be more identifiable. I am feeling like pinion bearing may be a place to look.

Jacked it up and moved the wheels. I’ll get a helper to try it out again. Pinion bearing is interesting. I’ll put that on my list. Thanks!

 

[ruggedrudgate]

Inspect the upper and lower rear control arms. When the bushings wear out it can cause the axle to rotate. Typically the passenger side upper control arm gets trashed sooner due to the heat from the exhaust. This may not be easy to inspect while on the vehicle, as the bushings are somewhat difficult to see. They are easy to remove, and the uppers can be tested with a long screw driver and testing if they flex easily. Any cracks/tears they should be replaced.

See this is interesting. Something I’ve noticed as well that I forgot to mention was the feeling on the axle sliding backwards when accelerating. On to check the bushings!

 

[ruggedrudgate]

Inspect the upper and lower rear control arms. When the bushings wear out it can cause the axle to rotate. Typically the passenger side upper control arm gets trashed sooner due to the heat from the exhaust. This may not be easy to inspect while on the vehicle, as the bushings are somewhat difficult to see. They are easy to remove, and the uppers can be tested with a long screw driver and testing if they flex easily. Any cracks/tears they should be replaced.

Done and just replaced. Holy smokes they were bad. They were being replaced anyway I didn’t realize how much my back end was sliding and damn is the ride better. Tightened it up real nice. I have every bushing for the 100 in a bag and this is kind of forcing me to put them all in. BUT the change kind of made the weird rear end problem change how it presents itself. Rotational knock at rear end when decelerating. Does it once (three short knocks/shudders) then it’s over. So onto the next idea. Crankshaft is going to be pulled next.

 

[Trapper50cal]

Crankshaft? or driveshaft?

 

[GerLC100]

uuuuuuups :-D

 

[ruggedrudgate]

Crankshaft? or driveshaft?

If it's got a shaft, I'm replacing it.

 

[ruggedrudgate]

The issue is making its way around the rear end. It’s now officially and consistently on the rear passenger side. A slight knock when accelerating from a standstill. I put it in 2nd start and it didn’t knock/clunk. Doesn’t happen when releasing gas pedal or while accelerating when rolling. The mystery continues!

 

[2000UZJ]

The issue is making its way around the rear end. It’s now officially and consistently on the rear passenger side. A slight knock when accelerating from a standstill. I put it in 2nd start and it didn’t knock/clunk. Doesn’t happen when releasing gas pedal or while accelerating when rolling. The mystery continues!

I'd send quite a bit of grease through the driveshaft for the slip joint, as well as the spider bearings. I flushed mine with Mobile 1 Red and no more knock. When coming off a speed bump, it sounded like somebody hitting the underside of the body with a hammer. I also took the time to spray a degreaser, and a few other cleaning products where the zerks were and cleaned everything really nice. Much easier to see what you are doing, clean up, etc.

 

[ruggedrudgate]

I'd send quite a bit of grease through the driveshaft for the slip joint, as well as the spider bearings. I flushed mine with Mobile 1 Red and no more knock. When coming off a speed bump, it sounded like somebody hitting the underside of the body with a hammer. I also took the time to spray a degreaser, and a few other cleaning products where the zerks were and cleaned everything really nice. Much easier to see what you are doing, clean up, etc.

Appreciate that. Did you pull the shaft off and take it apart to clean it, or did you just force it though the zerks? It takes quite a bit of force to get it all the way through. So much so that I was concerned about the pressure so I unscrewed the zerk and it popped out with a pop noise when it was almost out and grease poured out. Mine does feel like a hammer hitting the rear axle.

 

[2000UZJ]

Appreciate that. Did you pull the shaft off and take it apart to clean it, or did you just force it though the zerks? It takes quite a bit of force to get it all the way through. So much so that I was concerned about the pressure so I unscrewed the zerk and it popped out with a pop noise when it was almost out and grease poured out. Mine does feel like a hammer hitting the rear axle.

I did not take it off/apart. I cleaned everything nicely and then used my trusty grease gun and slowly pushed the old out. The shaft itself took quite a while for the old to get pushed out. I’m thinking somebody used the wrong type. It was black and looked pretty nasty.