Bump/Jerk Feeling When Starting, Stopping

I've got a '13 Tacoma Off Road with no after market mods, and I've started experiencing a weird bumping sensation when starting and stopping. It almost feels like I'm pulling a trailer, or like I'm on a roller coaster catching the chain that takes you up the track. In fact there have been a few times that I'm at a complete stop and it feels like a car behind me bumped me very lightly. And there's no one behind me!

While driving, it shifts just fine. Brakes appear to be fine.

Anyone experience this, or have thoughts on what it might be so I can better explain it to the dealership mechanics?

 

Welcome to TW.

Lots of talk on this as always.

I have proven it to be the driveshaft binding or lack or lubrication on my truck.

The splines on the driveshaft mate with the splines on the tailshaft of the trans, there is not enough lube and binds so it needs to be greased. Downside is you gotta pull the shaft to grease it as there is no zerk. You can add one.

Dealer is just going to tell you it is normal.

I grease mine once a year or longer and never have the issue anymore.

Going forward if you search on TW it has been answered 2-8 times already.

 

Thank you for not citing "axle wrap" as the cause of this. I concur with your response

 

I appreciate the response. I actually have been looking for similar threads; I come close, but I'm not sure it's the same issue I'm describing. Plus, I'm not quite experienced enough with the site. I'll get better! Thanks so much.

 

Is it a big deal to add the part with a zerk?

 

After you lubed the driveshaft , does the issue remain ?
Axle wrap as far as I am concerned

 

Axle wrap always happens on any stock setup leaf spring vehicle just depends how much and the cause of it.

There are other rear leaf suspension setups that were developed to limit axle wrap under torque loading/unloading situatations. On high torque applications there are 4 links or torque arms to solve the issue. Most stock vehicles it is not a huge issue, toyota screwed the pooch it seems since it is common even on low mileage trucks. Typically it creeps up at 30K or more from what I have seen on various trucks, some never experience it. There other factors such as driveline angles and how many joints to cancel out the angles.

Back to the concern at hand.

Yes greasing the splines solves the issue. The grease does go away slowly by movement of the shaft and trans fluid breaking it down. I use a marine grease.

There is a blue coating on the trailshaft that acts as a self lube but it does not work that great. Sometimes the driveshaft splines are hard chromed to give a slick surface on other makes and models. This has been a issue on trucks for years.

Grease it and all is well.

As for adding a zerk it is possible. You need to drill and tap so you can add grease when needed. I prefer to pull the shaft, clean it and reapply new grease. It does not take that long, 30min max if I go at a slow pace.

 

sub'ed

 

If you are looking for long term info. Mine lasts about a year before having to regrease the slip yoke again.

Posted about this before and others have tried it, with the same positive results. While others just keep suggesting to replace springs before even trying this.

 

I just purchased a '11 Taco 4x4 on may 2014.

My Taco had that awkward feeling too, I would have described it as the transmission upshifting prematurely when starting and downshifting late when stopping.

After reading on here for a bit about the issue, I greased my axles using the Zerks and the issue went away for about a week. Its back but it is very faint compared to being obnoxious before I greased it.

The only spot I didn't grease is that joint that has no zerk on it. That might be where I still feel that faint bump.

so apparently TW was correct and even though it seems strange, greasing the axles works.

 

Not talking about greasing the axles or u-joints in this post, just the slip yoke. You do not grease the axles, I believe you mean the u-joints.

 

I will say thumbs up for the slip yoke being the cause too, had the exact same problem and even falsely accused and elderly man of bumping into me at a stop light one day. Greasing the slip joint solves it but as someone else stated it needs to be re greased often. It is really easy to drill and tap it for a zerk and you can get zerks anywhere...got mine at Lowes. I pump new grease into every zerk on my truck after every oil change, everything connected to the drive shaft destroys grease so fast it is alarming.

 

Let's say you DON'T grease the yoke, is there long term failure in the future?

 

Just as lj973gm said, the dealer told me that this is normal. Several people at the dealership were familiar with this problem on Tacomas and 4Runners. As my vehicle is still under warranty, I told them that I'm not happy with it and want it fixed. They refused.

I went above their heads and contacted the Toyota Warranty Department and opened a "case". Once that ball got rolling, I received a call from the dealership, telling me that there is in fact a "bulletin" on this problem and that they would do a warranty replacement of the rear propeller drive shaft assembly with center support bearing.

After the warranty work (and some new scratches on my truck), the problem is gone. For now. Picked it up two days ago.

Should you choose to pursue warranty work, I do not know the details of this bulletin.

 

Sounds like slip yolk to me. Or AC cycling on.

 

Yup it sounds like the slip yoke is binding and releasing causing the jerk. One cause of the binding i have found is axle wrap and the lack of grease in the yoke zerk. Possibly look into a new one peice or rebuilt to solve the problem.