Truck lunging forward in between breaking and accelerating

So the last week or so my 09 has occasionally been lunging forward in between breaking and accelerating. First noticed it when somebody cut me off and I had to slam on the brakes. I wanted to tailgate them so I accelerated pretty hard. The truck kinda hesitated than had a hard knock before it started to accelerate. It did when rolling through a stop sign also, although much softer. Any ideas? Going to bring it to the mechanic at the end of the week. Just wondering what I’ll be looking at.

 

Transmission fluid level may be low.

 

How many miles? Are u sure it’s hesitating? Any vibration? Wouldn’t hurt to check the u joints and the driveshaft slip yoke sometimes the yokes get sticky and can clunk. But if there is a hesitation prolly a different issue

 

I’ll check that out.

 

120k. U joints are fairly new, had them replaced around 95k or so. Maybe the need to be greased?

 

no vibration and definitely hesitating. I’m here’s a solid pause before it starts to accelerate again. It kinda feels like when your back wheels are on ice or something slick and they aren’t getting any traction then you hit a dry spot and the grab. That’s what the thud feels like after the hesitation.

 

Nah prolly not but doesn’t hurt to grease them anyway, see if yours has a slip yoke on the driveshaft only the 4x4s had the slip yoke u can grease that that would make a clunk noise

 

Could be the tranny auto or manual?

 

That's called Axle wrap.
Under braking leaf springs get S shaped then released tension when brakes are released feels like kick in the butt.

 

Definitely feels like a kick in the butt. What’s the fix for that?

 

Don’t think it’s axle wrap he said from a rolling start. Never hurts to investigate tho

 

Leaf spring replacement or live with it until it does it at every stop.
Check your leaf springs for cracks or broken leafs and Toyota owners website to run your VIN# for possible leaf springs service campaign or recalls.

 

Ya sorry to tell you but I think people would agree with me especially with a rolling start. Do you own a 4.0 Tacoma? I drive these daily and many different ones considering I’m a tech and specialist in suspension, and I don’t experience this issue often. But without being there we are all guessing and shooting ideas. Also new issue and he told me that he was going like 25-30mph when it did this

 

You’ve been around long enough to know that nobody cares. Lot of talent on this board, and it doesn’t take a specialist to know how axle wrap works.

 

It’s My opinion that’s not the issue but I mentioned to Check it out maybe it’s completely blown and rusted out, out but we arnt there to see in person I’m just trying to help out not get In A pissing fight sorry if I offended you in anyway.

 

Your professional opinion is appreciated. Please don't let the negativity discourage you from providing your opinions and best guess. I know how it is, sometimes it really difficult to give the correct diagnosis even with a good description or video of the problem.

 

Without any diagnostic information posted , my best " guess " is listed below in the link



http://bluegrasstoday.com/wp-content/uploads/2012/07/a750e_shudder.pdf

 

Thanks for that link. It's rare, but occasionally I'll have these symptoms. Usually mild but once it did feel like I had been bumped. Got only about 90k on the tranny now.

 

I read on another thread that if it is an axle wrap issue some people are adding additional clamps onto the leaf springs. Has anyone had experience adding these and what is your opinion? what types and where if it works? I have a 4x4 '10 that the previous owner installed a 3" lift. Every time I accelerate it gives me as described by @Black DOG Lila, a nice "kick in the butt" which is more like a drop that I can feel just off of a full stop. I'd like to keep my lift so the recommended springs I saw elsewhere were the Dakar's.

 

Last night driving to work when stopping at a light I got a pretty sharp knock from the rear followed by a lunge forward. This was right when I came to a full stop. I was trying to recreate the hesitation and lunge during the day, but couldn’t. One thing to note is it was about 50 degrees yesterday. Pretty sure every time it’s happened it was much colder. Last night it was about 20 degrees so I don’t know if that has something to do with it. Also took a look at my leaf springs and they look pretty good to me. Didn’t notice anything that looked questionable. I’m starting to lean towards it being something with the differential or driveshaft.