Help! Random 09 Tacoma bump!!

Hi! I have a 2009 Tacoma Trd with a 4.0 liter v6. It has 250,000 miles. When driving from 20-40 mph below 2000 rpm I get a bump. The bump is sometimes hardly noticeable and sometimes really intense. It’s hard to re-create and is inconsistent. I drive it in 4th gear a lot and not in overdrive and in very rarely does it. But when I’m normal drive it happens often. The shop diagnosed it as a bad trans. Got the trans replaced, motor mounts, and trans mounts all replaced… still does it. Then they said it was u-joints and a carrier bearing. Those were replaced… still does it. With 5k down the drain I’m feeling kinda hopeless. It’s coming from the front of the truck and won’t happen above 2000rpm. I think it’s a misfire. I have replaced spark plugs and it still does it. Thinking about going and replacing the wiring and ignition coils. Then maybe fule injectors? I hope someone else out there has dealt with this. Thanks, Aiden.

 

so, I know there was a TSB about 2nd gens feeling a bump when stopped when the truck settles at a light it feels like i got driven into. but yours is different?

is it the trans kicking down to shift?

 

No it’s not shifting, that’s the weird part. The bump is coming front the very front of the truck. It’s like a jolt. It’s only when slowly accelerating below 2000 rpm. I’m stumped. And the Mechanics are out of luck too…

 

wheel bearings are in good shape? any play in the CV axles? and the 4wd is for sure not engaged?

 

Slip yoke binding up and releasing? Any codes?

 

Yeah, it’s in 2wd and the bearings and cv axles are fairly new.

 

No codes, and we put a new slip yoke on. We thought that was the problem but it’s not.

 

You mean the shop fired the parts canon at it, and started with the big stuff first.
Yikes!

It’s hard to tell from your description, this is one of those things I need to feel/experience myself.

Either way, don’t go back to that shop. Ever.

 

With the truck idling is the tachometer needle steady or does it bounce a little bit?

 

I definitely won’t be back… lol. The engine starts immediately and for the most part runs smooth. It may bounce a little. It sounds a little “clanky”. I’ll have to video the bump/jolt.