Check your U-Bolts!!!

This is a thread in response to a recent manual transmission thread about clunky drivetrains... specifically to post #70 of this thread: https://www.tacomaworld.com/threads/manual-transmission-1st-2nd-gear.448567/page-4#post-17631671

I've had my '17 DCSB OR for almost a year and it's never had what I would call a "smooth" drivetrain--especially compared to my '04 Taco. When crawling around in 1st gear through parking lots, over speed bumps, small off-road obstacles, or when shifting from 1st to 2nd, it's always had a bit of a clunky noise/feeling coming from the middle/rear section of the truck. I had the dealer look at it a few months back and got the standard response... "It's normal".

After reading the above thread, I saw a post about the u-bolt nuts being loose. I crawled under mine with a 19mm socket and a torque wrench and sure enough, they were unbelievably loose! At best, they were at 20-25 ft lbs.

After torquing them to 52 ft lbs (I got nearly a full rotation before the torque wrench broke away!) last night I was really astonished on my drive to work this morning. About 75% of the clunky noise/feeling is gone and the transition from 1st to 2nd feels a good bit smoother! Makes me think there is more loose hardware somewhere that is causing the rest of the noise. I will be hitting every single fastener I can get my hands on and verifying proper torque--there is no doubt in my mind that I will find more.

Shame on you, Toyota!

 

Mine's pretty clunky too. I'll check them tonight.

And mine's clunky even when in gear or coasting. Not just shifting. The first thing that popped into my head was those u-bolts but I keep forgetting to check them.

 

Yeah... funny story here. I took my truck into the dealer and was complaining about how the truck was hitting every bump in the road so hard it was really starting to legitimately hurt my back. Like I would get to the point of tensing up before a bump in the road knowing it was about to shoot up my spine. Asked the dealer to check torque... said all was good. I got home and pulled out my torque wrench and I'd be shocked if they were over 20... Tightened them up and all was good and nice and soft like I expected.

I mentioned this to the dealer on my next visit and their response... "if anything looser u-bolts should make it ride smoother..." and from then on it was clear the only maintenance I could get done reliably would be by my own hands.

 

Oddly enough, I have an appointment this afternoon to get the TSB done for the rear end whine... I'll be double checking all their work.

 

i have an appointment this Thursday to get 1" spacers installed and a set of Sumo springs at the dealership. I'l definitely be making sure they document the torque spec has been set correctly.

I do not let the dealers away with anything and demand they specify what spec they torqued things to and check when i get home if i can . That way if it was done incorrectly and causes damage i have proof they lied.

 

OK, first a confession -- I have the mechanical aptitude of a trained chimpanzee.

I would like to check my U-bolts. I have a torque wrench, 1/2 and 3/8 ratchets, assorted sockets and extenders. I know how to use these tools. Once I get my creaky 68 year old body under the truck, will it be self-evident what I'm looking for and need to do?

 

Yes. Find the u-bolts attached to the rear axle ... the nuts will be staring you right in the face when you crawl underneath the rear. There's a total of eight 19mm nuts you will need to tighten--4 on the left, 4 on the right.

 

I'm always a little suspicious when people say they know what a bolt was torqued to - just because it took 28 ft-lbs to back a bolt out doesn't mean that it was torqued to 28 when it went in

 

True, but if you get 1/2 a turn before it clicks at 50 ft lb's, it was no where near torqued to spec.

 

I didn't back it out--set the wrench to 52 and torqued.

I can't give you a specific number of what they were torqued to, but I've been a military equipment/aircraft mechanic for longer than many here have been alive and am very familiar with what 20-30 foot pounds feels like--it was NOWHERE near 50 ft lbs.

 

Let us know how that goes for ya! Respond to one of the howl/diff threads with your results if you can.

 

Time to hit a different dealership! They don't deserve your business...

 

Hey @Jeffro250 where is the shout-out?

 

I didn't know you could tag people... I'm not that tech-savvy.

But I do appreciate your advice!

 

Also check that the spare tire is cranked up tight

 

@remgu2000 Looks like this has been an issue from the factory. Yours should be good and tight.

 

U-bolts torque is 75lb.

 

This...

 

Never forget!

 

That will go down in history!