Tundra Brake TSB

[Andy]

Yeah, I was pretty psyched and so far I am very happy with the new brakes. I hope they hold...so far so good!

[2DaMax]

Just received an email from Gary at Wheeler's Offroad and they are currently working on the new kevlar pads that will fit in the new calipers. No estimate on when it'll be released.

[DCTundraGA]

Originally posted by SeqStet
I had post-TSB-shudder syndrome while braking. An alingment solved it.

How does an alignment solve the problem? If it were out of alignment wouldn't it shake all the time?

[SeqStet]

I see your logic. Good question. No, mine did not shake all the time. The front wheels simply slid in misalignment until I applied the brakes.

Upon braking, the weight of the truck shifted to the front increasing the traction in which it was no longer a slide of the front wheels. It became a hop which really feels like a vibration. I guess it really boils down to how bad the alignment is off.

But putting more weight to the front (as in braking) will certainly intensify it.

This is just my $0.02 worth. I'm not a professional mechanic or ANYTHING. I just imagine how some things work (or may work). Hope this helps.

[DJ]

Originally posted by TundraGA
How does an alignment solve the problem? If it were out of alignment wouldn't it shake all the time?

The problem is the effect of braking on marginal steering stability. You might find some previous posts of mine about this if you look WAY back in the archives, and if they are still there.

The steering axis of a wheel is a line throught the upper and lower ball joints for that wheel -- it is the axis about which the wheel turns to steer the vehicle. Caster is the lean toward the rear, when viewed from the side, of the steering axis. The purpose of having the steering axis lean toward the rear is that it generates forces which cause the left wheel to steer to the right, and the right wheel to steer to the left. These forces are equal (i.e. balanced) when the vehicle is steered straight ahead. If you steer to the right, the force steering the right wheel to the left increases, and the force steering the left wheel to the right decreases -- this causes the wheels to try to steer back straight ahead.

This produces "steering stability", and it's VERY desireable.

The vehicle should be aligned with sufficient caster so this works well. If you decrease caster, the steering forces decrease, and so steering stability decreases. If you decrease it enough, steering becomes unstable and the front wheels vibrate, which is usually described as "shimmy".

Now to braking. When you apply the brakes, the front end dives down a bit and the rear end rises up a bit. This makes the steering axis lean a bit less toward the rear, and so decreases the actual caster the suspension experiences during braking. In short, braking decreases steering stability. How much? If the drop in the front plus the rise in the rear equals one inch on the Tundra, the net decrease in caster is 0.47 degrees. That's a BIG change in caster.

So, if the alignment is marginally stable, meaning it has just enough caster that it doesn't vibrate, then it might be unstable during braking. The cure is proper alignment and sufficient caster. That's a somewhat simplistic overview, but it illustrates the problem.

[DCTundraGA]

Thanks for the feedback guys. I'll take it to the dealer and see what's going on.

[brunosan]

Yes i got them done already!!! previously the dealer replaced all rotors drums pads shoes @ 8k and @ 18k...shaking came back @ 20K....so they ordered the Real Fix Nov 1 and i got it done 1 week before Xmas!!!

Smooth sailing yes indeed...lets go to LA from SAN fran....when i hit the grapevine Downhill...BOOM!!! Shake shake shake!!! i feel it and i feel it good...its coming from the rear...the front is good the the rear has the same problem!!!!

i submitted paper work for arbitration...meeting on Feb 3, 2003

so 3 times rotors and drums !!
replaced rear leaf springs done
check engine- replace o2 sensor
now engine light is back on...and i aint going back until this arbiration meeting is over..

so now i still have rear shimmy and engine light on..

will i win my arbitration? i feel like I already live at the toyota dealer...and im sick!!!!! ill never buy a toyota again!!!

any suggestions?
brunosan@yahoo.com
cell- 650 580 6456

AL

[brunosan]

Yes i got them done already!!! previously the dealer replaced all rotors drums pads shoes @ 8k and @ 18k...shaking came back @ 20K....so they ordered the Real Fix Nov 1 and i got it done 1 week before Xmas!!!

Smooth sailing yes indeed...lets go to LA from SAN fran....when i hit the grapevine Downhill...BOOM!!! Shake shake shake!!! i feel it and i feel it good...its coming from the rear...the front vibration seems to be fixed ........ the the rear has the same problem!!!!

i submitted paper work for arbitration...meeting on Feb 3, 2003

so 3 times rotors and drums !!
replaced rear leaf springs done
check engine- replace o2 sensor
now engine light is back on...and i aint going back until this arbiration meeting is over..

so now i still have rear shimmy and engine light on..

will i win my arbitration? i feel like I already live at the toyota dealer...and im sick!!!!! ill never buy a toyota again!!!

any suggestions?
brunosan@yahoo.com
cell- 650 580 6456

AL

Moderators Note: The thread "POST front/rear brake TSB!! YUK!!!" has been merged with "Post brake TSB shudder?" as they pertain to the same topic. --- Possum

[huskies]

DJ,

Just had the brake TSB performed last week. Do I need a new alignment after the TSB?

I've had two alignments pre TSB already and the tires forced balanced. The first was to correct the misaligned steering wheel. The second was to correct the vibes after the first alignment, this time they aligned the truck to your specs. This took care of the problem. But now after the TSB I am feeling some small vibes again. What do you recommend?

Thanks

[mitchr]

Droped off the Tundra to get the total replacement of the front brakes and the new heavier drums on the rear brakes. I will update on the results later.
__Mitch

[tampatundra]

my brake pedal vibrates (up and down pulsation)again after the tsb. started less than 5000 miles after. doesn't matter what the temperature is. in fla we've had 70's to 20's in the temp dept.

[tampatundra]

i had my arbitration. brake pulsates again after 5000 miles of having tsb performed. i don't know if vibes were enuf to satisfy the arbitrator though. he didn't drive it and neither would the svc. mgr. nor the factory rep. they claim from the back seat everything felt normal.

[2DaMax]

Wow that sux. Did they replace your front calipers and rear drums?

Originally posted by tampatundra
my brake pedal vibrates (up and down pulsation)again after the tsb. started less than 5000 miles after. doesn't matter what the temperature is. in fla we've had 70's to 20's in the temp dept.

[Joon]

Originally posted by 2DaMax
That's odd because to get the TSB you have to present to them your complaints regarding the vibrations you feel when braking and if they can duplicate the problem then that qualifies your truck for TSB. It's a very costly repair so they won't perform it unless you truly have the brake issues. I guess some dealers are different than others.

I didn't experience any shuddering in my brakes but they went and replaced both front and rear. The dealer paid for everything including rental car.. but i guess they should since i won't be w/o any car.. i just got it so i haven't really got the feel for it, but it feels different.

[fcal]

Anyone have front end vibration problems after TSB?
I noticed that around 60mph, my steering wheel vibrates slightly and only some of the time.
I just put on IS rims and had them balanced twice, at 2 different shops.