Rear Spring TSB Problems?

Dudes,

I got my rear spring TSB and rides great. However, I had to bring it back for an alignment, again, as it was drifting. Alignment went well for a few weeks and now it seems to drift again. Any ideas? Also, I've always had a rumble when driving 25mph, could these two be related?

Other threads have mentioned road force balance, how is that different than balancing?

 

The TSB includes an allignment.

When you took the truck back for another allignment.... What did they say?
Did they give you the allignment specs? Did they mention that anything was out of allignment?

Are you still under warrantee? Keep taking it back and complain. It's not necessarily anything to do with the allignment, but could be something else going wrong and why it's not staying IN allignment OR 'feels floaty'.

 

The only thing on my receipt was that an alignment was performed, no specs. I mentioned the truck has a tough time keeping straight.

 

I needed to bring mine back for a better alignment after my TSB. The warranty guys should regard this as a simple deal.

 

Ask for a printout of specs before and after! Maybe you have a tremendously slow leak in a tire and as it looses air the truck begins to drift.

 

I think you nailed it. I lost 2psi in the last 1200 miles/month. 30psi seemed to do the trick. And I hate these dunlops!

 

30psi sounds a little light..
You can see videos on you-tube of thermal imaging of an under inflated tire vs. a properly inflated tire, it's amazing the amount a tire "overheats" without the proper pressure. Overheated tires not only reduce tire life, but also effect handling immensely (ask a NASCAR driver).
The vehicle manufacturers want the vehicle to ride comfortably, the tire manufacturers want performance & longevity & need to stand behind their warranty (notice how Vehicle Manufacturers warranty everything BUT tires!). I go with what the tire maker recommends.
I use the 10%-20% rule.. If the max tire pressure (via tire maker) is 44psi (most 'P' type tires) I use 36-40psi, If it's 80psi (most 'LT' type tires), I use 60-70psi (you can maybe lighten do 55psi for a very light vehicle, but no less imo)

Hope this advise helps you out..

 

WOW- Bad advice coming from an ASE master tech.

You NEVER go by what the tire manufacture recommends. The tires have been tested on that particular vehicle by the manufacture to determin the proper inflation. You learn this is basic automotive 101.

 

I just looked at the PSI on the sticker on the drivers well. I will look tomorrow to see what the tire wall says.

 

Use the door sticker...or chalk test them. The tire specs are only to keep you from blowing them up.

 

Sounds great. I had max 65 psi tires on my 07 Taco and ran them at 50. Anything less and I got horrible fuel mileage, anything more and I felt like Barney Rubble.

 

So, you would recommend underinflation if the automotive manufacturer recommended it? That's ludicrous. I understand what you're saying I am just explaining why "NEVER" is not the correct term to be using.

 

Where do they do this 'tire testing'? I can tell you that they do none. They rely on the tire manufacturer to provide tires based on a bid spec, which includes little more then size & expected load range, & then they go with the lowest bid. There is no test & exclusion process on any vehicle but the most high-end..

So folks should follow the Manufacturers advise blindly, as you state, disregarding terrain conditions, tire compound, tread design, etc-etc-etc? All of these things contribute to the thermal conditions of a tire, which is the only aspect of things that you can control.

If you are a "mechanic" then you should have an infra-red thermometer at your disposal. Drive your vehicle on a hot blacktop highway for 10min at 60mph with the manufacturers recommended pressure & check your tire temp, then do the same thing at the '10-20% under tire makers pressures' I recommend, i think you'll be surprised.

 

Haha! Me likey!^

 

Once again, you NEVER go by what the tire manufature recommends, I don't mind using the word when the statement is CORRECT.

While working for GM as a regional instructor, I went to Detroit several times and have seen with my own eyes testing of tires at different pressures, and have discussed the nature of doing so with an engineer, so to presume they do not is ridiculous.

Yes, many different technicians (NOT MECHANIC) opinions will differ, but the bottom line is if Toyota felt like the PSI should be 42, they would recommend it. After all, fuel mileage would increase and they could advertise better specs. It's a compromise. Fuel mileage / ride quality.

I don't really care if you take my advice or not. Bottom line, any GOOD technician will tell you to use the vehicles recommendations over the manufacture. That being said, if you replace the tires with a different size, then everything obviously changes.

 

So if Toyota told you to run the tires at 12 psi and the tire manufacturer recommended 40 psi you would run them at 12psi? I think you need to rethink your logic. Yes, an auto manufacturer would not set themselves up for a lawsuit but that is exactly what you are saying.

 

12psi to 40psi is quite the variation! I agree, I a tire should be set at specs that work well with the vehicle, not the showroom floor!

 

Okay, back on topic. OP, does one wheel stick out farther than the other in the rear?

 

Not trying to be controversial, but I thought we were on topic.
Wasn't it the OP who posted the statement that a change in tire pressure seemed to remedy his drifting issue?
Please advise, does clarifying the OP's solution (& any others contributing to a thread) constitute as moving 'off topic'? as it certainly was not my intention to 'hi-jack' this thread