Can spare break the 4WD differential?!

[jpete]

I have an 2003 Tundra that I've only had for a few months. The other day I had to engage the 4WD because I was sliding into a ditch. The 4WD made a popping sound but did engage. When I got back on the pavement and disengaged the 4 HI, while going about 5mph, the truck made a very loud pop and it kind of hopped like I'd run something over. Now, it does this every time I disengage the 4WD. So, I took it into the dealer since I have the certified used warranty.

To say I'm disappointed with the Toyota dealer would be an understatement. The first phone call I got was to tell me nothing was wrong- I just need to put it in neutral when I shift in and out of 4 HI! The guy seemed genuinely surprised when I told him the truck had shift on the fly! The guy then asked if the 4WD went out when I "blew out my front tire" (I have the full size spare on). I told him the two were unrelated- the tire went down a couple of weeks ago- the sidewall started to split.

They then called me back later saying they couldn't troubleshoot any further without opening up the differential. I'm no mechanic but I figured that would be the first thing they'd want to do. They said they can't get to it this week after all and want me to bring it back next week. They also tried to insinuate it might not be covered under warranty. They basically wanted me to take it like it is and just shift into neutral. I let them give it to me today but said I want it fixed.

When I went to pick it up I had an interesting discussion with the service manager. He said he thought it would be something simple so he had me bring it in even though their "expert" is in school this week. I'm surprised a Toyota dealership in Wisconsin only has one guy that is good with 4WD! Then, he wanted to talk about the spare tire. He tried to tell me that the difference in wear could be enough to cause problems for the 4WD. He said he'd only been with Toyota for a month and a half but that on Dodge trucks they wouldn't go into overdrive if the tires had uneven wear of more than 1/8th inch. I told him that was crap and a design flaw. I bought a Toyota not a crappy Dodge. I didn't pay more than $5,000 more for a Toyota to have the service guy compare it to a Dodge! I also said if the truck was that sensitive to tire wear then there should be a warning in the owners manual. Since there isn't, it would not be my fault if that somehow was the cause.

Getting to the point, is he full of crap? Is there any way having one tire with more tread could cause problems with the 4WD? If so, what is the point of the spare? I should also mention the spare was brand new but the other tires aren't exactly bald.

Any insight you tech gurus might have would be great.

 

[5280Hawk]

That dude is Dumb.

The differential is there to compensate for any uneven rotation of the tires. Whether it is going around a corner - where one tire has to travel more distance - or slightly different tire wear, (your truck is probably pulling one direction with the spare on there, but that's it.)

I think the 4wd engages in the Transfer case anyway, not the differential.

 

[KliersLC]

Total crap.

make them fix it.

 

[semlin]

unbelievable crap.

 

[Hank]

Sounds like you were at Bergstrom Toyota maybe? IIRC that service manager is new with the new store. I need more info. What position was the spare tire in? How long? How long in 4x4? What surfaces were run on? What is the milage on the truck? BTW, I'm looking in an 05 Tundra owners manual and it DOES specify that a different size tire can damage the differential and transfercase. It can and does. Toyota had numerous complaints about this issue and replaced thousands of differentials and some T-cases for similar issues. I had at least 10 front Tudra diffs that were replaced under warranty at a certain local dealership in my possesion for a couple years. The ones we inspected were fine and "within spec" and exhibited normal wear patterns for their corresponding age.

Get me more info, or if you are close, maybe the truck........

BTW, I have been driving a Ram 1500 4x4 for work for 2 months. As most know I am Tundra hunting. If I thought that a Tundy was going to drive the same, I'd buy this dodge. It better not be the same. This thing sucks.

 

[semlin]

how could a tire size impact the t-case?? there is a differential in between merging things into one drive shaft. how would the t-case even know there was a tire difference?

 

[Hank]

Fawkit, I had a big long explanation with large words. Try it. Put a vehicle in 4x4, put a 33 on one corner and the rest 31's. Sooner than later the T-case will bind and or give way. I have played the game in my parking lot try it.

 

[semlin]

ok thanks, I appreciate the knowledge even if i don't understand it. come to think of it, it is the viscous slip in the central differential that burns out in an 80 series when you have an irregular tire so presumably it has to do with the t-case being unable to compensate for different rotational speed at the same road speed.

 

[Hank]

Semlin, you are understanding. The issue with the Viscous coupling wear is quite similar. Two open diffs but sooner or later the T-case gets beat up. The 80 series and the ZJ, WJ Jeeps had the same issue.

 

[jpete]

More information

Thanks for all the posts so far. I had the spare on the front right for about two weeks before this happened. When looking at getting the tire fixed (before I found out it was a split sidewall) the tire sales guy said I probably have about 10,000 miles on the remaining three so they are not terribly bald. All four tires are the same size, minus the wear.

This is the first time I've put it into 4WD in a few months. The truck has 61,300 miles total. I put just over 5,000 of those miles on it and have had it since around March. I took it to Kolosso Toyota and am now considering Bergstrom or LeMieux.

Here are the details of what happened. I went to make a U-turn. It had rained a bit lately so the gravel shoulder was soft. I ended up sliding into the ditch a bit. The overall grade was not steep at all. I did have the wheel turned a good amount because I was turning. I started to slide further into the ditch so I engaged the 4 HI button. I was not going very fast at all. That is when it first made an extremely loud pop. The 4WD did engage. I only drove maybe 20 feet in 4WD before shifting back to 2 HI. It then made an extremely loud pop and hopped- it felt like I ran over a speed bump. I tried going in and out of 4WD a few times and it always goes in fine but pops and hops coming out. I even tried going in reverse for a bit.

That is the whole story. Do you think tire wear is enough to cause this problem? If so, do you think they will try to deny my warranty claim as caused by abuse?

I hear what you are saying about mismatched tires being hard on a truck but I can't believe tread wear could be enough of a difference. I don't really see how this is any different than if one side is in slightly deeper mud than the other. That happens all the time. I could see if I did this over an extended period.

I guess the good part is this is justification enough to replace all four tires. I wanted a more aggressive tread anyway but the wife was fighting me.

Regardless of what the cause, I still think the dealer is yanking my chain and I'm still ticked he wasted my time having me bring it in when he had no intention of fixing it.

Finally, if Toyota tries to not cover this under warranty this is one 03 Tundra going on the market. I'll be officially done with Toyota. That is pretty sad because I really am a huge Toyota fan right now.

 

[semlin]

if you did not ever run it in 4wd with the spare on then I don't see how that could be the problem if the spare was on the front. the front is only hooked up to the driveline when in 4wd and it would require some sustained 4wd operation for the different sized tires to do any damage.

 

[5280Hawk]

The Bottom line is that there is no way it was the tire tread, period.

I'd say you have a transfer case problem.

 

[KliersLC]

The only way that running a odd size on the front axle will affect the transfer case is if you run it in 4WD on pavement for extended periods of time. Running in 2wd should be fine almost indefinitely, especially with the only size difference being tire wear.

 

[Mark W]

Were you spinning the tires when you engaged 4x4?


Mark...

 

[jpete]

tire spinnin

I believe the tires were spinning. I'm curious why you would ask? In my mind, the main benefit of having a shift on the go 4x4 system is it allows you to engage the 4WD whenever you need it. For me this is usually when I'm already in the soup and spinning. My 1991 Toy with 212,000 miles engaged into 4WD whenever I tried, even if I was spinning out. That truck was bullet-proof except for the rust (lots of rust).

 

[KliersLC]

I believe the tires were spinning. I'm curious why you would ask? In my mind, the main benefit of having a shift on the go 4x4 system is it allows you to engage the 4WD whenever you need it. For me this is usually when I'm already in the soup and spinning. My 1991 Toy with 212,000 miles engaged into 4WD whenever I tried, even if I was spinning out. That truck was bullet-proof except for the rust (lots of rust).

If the rear tires were spinning, and you dropped it into 4wd, then you took a spinning system and mated it to a halted system. This means you probly broke something. I'd keep quiet about that if you want them to fix it.

 

[Mark W]

I believe the tires were spinning. I'm curious why you would ask? In my mind, the main benefit of having a shift on the go 4x4 system is it allows you to engage the 4WD whenever you need it. For me this is usually when I'm already in the soup and spinning. My 1991 Toy with 212,000 miles engaged into 4WD whenever I tried, even if I was spinning out. That truck was bullet-proof except for the rust (lots of rust).

If you understood what was going on inside the workings you wouldn't wonder why I asked. No 4x4 system is designed to be engaged when there is a differential in the speed of the components. Especially when there is power behind it all too. Sudden loading snaps parts. That is NOT how the system is meant to be engaged.

Your '91 was not intended to be shifted into 4x4 while the rear tires were powered and spinning. Neither was your Tundra.

Sounds like you got away with it in the '91. Sounds like you didn't with the tundra.


Mark...

 

[Hank]

Mark is making a good point. I'm not inferring that the Tundra in question was damaged by an odd size tire, only that it can happen and has been an issue with Tundras. I would assume this Tundra has an interior problem in the T-case. I'd check it out for him as stated before but if the warranty will cover it, go for it.

 

[jpete]

educate me on 4WD shift techniques

Okay, you all have me really confused about the spinning thing. I'm an electrical guy and fix airplanes but wrenching on trucks isn't my thing. (That is why I bought a newer truck with a warranty.)

However, I am originally a Kansas redneck and have been driving 4x4's since high school- 17 years now. I've always thought of myself as someone who doesn't abuse his trucks or do anything too stupid. (I'm no pro like must of the Ih8mudders which is why I'm here asking.)

Of all the times I've needed 4x4, this is by far the least daring or extreme. I've never damaged a transfer case. In this case, I was crawling along, doing a U-turn, when I went a little wide off the shoulder and started sliding.

So, how am I supposed to engage the 4WD? The owners manual says I can be going as fast as 40mph when I engage 4HI. If I'm going too fast, the thing won't engage. I have not tested this- I'm simply going off the manual. Granted, I understand you shouldn't be on the gas when you engage. I wasn't in this case nor ever in the past. All of my other trucks have had floor shifters so it would be nearly impossible to reach down and shift while staying on the gas. Are you saying I should shift into neutral?

I'm seriously not being argumentative. I want to learn and I don't want to jack up my truck. I've had it less than six months. I'm expecting to get at least another 10 years and 150,000 miles out of this truck. And if I'm at fault I'll pay for the repairs. I'm just having a hard time believing I did anything wrong or abusive. I can think of quite a few times I was in much worse situations with other trucks and never did any damage. This includes episodes in an 86 s-10 and an 88 full-size blazer. I'm not normally that lucky so I would've thought that if I was doing it wrong I would have broken many other transfer cases by now. I appreciate everyones posts.

 

[Mark W]

You can be going as fast as you want to when you shift into or out of 4x4. It is not the fact that the rig is moving or that the tires are moving that causes a problem.

What you can't do, and what does cause problems is to shift into 4wd from 2wd while you are on the gas in a low traction situation and the rear tires are spinning. If you do that, the the moving parts are suddenly being connected to the non-moving parts (the front system is not powered while in2wd and so none of it is spinning like the rear components. There is no give or "cushion" in the drivetrain. When you try to instantly accelerate the front system to the speed that the rear is already moving... If you can even get it to engage in the first place... Things break.

You can shift into 4wd while the tires are not moving. You can shift while they are all moving at the same speed. But you can't do it while the rear tires are moving faster than the front tires(spinning in the mud for example).


Mark...