Off-Road Tires & Lift cause Rear Diff. Damage?

Good Morning!

Dealing with my son's 2010 Tacoma Prerunner (with the locking rear Diff.) whose rear differential has to be replaced. This is the second time this has happened. The original factory one and, now, the replacement rebuilt one. Ugh. He off handedly mentions something about the big tires and lift possibly affecting his Rear Diff. So, I need to ask you all. Is it possible that his rear diff has gone out because of anything to do with these big tires and a 3" lift? He is a student and doesn't pull anything heavy. Thank you.

 

Sounds like he is beating the shit out of it. I’m turning E load range 35s on my stock diff and haven’t had 1 issue

 

I suspect it has less to do with the lift and tires than the way the truck is driven, or, the quality /reliability of the last rear end you put in.

 

Maybe by driving around on pavement with the locker on.

 

Yes changing the angles with a lift can indeed cause problems.

3” is not uncommon, but once you cross the 2” mark there are steeper angles and relevant stresses on all parts, especially if the lift was done on the cheap.

Larger tires in and of themselves are not a big concern unless his driving style is to purposely do burn outs on corners a lot, again adding stress to the parts.

 

I honestly don't think he's driving irresponsibly but, I've been wrong before. Anything is possible, I suppose. Thank you for your reply!

 

Yes, I do think that this one going out does have something to do with the person who worked on it last. I should add that the truck was rear ended just after the rebuild so, there's that factor to consider also. However, he drove the truck 50,000 plus miles after the accident with the rebuilt RD with no problem. We had State Farm evaluate if the rear ending could have caused this delayed damage. Of course, they said it couldn't reasonably be connected to the accident.

 

I'll ask him if he's done this, as a habit, and make sure he doesn't do this in the future. Thank you.

 

I’d agree with others that the lift and tires is not what’s causing the failures, it’s something else. Either driving habits, or incorrect rear end install, etc.

 

Thank you.He was doing all kinds of modifications and I wasn't smart enough to know that I should be checking on the quality of the work being done. I do question how this lift was done. How would it "being done on the cheap" affect the integrity of the rear diff.? I want to correct anything that has been done that could be causing this RD issue. (In case it matters, his RD has a 4.1 ratio)

 

I do question the quality of the rebuild. We trusted the mechanic and just didn't ask enough questions, out of ignorance.

What types of driving habits can cause a rear diff. to go bad/break? I'm taking notes to talk to him about. He absolutely LOVES this truck and keeps it immaculately clean. He has a detailing business and washes it all the dang time. I don't think he has been abusing it but, again, I could be wrong on that.

 

this, he should also be handling and paying for his own vehicle repairs at his age not his mom, even if he is a high schooler if he is not respecting his truck, if you want to play you got to pay no matter what age

 

Locking diff's don't hold up as well to stress as standard diff's. Larger tires and lift WILL cause even more stress and wear out parts faster. But even with that I think something else is going on, they shouldn't be wearing out that fast even with larger tires.

When I was in college, 1976-1980 I had a 1975 Jeep truck with full time 4X4. It was essentially AWD, but with a switch that would lock the transfer case into true 4X4 for off road driving. I had to have 2 transfer cases rebuilt in just a few months after buying the truck. It was only after the 2nd repair that I discovered the vacuum lines that locked the transfer case had somehow been reversed. I was driving on pavement with the transfer case locked in 4X4. I was smart enough to know that I wasn't supposed to do that, and had the switch in the right position. But wasn't experienced enough to recognize the problem until after it cost me a lot of money. I knew that I wasn't abusing the truck, but it took a while to convince dad it wasn't my fault.

Your son may be pushing things harder than they were designed, especially with the added stress of larger tires and the lift. Maybe not.

 

Thank you, Marshall. After all the information we’ve gotten from everyone, my husband and I have almost decided to sell it as is and get something else for him. It’s a beautiful truck but, I just don’t think it’s going to be smart to put this much money into it. We’ve been going back and forth on selling or repairing.

It’s a 2010 with 163,000 miles on it. Needs the rear diff or whole assembly replaced, has a leak that our mechanic feels is coming from the drive chain case/housing and, now, I feel I need to replace the tires and rims to normal tires to reduce stress on the RD. Sounds like too much to be worth doing. It also was rear ended and fully repaired by insurance but, is another factor to consider. I honestly do not think he is intentionally abusing it.

Thank you for sharing your story. I think we’ll just cut our losses and move on. My son’s going to be very disappointed. :/

 

its very uncommon to replace 2 rear diffs on a Toyota truck they just don't fail if properly maintained and driven right, using the rear locker is only to be used as a last ditch attempt to get a stuck vehicle out of a situation. more than likely was using the locker engaged on pavement, a lift and bigger tires will not come close to smoking a Toyota truck rear diff, 163k miles is considered low mileage on these vehicles.

 

I understand your position. He is a college student athletes (baseball) and we think his “job” is school, for now. He works hard with his detailing business when he has any off time and uses his money wisely, otherwise. Soon enough he’ll be independent. He’s working hard towards that goal.

 

If he got 50,000 out of the last diff it seems crazy to sell the vehicle instead of repairing it or at least figuring out what caused it to fail before you sell a broken truck at what is likely going to be a big loss.

When the diff is replaced you need to follow a break in and make sure you stay on top of fluid changes. Also, could it have sucked in some water from the breather at some point? If that's what caused the failure you can prevent it in the future with about $20 in parts to relocate the diff breather.

 

if I was him I would keep his truck but since we are talking to his mom its a little unusual, if he was responding here he could tell us what happened and when and we can give a accurate answer on whats going on, I wouldn't sell that truck for anything it looks in excellent condition IMO. maybe you can tell him to sign on to TW, theres lots of people here we vast experience in these matters and could help immensely.

 

Anytime you add larger, heavier tires you're adding more stress to the drivetrain and suspension components. That said, it shouldn't be blowing up differentials so fast.

At the core of it, its a good vehicle still. I think I would either go back to stock or get some narrower/lighter tires.

Or sell it to him and let him take the responsibility - the equation is a whole lot different when its your own wallet on the line.

 

An easy way to tell if he's driving it hard is to check rear tire wear. With the larger tires and hard acceleration on pavement itwould be hard on the diff and his rear tires would be wearing out faster.