Diagnosing lack of AWD: Pics and symtoms

First, I am aware of the transfer case breaking issue that is widely publicized. In fact, I thought I had this issue. But now not sure.

1) Last year, I hit the accelerator hard to pass, and I heard a loud bang and then a bunch of crunching. Then is subsided and has been quiet ever since.
2) However, in the rain, I first noticed that I only have front wheel drive, as the front wheel spun and TCS light went off. Ok, I broke something.
3) When I lift the truck off ground, when I spin the front wheel, the rear doesn't turn, not the rear axle driveshaft. When I spin the axle, the rear wheels spin.
4) While car is running, both front wheels spin, rears do not. Now - I heard there is some computer control involved, so not sure.
5) I removed the transfer case (what a pain...). BUT, it seems to be working. I can turn the trans shaft on it, and the rear axle plate spins. Surprised. The trans gear seems quite stripped though.

IMG_4150_sm_zpstdzgdjge.jpeg


6) The input on the trans also looks stripped. And there is rusty dust piled up. What is that? I see it in other photos on the net.

IMG_4149_sm_zpswrnqomys.jpeg


7) When I spin the front wheel, I can see on the transmission that the inner gear spins, but the large outer gear does not. Is that my issue - the differential? Or is that normal when spun by hand?


Basically, I am trying to figure out if its stripped gears, or a destroyed diff. Or both... Any experience here on my above symptoms??

THANKS!


Derek
2010 CX-9 Grand Touring
2017 Miata RF Launch Edition
 
there is a million post on this problem, search this forum carefully. You need to replace the transmission because the diff (in the transmission) isn't a part that can be sold by the dealer. Seems like someone found a replacement source on ebay so if you want to repair it you will have to remove the transmission and change the diff as well as put a new transfer case because those splines are chewed up. Either that or you keep it FWD if you don't live in a snowy place.

Your transfer case might still be good, i have the same problem, my transfer case is good but the splines are chewed up.
 
Thanks Puma. Sorry for late reply, I didn't get a reply indication, maybe my settings.

Anyway - I was trying to see if the symptoms I explained indicated a blown up diff. If you are saying, yes, then replacing both the trans and the case is almost the value of the truck and not worth it. Kinda sad I went through all that work for nothing, but at least I know... Gonna put it back together and call it 2WD, nothing I can do about it.

Derek
 
From what I have read you don't even need to put that transfer case back in and you can also remove the driveshaft to the rear. If you're going to be FWD anyway may as well save hauling that added weight around.
 
Yes, I think Puma said that in the other 10 page thread I just read...

Puma - there doesn't appear to be any trans fluid leaking from the diff area, so I can just leave off the transfer case, remove the driveshaft? What about the rear diff, just remove the driveshaft from it and that's it?

It would save me a great deal of time to just leave the PTU off, that's for sure. Let me know if there are any special steps, I think I will do it. Heck, it would save the next owner a bunch of time if they want the parts and fix the trans.
 
yes you can leave the the transfer case off as well as the driveshaft. As far as the rear diff goes, i personnally left mine in place because if you take it out, you will need to remove the rear axles and the rear axles also have the teeth for the ABA so if you remove the rear axles, you will lose ABS too. You could tear the axles apart and keep just the outer portion of it on the rear hubs but i didn't try that. We used to it this way on 2wd conversion on an awd Porsche so the ABS could still work.

I didn't take mine out because i was still hoping for a cheap solution to repair the vehicule, i might have found it but it won't be before next fall. One other solution is to buy a new diff and new transfer case which would cost around 1500 i guess but that's without calculating time if you need to pay someone to do it, removing transmission and opening it is no easy task.
 
I wasn't implying to remove rear diff, just wondering about the clutch and wiring.

Also, if I sell this car, would a prospective buyer rather have the car original but broken, or with removed PTU to make job easier to fix? Hmm.
 
I wasn't implying to remove rear diff, just wondering about the clutch and wiring.

Also, if I sell this car, would a prospective buyer rather have the car original but broken, or with removed PTU to make job easier to fix? Hmm.

Leaving it out will save labor for any potential buyer. If things were in that shape and I could look directly at the damaged splines having it out of there would not bother me in the least as a buyer.
 
yeah sorry didn't read that right, yes just take out driveshaft and you are done, nothing special to do afterwards.

I wouldn't mind as a buyer having the transfer case off if it come with the car, what would bother me is someone putting it back and not declare the awd doesn't work
 
yeah sorry didn't read that right, yes just take out driveshaft and you are done, nothing special to do afterwards.

I wouldn't mind as a buyer having the transfer case off if it come with the car, what would bother me is someone putting it back and not declare the awd doesn't work

And that says it all....
 
I had exactly the same experience.
A few years ago, I finished a 10 hr highway drive home from a ski trip. Arrived home on my street and accelerated across some snow and heard and felt the same 'bang' you describe. Rear wheels attempted to engage, the transfer case must have failed, and put reverse torque on the transmission output shaft, stripped the splines.
Mazda and the dealer warrantied the transfer case, but not the transmission. At least they worked with a local transmission shop to source a used output shaft, and rebuild my transmission with that, for about $2K. Rather than 7K quoted for new transmission. Other than three total warranty transfer cases, it has held up.

But the truck drives normally in Front WD. You'd never know the problem exists unless you get into mud or snow.
 
I had exactly the same experience.
A few years ago, I finished a 10 hr highway drive home from a ski trip. Arrived home on my street and accelerated across some snow and heard and felt the same 'bang' you describe. Rear wheels attempted to engage, the transfer case must have failed, and put reverse torque on the transmission output shaft, stripped the splines.
Mazda and the dealer warrantied the transfer case, but not the transmission. At least they worked with a local transmission shop to source a used output shaft, and rebuild my transmission with that, for about $2K. Rather than 7K quoted for new transmission. Other than three total warranty transfer cases, it has held up.

But the truck drives normally in Front WD. You'd never know the problem exists unless you get into mud or snow.

Hi Singletrack,

What about lights on the dashboard?

Regards
 
No warning lights were triggered with this. The rear diff solenoid would still engage, but since there was no power getting to the rear wheels, they weren't being driven. But the car didn't know nothing was happening. If the front wheels slipped, the traction control lights would come on, but that would be normal if some wheels where spinning faster than others.
 

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