The launch is mightier than the gearbox?

[3zercrowd]

OK
So here is daves (youda's) centre diff pictured below:

As you can see below its smashed.

Turns out he had launched it and it went bang/heard a noise, so he babied it back to my place.

We had an arguement over the causes :lol:

Everyone I/we (josh) have talked to (and myself/josh) thinks it was the running of the 14's on the rear with 17's up front for a week or so causing the centre diff to cark itself which in turn the chunks from the centre diff lodged into the front diff which chewed out the housing and punched 2 holes in the housing spilling oil all over the road outside my house


Now to clear things up. What do you think happened and what do you think the causes were? For the gearbox GURUs also, what do you think happened? Im sure there is a lesson here for all of us :wink:

 

[NZVR4]

whilst it could have been just due to the hard launch but most likely the result of running different wheels front and back,the same thing happened to my old vr4,15's on the front and 18's on the rear equalled one broken driveline

 

[Pinataman]

I believe that the problem was the different sized tyres (wheels). My brother works for caterpillar in mining and he has seen it happen to face grinders in the pit. The difference in rotational distance "winds up the diff" and it eventually fails. This what he told me I don't know if it applies here but I think it may.

 

[CLuTZ]

Everyone I/we (josh) have talked to (and myself/josh) thinks it was the running of the 14's on the rear with 17's up front for a week or so causing the centre diff to cark itself

Seems to me like you already know what caused it??

 

[3zercrowd]

Everyone I/we (josh) have talked to (and myself/josh) thinks it was the running of the 14's on the rear with 17's up front for a week or so causing the centre diff to cark itself

Seems to me like you already know what caused it??

LOL THINKS that.....what about you DRE?

I mean is there anything else we should be looking at?

 

[CLuTZ]

Everyone I/we (josh) have talked to (and myself/josh) thinks it was the running of the 14's on the rear with 17's up front for a week or so causing the centre diff to cark itself

Seems to me like you already know what caused it??

LOL THINKS that.....what about you DRE?

I mean is there anything else we should be looking at?

no??

 

[JSTYLE]

I believe that the problem was the different sized tyres (wheels). My brother works for caterpillar in mining and he has seen it happen to face grinders in the pit. The difference in rotational distance "winds up the diff" and it eventually fails. This what he told me I don't know if it applies here but I think it may.

on the money.

Jon

 

[Jonson]

either way its a bit messed up :shock:

 

[Entaran]

Different sized wheels

centre differential diff

^^

Just adding search terms.

I have nothing else to add to this topic, the reason it blew is outlined above and is a well known thing.

 

[3zercrowd]

:lol: Yeah i know.

Try telling dave that :wink: :roll: :lol:

 

[youda]

Ok to clear a few things up, the car had the different sized wheels on the car for a grand total of about 4 days and during this time rarely used. During the launch the car went clunk but was still drivable!!!!!!!. once finished looking under the car the centerbering bolts where both loose had one chewed out engine mount and wheel alignment was out about 12 degrees. I know about drive shaft windup and highly doubt this was the cause as none of the wheels moved when jacking the car up and the car did not free up when in reverse (before the clunk occurred). The gearbox had also runnout of oil as if you look at the crack in the pics above the oil leaked out on the road. I seriously dount the gearbox could have worn that far through and had a blown front diff without me knowing.


to be continued.........

 

[rob323]

um, is it the front diff that broke or the centre diff?

 

[3zercrowd]

um, is it the front diff that broke or the centre diff?

Centre is smashed. The top bearing on the front diff has metal in it too because it is hard to move at times and jumps/binds.

 

[UDLOOZ]

The main cause of it breaking was due too the different size wheels... ( plus i do recall you saying you run more than one person that day too Dave?" ) Why i mention this is simply cause you would have been able to drive around with the different size rims "if you drove normally" for quite a while.. but those few race starts you done was just enough to do the damage... " You can only stretch a rubber band so much before it breaks... and the same sorta thing apply's with this situation..

 

[3zercrowd]

you have got to be nuts to run different size rims/tyres on a 4wd.

i thought everybody knew that

Expensive lesson to learn.
same deal as running mis-matched ratios, front to rear.
Blow your centre diff in no time.

Ok to clear a few things up, the car had the different sized wheels on the car for a grand total of about 4 days and during this time rarely used.

So even after 4 days?

Absolutely nothing else could have caused it?
Loose centre bearing?
Loss of oil causing a centre diff bearing to fail?

Daves just adament that running the different size wheels didnt do it. Even though I believe it was the 2 different sizes, and i did warn him about it before he put them on, even offering to pay for him to get 2 2nd hand tyres for the 14's or the 17's to make a full set up.

I just dont want anyone else to go through the same trouble we have had to go through getting a 2nd hand box shipped up here to Townsville, and pulling 2 gearboxes out and mucking around with it all.


Thanks

Dane

 

[3zercrowd]

From GVR4:

Absolutely nothing else could have caused it?

The proof will be evident after examination of the spider gears.

Loose centre bearing?

Not sure what you mean, tailshaft support bearing?

Loss of oil causing a centre diff bearing to fail?

The fith gears would be burnt before anything else happens.
Looking at the pics you sent me, I cannot make out any damaged bearings or damage caused by lack of oil.


When you fit different tyres or mismatched ratios, the gears inside the centre diff spin thier little c#nts out and get extremely hot in the bores and thrust surfaces. They will the try to 'weld' themselves to the cross and the wall of the centre diff housing (this is not possible because they are still being forced to spin thier little c#nts out and the only course of escape for this inertia will be to pop the teeth off the spider gears)

 

[youda]

ok, to keep it simple for four days i could have thrashed the living f@#k out of the car and the dif should not have blown because of wheels, different sized wheels cause progressive damage to the gearboxnot one big blowout.

and yes tailshaft support bearing aka center bearing was loose, when letting the clutch off while the car was on jack stands there was alot of movement in the rear driveshaft im talking about 4-5inches of movement back and forward of the car

 

[Mr Gears]

ok, to keep it simple for four days i could have thrashed the living f@#k out of the car and the dif should not have blown because of wheels, different sized wheels cause progressive damage to the gearboxnot one big blowout.

Well... what can I say, I am not interested in arguing the point. I am not responsible for your problems, you can drive around on different size tyres all you like. Good luck to you. Have fun wasting time and money.

Just remember to post up the pics of the internals of your centre diff, when you dismantle it, so we can see the damage as I have described it.

 

[NZVR4]

mine blew after one day of running mismatched wheel sizes,whilst other issues can cause failure in my experiance everytime someone runs different size wheels they either blow or some serious wear is caused and they blow after the correct size wheels are put back on

 

[moi]

maybe the underlying issue here is the hard launch? Wear and tear over time causes failures. I have had the same breakage and it was due to high revs and sidestepping clutch, went clunk (bang). Also reverted itself to rear wheel drive mode (lots of fun) but still driveable (noisy) as I drove it home from the track. Also all wheels binded up while turning corners. No doubt different size wheels would cause binding up however over the course of 4 days with minimal driving probably would not have caused much damage.