Can Diff Backlash Blow Boxes?

[reCOUPErator]

hey guys you may have seen one of my earlier posts,

i drive a 93 r32 rb20det 5speed, pretty much stock running 13psi.

any ways i have gone through around 7 re built boxes.... got it all done under warranty, but have been told that he will not do any more under warranty so its time 2 get serious, the last thing he has said it could be is diff back lash, it isn 2 bad but there is a bit there...

any other ideas

have been blowin (lossin) 5th gear blowing a 3rd a syncro moved... etc. but the last 2 have lost 5th so we are focusin more on that one!

um im about too put some power through the car (200ish atw) and am probably about 2 put a RB25 box in it however before i invest in that i want too try and nut out that problem incase it is anythin in the car causin it.

all help appreciated thanks

lee

Edited February 1, 2009 by reCOUPErator

[reCOUPErator]

15 views and no opinons

need help asap guys pls

before another one pops lol

[Al]

VERY unusual, hence the lack of responses.

I have an r33 GTST (rb25det) and have had a fair bit of diff back-lash for the last 4yrs. The car has been making over 280rwkw during that time, currently making 320rwkw, the back-lash hasn't gotten worse and no problems with the gearbox either. I also do a bit of motorsports and motorkahna days.

I am aware that the rb25 box has a strong reputation, but a mate is running an rb20 box is his 270rwkw r32 and hasn't had any issues at all.

If you are already thinking of the option to get a rb25 box, then do it, as you'll eliminate two possible issues:

1/ the strength of the rb20 box

2/ the repairer.

Also your driving style can also effect how long you gearbox last

Another issue could be your clutch: I have had two mates blow their gearboxes due to having a solid center clutch. A spring center clutch dampens the shock to the gearbox, during gear changes.

[SteveL]

The answer to you question is 'highly unlikely'.

The fact that you keep 'blowing' 5th tells me straight away that this is a driving style problem. 5th is overdrive and designed for highway cruising....and that's pretty much it. Had you broken one or maybe even two I would have said it was bad luck.....but 7 is a bit much and I'm not surprised the supplier wants to walk away (and yes, I understand they weren't all 5th gear failures).

Sorry but you either need to moderate your driving style or get something more durable.

[mid life crisis]

ive got a r32 auto trans laying around that maybe better suited to your style of driving :-)

[grigor]

[quote name='Al' date='2 Feb 2009, 04:23 PM' post='4403111'

If you are already thinking of the option to get a rb25 box, then do it, as you'll eliminate two possible issues:

1/ the strength of the rb20 box

2/ the repairer.

Also your driving style can also effect how long you gearbox last

[/quote

Agreed,

BUT I'm suggesting the repairer.

For an Rb20 to make any serious power in 5th, he's got to be doing >200kph.

Look at your typical 200rwkw Rb20 dyno chart, big power isn't happening until way at the top end.

There simply isn't sufficient torque happening at around 100kph in 5th to pull the skin off a custard.

Your typical Rb20 gearbox damage is in 3rd where the engine can develop Hp. via big RPM. Not so much 1st or 2nd as traction issues limit the load.

With decent power, the layshaft input gear will shear off the woodruff keys and that's it.

[bubba]

My RB20 boxes had the input shaft bearing die, my guess was due to too many 2nd gear clutch drops

[Al]

15 views and no opinons

need help asap guys pls

before another one pops lol

5 replies and no comment/feedback

[Al]

I take that back ; just noticed all replies were done with 24hrs, sorry

[reCOUPErator]

lol

i only use 5th for like over 80kph speeds

dont sit in 5th at 50kph lagging it up and stuff...

lol well i did blow a 3rd but that was going from 4th too third at low ish revs too speed up... didn like it really

i have been driving for over 4 years, have owned 10 cars 8 of witch are manuals, none at all front wheel drive...

and none jus stock pieces of junk either and have never blown a box, clutch or diff untill now!

the clutch is a extreem hd ceramic button clutch with a sprung centre!!

yeah real mature on the auto comment... real helpful..

yeah apreciate all the other help on it... keep opinions and shit flowing if you have them...

thanks guys

[blind_elk]

lol well i did blow a 3rd but that was going from 4th too third at low ish revs too speed up... didn like it really

I've done that dozens of times - never blown a box. I remember once in my 240Z, taking off on a slight uphill, with tandem trailer and garage hoist - in 3rd gear! Didn't blow up the gearbox, though.

i have been driving for over 4 years

So? When you get to 10 times that, then start crowing.

, have owned 10 cars 8 of witch are manuals, none at all front wheel drive...

and none jus stock pieces of junk either and have never blown a box, clutch or diff untill now!

the clutch is a extreem hd ceramic button clutch with a sprung centre!!

yeah real mature on the auto comment... real helpful..

yeah apreciate all the other help on it... keep opinions and shit flowing if you have them...

thanks guys

I have a RB25DET in my 32 GTS4, and it has pushed 180kW out through all 4 (probably 250 out the rear). It has a HD clutch and lightweight flywheel. The box is still going strong. (maybe GTS4 boxes are a bit stronger, but they were still only designed to handle a RB20DET).

I used to have a 180B SSS. It was my daily, my race car, my rally car, my motorkhana car. It ran twin 45 Webers. In 300k of hammering, the only failure was the 1st gear layshaft bearing collapsed.

My experience is that Nissan gearboxes are close to indestructible. I find it difficult to believe that your gearboxes have been rebuilt with faulty components 7 times. I'm inclined to side with SteveL about your driving style being a significant contributor to the problem (regardless of what your previous cars did).

[bubba]

I have a RB25DET in my 32 GTS4, and it has pushed 180kW out through all 4 (probably 250 out the rear).

Sorry, just need to call shenanigans on that comment about awkw to rwkw.. unless you were wheelspinning on the dyno then there would have be no torque split to the front wheels.. so 180awkw to 250rwkw is a bit of a stretch...

[reCOUPErator]

pffttt.... LOL

talk like a hero mate??

was merely explaining everythin, including my background too set a picture, was not crowing so get off your high horse!

nissan boxes indestructable, lol, i know someone that has gone through 4 boxes in a 220rwkw rb20det, and a guy that blew a 20det box on the nissan silvia ben simpson memorial cruise, you saying all of these and any one that has blown a nissan box cant drive?

you were lucky with all your boxes then hey...

im sorry but useless comments just bagging on what im saying dont help... not constructive criticism!

getting damn frustrated with this and appreciate all other help.

...

last box blew when i ws cruisin down the high way at 100kmh heared a whine turned music down and gently accelerated up2 probablyh 105kmh too see if the whine changed increased or stopped, looked down at the gear stick and it gently popped out of 5th, clutched and put back in 5th and there was nothing there just free spins!

thanks

lee

[ices_performance_centre]

can u be more specific ? is the nut that that hold fifth coming loose or is the counter shaft breaking? or is the sleeve stripping. ?

Yes to much backlash in a diff will cause the gears to hammer hard every time u acclerate/declerate nissan boxes are very touchy to this,

I would also reccomend Checking that you have a soft centre clutch,

if you in melb by anychance drop into my shop

[DECIM8]

Look Im going to say its fluid.. Cant see any other reason.

[reCOUPErator]

un sure on what it is exactilly mate..

might ring the supplier tomorrow and ask him!

has had at least 2 different fluids in it id say if not 3!

the back lash isn disgusting but there is a bit there, not like it clunks every time you take off or shift or accelerate or de accelerate!

Edited February 4, 2009 by reCOUPErator

[blind_elk]

Sorry, just need to call shenanigans on that comment about awkw to rwkw.. unless you were wheelspinning on the dyno then there would have be no torque split to the front wheels.. so 180awkw to 250rwkw is a bit of a stretch...

Sidebar - then how do you measure awkw? Because the rears are rotating on the drum and the fronts are stationary, ATTESSA thinks you have wheelspin, so engages the fronts, transmitting power to the front roller (of a 4WD dyno). When I had the RB20, I had it on a 4WD dyno, in AWD and RWD modes - there was about 25% more rwkw than awkw.

[bubba]

How do you measure awkw? on an 4-wheel dyno..

You shouldn't be on a 2WD dyno in a 32gts4 without turning attessa off or pulling the fuse.. the car would be trying to launch off the dyno with the front wheels grabbling for traction, and considering the 32 ATTESSA doesn't run any preload, I find your figures hard to stomache.

OK so, you think you had 25% more rwkw than awkw.. with 180awkw that would make it 225rwkw.. I still find it hard to believe there was a 60rwhp difference (let alone the ~95rwhp you originally claimed), unless you were wheelspinning on the dyno and with 180awkw RB25, I highly doubt that was the case.

[blind_elk]

How do you measure awkw? on an 4-wheel dyno..

You shouldn't be on a 2WD dyno in a 32gts4 without turning attessa off or pulling the fuse.

Doh! Did I ever say it was on a 2WD dyno?

. the car would be trying to launch off the dyno with the front wheels grabbling for traction, and considering the 32 ATTESSA doesn't run any preload, I find your figures hard to stomache.

I had it on a 4WD dyno, bozo. How else do you think I was able to quote a awkW figure? (I pulled the fuse to run it in RWD mode)

OK so, you think you had 25% more rwkw than awkw.. with 180awkw that would make it 225rwkw.. I still find it hard to believe there was a 60rwhp difference (let alone the ~95rwhp you originally claimed), unless you were wheelspinning on the dyno and with 180awkw RB25, I highly doubt that was the case.

I don't see your point. Should I have more kw? And WTF has wheelspinning got to do with the price of fish at the egg market?

[bubba]

Bozo, lol.

Nice of you to resort to name calling.

I still don't believe your 180awkw to 250rwkw claim.

Edited February 5, 2009 by bubba