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5th gear in gu

Posted: Tue Jul 20, 2004 7:19 pm
by jp
i just blew 5th gear in my gu patrol coil cab and looks like nissan will fix at there cost even though it is out of warranty.anyone else had the same prob?

Posted: Tue Jul 20, 2004 7:24 pm
by big red
heard of a few in 3 litre wagons [same gearbox]
good to know nissan will come to the party.
they change a few bits when they fix them ...wider gear or something.

what K's and year is yours.

my 99 has just over 100,000 k's and all seems ok so far.

Posted: Tue Jul 20, 2004 9:12 pm
by mr Z
i heard anything after may 2000 should be ok, is this true?

i have a june 2000 (complianced) coil cab with 40k on the clock and the 5th gear is my only concern :?

is it ok to tow in 5th? i keep hearing different stories

Posted: Tue Jul 20, 2004 9:17 pm
by roly
i got one of the 1st new mainshafts in july 2002

it affects series 2 GU's , april 2000 to about june 2002 build


i towed 10,000kms a race pajero across aust and ban it went a few months later, still drove to melb and back in 4th though ;)


Roly

Posted: Tue Jul 20, 2004 10:29 pm
by heathgu
Yep mine did 5 gear, it stripped the main shaft not gear itself. Replaced no worries except had to have gear box rebuilt 20,000 later with case hardening wearing off idler shaft causing noise box.

Since then have been running synthetic gear oil had no worries.

Posted: Wed Jul 21, 2004 1:15 pm
by flexy trol
what type of noise do you normally get before it sh#ts it self is it a grinding or druming sound at a certain speed or does it happend real sudden. sam

Posted: Wed Jul 21, 2004 1:19 pm
by roly
drive along and then it feels like it jumped out of 5th but its still in 5th

and thats all

Posted: Thu Jul 22, 2004 8:13 pm
by jp
mine is 5/2000 4.2t with 90,000 on the clock,it made no noise at all before sh#ting itself but one hell of a noise when it did and also makes the noise at idle and in reverse.

Posted: Thu Jul 22, 2004 8:16 pm
by mr Z
were you still able to drive it?

Posted: Fri Jul 23, 2004 12:16 am
by big red
roly wrote:i got one of the 1st new mainshafts in july 2002

it affects series 2 GU's , april 2000 to about june 2002 build


i towed 10,000kms a race pajero across aust and ban it went a few months later, still drove to melb and back in 4th though ;)


Roly

mines a series one so maybe they are different ?

Posted: Fri Jul 23, 2004 9:25 pm
by jp
can still drive it just cant put it into 5th.it goes in to the workshop monday to get fixed

Posted: Sat Mar 25, 2006 2:29 pm
by beretta
Okay I've dug this golden oldie up cos my folks are on their way up from Melbourne and their GU TD42T has dropped 5th gear and they're cruising along in 4th, what I need to know is can they keep driving it without doing more damage and can it be driven back from Sydney down to Melbourne to get it fixed by their own mechanic or should they get it fixed in Sydney while they're here?

Posted: Sat Mar 25, 2006 7:33 pm
by notso
When I did mine they told me to drive it to the nearest Nissan dealer. I asked is it going to damge it more. the said no. But I reckon iy will wreck the bearings as when I insisted Nissan put all new bearings in it as well as the Fix Kit

Posted: Sat Mar 25, 2006 8:48 pm
by bogged
Dude in our club drove from Darwin to Melbourne adn then got it fixed.

But IMHO the less you drive it the better off you would be.

Posted: Sun Mar 26, 2006 10:34 am
by beretta
Yeah, it has done exactly as someone described above, driving along in 5th, they said it felt like it popped out of gear and then nasty grinding noise, which was obviously the 5th gear spinning on the main shaft from what people have said above. Its a 99 model brought in 2000, just had a turbo upgrade done, wonder if that didn't help?

Gonna see if the transport company I used to drive for can chuck it on the back of one of their Bdoubles or maybe give finemores a ring, I don't think they should drive it home in 4th, you never know what floating around in the box now (lots of little metals bits! :bad-words: ).

Posted: Mon Mar 27, 2006 10:54 am
by beretta
Okay the car is here in Sydney and is going to Traction 4 to be repaired, does anyoen know if Traction 4 are any good at this type of work, I've heard the name before but haven't heard much about them myself?

Posted: Mon Mar 27, 2006 11:18 am
by bogged
beretta wrote:Okay the car is here in Sydney and is going to Traction 4 to be repaired, does anyoen know if Traction 4 are any good at this type of work, I've heard the name before but haven't heard much about them myself?
What is their hourly rate compared to Nissan dealer? Nissan probably done a few of these now.

Posted: Mon Mar 27, 2006 11:27 am
by beretta
Fair question mate and thanks, I don't know, but to be honest not too concerned about the rates I assume they're fair and around market rate, just want it fixed by people who know what they're doing, I would have more faith in a reputable 4wd shop than a Nissan dealer's apprecntice. They're doing a lot of trips in the coming months including Cape york for a good stint so want it fixed properly and reliably.

Posted: Mon Mar 27, 2006 11:29 am
by morkz
I would take it to a gearbox specialists rather than 4wd specialist as most of 4wd shops actually sub contract it out and all they do is put the box in and out of the vehicle.

Posted: Mon Mar 27, 2006 11:31 am
by bogged
morkz wrote:I would take it to a gearbox specialists rather than 4wd specialist as most of 4wd shops actually sub contract it out and all they do is put the box in and out of the vehicle.
good point.

Posted: Mon Mar 27, 2006 11:35 am
by beretta
morkz wrote:I would take it to a gearbox specialists rather than 4wd specialist as most of 4wd shops actually sub contract it out and all they do is put the box in and out of the vehicle.
Hmmm yes very good point Morkz, only drama is, I wouldn't know where to start in Sydney so for now it will have to go to a 4wd specialist.

Posted: Mon Mar 27, 2006 12:52 pm
by morkz
beretta wrote:
morkz wrote:I would take it to a gearbox specialists rather than 4wd specialist as most of 4wd shops actually sub contract it out and all they do is put the box in and out of the vehicle.
Hmmm yes very good point Morkz, only drama is, I wouldn't know where to start in Sydney so for now it will have to go to a 4wd specialist.
why not just post up in general 4x4 tech a reputabale gearbox recon guy in sydney i'm sure someone on this board would have good recommendation.

Also i wouldnt rule out nissan cause if it does shit itself you will have more calling back on nissan as they are larger company to deal with.

so my recommendations stand above

Posted: Sat Apr 01, 2006 7:47 am
by HL
mr Z wrote:i heard anything after may 2000 should be ok, is this true?

i have a june 2000 (complianced) coil cab with 40k on the clock and the 5th gear is my only concern :?

is it ok to tow in 5th? i keep hearing different stories
You can tell if it is likely to go by looking at the colour of the oil. It goes dark brown (coffee) well before it fails completely.
I had my gearbox (Feb 2001) replaced under warranty last year. I did have the exented warranty. The car had only done 50,000 and it was starting to get hard to shift out of 5th after a long run.
It only took them 4 weeks to replace the box after stuffing around for a week deciding what to do. The mainshaft/gear were upgraded in dec 2002 according to Nissan tech guy I talked to. So, any truck built before then would be suspect.

Cheers

Posted: Sun Apr 02, 2006 6:45 pm
by j-top paj
is it only the series 2s that it happens to?
il more than likely be getting a series 1 and hope i dont have this problem

Posted: Sun Apr 02, 2006 7:43 pm
by HL
Hi....
I have heard any between 1999 and end of 2002 may be prone to this. I think it is not so much a manufacturing defect than a design issue. These boxes have been around since the early 4.2's and those engines only had about 250nm of torque. The 3.0 has around 350nm and so do the turbo 4.2's, so they have a lot more ability to twist the splines in overdrive and this seems to be what is happening. The later boxes have a longer spline for the 5th gear. Just my thoughts.
Cheers

Posted: Tue May 29, 2007 9:26 pm
by raptorthumper
I thought i would post pics of the new parts available for GU 5 speed boxes, that are much stronger. I believe both series 1 and 2 GU's are affected. No more failed 5th gears.

Parts are available from nissan for $513 approx but you can get a better price if you have a good relationship with dealer. Nissan acknowledge the problem.


I suggest if you have an early GU 5 speed i would replace with new parts during a clutch change for peace of mind.




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Posted: Wed May 30, 2007 8:13 pm
by Modified Toy
Seen a few of these replaced but all the ones i have seen the gear was loose on the spline causing it to wear the spline quicker but the new one has a longer spline as shown but i would think another 10mm would not make mutch difference but the new gear is a press fit on the main shaft instead of slip on i also believe the diesel engine would contribute to this as 60 series toyota autos have the same prob but they loose all drive and this is common as hell in the diesel only to.

Posted: Wed May 30, 2007 9:39 pm
by raptorthumper
Yep agree. The loose fit does wear the spline with torsional vibrations, and there is no doubt a press fit will stop/eliminate the wear rate. Torsional vibrations are worse on the diesel motors and a loose fit wears the spline. It's not a strength issue - only wear related, due to poor manufacturing tolerances.

An extra 10mm of spline reduces the stress on the spline significantly however. Anyway very, very doubtful it will ever fail again with the new design.

Just wanted to get people aware of it. Haven't heard if many TB45 petrol motors have suffered the same fate as the ZD30 and TD42T's.
Grant.

Posted: Thu May 31, 2007 12:05 pm
by flyreels
HL wrote:Hi....
I have heard any between 1999 and end of 2002 may be prone to this. I think it is not so much a manufacturing defect than a design issue. These boxes have been around since the early 4.2's and those engines only had about 250nm of torque. The 3.0 has around 350nm and so do the turbo 4.2's, so they have a lot more ability to twist the splines in overdrive and this seems to be what is happening. The later boxes have a longer spline for the 5th gear. Just my thoughts.
Cheers
Hi so this would include the Gu series III then as well as they came out in Oct 2001?
Thanks Peter

Posted: Thu May 31, 2007 8:03 pm
by raptorthumper
I am inclined to think it would, but only real way to tell is pull the rear housing off the box and check for the extra boss on the 5th gear.