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8th July 2012, 06:47 PM
#1
Beginner
Patrol GQ Auto - RE4R03A - Missing Gears Diagnosis and Repair
Hi all,
As I mentioned in my 'Member's Ride' post a week or so ago (http://www.nissanpatrol.com.au/forum...-Roof-GQ-Wagon), my recently acquired GQ Safari has lost some gears in the auto transmission .
Having not had it for very long, nor having had an auto before, I had no idea what gears it had dropped. When I bought it the oil in the dipstick looked and smelt good so in a fit of vain hope I wondered whether it was 1st and 4th that I had lost, meaning it could be a solenoid in the valve body or simple electrical fault.
Out with the multimeter and service manual I checked all electrical components (solenoids, switches etc.) against specification. All was fine. Next, I drove around checkin the solenoid feed from the Transmission Control Unit (TCU) but again the electrical side was all behaving nicely to spec. Damn!
Next, I thought hmmmm....maybe its a stuck solenoid (more hope rather than anticipation!). So, I got some fresh ATF, filter kit and valve body gaskets and start to strip down the box with it still on the truck to rebuild the valve body, but found this in the pan.....
And that signalled then end of my hopes it was minor electrical fault! lol
Looked to me at this point that some bands or clutches had been melted at some stage by overheating. It also smelled burned to all hell. Taking a peek up into the tranny sump I also notice that the reverse clutch brake band is burnt up and has no friction material left on it. This pretty much nails the problem as being a lack of 2nd and 4th rather than 1st and 4th (brake band is required by 2nd and 4th) so at least I know what I am dealing with.
So at this point I kind of know the job is going to be a little bigger than I thought. So the plan changes to this:
1 - Rebuild valve body and check all components.
2 - Remove transmission from Patrol.
3 - Strip transmission and check all parts for wear against the service manual.
4 - Order and replace the required components.
5 - Put box back in patrol.
6 - If it works again, put on a transmission cooler.
7 - Drive it for a bit.
8 - If it is still good get a Nomad valve body from Wholesale Automatics and do a DIY lock-up torque converter mod to leave me with a solid box.
Thats the plan anyway! I am going to be doing it all myself.....mainly just for the hell of it! I think I might be mad! I will update this thread as things pro/regress!
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The Following 2 Users Say Thank You to waflyer For This Useful Post:
AB (8th July 2012), NissanGQ4.2 (8th July 2012)
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8th July 2012 06:47 PM
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8th July 2012, 07:01 PM
#2
Patrol God
Good luck with that, big job ahead no doubt, look forward to updates
04 ST 3lt auto, not enough Mods to keep me happy, but getting there
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8th July 2012, 07:03 PM
#3
Beginner
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The Following 3 Users Say Thank You to waflyer For This Useful Post:
AB (8th July 2012), Ade (8th July 2012), soulburner2000 (11th April 2013)
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8th July 2012, 07:15 PM
#4
Beginner
RE4R3A Removal and Disassembly
So, with the valve body removed (and rebuilt) and the brake band the apparent culprit for the loss of 2nd and 4th, me and mate start to drop the box. First up we jack up the truck at the front, drop both prop shafts and disconnect all the electrical cables in the engine bay. I managed to borrow a trolley from work to lower the box on that is pretty much the same as a gearbox jack. It fits the bill except that it wont drop low enough to allow us to drag the box from under the truck. However, it gets it close enough to the ground that with cunning use of a series of chocks we managed to lower it manually the last 200mm (with a few heart in mouth moments!).
Daft things we forgot:
1 - The exhaust bracket on the side of the N/S gearbox mount.
2 - The four bolts connecting the torque converter to the flex plate (essentially the auto equivalent of the flywheel).
Once we remembered these last few bits dropping the box off was pretty easy. Our job was made harder by not being able to jack the truck up as high was we would have liked due to the roof in the garage at my rented townhouse. Definitely recommend a proper gearbox jack if you can get one.
Here is the truck jacked up with the makeshift gearbox jack in place:
Few hours later and the box is out and on the floor:
Took us most of a day (in between snags and beers) to drop the box. Next step is to strip the unit down and have look at the insides....
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The Following User Says Thank You to waflyer For This Useful Post:
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8th July 2012, 08:54 PM
#5
Rotaredom
Hi mate, good luck.....been through this all before, not a job for the faint hearted, have you seen the internals of the auto boxes before?
Time is never wasted when your wasted all the time
WARNING: Towballs used for recoveries can, and do kill people and damage property.
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8th July 2012, 09:01 PM
#6
I wonder if this will help save it from happening again.
http://www.ebay.com/itm/Nissan-RG4R0...-/200485056179
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8th July 2012, 09:05 PM
#7
Rotaredom
Originally Posted by
97_gq_lwb
yep they help
Time is never wasted when your wasted all the time
WARNING: Towballs used for recoveries can, and do kill people and damage property.
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8th July 2012, 09:39 PM
#8
Beginner
Originally Posted by
NissanGQ4.2
Hi mate, good luck.....been through this all before, not a job for the faint hearted, have you seen the internals of the auto boxes before?
Hi mate,
Not seen inside of one before today. In fact it was your thread I think that made me decide it was DIY all the way. I don't need the truck as daily driver so the time it takes to do it is no issue, so it will be steady steady time wise.
Started the disassembly this arvo, but realised I need a clutch spring compressor to remove the clutch packs. What did you do with yours? Did you buy a clutch spring compressor or make one?
Cheers,
Sam
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8th July 2012, 09:41 PM
#9
Beginner
Yep, one of these (http://www.ebay.com/itm/Nissan-RG4R0...-/200485056179), or the nomad valve body upgrade from Wholesale Automatics seem the go.
On the other hand I was under the impression that with overheating being a common problem, a nice big oil cooler might be good preventative medicine?
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8th July 2012, 09:58 PM
#10
Rotaredom
Made one up Sam, but if you can buy one I would buy one, was a pain to remove the clutch packs
Cheers
Todd
Time is never wasted when your wasted all the time
WARNING: Towballs used for recoveries can, and do kill people and damage property.
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