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Aussie FJ40
30th April 2015, 01:40 PM
I have read that there are some 5 speed gearboxes in the GQ's that are stronger than some others,I'm running an LS3 (400kw) and wondering what is the best box out of the 5 speeders, I think mine has a synchro problem as there is a bit of difficulty engaging 1st and I will get the box recoed or buy another,how do you differentiate between boxes?thanks

threedogs
30th April 2015, 02:19 PM
I recall 500nm being about max for the GQ/GU 5 speed

nissannewby
30th April 2015, 05:33 PM
Most gq boxes are pretty good it was the early gu that had problems with 5th gear but this was revised from late 03 and any failures inside warranty period on the earlier ones were replaced with an uprated shaft and gear.

The 5 speed behind td42,tb42, tb45, tb48, zd30 are good for up to about 700nm before the reliability is questionable.

With a 400kw ls3 any reason you want to insist on the manual? Surely an auto would be a mu cheaper better option.

Parksy
30th April 2015, 08:11 PM
Just to add onto what nissannewby said, the stronger boxes had a cast iron housing. The "weaker" manual box had an alloy housing.

growler2058
30th April 2015, 08:21 PM
Isnt the box from the rb30 GQ's smaller than the others?

Parksy
30th April 2015, 10:16 PM
Yep sure is.

kevin07
30th April 2015, 10:47 PM
just a question could you elaborate on the first gear thing. now lets say your sitting at the lights, and you push the clutch in and put it in first and its hard to go in or does it go in after a few seconds. could you just explain what its doing. and yes im thinking of a specific problem

nissannewby
30th April 2015, 10:48 PM
Isnt the box from the rb30 GQ's smaller than the others?

Yes pretty much the same as the one behind the RD28. These boxes aren't quite as strong as their bigger brothers.

nissannewby
30th April 2015, 10:49 PM
Just to add onto what nissannewby said, the stronger boxes had a cast iron housing. The "weaker" manual box had an alloy housing.

When did they become alloy? This is new to me and I have been under a few patrols.

nissannewby
30th April 2015, 10:52 PM
just a question could you elaborate on the first gear thing. now lets say your sitting at the lights, and you push the clutch in and put it in first and its hard to go in or does it go in after a few seconds. could you just explain what its doing. and yes im thinking of a specific problem

Also to add to this are you using the correct spec oil for the box?

BigRAWesty
1st May 2015, 06:15 AM
Also to add to this are you using the correct spec oil for the box?
My brother told me first is not syncro'd so if you try selecting first while moving it'll be difficult??
Is this true??
I've never looking into but I also can't select first unless stopped or atleast just rolling.

Parksy
1st May 2015, 08:25 AM
When did they become alloy? This is new to me and I have been under a few patrols.

Should have elaborated a bit more. What I meant was the box that came behind the RB30 or 2.8 came out with the smaller box which had an alloy housing. The box is physically smaller and I'm pretty sure this box was fitted to some other model nissans.

Parksy
1st May 2015, 08:30 AM
Ist gear is syncroed. If it's not changing right id start by replacing the oil and re filling with a GL4 spec oil. GL5 stuff is to be avoided because this stuff will eat away at the brass syncros and it also has a lower friction coefficient, which means the syncroes won't work as they should. They do rely on friction to match gear speeds so this is why it can cause difficult shifting.

nissannewby
1st May 2015, 10:33 AM
My brother told me first is not syncro'd so if you try selecting first while moving it'll be difficult??
Is this true??
I've never looking into but I also can't select first unless stopped or atleast just rolling.


Ist gear is syncroed. If it's not changing right id start by replacing the oil and re filling with a GL4 spec oil. GL5 stuff is to be avoided because this stuff will eat away at the brass syncros and it also has a lower friction coefficient, which means the syncroes won't work as they should. They do rely on friction to match gear speeds so this is why it can cause difficult shifting.

1st is not synchro. Well neutral to first isnt neither 2 to 1. 1st is straight cut but will be synchro to 2nd on up shift. Reverse is also straight cut. Neutral to 1st doesnt need to be synchro as you are stopped. And also as westy has stated sometimes it just needs a reset like a clutch engage/disengage or a little roll forward/back and you will feel it line up.

Parksy
1st May 2015, 10:39 AM
I pulled a tb42e box apart and I swear that all gears had syncros(will have to confirm but don't think reverse did) and there are no straight cut gears.
http://img.photobucket.com/albums/v92/Pakas/7D93B086-7BD1-4450-B325-4496AEC93737_2.jpg (http://smg.photobucket.com/user/Pakas/media/7D93B086-7BD1-4450-B325-4496AEC93737_2.jpg.html)

Aussie FJ40
1st May 2015, 11:25 AM
just a question could you elaborate on the first gear thing. now lets say your sitting at the lights, and you push the clutch in and put it in first and its hard to go in or does it go in after a few seconds. could you just explain what its doing. and yes im thinking of a specific problem

notchy into first gear at standstill,slide it into 4th and it goes into 1st no problem,not sure on the oil but I will change to a recommended oil for the TD42 box,oil suggestions please as everyone has an opinion but I will go with the general consensus,am looking at auto conversion so thoughts on the best auto conversion would be appreciated, I don't have a problem with mechanicals I'm just new to patrols,thanks

kevin07
1st May 2015, 12:06 PM
ok could you start the car put the clutch in and hold for 10 seconds then put in 1st does it go straight in or is the same

nissannewby
1st May 2015, 01:30 PM
Putting it on 4h doesnt change anything in the gearbox. It might possibly slightly turn the shaft allowing first to line up better and be more easily selected.

kevin07
1st May 2015, 03:20 PM
Putting it on 4h doesnt change anything in the gearbox. It might possibly slightly turn the shaft allowing first to line up better and be more easily selected.

correct im trying to find out if its a hydraulic problem

Aussie FJ40
1st May 2015, 05:27 PM
Putting it on 4h doesnt change anything in the gearbox. It might possibly slightly turn the shaft allowing first to line up better and be more easily selected.

not putting it in 4h,if you just slip it into 4th gear it will slip into 1st no problem,put a new master cylinder on as it was weeping a bit but just realised the bleeder on the firewall is part of the system and bled the system again and a fair bit better,there is no air in the system so that is not the issue now,can still be a bitch at times to get into 1st, I really think it's a synchro problem as it won't slip into 5th easily at times,I'm really considering auto ,finding good gearbox mechanics is not as easy as it used to be,will delve a little more into the auto

Parksy
1st May 2015, 06:39 PM
Check your clutch rod length. I think it is 130mm from the firewall to the eye end. Best to check in the manual first to confirm. Surprised how much a couple of turns of the turn-buckle can make. Look under your dash at the clutch pedal linkage to see it. It's the rod that goes into the booster.