I have a much older manual 1996 Nissan Patrol 4.2 EFI & pulled my 2.6 ton van for around 200,000 km with no gearbox troubles.
When I first got it with 50,000 km on the clock, my 'old school' mechanic recommended the I never use 5th gear when towing. I followed that advice except on one or two occasions when on smooth freeways with following wind. I could not detect any significant fuel advantage.
I also rang the then Nissan Qld Service Manager & he agreed with my mechanic.
When in Darwin having a thrust bearing replaced (for the second time & the bloody thing is noisy again - a >$1000 job) the mechanic there showed me a stripped gearbox shaft that he replaced from a vehicle that had been used to tow in 5th. Something about the gear that meshed with the spline on the shaft being too narrow. He said that he could fix that by fitting a second gear. He said that this was a common problem.
I believe that gear box specialists have modifications that overcome this issue.
I'm more comfortable towing in 4th.
-- Edited by Cupie on Tuesday 27th of October 2015 10:57:47 AM
cooccoocha, you have a lemon. this has been discussed before on other forums, there is a web site by a particular gear box business that knows your exact problem.
I cannot remember the name. All manufactures recommend that you do not use overdrive whenever you are towing.
All manual gearboxes are designed so that 4th gear is 1:1 ration and is the strongest gear in the box. 5th is usually 3/4 (1:0.75) and in the case of a dunny door 6th is 1/2 1: 0.5). Tow in 5th if it takes your fancy but when the box goes U/S you will only have yourself to blame.
Larry
I had a 2002 3ltr DiTD manual which had done 192,000klm's of which 80,000 towing a 2000kg van all over Australia and only ever towed in 4th gear and never had an ounce of trouble. The reason for selling was that we upgraded the Van and I felt it was putting to much strain on the engine. You will find the remainder of the drive train is as tough as the 4.2lt with only the gearing is different.
I did try towing in 5th gear across the Nullabour in 2007 but found that the fuel consumption was greater and the vehicle was not as responsive, so remained towing in 4th ever since, I also found that around the 90 - 95klm's per hour the tacho was showing similar RPM,s to cruising at 110klm's in 5th gear on the freeway.
I know of four owners of manual 3L GU patrols that have had stripped 5th gear using it while towing.
Either new or recondition gearboxes fitted to fix the issue
Know of one 4.2L GU owner that stripped his 5th gear towing and to fix it had a shaft and gear fitted from the earlier GQ model
In the GU series for some reason Nissan made the 5th and shaft half the size of the GQ series 4.2L models.
I own a Maverick (GQ in disguise) and don't use 5th gear towing, even though it can up to 1.5T in that gear, my van is 1.8T and max towing is 2.5T...never will use it at all towing.
