Nissan 4.2 Turbo Diesel Gearbox Failure
Submitted: Thursday, Aug 22, 2002 at 00:00
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Peter
I have a 2000 Nissan Patrol 4.2 Turbo Diesel and tow a 22ft Caravan regularly. The 5th gear failed completely at 62000Klm and when it was picked up the mechanic was not surprised and advised me it happens quite often to the patrols that tow trailers at approx 60000klm. When it was repaired ( under Warenty ) the service staff then advised me that they had replaced the main shaft and 5th gear with a updated version but I should not tow in 5th or travel with the car under stress in 5th gear , eg up hills or at less than 80KPH. It appears Nissan staff are aware of an problem with the 5th gear but just forgot to tell me the important restictions when purchasing the vehicle even though I had selected it for its towing capacity and power at the time. Has anyone else had there gearbox fail in this way and what was Nissans response? Also has anyone been advised by Nissan of any restrictions in using 5th gear.
Reply By: justin- Thursday, Aug 22, 2002 at 00:00
Thursday, Aug 22, 2002 at 00:00
never tow in 5th in any vehicle any mechanic with a mecanical understanding of gearbox workings can explain.
AnswerID:
5932
Reply By: Member - Trevor - Thursday, Aug 22, 2002 at 00:00
Thursday, Aug 22, 2002 at 00:00
Peter - To get the overdrive 5th gear in any vehicle the shaft/bearings etc are small and can not take a heavy constant load. Sorry, but fourth is direct and is the way to go. Trev
AnswerID:
5940
Reply By: StephenF - Friday, Aug 23, 2002 at 00:00
Friday, Aug 23, 2002 at 00:00
I agree with Justin and Trevor. Fifth gear (or fourth in an auto) is only designed for low-torque operation. Using it when towing will put it under a load that it was never designed for.
AnswerID:
5948
Follow Up By: Peter - Saturday, Aug 24, 2002 at 00:00
Saturday, Aug 24, 2002 at 00:00
Thanks to all who replied but I am still concerned that this common knowledge that we should not use 5th gear by the some end users is not pointed out in any manufacturers handbook. I have spoken to many other caravaners in SA over the last year and very few have been informed of the restriction and some have even been informed by the manufacturers dealers that its OK to tow in 5th. The Dealer who sold me the vehicle was in fact keen to sell the vehicle on its merits of which one was the better economy of 5th while towing at higher speed?
FollowupID:
2623
Reply By: PETER - Friday, Aug 23, 2002 at 00:00
Friday, Aug 23, 2002 at 00:00
G'day all this is another peter . i almost bought an st 3 ltr automatic but seem to have settled on the pagero diesel 3 ltr extreem auto.
i also tow a van and that is why i must change from my 1999 disco automatic .
do you mean that if i drive in auto i may damage my gearbox if it automatically selects overdrive ?
regards peter
AnswerID:
5949
Reply By: StephenF - Friday, Aug 23, 2002 at 00:00
Friday, Aug 23, 2002 at 00:00
For towing, the rule of thumb is to use the gear that gives you direct drive through the transmission, ie. 1:1 ratio. This is normally one gear below top (probably 4th in the Pajero -
check your handbook). Don't let an auto select overdrive - manually lock it in the 1:1 gear.
AnswerID:
5956
Follow Up By: Peter - Saturday, Aug 24, 2002 at 00:00
Saturday, Aug 24, 2002 at 00:00
thanks very much for that info - i thought that all i did was select d and off she went.
being as stupid as i am how do i know the ratio of 1:1 . on the pajero i can select manual so i presume that i do not shift into 5th when towing my van is this correct sorry to appear so thick regards peter
FollowupID:
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Follow Up By: Stephenf - Saturday, Aug 24, 2002 at 00:00
Saturday, Aug 24, 2002 at 00:00
Peter, 4th gear on the current model Pajero auto is the 1:1 ratio (the gear ratios should be in the owners handbook). I'm not sure what the Pajero gear selector looks like, but it would normally have something like 1,2,3,4,D. The new Pajero also has a manual mode, where you shift the lever by hand and it works just like a clutchless manual. I assume that you would either select 4th in auto mode (which will prevent it changing to 5th) or manually change up through the gears to 4th. Can any Pajero owners help out here?
FollowupID:
2618
Reply By: Member - Jim - Saturday, Aug 24, 2002 at 00:00
Saturday, Aug 24, 2002 at 00:00
This is more of a problem with manuals as an automatic will change down when load is increased.
The problem of "wearing out" the idler shaft and bearings on 5th gear is caused by the amount of torque being put into it. With new vehicles having more power and the installation of turbos etc. on diesel engines you go up and over hills in 5th gear "because you can".
As all previous posts have mentioned despite being told by others or not by a salesman the message only hits
home when you learn the hard way.
Happy towing
AnswerID:
6010
Reply By: StephenF - Sunday, Aug 25, 2002 at 00:00
Sunday, Aug 25, 2002 at 00:00
As I understand it, when using the 1:1 ratio the input and output shafts of the transmission are virtually locked together, with the rest of the gears just idling along under no load. Also, I don't think autos are less of a problem than manuals. Even on the flat the motor is generating a lot more torque when towing just to overcome wind resistance, and autos tend to hang on to top gear if left to their own devices. I think it's pretty poor that manufacturers and salespeople don't warn buyers about something like this. As Jim said (and other people have experienced) you only find out the hard way. Thank goodness for the Internet and forums like this where people can share their experiences and knowledge.
AnswerID:
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Reply By: PETER - Sunday, Aug 25, 2002 at 00:00
Sunday, Aug 25, 2002 at 00:00
thanks from an old boy that believed d on auto and go - i will now make sure that my brand new pajero will never move into 5th when towing my van - thanks again regards peter
AnswerID:
6017
Reply By: Michael - Monday, Oct 21, 2002 at 00:00
Monday, Oct 21, 2002 at 00:00
You guys have got me worried now, my 2000 gu 4.2 has done 225,000kms over the past 3 years, heaps of it with a horse float, jayco camper and a off road trailer through the middle last year. All in fifth gear i might add, i'm worried aabout driving it out the
gate now. Thaanks for the imfo guys,, Michael.
AnswerID:
7741