Auto box plus overdrive

[Wheelie]

Wondering if you guys can help me, my patrol has a 4 speed auto box plus over drive when I'm driving on a level road at say 65 in overdrive i.e. 5th gear at approx 2400 rpm and I switch the od off I assume it should drop to 4th and the revs increase by say 500. Mine seems to drop into 3rd with a rpm of about 3300 this is not right is it. And also when travelling on a slight incline in overdrive it changes gear far to easily i.e. No change in throttle position, again my speed is about 65 mph

 

[solarman216]

Sure someone who has Auto knowlege will be allong soon, I can only side with you in that it does not sound right, could be a simple switching issue like kick down switch stuck or maybe you have a sport mode? Rick

 

[Wheelie]

Yes I have a 3 way switch, hold, at, and power

 

[solarman216]

Briggie knows about that one, Rick

 

[briggie]

leave the 3 way switch in the middle position , ie not on hold or power

a quick look at the workshop manual will tell you exactly which mode to use for each condition , but basically one will prolong the gearchange and one will shorten it , auto ( centre position ) is normal mode

 

[Wheelie]

That's where it is, I believe power holds it in gear longer and hold removes 1st gear but still have the overdrive issue in all settings

 

[briggie]

That's where it is, I believe power holds it in gear longer and hold removes 1st gear but still have the overdrive issue in all settings

assuming you have checked atf for level and colour ( should be cherry red ) it sounds normal to me , my mistral would do the same , the Nissan auto box is kinda different to others , but of course I remain to be proved wrong

 

[Wheelie]

ATF is clean and red with no burnt smell, so are you saying that from overdrive at 65 mph to overdrive off it goes to 3rd gear? Doesn't seem right to me, dropping to 4th would be logical

 

[briggie]

ATF is clean and red with no burnt smell, so are you saying that from overdrive at 65 mph to overdrive off it goes to 3rd gear? Doesn't seem right to me, dropping to 4th would be logical

must admit it seems a bit of a drop , but strictly speaking it doesn't have a 5th gear , its more like a prolonged 4th if that makes sense , so dropping from 4th to 3rd is reasonable , all I can say is both my mistrals would do the same

 

[Blocky10]

My terrano only has 3 speeds plus overdrive.
You are right in saying the revs increase by about 500rpm when it comes out of overdrive and into 3rd.
I've always had my 3 position switch on the middle (normal)

 

[macabethiel]

Gear shift change pattern.

If I understand you right you are thinking that overdrive 4th behaves like a 5 th gear and when the engine starts to be subject to an increase in load you are expecting it to drop into none overdrive 4th rather than shifting down the one gear into 3 rd.

My old r3mR was just the same as yours unless I was doing say 85-90 then if I floored the throttle or it was on an incline it would just drop out of overdrive as the road speed was too fast for 3 rd gear.

I would first of all switch off the overdrive and then drive it up to 70 mph and note the revs and road speed for the upward gear shifts on a light throttle then note the change down speeds when coasting down to a stop. Then repeat with a foot planted hard to the floor so the kickdown switch is engaged. Then make a note of the revs and road speed for the upward shifts.

Having done that repeat the above with overdrive engaged and look at the numbers again and you might feel it's OK. As others have said using the middle position on the power switch if you have one.

If you still suspect its not right then two other things will cause strange gearshift patterns in my experience and are worth eliminating before thinking the box is faulty.

1) If the ATF is even slightly overfull it will often cause excessive gear shifts make sure you check the level when the engine and transmission are at normal working temperature with the engine running in Park position on a level road. A quarter of a pint of excess ATF may cause problems often if the level is slightly below level it will drive just fine.

2) The grade of ATF will also affect change shift points I always used fully synthetic ATF Dexron 3 or higher due to it's better temperature stability providing more consistent gear shifts especially on long journeys.

I used Fuchs Titan 4000 ATF or Titan 4400 when it was on offer If money is no object then go for fully synthetic Dexron 4 grade but it takes a couple of fluid changes to get the benefit due to the capacity of the Torque Convertor.

In my experience there has never been a problem with upgrading the ATF as Dexron Fluids have changed over the years. It's going backwards that is a no-no. If the original spec is Dexron 3 don't use Dexron 2.

Just my personal experience from driving Automatics since the 1970's.

 

[Barrbeast]

Just a correction (which might explain things a little), Trol auto box is 4 speed only which is Nissan for 3 + overdrive ie. 4th speed is overdrive (I've got a brochure).

 

[macabethiel]

Just a correction (which might explain things a little), Trol auto box is 4 speed only which is Nissan for 3 + overdrive ie. 4th speed is overdrive (I've got a brochure).

So it's not like the r3mR with an o/d switch in the gear lever ?

 

[rayf3262]

The auto transmission fitted to the European built Terrano was the Jatco RE4R01A.

Possibly the same or similar unit was fitted to the Patrol too.

https://en.wikipedia.org/wiki/Jatco_4R01_transmission

http://shop.ukrtrans.biz/wp-content/uploads/catalogs/RE4R01A.pdf

 

[Barrbeast]

So it's not like the r3mR with an o/d switch in the gear lever ?

Not sure bud, but Wheelie seems to think there is a 4th speed before overdrive ie. with overdrive off it should still give 4 speeds. That's incorrect, the Trol 4 speed auto is actually 3 speeds + overdrive. Overdrive is the 4th speed so with o/d turned off there will only be 3 speeds.

 

[Banshee]

Not sure bud, but Wheelie seems to think there is a 4th speed before overdrive ie. with overdrive off it should still give 4 speeds. That's incorrect, the Trol 4 speed auto is actually 3 speeds + overdrive. Overdrive is the 4th speed so with o/d turned off there will only be 3 speeds.

Pffffffffttttt 3 gears!!!!! I'll stick with my manual :naughty

 

[Blocky10]

Pffffffffttttt 3 gears!!!!! I'll stick with my manual :naughty

:lol yeah right:naughty

 

[macabethiel]

Speeds on Autoboxes it's not what you think !

Pffffffffttttt 3 gears!!!!! I'll stick with my manual :naughty

You can't really compare directly the number of gears on a manual box with those on an old fluid valve block design automatic. Later design gearboxes like the 8 and 9 speed automatics in the likes of BMW & Mercedes or the excellent dual clutch autos by VW are directly comparable........Pffffffff who makes an 8 speed manual outside of road hualage ?

On the older fluid block design automatic gearboxes each "speed or gear" as marked on the gearshift gates as D,D1,4,3,2,L etc these markings just represents a cluster of gear ratios within each gear range.

Give you an example back in the 60's Vauxhall sold three systems as boxes were developed from the U.S. The first was sold on the Cresta models as the "Hydramatic" , later on "Powerglide" until it eventually became just an "Automatic" when they fitted the GM Strasbourg 4 speed gearbox that was so good it was made under licence by Rolls Royce for their cars.

I remember driving the new "Powerglide" as it only had two forward "gears" D & 1st and my Dad ran one as a Demostrator I think it was fitted to a Vauxhall Viscount (based on a Cresta 3.3 litre with electric windows, wood trim etc). When you got down to the small print the first gear actually had the equivalent of a staggering 273 ratios - It would do well over 70 mph in first gear !

Later developments then started to include auto lock torque converters and sadly the current range of solenoid gear change designs and the dreaded CCTV.

I know I am biased as I have been driving automatics since 1965 and I drove the dreadful Borward based automatics but like the old days of 3 speed manuals with no synchromesh the game has change. With the exception of towing a heavy horse box or caravan I see no merit in a manual gearbox. That's probably why F1 cars are not manual !

 

[Blocky10]

Give you an example back in the 60's Vauxhall sold three systems as boxes were developed from the U.S. The first was sold on the Cresta models as the "Hydramatic" , later on "Powerglide" until it eventually became just an "Automatic" when they fitted the GM Strasbourg 4 speed gearbox that was so good it was made under licence by Rolls Royce for their cars.

Er did it go like er GREASED LIGHTNING :lol

Keep talking oh keep talking:lol

 

[Wheelie]

If I understand you right you are thinking that overdrive 4th behaves like a 5 th gear and when the engine starts to be subject to an increase in load you are expecting it to drop into none overdrive 4th rather than shifting down the one gear into 3 rd.

My old r3mR was just the same as yours unless I was doing say 85-90 then if I floored the throttle or it was on an incline it would just drop out of overdrive as the road speed was too fast for 3 rd gear.

I would first of all switch off the overdrive and then drive it up to 70 mph and note the revs and road speed for the upward gear shifts on a light throttle then note the change down speeds when coasting down to a stop. Then repeat with a foot planted hard to the floor so the kickdown switch is engaged. Then make a note of the revs and road speed for the upward shifts.

Having done that repeat the above with overdrive engaged and look at the numbers again and you might feel it's OK. As others have said using the middle position on the power switch if you have one.

If you still suspect its not right then two other things will cause strange gearshift patterns in my experience and are worth eliminating before thinking the box is faulty.

1) If the ATF is even slightly overfull it will often cause excessive gear shifts make sure you check the level when the engine and transmission are at normal working temperature with the engine running in Park position on a level road. A quarter of a pint of excess ATF may cause problems often if the level is slightly below level it will drive just fine.

2) The grade of ATF will also affect change shift points I always used fully synthetic ATF Dexron 3 or higher due to it's better temperature stability providing more consistent gear shifts especially on long journeys.

I used Fuchs Titan 4000 ATF or Titan 4400 when it was on offer If money is no object then go for fully synthetic Dexron 4 grade but it takes a couple of fluid changes to get the benefit due to the capacity of the Torque Convertor.

In my experience there has never been a problem with upgrading the ATF as Dexron Fluids have changed over the years. It's going backwards that is a no-no. If the original spec is Dexron 3 don't use Dexron 2.

Just my personal experience from driving Automatics since the 1970's.

Patrol Y 61 auto box is a RE4R03A 4speed but does not state its overdrive, yes you are correct in your first paragraph that's exactly what I'm expecting. I have counted the rev drops whilst driving and there are defiantly 5 drops in revs. 1st gear drop to 2nd gear drop to 3rd gear drop to 4th gear all with overdrive on, then there is a 200 to 300 rpm drop when in 4th which I assumed was the overdrive. I will check the fluid level tomorrow when it's at temp. Then do the test you suggest